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Matarazzo M, Pérez-Soriano A, Vafai N, Shahinfard E, Cheng KJC, McKenzie J, Neilson N, Miao Q, Schaffer P, Shinotoh H, Kordower JH, Sossi V, Stoessl AJ. Misfolded protein deposits in Parkinson's disease and Parkinson's disease-related cognitive impairment, a [ 11C]PBB3 study. NPJ Parkinsons Dis 2024; 10:96. [PMID: 38702305 PMCID: PMC11068893 DOI: 10.1038/s41531-024-00708-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2023] [Accepted: 04/11/2024] [Indexed: 05/06/2024] Open
Abstract
Parkinson's disease (PD) is associated with aggregation of misfolded α-synuclein and other proteins, including tau. We designed a cross-sectional study to quantify the brain binding of [11C]PBB3 (a ligand known to bind to misfolded tau and possibly α-synuclein) as a proxy of misfolded protein aggregation in Parkinson's disease (PD) subjects with and without cognitive impairment and healthy controls (HC). In this cross-sectional study, nineteen cognitively normal PD subjects (CN-PD), thirteen cognitively impaired PD subjects (CI-PD) and ten HC underwent [11C]PBB3 PET. A subset of the PD subjects also underwent PET imaging with [11C](+)DTBZ to assess dopaminergic denervation and [11C]PBR28 to assess neuroinflammation. Compared to HC, PD subjects showed higher [11C]PBB3 binding in the posterior putamen but not the substantia nigra. There was no relationship across subjects between [11C]PBB3 and [11C]PBR28 binding in nigrostriatal regions. [11C]PBB3 binding was increased in the anterior cingulate in CI-PD compared to CN-PD and HC, and there was an inverse correlation between cognitive scores and [11C]PBB3 binding in this region across all PD subjects. Our results support a primary role of abnormal protein deposition localized to the posterior putamen in PD. This suggests that striatal axonal terminals are preferentially involved in the pathophysiology of PD. Furthermore, our findings suggest that anterior cingulate pathology might represent a significant in vivo marker of cognitive impairment in PD, in agreement with previous neuropathological studies.
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Affiliation(s)
- Michele Matarazzo
- Djavad Mowafaghian Centre for Brain Health, Pacific Parkinson's Research Centre, University of British Columbia & Vancouver Coastal Health, Vancouver, BC, Canada
- HM CINAC, Hospital Universitario HM Puerta del Sur, Móstoles, Madrid, Spain
- Department of Medicine, Faculty of Medicine, Complutense University of Madrid, Madrid, Spain
| | - Alexandra Pérez-Soriano
- Djavad Mowafaghian Centre for Brain Health, Pacific Parkinson's Research Centre, University of British Columbia & Vancouver Coastal Health, Vancouver, BC, Canada
| | - Nasim Vafai
- Department of Physics and Astronomy, University of British Columbia, Vancouver, BC, Canada
| | - Elham Shahinfard
- Department of Physics and Astronomy, University of British Columbia, Vancouver, BC, Canada
| | - Kevin Ju-Chieh Cheng
- Department of Physics and Astronomy, University of British Columbia, Vancouver, BC, Canada
| | - Jessamyn McKenzie
- Djavad Mowafaghian Centre for Brain Health, Pacific Parkinson's Research Centre, University of British Columbia & Vancouver Coastal Health, Vancouver, BC, Canada
| | - Nicole Neilson
- Djavad Mowafaghian Centre for Brain Health, Pacific Parkinson's Research Centre, University of British Columbia & Vancouver Coastal Health, Vancouver, BC, Canada
| | | | | | - Hitoshi Shinotoh
- Department of Functional Brain Imaging Research, National Institute of Radiological Sciences, Chiba, Japan
| | - Jeffrey H Kordower
- ASU-Banner Neurodegenerative Disease Research Center and School of Life Sciences, Arizona State University, Tempe, AZ, USA
| | - Vesna Sossi
- Department of Physics and Astronomy, University of British Columbia, Vancouver, BC, Canada
| | - A Jon Stoessl
- Djavad Mowafaghian Centre for Brain Health, Pacific Parkinson's Research Centre, University of British Columbia & Vancouver Coastal Health, Vancouver, BC, Canada.
- Division of Neurology, Department of Medicine, University of British Columbia, Vancouver, BC, Canada.
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Alagaratnam J, Thornhill JP, Fan Z, Vera JH, Underwood J, Hall R, Searle G, Owen D, Edison P, Fidler S, Winston A. Differences in neuroinflammation in people who started antiretroviral treatment during primary versus chronic HIV infection: an 18kDa Translocator protein (TSPO) positron emission tomography (PET) study. J Neurovirol 2024:10.1007/s13365-024-01200-3. [PMID: 38575831 DOI: 10.1007/s13365-024-01200-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2023] [Revised: 02/27/2024] [Accepted: 03/01/2024] [Indexed: 04/06/2024]
Abstract
Persistent inflammation is described in people with HIV (PWH) on antiretroviral treatment (ART). Early ART initiation is associated with reduced inflammation. We aimed to evaluate neuroinflammation, using translocator protein (TSPO) [11C]PBR28 PET neuroimaging in PWH who initiated ART during acute HIV (aPWH) versus chronic HIV infection (cPWH) versus a control population. This was a cross-sectional, observational study. All participants underwent [11C]PBR28 PET-CT neuroimaging. Using a two-tissue compartment model, total volume of distribution (VT) and distribution volume ratios (DVR) using cortical grey matter as a pseudo-reference region at 20 regions of interest (ROIs) were calculated. Differences in VT and DVR were compared between groups using the Kruskall-Wallis test. Seventeen neuro-asymptomatic male PWH on ART (9 aPWH, 8 cPWH) and 8 male control participants (CPs) were included. Median (interquartile range, IQR) age was 40 (30, 46), 44 (41, 47) and 21 (20, 25) years in aPWH, cPWH and CPs, respectively. Median (IQR) CD4 (cells/µL) and CD4:CD8 were 687 (652, 1014) and 1.37 (1.24, 1.42), and 700 (500, 720) and 0.67 (0.64, 0.82) in aPWH and cPWH, respectively. Overall, no significant difference in VT and DVR were observed between the three groups at any ROIs. cPWH demonstrated a trend towards higher mean VT compared with aPWH and CPs at most ROIs. No significant differences in neuroinflammation, using [11C]PBR28 binding as a proxy, were identified between cPWH, aPWH and CPs. A trend towards lower absolute [11C]PBR28 binding was seen amongst aPWH and CPs, suggesting early ART may mitigate neuroinflammation.
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Affiliation(s)
- Jasmini Alagaratnam
- Department of Sexual Health & HIV, Chelsea & Westminster Hospital NHS Foundation Trust, London, UK.
- Department of Infectious Disease, Faculty of Medicine, Imperial College London, London, UK.
| | - John P Thornhill
- Blizard Institute, Barts & the London School of Medicine & Dentistry, Queen Mary University of London, London, UK
| | - Zhen Fan
- Invicro, A Konica Minolta Company, London, UK
| | - Jaime H Vera
- Department of Global Health and Infection, Brighton and Sussex Medical School, London, UK
| | - Jonathan Underwood
- Division of Infection and Immunity, School of Medicine, Cardiff University, UHW Main Building, Heath Park, Cardiff, CF14 4XN, UK
| | - Rebecca Hall
- Department of Infectious Disease, Faculty of Medicine, Imperial College London, London, UK
| | | | - David Owen
- Department of Brain Sciences, Imperial College London, London, UK
| | - Paul Edison
- Department of Brain Sciences, Imperial College London, London, UK
| | - Sarah Fidler
- Department of Infectious Disease, Faculty of Medicine, Imperial College London, London, UK
- Department of Genitourinary Medicine & HIV, St Mary's Hospital, Imperial College Healthcare NHS Trust, London, UK
| | - Alan Winston
- Department of Infectious Disease, Faculty of Medicine, Imperial College London, London, UK
- Department of Genitourinary Medicine & HIV, St Mary's Hospital, Imperial College Healthcare NHS Trust, London, UK
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Knyzeliene A, MacAskill MG, Alcaide-Corral CJ, Morgan TEF, Henry MC, Lucatelli C, Pimlott SL, Sutherland A, Tavares AAS. [ 18F]LW223 has low non-displaceable binding in murine brain, enabling high sensitivity TSPO PET imaging. J Cereb Blood Flow Metab 2024; 44:397-406. [PMID: 37795635 PMCID: PMC10870961 DOI: 10.1177/0271678x231205661] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/05/2023] [Revised: 09/01/2023] [Accepted: 09/09/2023] [Indexed: 10/06/2023]
Abstract
Neuroinflammation is associated with a number of brain diseases, making it a common feature of cerebral pathology. Among the best-known biomarkers for neuroinflammation in Positron Emission Tomography (PET) research is the 18 kDa translocator protein (TSPO). This study aims to investigate the binding kinetics of a novel TSPO PET radiotracer, [18F]LW223, in mice and specifically assess its volume of non-displaceable binding (VND) in brain as well as investigate the use of simplified analysis approaches for quantification of [18F]LW223 PET data. Adult male mice were injected with [18F]LW223 and varying concentrations of LW223 (0.003-0.55 mg/kg) to estimate VND of [18F]LW223. Dynamic PET imaging with arterial input function studies and radiometabolite studies were conducted. Simplified quantification methods, standard uptake values (SUV) and apparent volume of distribution (VTapp), were investigated. [18F]LW223 had low VND in the brain (<10% of total binding) and low radiometabolism (∼15-20%). The 2-tissue compartment model provided the best fit for [18F]LW223 PET data, although its correlation with SUV90-120min or VTapp allowed for [18F]LW223 brain PET data quantification in healthy animals while using simpler experimental and analytical approaches. [18F]LW223 has the required properties to become a successful TSPO PET radiotracer.
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Affiliation(s)
- Agne Knyzeliene
- BHF-University of Edinburgh Centre for Cardiovascular Science, University of Edinburgh, Edinburgh, UK
- Edinburgh Imaging, University of Edinburgh, Edinburgh, UK
| | - Mark G MacAskill
- BHF-University of Edinburgh Centre for Cardiovascular Science, University of Edinburgh, Edinburgh, UK
- Edinburgh Imaging, University of Edinburgh, Edinburgh, UK
| | - Carlos J Alcaide-Corral
- BHF-University of Edinburgh Centre for Cardiovascular Science, University of Edinburgh, Edinburgh, UK
- Edinburgh Imaging, University of Edinburgh, Edinburgh, UK
| | - Timaeus EF Morgan
- BHF-University of Edinburgh Centre for Cardiovascular Science, University of Edinburgh, Edinburgh, UK
- Edinburgh Imaging, University of Edinburgh, Edinburgh, UK
| | | | | | - Sally L Pimlott
- West of Scotland PET Centre, Greater Glasgow and Clyde NHS Trust, Glasgow, UK
| | | | - Adriana AS Tavares
- BHF-University of Edinburgh Centre for Cardiovascular Science, University of Edinburgh, Edinburgh, UK
- Edinburgh Imaging, University of Edinburgh, Edinburgh, UK
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Schoenberg PLA, Song AK, Mohr EM, Rogers BP, Peterson TE, Murphy BA. Increased microglia activation in late non-central nervous system cancer survivors links to chronic systemic symptomatology. Hum Brain Mapp 2023; 44:6001-6019. [PMID: 37751068 PMCID: PMC10619383 DOI: 10.1002/hbm.26491] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2023] [Revised: 08/21/2023] [Accepted: 09/06/2023] [Indexed: 09/27/2023] Open
Abstract
Prolonged inflammatory expression within the central nervous system (CNS) is recognized by the brain as a molecular signal of "sickness", that has knock-on effects to the blood-brain barrier, brain-spinal barrier, blood-cerebrospinal fluid barrier, neuro-axonal structures, neurotransmitter activity, synaptic plasticity, neuroendocrine function, and resultant systemic symptomatology. It is concurred that the inflammatory process associated with cancer and cancer treatments underline systemic symptoms present in a large portion of survivors, although this concept is largely theoretical from disparate and indirect evidence and/or clinical anecdotal reports. We conducted a proof-of-concept study to link for the first time late non-CNS cancer survivors presenting chronic systemic symptoms and the presence of centralized inflammation, or neuroinflammation, using TSPO-binding PET tracer [11 C]-PBR28 to visualize microglial activation. We compared PBR28 SUVR in 10 non-CNS cancer survivors and 10 matched healthy controls. Our data revealed (1) microglial activation was significantly higher in caudate, temporal, and occipital regions in late non-central nervous system/CNS cancer survivors compared to healthy controls; (2) increased neuroinflammation in cancer survivors was not accompanied by significant differences in plasma cytokine markers of peripheral inflammation; (3) increased neuroinflammation was not accompanied by reduced fractional anisotropy, suggesting intact white matter microstructural integrity, a marker of neurovascular fiber tract organization; and (4) the presentation of chronic systemic symptoms in cancer survivors was significantly connected with microglial activation. We present the first data empirically supporting the concept of a peripheral-to-centralized inflammatory response in non-CNS cancer survivors, specifically those previously afflicted with head and neck cancer. Following resolution of the initial peripheral inflammation from the cancer/its treatments, in some cases damage/toxification to the central nervous system occurs, ensuing chronic systemic symptoms.
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Affiliation(s)
- Poppy L. A. Schoenberg
- Department of Physical Medicine and RehabilitationVanderbilt University Medical CenterNashvilleTennesseeUSA
- Osher Center for Integrative HealthVanderbilt University Medical CenterNashvilleTennesseeUSA
| | - Alexander K. Song
- Department of NeurologyVanderbilt University Medical CenterNashvilleTennesseeUSA
- Vanderbilt Brain InstituteVanderbilt UniversityNashvilleTennesseeUSA
| | - Emily M. Mohr
- Osher Center for Integrative HealthVanderbilt University Medical CenterNashvilleTennesseeUSA
| | - Baxter P. Rogers
- Vanderbilt Brain InstituteVanderbilt UniversityNashvilleTennesseeUSA
- Department of Radiology and Radiological SciencesVanderbilt University Medical CenterNashvilleTennesseeUSA
| | - Todd E. Peterson
- Vanderbilt Brain InstituteVanderbilt UniversityNashvilleTennesseeUSA
- Department of Radiology and Radiological SciencesVanderbilt University Medical CenterNashvilleTennesseeUSA
| | - Barbara A. Murphy
- Division of Hematology and OncologyVanderbilt‐Ingram Cancer CenterNashvilleTennesseeUSA
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Matheson GJ, Ge L, Zhang M, Sun B, Tu Y, Zanderigo F, Forsberg Morèn A, Ogden RT. Parametric and non-parametric Poisson regression for modelling of the arterial input function in positron emission tomography. EJNMMI Phys 2023; 10:72. [PMID: 37987874 PMCID: PMC10663416 DOI: 10.1186/s40658-023-00591-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2023] [Accepted: 11/06/2023] [Indexed: 11/22/2023] Open
Abstract
Full quantification of Positron Emission Tomography (PET) requires an arterial input function (AIF) for measurement of certain targets, or using particular radiotracers, or for the quantification of specific outcome measures. The AIF represents the measurement of radiotracer concentrations in the arterial blood plasma over the course of the PET examination. Measurement of the AIF is prone to error as it is a composite measure created from the combination of multiple measurements of different samples with different equipment, each of which can be sources of measurement error. Moreover, its measurement requires a high degree of temporal granularity for early time points, which necessitates a compromise between quality and quantity of recorded samples. For these reasons, it is often desirable to fit models to this data in order to improve its quality before using it for quantification of radiotracer binding in the tissue. The raw observations of radioactivity in arterial blood and plasma samples are derived from radioactive decay, which is measured as a number of recorded counts. Count data have several specific properties, including the fact that they cannot be negative as well as a particular mean-variance relationship. Poisson regression is the most principled modelling strategy for working with count data, as it both incorporates and exploits these properties. However, no previous studies to our knowledge have taken this approach, despite the advantages of greater efficiency and accuracy which result from using the appropriate distributional assumptions. Here, we implement a Poisson regression modelling approach for the AIF as proof-of-concept of its application. We applied both parametric and non-parametric models for the input function curve. We show that a negative binomial distribution is a more appropriate error distribution for handling overdispersion. Furthermore, we extend this approach to a hierarchical non-parametric model which is shown to be highly resilient to missing data. We thus demonstrate that Poisson regression is both feasible and effective when applied to AIF data, and propose that this is a promising strategy for modelling blood count data for PET in future.
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Affiliation(s)
- Granville J Matheson
- Department of Biostatistics, Columbia University Mailman School of Public Health, New York, NY, 10032, USA.
- Department of Psychiatry, Columbia University, New York, NY, 10032, USA.
- Molecular Imaging and Neuropathology Division, New York State Psychiatric Institute, New York, NY, 10032, USA.
- Department of Clinical Neuroscience, Center for Psychiatry Research, Karolinska Institutet and Stockholm County Council, Stockholm, 171 76, Sweden.
| | - Liner Ge
- Department of Biostatistics, Columbia University Mailman School of Public Health, New York, NY, 10032, USA
| | - Mengyu Zhang
- Department of Biostatistics, Columbia University Mailman School of Public Health, New York, NY, 10032, USA
- Department of Biostatistics and Data Science, School of Public Health, University of Texas Health Science Center at Houston, Houston, TX, 77030, USA
| | - Bingyu Sun
- Department of Biostatistics, Columbia University Mailman School of Public Health, New York, NY, 10032, USA
- Department of Neuroscience, University of Rochester Medical Center, Rochester, NY, 14642, USA
| | - Yuqi Tu
- Department of Biostatistics, Columbia University Mailman School of Public Health, New York, NY, 10032, USA
| | - Francesca Zanderigo
- Department of Psychiatry, Columbia University, New York, NY, 10032, USA
- Molecular Imaging and Neuropathology Division, New York State Psychiatric Institute, New York, NY, 10032, USA
| | - Anton Forsberg Morèn
- Department of Clinical Neuroscience, Center for Psychiatry Research, Karolinska Institutet and Stockholm County Council, Stockholm, 171 76, Sweden
| | - R Todd Ogden
- Department of Biostatistics, Columbia University Mailman School of Public Health, New York, NY, 10032, USA
- Department of Psychiatry, Columbia University, New York, NY, 10032, USA
- Molecular Imaging and Neuropathology Division, New York State Psychiatric Institute, New York, NY, 10032, USA
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Liu Y, Yang W, Xue J, Chen J, Liu S, Zhang S, Zhang X, Gu X, Dong Y, Qiu P. Neuroinflammation: The central enabler of postoperative cognitive dysfunction. Biomed Pharmacother 2023; 167:115582. [PMID: 37748409 DOI: 10.1016/j.biopha.2023.115582] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2023] [Revised: 09/21/2023] [Accepted: 09/22/2023] [Indexed: 09/27/2023] Open
Abstract
The proportion of advanced age patients undergoing surgical procedures is on the rise owing to advancements in surgical and anesthesia technologies as well as an overall aging population. As a complication of anesthesia and surgery, older patients frequently suffer from postoperative cognitive dysfunction (POCD), which may persist for weeks, months or even longer. POCD is a complex pathological process involving multiple pathogenic factors, and its mechanism is yet unclear. Potential theories include inflammation, deposition of pathogenic proteins, imbalance of neurotransmitters, and chronic stress. The identification, prevention, and treatment of POCD are still in the exploratory stages owing to the absence of standardized diagnostic criteria. Undoubtedly, comprehending the development of POCD remains crucial in overcoming the illness. Neuroinflammation is the leading hypothesis and a crucial component of the pathological network of POCD and may have complex interactions with other mechanisms. In this review, we discuss the possible ways in which surgery and anesthesia cause neuroinflammation and investigate the connection between neuroinflammation and the development of POCD. Understanding these mechanisms may likely ensure that future treatment options of POCD are more effective.
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Affiliation(s)
- Yang Liu
- Department of Oncology, Shengjing Hospital of China Medical University, Shenyang 110004, Liaoning province, China
| | - Wei Yang
- Department of Infectious Disease, Shengjing Hospital of China Medical University, Shenyang 110004, Liaoning province, China
| | - Jinqi Xue
- Department of Oncology, Shengjing Hospital of China Medical University, Shenyang 110004, Liaoning province, China
| | - Juntong Chen
- Zhejiang University School of Medicine, Hangzhou 311121, Zhejiang province, China
| | - Shiqing Liu
- Department of Anesthesiology, Shengjing Hospital of China Medical University, Shenyang 110004, Liaoning Province, China
| | - Shijie Zhang
- Department of Anesthesiology, Shengjing Hospital of China Medical University, Shenyang 110004, Liaoning Province, China
| | - Xiaohui Zhang
- Department of Anesthesiology, Shengjing Hospital of China Medical University, Shenyang 110004, Liaoning Province, China
| | - Xi Gu
- Department of Oncology, Shengjing Hospital of China Medical University, Shenyang 110004, Liaoning province, China.
| | - Youjing Dong
- Department of Anesthesiology, Shengjing Hospital of China Medical University, Shenyang 110004, Liaoning Province, China.
| | - Peng Qiu
- Department of Anesthesiology, Shengjing Hospital of China Medical University, Shenyang 110004, Liaoning Province, China.
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Mahmud M, Wade C, Jawad S, Hadi Z, Otoul C, Kaminski RM, Muglia P, Kadiu I, Rabiner E, Maguire P, Owen DR, Johnson MR. Translocator protein PET imaging in temporal lobe epilepsy: A reliable test-retest study using asymmetry index. FRONTIERS IN NEUROIMAGING 2023; 2:1142463. [PMID: 37554649 PMCID: PMC10406252 DOI: 10.3389/fnimg.2023.1142463] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/11/2023] [Accepted: 02/24/2023] [Indexed: 08/10/2023]
Abstract
Objective Translocator protein (TSPO) targeting positron emission tomography (PET) imaging radioligands have potential utility in epilepsy to assess the efficacy of novel therapeutics for targeting neuroinflammation. However, previous studies in healthy volunteers have indicated limited test-retest reliability of TSPO ligands. Here, we examine test-retest measures using TSPO PET imaging in subjects with epilepsy and healthy controls, to explore whether this biomarker can be used as an endpoint in clinical trials for epilepsy. Methods Five subjects with epilepsy and confirmed mesial temporal lobe sclerosis (mean age 36 years, 3 men) were scanned twice-on average 8 weeks apart-using a second generation TSPO targeting radioligand, [11C]PBR28. We evaluated the test-retest reliability of the volume of distribution and derived hemispheric asymmetry index of [11C]PBR28 binding in these subjects and compared the results with 8 (mean age 45, 6 men) previously studied healthy volunteers. Results The mean (± SD) of the volume of distribution (VT), of all subjects, in patients living with epilepsy for both test and retest scans on all regions of interest (ROI) is 4.49 ± 1.54 vs. 5.89 ± 1.23 in healthy volunteers. The bias between test and retest in an asymmetry index as a percentage was small (-1.5%), and reliability is demonstrated here with Bland-Altman Plots (test mean 1.062, retest mean 2.56). In subjects with epilepsy, VT of [11C]PBR28 is higher in the (ipsilateral) hippocampal region where sclerosis is present than in the contralateral region. Conclusion When using TSPO PET in patients with epilepsy with hippocampal sclerosis (HS), an inter-hemispheric asymmetry index in the hippocampus is a measure with good test-retest reliability. We provide estimates of test-retest variability that may be useful for estimating power where group change in VT represents the clinical outcome.
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Affiliation(s)
- Mohammad Mahmud
- Department of Brain Sciences, Imperial College London, London, United Kingdom
| | - Charles Wade
- Department of Brain Sciences, Imperial College London, London, United Kingdom
| | - Sarah Jawad
- Department of Brain Sciences, Imperial College London, London, United Kingdom
| | - Zaeem Hadi
- Department of Brain Sciences, Imperial College London, London, United Kingdom
| | - Christian Otoul
- Clinical Imaging Translational, UCB Pharma SA, Brussels, Belgium
| | - Rafal M. Kaminski
- Department of Medicinal Chemistry, Faculty of Pharmacy, Jagiellonian University Medical College, Krakow, Poland
| | | | - Irena Kadiu
- Clinical Imaging Translational, UCB Pharma SA, Brussels, Belgium
| | - Eugenii Rabiner
- Translational Applications, Invicro LLC, London, United Kingdom
| | - Paul Maguire
- Clinical Imaging Translational, UCB Pharma SA, Brussels, Belgium
| | - David R. Owen
- Department of Brain Sciences, Imperial College London, London, United Kingdom
| | - Michael R. Johnson
- Department of Brain Sciences, Imperial College London, London, United Kingdom
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Roussakis AA, Gennaro M, Gordon MF, Reilmann R, Borowsky B, Rynkowski G, Lao-Kaim NP, Papoutsou Z, Savola JM, Hayden MR, Owen DR, Kalk N, Lingford-Hughes A, Gunn RN, Searle G, Tabrizi SJ, Piccini P. A PET-CT study on neuroinflammation in Huntington's disease patients participating in a randomized trial with laquinimod. Brain Commun 2023; 5:fcad084. [PMID: 37020532 PMCID: PMC10069663 DOI: 10.1093/braincomms/fcad084] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2021] [Revised: 12/19/2022] [Accepted: 03/17/2023] [Indexed: 04/05/2023] Open
Abstract
Microglia activation, an indicator of central nervous system inflammation, is believed to contribute to the pathology of Huntington's disease. Laquinimod is capable of regulating microglia. By targeting the translocator protein, 11C-PBR28 PET-CT imaging can be used to assess the state of regional gliosis in vivo and explore the effects of laquinimod treatment. This study relates to the LEGATO-HD, multi-centre, double-blinded, Phase 2 clinical trial with laquinimod (US National Registration: NCT02215616). Fifteen patients of the UK LEGATO-HD cohort (mean age: 45.2 ± 7.4 years; disease duration: 5.6 ± 3.0 years) were treated with laquinimod (0.5 mg, N = 4; 1.0 mg, N = 6) or placebo (N = 5) daily. All participants had one 11C-PBR28 PET-CT and one brain MRI scan before laquinimod (or placebo) and at the end of treatment (12 months apart). PET imaging data were quantified to produce 11C-PBR28 distribution volume ratios. These ratios were calculated for the caudate and putamen using the reference Logan plot with the corpus callosum as the reference region. Partial volume effect corrections (Müller-Gartner algorithm) were applied. Differences were sought in Unified Huntington's Disease Rating Scale scores and regional distribution volume ratios between baseline and follow-up and between the two treatment groups (laquinimod versus placebo). No significant change in 11C-PBR28 distribution volume ratios was found post treatment in the caudate and putamen for both those treated with laquinimod (N = 10) and those treated with placebo (N = 5). Over time, the patients treated with laquinimod did not show a significant clinical improvement. Data from the 11C-PBR28 PET-CT study indicate that laquinimod may not have affected regional translocator protein expression and clinical performance over the studied period.
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Affiliation(s)
| | - Marta Gennaro
- Brain Sciences, Imperial College London, Hammersmith Hospital, London W12 0NN, UK
| | | | | | | | | | - Nicholas P Lao-Kaim
- Brain Sciences, Imperial College London, Hammersmith Hospital, London W12 0NN, UK
| | - Zoe Papoutsou
- Brain Sciences, Imperial College London, Hammersmith Hospital, London W12 0NN, UK
| | | | - Michael R Hayden
- Centre for Molecular Medicine and Therapeutics, BC Children’s Hospital and Research Institute, University of British Columbia, Vancouver V5Z 4H4, Canada
| | - David R Owen
- Brain Sciences, Imperial College London, Hammersmith Hospital, London W12 0NN, UK
| | - Nicola Kalk
- Brain Sciences, Imperial College London, Hammersmith Hospital, London W12 0NN, UK
| | - Anne Lingford-Hughes
- Brain Sciences, Imperial College London, Hammersmith Hospital, London W12 0NN, UK
| | - Roger N Gunn
- Brain Sciences, Imperial College London, Hammersmith Hospital, London W12 0NN, UK
- Invicro, Hammersmith Hospital,, London W12 0NN, UK
| | | | - Sarah J Tabrizi
- Huntington’s Disease Centre, Department of Neurodegenerative Disease, UCL Queen Square Institute of Neurology, London WC1N 3BG, UK
| | - Paola Piccini
- Brain Sciences, Imperial College London, Hammersmith Hospital, London W12 0NN, UK
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PET Imaging of Neuro-Inflammation with Tracers Targeting the Translocator Protein (TSPO), a Systematic Review: From Bench to Bedside. Diagnostics (Basel) 2023; 13:diagnostics13061029. [PMID: 36980337 PMCID: PMC10047854 DOI: 10.3390/diagnostics13061029] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2023] [Revised: 03/03/2023] [Accepted: 03/07/2023] [Indexed: 03/11/2023] Open
Abstract
Parkinson’s disease is the second most common neurodegenerative disorder, affecting 2–3% of the population of patients >65 years. Although the standard diagnosis of PD is clinical, neuroimaging plays a key role in the evaluation of patients who present symptoms related to neurodegenerative disorders. MRI, DAT-SPECT, and PET with [18F]-FDG are routinely used in the diagnosis and focus on the investigation of morphological changes, nigrostriatal degeneration or shifts in glucose metabolism in patients with parkinsonian syndromes. The aim of this study is to review the current PET radiotracers targeting TSPO, a transmembrane protein that is overexpressed by microglia in another pathophysiological process associated with neurodegenerative disorders known as neuroinflammation. To the best of our knowledge, neuroinflammation is present not only in PD but in many other neurodegenerative disorders, including AD, DLB, and MSA, as well as atypical parkinsonian syndromes. Therefore, in this study, specific patterns of microglial activation in PD and the differences in distribution volumes of these radiotracers in patients with PD as compared to other neurodegenerative disorders are reviewed.
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Tan Z, Haider A, Zhang S, Chen J, Wei J, Liao K, Li G, Wei H, Dong C, Ran W, Li Y, Li Y, Rong J, Li Y, Liang SH, Xu H, Wang L. Quantitative assessment of translocator protein (TSPO) in the non-human primate brain and clinical translation of [ 18F]LW223 as a TSPO-targeted PET radioligand. Pharmacol Res 2023; 189:106681. [PMID: 36746361 DOI: 10.1016/j.phrs.2023.106681] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/07/2022] [Revised: 01/12/2023] [Accepted: 01/30/2023] [Indexed: 02/05/2023]
Abstract
OBJECTIVES Translocator protein 18 kDa (TSPO) positron emission tomography (PET) can be harnessed for the non-invasive detection of macrophage-driven inflammation. [18F]LW223, a newly reported TSPO PET tracer which was insensitive to rs6971 polymorphism, showed favorable performance characteristics in a recent imaging study involving a rat myocardial infarction model. To enable quantitative neuroimaging with [18F]LW223, we conducted kinetic analysis in the non-human primate (NHP) brain. Further, we sought to assess the utility of [18F]LW223-based TSPO imaging in a first-in-human study. METHODS Radiosynthesis of [18F]LW223 was accomplished on an automated module, whereas molar activities, stability in formulation, lipophilicity and unbound free fraction (fu) of the probe were measured. Brain penetration and target specificity of [18F]LW223 in NHPs were corroborated by PET-MR imaging under baseline and pre-blocking conditions using the validated TSPO inhibitor, (R)-PK11195, at doses ranging from 5 to 10 mg/kg. Kinetic modeling was performed using one-tissue compartment model (1TCM), two-tissue compartment model (2TCM) and Logan graphical analyses, using dynamic PET data acquisition, arterial blood collection and metabolic stability testing. Clinical PET scans were performed in two healthy volunteers (HVs). Regional brain standard uptake value ratio (SUVr) was assessed for different time intervals. RESULTS [18F]LW223 was synthesized in non-decay corrected radiochemical yields (n.d.c. RCYs) of 33.3 ± 6.5% with molar activities ranging from 1.8 ± 0.7 Ci/µmol (n = 11). [18F]LW223 was stable in formulation for up to 4 h and LogD7.4 of 2.31 ± 0.13 (n = 6) and fu of 5.80 ± 1.42% (n = 6) were determined. [18F]LW223 exhibited good brain penetration in NHPs, with a peak SUV value of ca. 1.79 in the whole brain. Pre-treatment with (R)-PK11195 substantially accelerated the washout and attenuated the area under the time-activity curve, indicating in vivo specificity of [18F]LW223 towards TSPO. Kinetic modeling demonstrated that 2TCM was the most suitable model for [18F]LW223-based neuroimaging. Global transfer rate constants (K1) and total volumes of distribution (VT) were found to be 0.10 ± 0.01 mL/cm3/min and 2.30 ± 0.17 mL/cm3, respectively. Dynamic PET data analyses across distinct time windows revealed that the VT values were relatively stable after 60 min post-injection. In a preliminary clinical study with two healthy volunteers, [18F]LW223 exhibited good brain uptake and considerable tracer retention across all analyzed brain regions. Of note, an excellent correlation between SUVr with VT was obtained when assessing the time interval from 20 to 40 min post tracer injection (SUVr(20-40 min), R2 = 0.94, p < 0.0001), suggesting this time window may be suitable to estimate specific binding to TSPO in human brain. CONCLUSION Our findings indicate that [18F]LW223 is suitable for quantitative TSPO-targeted PET imaging in higher species. Employing state-of-the-art kinetic modeling, we found that [18F]LW223 was effective in mapping TSPO throughout the NHP brain, with best model fits obtained from 2TCM and Logan graphical analyses. Overall, our results indicate that [18F]LW223 exhibits favorable tracer performance characteristics in higher species, and this novel imaging tool may hold promise to provide effective neuroinflammation imaging in patients with neurological disease.
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Affiliation(s)
- Zhiqiang Tan
- Center of Cyclotron and PET Radiopharmaceuticals, Department of Nuclear Medicine and PET/CT-MRI Center, The First Affiliated Hospital of Jinan University, Guangzhou 510630, China
| | - Ahmed Haider
- Department of Radiology and Imaging Sciences, Emory University, 1364 Clifton Rd, Atlanta, GA 30322, USA
| | - Shaojuan Zhang
- Center of Cyclotron and PET Radiopharmaceuticals, Department of Nuclear Medicine and PET/CT-MRI Center, The First Affiliated Hospital of Jinan University, Guangzhou 510630, China
| | - Jiahui Chen
- Department of Radiology and Imaging Sciences, Emory University, 1364 Clifton Rd, Atlanta, GA 30322, USA
| | - Junjie Wei
- Center of Cyclotron and PET Radiopharmaceuticals, Department of Nuclear Medicine and PET/CT-MRI Center, The First Affiliated Hospital of Jinan University, Guangzhou 510630, China
| | - Kai Liao
- Center of Cyclotron and PET Radiopharmaceuticals, Department of Nuclear Medicine and PET/CT-MRI Center, The First Affiliated Hospital of Jinan University, Guangzhou 510630, China
| | - Guocong Li
- Center of Cyclotron and PET Radiopharmaceuticals, Department of Nuclear Medicine and PET/CT-MRI Center, The First Affiliated Hospital of Jinan University, Guangzhou 510630, China
| | - Huiyi Wei
- Center of Cyclotron and PET Radiopharmaceuticals, Department of Nuclear Medicine and PET/CT-MRI Center, The First Affiliated Hospital of Jinan University, Guangzhou 510630, China
| | - Chenchen Dong
- Center of Cyclotron and PET Radiopharmaceuticals, Department of Nuclear Medicine and PET/CT-MRI Center, The First Affiliated Hospital of Jinan University, Guangzhou 510630, China
| | - Wenqing Ran
- Center of Cyclotron and PET Radiopharmaceuticals, Department of Nuclear Medicine and PET/CT-MRI Center, The First Affiliated Hospital of Jinan University, Guangzhou 510630, China
| | - Ying Li
- Center of Cyclotron and PET Radiopharmaceuticals, Department of Nuclear Medicine and PET/CT-MRI Center, The First Affiliated Hospital of Jinan University, Guangzhou 510630, China
| | - Yuefeng Li
- Guangdong Landau Biotechnology Co. Ltd., Guangzhou 510555, China
| | - Jian Rong
- Department of Radiology and Imaging Sciences, Emory University, 1364 Clifton Rd, Atlanta, GA 30322, USA
| | - Yinlong Li
- Department of Radiology and Imaging Sciences, Emory University, 1364 Clifton Rd, Atlanta, GA 30322, USA
| | - Steven H Liang
- Department of Radiology and Imaging Sciences, Emory University, 1364 Clifton Rd, Atlanta, GA 30322, USA.
| | - Hao Xu
- Center of Cyclotron and PET Radiopharmaceuticals, Department of Nuclear Medicine and PET/CT-MRI Center, The First Affiliated Hospital of Jinan University, Guangzhou 510630, China.
| | - Lu Wang
- Center of Cyclotron and PET Radiopharmaceuticals, Department of Nuclear Medicine and PET/CT-MRI Center, The First Affiliated Hospital of Jinan University, Guangzhou 510630, China.
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Owen DR, Phillips A, O’Connor D, Grey G, Aimola L, Nicholas R, Matthews PM. Human pharmacokinetics of XBD173 and etifoxine distinguish their potential for pharmacodynamic effects mediated by translocator protein. Br J Clin Pharmacol 2022; 88:4230-4236. [PMID: 35524344 PMCID: PMC9545781 DOI: 10.1111/bcp.15392] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2022] [Revised: 04/26/2022] [Accepted: 04/29/2022] [Indexed: 11/29/2022] Open
Abstract
XBD173 and etifoxine are translocator protein (TSPO) ligands that modulate inflammatory responses in preclinical models. Limited human pharmacokinetic data is available for either molecule, and the binding affinity of etifoxine for human TSPO is unknown. To allow for design of human challenge experiments, we derived pharmacokinetic data for orally administered etifoxine (50 mg 3 times daily) and XBD173 (90 mg once daily) and determined the binding affinity of etifoxine for TSPO. For XBD173, maximum plasma concentration and free fraction measurements predicted a maximal free concentration of 1.0 nM, which is similar to XBD173 binding affinity. For etifoxine, maximum plasma concentration and free fraction measurements predicted a maximal free concentration of 0.31 nM, substantially lower than the Ki for etifoxine in human brain derived here (7.8 μM, 95% CI 4.5-14.6 μM). We conclude that oral XBD173 dosing at 90 mg once daily will achieve pharmacologically relevant TSPO occupancy. However, the occupancy is too low for TSPO mediated effects after oral dosing of etifoxine at 50 mg 3 times daily.
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Affiliation(s)
- David R. Owen
- Department of Brain SciencesImperial College LondonLondon
| | | | | | - Gabrielle Grey
- Department of Brain SciencesImperial College LondonLondon
| | - Lina Aimola
- Department of Brain SciencesImperial College LondonLondon
| | | | - Paul M. Matthews
- Department of Brain SciencesImperial College LondonLondon
- UK Dementia Research Institute CentreImperial College LondonLondonUK
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Revilla EM, Gallezot JD, Naganawa M, Toyonaga T, Fontaine K, Mulnix T, Onofrey JA, Carson RE, Lu Y. Adaptive data-driven motion detection and optimized correction for brain PET. Neuroimage 2022; 252:119031. [PMID: 35257856 PMCID: PMC9206767 DOI: 10.1016/j.neuroimage.2022.119031] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2021] [Revised: 02/16/2022] [Accepted: 02/21/2022] [Indexed: 12/03/2022] Open
Abstract
Head motion during PET scans causes image quality degradation, decreased concentration in regions with high uptake and incorrect outcome measures from kinetic analysis of dynamic datasets. Previously, we proposed a data-driven method, center of tracer distribution (COD), to detect head motion without an external motion tracking device. There, motion was detected using one dimension of the COD trace with a semiautomatic detection algorithm, requiring multiple user defined parameters and manual intervention. In this study, we developed a new data-driven motion detection algorithm, which is automatic, self-adaptive to noise level, does not require user-defined parameters and uses all three dimensions of the COD trace (3DCOD). 3DCOD was first validated and tested using 30 simulation studies (18F-FDG, N = 15; 11C-raclopride (RAC), N = 15) with large motion. The proposed motion correction method was tested on 22 real human datasets, with 20 acquired from a high resolution research tomograph (HRRT) scanner (18F-FDG, N = 10; 11C-RAC, N = 10) and 2 acquired from the Siemens Biograph mCT scanner. Real-time hardware-based motion tracking information (Vicra) was available for all real studies and was used as the gold standard. 3DCOD was compared to Vicra, no motion correction (NMC), one-direction COD (our previous method called 1DCOD) and two conventional frame-based image registration (FIR) algorithms, i.e., FIR1 (based on predefined frames reconstructed with attenuation correction) and FIR2 (without attenuation correction) for both simulation and real studies. For the simulation studies, 3DCOD yielded -2.3 ± 1.4% (mean ± standard deviation across all subjects and 11 brain regions) error in region of interest (ROI) uptake for 18F-FDG (-3.4 ± 1.7% for 11C-RAC across all subjects and 2 regions) as compared to Vicra (perfect correction) while NMC, FIR1, FIR2 and 1DCOD yielded -25.4 ± 11.1% (-34.5 ± 16.1% for 11C- RAC), -13.4 ± 3.5% (-16.1 ± 4.6%), -5.7 ± 3.6% (-8.0 ± 4.5%) and -2.6 ± 1.5% (-5.1 ± 2.7%), respectively. For real HRRT studies, 3DCOD yielded -0.3 ± 2.8% difference for 18F-FDG (-0.4 ± 3.2% for 11C-RAC) as compared to Vicra while NMC, FIR1, FIR2 and 1DCOD yielded -14.9 ± 9.0% (-24.5 ± 14.6%), -3.6 ± 4.9% (-13.4 ± 14.3%), -0.6 ± 3.4% (-6.7 ± 5.3%) and -1.5 ± 4.2% (-2.2 ± 4.1%), respectively. In summary, the proposed motion correction method yielded comparable performance to the hardware-based motion tracking method for multiple tracers, including very challenging cases with large frequent head motion, in studies performed on a non-TOF scanner.
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Affiliation(s)
- Enette Mae Revilla
- Department of Radiology and Biomedical Imaging, Yale University, PO Box 208048, New Haven, CT 06520-8048, USA
| | - Jean-Dominique Gallezot
- Department of Radiology and Biomedical Imaging, Yale University, PO Box 208048, New Haven, CT 06520-8048, USA
| | - Mika Naganawa
- Department of Radiology and Biomedical Imaging, Yale University, PO Box 208048, New Haven, CT 06520-8048, USA
| | - Takuya Toyonaga
- Department of Radiology and Biomedical Imaging, Yale University, PO Box 208048, New Haven, CT 06520-8048, USA
| | - Kathryn Fontaine
- Department of Radiology and Biomedical Imaging, Yale University, PO Box 208048, New Haven, CT 06520-8048, USA
| | - Tim Mulnix
- Department of Radiology and Biomedical Imaging, Yale University, PO Box 208048, New Haven, CT 06520-8048, USA
| | - John A Onofrey
- Department of Radiology and Biomedical Imaging, Yale University, PO Box 208048, New Haven, CT 06520-8048, USA; Department of Urology, Yale University, New Haven, CT, USA; Department of Biomedical Engineering, Yale University, New Haven, CT, USA
| | - Richard E Carson
- Department of Radiology and Biomedical Imaging, Yale University, PO Box 208048, New Haven, CT 06520-8048, USA; Department of Biomedical Engineering, Yale University, New Haven, CT, USA
| | - Yihuan Lu
- Department of Radiology and Biomedical Imaging, Yale University, PO Box 208048, New Haven, CT 06520-8048, USA.
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Fang YHD, McConathy JE, Yacoubian TA, Zhang Y, Kennedy RE, Standaert DG. Image Quantification for TSPO PET with a Novel Image-Derived Input Function Method. Diagnostics (Basel) 2022; 12:1161. [PMID: 35626315 PMCID: PMC9140104 DOI: 10.3390/diagnostics12051161] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2022] [Revised: 05/02/2022] [Accepted: 05/03/2022] [Indexed: 01/27/2023] Open
Abstract
There is a growing interest in using 18F-DPA-714 PET to study neuroinflammation and microglial activation through imaging the 18-kDa translocator protein (TSPO). Although quantification of 18F-DPA-714 binding can be achieved through kinetic modeling analysis with an arterial input function (AIF) measured with blood sampling procedures, the invasiveness of such procedures has been an obstacle for wide application. To address these challenges, we developed an image-derived input function (IDIF) that noninvasively estimates the arterial input function from the images acquired for 18F-DPA-714 quantification. Methods: The method entails three fully automatic steps to extract the IDIF, including a segmentation of voxels with highest likelihood of being the arterial blood over the carotid artery, a model-based matrix factorization to extract the arterial blood signal, and a scaling optimization procedure to scale the extracted arterial blood signal into the activity concentration unit. Two cohorts of human subjects were used to evaluate the extracted IDIF. In the first cohort of five subjects, arterial blood sampling was performed, and the calculated IDIF was validated against the measured AIF through the comparison of distribution volumes from AIF (VT,AIF) and IDIF (VT,IDIF). In the second cohort, PET studies from twenty-eight healthy controls without arterial blood sampling were used to compare VT,IDIF with VT,REF measured using a reference region-based analysis to evaluate whether it can distinguish high-affinity (HAB) and mixed-affinity (MAB) binders. Results: In the arterial blood-sampling cohort, VT derived from IDIF was found to be an accurate surrogate of the VT from AIF. The bias of VT, IDIF was −5.8 ± 7.8% when compared to VT,AIF, and the linear mixed effect model showed a high correlation between VT,AIF and VT, IDIF (p < 0.001). In the nonblood-sampling cohort, VT, IDIF showed a significance difference between the HAB and MAB healthy controls. VT, IDIF and standard uptake values (SUV) showed superior results in distinguishing HAB from MAB subjects than VT,REF. Conclusions: A novel IDIF method for 18F-DPA-714 PET quantification was developed and evaluated in this study. This IDIF provides a noninvasive alternative measurement of VT to quantify the TSPO binding of 18F-DPA-714 in the human brain through dynamic PET scans.
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Affiliation(s)
- Yu-Hua Dean Fang
- Department of Radiology, Heersink School of Medicine, University of Alabama at Birmingham, Birmingham, AL 35294, USA;
- Center for Neurodegeneration and Experimental Therapeutics, Department of Neurology, Heersink School of Medicine, University of Alabama at Birmingham, Birmingham, AL 35294, USA; (T.A.Y.); (D.G.S.)
| | - Jonathan E. McConathy
- Department of Radiology, Heersink School of Medicine, University of Alabama at Birmingham, Birmingham, AL 35294, USA;
| | - Talene A. Yacoubian
- Center for Neurodegeneration and Experimental Therapeutics, Department of Neurology, Heersink School of Medicine, University of Alabama at Birmingham, Birmingham, AL 35294, USA; (T.A.Y.); (D.G.S.)
| | - Yue Zhang
- Department of Medicine, Heersink School of Medicine, University of Alabama at Birmingham, Birmingham, AL 35294, USA; (Y.Z.); (R.E.K.)
| | - Richard E. Kennedy
- Department of Medicine, Heersink School of Medicine, University of Alabama at Birmingham, Birmingham, AL 35294, USA; (Y.Z.); (R.E.K.)
| | - David G. Standaert
- Center for Neurodegeneration and Experimental Therapeutics, Department of Neurology, Heersink School of Medicine, University of Alabama at Birmingham, Birmingham, AL 35294, USA; (T.A.Y.); (D.G.S.)
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Nerella SG, Singh P, Sanam T, Digwal CS. PET Molecular Imaging in Drug Development: The Imaging and Chemistry Perspective. Front Med (Lausanne) 2022; 9:812270. [PMID: 35295604 PMCID: PMC8919964 DOI: 10.3389/fmed.2022.812270] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2021] [Accepted: 01/18/2022] [Indexed: 11/13/2022] Open
Abstract
Positron emission tomography with selective radioligands advances the drug discovery and development process by revealing information about target engagement, proof of mechanism, pharmacokinetic and pharmacodynamic profiles. Positron emission tomography (PET) is an essential and highly significant tool to study therapeutic drug development, dose regimen, and the drug plasma concentrations of new drug candidates. Selective radioligands bring up target-specific information in several disease states including cancer, cardiovascular, and neurological conditions by quantifying various rates of biological processes with PET, which are associated with its physiological changes in living subjects, thus it reveals disease progression and also advances the clinical investigation. This study explores the major roles, applications, and advances of PET molecular imaging in drug discovery and development process with a wide range of radiochemistry as well as clinical outcomes of positron-emitting carbon-11 and fluorine-18 radiotracers.
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Affiliation(s)
- Sridhar Goud Nerella
- Department of Neuroimaging and Interventional Radiology, National Institute of Mental Health and Neurosciences, Bengaluru, India
| | - Priti Singh
- Department of Medicinal Chemistry, National Institute of Pharmaceutical Education and Research, Hyderabad, India
| | - Tulja Sanam
- Department of Microbiology and Applied Sciences, University of Agricultural Sciences, Bangalore, India
| | - Chander Singh Digwal
- Department of Medicinal Chemistry, National Institute of Pharmaceutical Education and Research, Hyderabad, India
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15
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Gouilly D, Saint-Aubert L, Ribeiro MJ, Salabert AS, Tauber C, Péran P, Arlicot N, Pariente J, Payoux P. Neuroinflammation PET imaging of the translocator protein (TSPO) in Alzheimer's disease: an update. Eur J Neurosci 2022; 55:1322-1343. [PMID: 35083791 DOI: 10.1111/ejn.15613] [Citation(s) in RCA: 22] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2021] [Revised: 01/18/2022] [Accepted: 01/19/2022] [Indexed: 11/28/2022]
Abstract
Neuroinflammation is a significant contributor to Alzheimer's disease (AD). Until now, PET imaging of the translocator protein (TSPO) has been widely used to depict the neuroimmune endophenotype of AD. The aim of this review was to provide an update to the results from 2018 and to advance the characterization of the biological basis of TSPO imaging in AD by re-examining TSPO function and expression and the methodological aspects of interest. Although the biological basis of the TSPO PET signal is obviously related to microglia and astrocytes in AD, the observed process remains uncertain and might not be directly related to neuroinflammation. Further studies are required to re-examine the cellular significance underlying a variation in the PET signal in AD and how it can be impacted by a disease-modifying treatment.
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Affiliation(s)
- Dominique Gouilly
- ToNIC, Toulouse NeuroImaging Center, Université de Toulouse, Inserm, UPS, France
| | - Laure Saint-Aubert
- ToNIC, Toulouse NeuroImaging Center, Université de Toulouse, Inserm, UPS, France
| | - Maria-Joao Ribeiro
- Department of Nuclear Medicine, CHU, Tours, France.,UMR 1253, iBrain, Université de Tours, France.,Inserm CIC 1415, CHRU, Tours, France
| | - Anne-Sophie Salabert
- ToNIC, Toulouse NeuroImaging Center, Université de Toulouse, Inserm, UPS, France.,Department of Nuclear Medicine, CHU, Toulouse, France
| | | | - Patrice Péran
- ToNIC, Toulouse NeuroImaging Center, Université de Toulouse, Inserm, UPS, France
| | - Nicolas Arlicot
- UMR 1253, iBrain, Université de Tours, France.,Inserm CIC 1415, CHRU, Tours, France
| | - Jérémie Pariente
- ToNIC, Toulouse NeuroImaging Center, Université de Toulouse, Inserm, UPS, France.,Department of Cognitive Neurology, Epilepsy and Movement Disorders, CHU, Toulouse, France.,Center of Clinical Investigations (CIC1436), CHU, Toulouse, France
| | - Pierre Payoux
- ToNIC, Toulouse NeuroImaging Center, Université de Toulouse, Inserm, UPS, France.,Department of Nuclear Medicine, CHU, Toulouse, France
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16
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Alagaratnam J, Winston A. Molecular neuroimaging of inflammation in HIV. Clin Exp Immunol 2021; 210:14-23. [PMID: 35020855 PMCID: PMC9585552 DOI: 10.1093/cei/uxab013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2021] [Revised: 09/13/2021] [Accepted: 11/03/2021] [Indexed: 01/12/2023] Open
Abstract
People with HIV now have near-normal life expectancies due to the success of effective combination antiretroviral therapy (cART). Following cART initiation, immune recovery occurs, and opportunistic diseases become rare. Despite this, high rates of non-infectious comorbidities persist in treated people with HIV, hypothesized to be related to persistent immuno-activation. One such comorbidity is cognitive impairment, which may partly be driven by ongoing neuro-inflammation in otherwise effectively treated people with HIV. In order to develop therapeutic interventions to address neuro-inflammation in effectively treated people with HIV, a deeper understanding of the pathogenic mechanisms driving persistent neuro-inflammatory responses and the ability to better characterize and measure neuro-inflammation in the central nervous system is required. This review highlights recent advances in molecular neuroimaging techniques which have the potential to assess neuro-inflammatory responses within the central nervous system in HIV disease. Proton magnetic resonance spectroscopy (1H-MRS) has been utilized to assess neuro-inflammatory responses since early in the HIV pandemic and shows promise in recent studies assessing different antiretroviral regimens. 1H-MRS is widely available in both resource-rich and some resource-constrained settings and is relatively inexpensive. Brain positron emission tomography (PET) imaging using Translocator Protein (TSPO) radioligands is a rapidly evolving field; newer TSPO-radioligands have lower signal-to-noise ratio and have the potential to localize neuro-inflammation within the brain in people with HIV. As HIV therapeutics evolve, people with HIV continue to age and develop age-related comorbidities including cognitive disorders. The use of novel neuroimaging modalities in the field is likely to advance in order to rapidly assess novel therapeutic interventions and may play a role in future clinical assessments.
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Affiliation(s)
- Jasmini Alagaratnam
- Correspondence: Jasmini Alagaratnam, Clinical Trials Centre, Winston Churchill Wing, St. Mary’s Hospital, Praed Street, London W2 1NY, UK.
| | - Alan Winston
- Department of Infectious Disease, Faculty of Medicine, Imperial College London, London, UK,Department of Genitourinary Medicine & HIV, St Mary’s Hospital, Imperial College Healthcare NHS Trust, London, UK
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Marques TR, Veronese M, Owen DR, Rabiner EA, Searle GE, Howes OD. Specific and non-specific binding of a tracer for the translocator-specific protein in schizophrenia: an [11C]-PBR28 blocking study. Eur J Nucl Med Mol Imaging 2021; 48:3530-3539. [PMID: 33825022 PMCID: PMC8440284 DOI: 10.1007/s00259-021-05327-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2020] [Accepted: 03/21/2021] [Indexed: 11/24/2022]
Abstract
OBJECTIVE The mitochondrial 18-kDa translocator protein (TSPO) is expressed by activated microglia and positron emission tomography enables the measurement of TSPO levels in the brain. Findings in schizophrenia have shown to vary depending on the outcome measure used and this discrepancy in TSPO results could be explained by lower non-displaceable binding (VND) in schizophrenia, which could obscure increases in specific binding. In this study, we have used the TSPO ligand XBD173 to block the TSPO radioligand [11C]-PBR28 and used an occupancy plot to quantify VND in patients with schizophrenia. METHODS A total of 7 patients with a diagnosis of schizophrenia were recruited for this study. Each patient received two separate PET scans with [11C]PBR28, one at baseline and one after the administration of the TSPO ligand XBD173. All patients were high-affinity binders (HABs) for the TSPO gene. We used an occupancy plot to quantify the non-displaceable component (VND) using 2TCM kinetic estimates with and without vascular correction. Finally we computed the VND at a single subject level using the SIME method. RESULTS All patients showed a global and generalized reduction in [11C]PBR28 uptake after the administration of XBD173. Constraining the VND to be equal for all patients, the population VND was estimated to be 1.99 mL/cm3 (95% CI 1.90 to 2.08). When we used vascular correction, the fractional TSPO occupancy remained similar. CONCLUSIONS In schizophrenia patients, a substantial component of the [11C]PBR28 signal represents specific binding to TSPO. Furthermore, the VND in patients with schizophrenia is similar to that previously reported in healthy controls. These results suggest that changes in non-specific binding between schizophrenia patients and healthy controls do not account for discrepant PET findings in this disorder.
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Affiliation(s)
- Tiago Reis Marques
- Psychiatric Imaging Group, MRC London Institute of Medical Sciences (LMS), Hammersmith Hospital, Imperial College London, London, UK. .,Psychiatric Imaging Group, Institute of Clinical Sciences (ICS), Faculty of Medicine, Imperial College London, London, UK. .,Department of Psychosis Studies, Institute of Psychiatry, Psychology and Neuroscience, Kings College London, London, UK.
| | - Mattia Veronese
- Centre for Neuroimaging Sciences, Institute of Psychiatry, King's College London, London, UK
| | - David R Owen
- Division of Brain Sciences, Department of Medicine, Imperial College, London, UK
| | - Eugenii A Rabiner
- Centre for Neuroimaging Sciences, Institute of Psychiatry, King's College London, London, UK.,Invicro, London, UK
| | | | - Oliver D Howes
- Psychiatric Imaging Group, MRC London Institute of Medical Sciences (LMS), Hammersmith Hospital, Imperial College London, London, UK.,Psychiatric Imaging Group, Institute of Clinical Sciences (ICS), Faculty of Medicine, Imperial College London, London, UK.,Department of Psychosis Studies, Institute of Psychiatry, Psychology and Neuroscience, Kings College London, London, UK
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18
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Veronese M, Tuosto M, Marques TR, Howes O, Pascual B, Yu M, Masdeu JC, Turkheimer F, Bertoldo A, Zanotti-Fregonara P. Parametric Mapping for TSPO PET Imaging with Spectral Analysis Impulsive Response Function. Mol Imaging Biol 2021; 23:560-571. [PMID: 33475944 PMCID: PMC8277653 DOI: 10.1007/s11307-020-01575-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2020] [Revised: 11/27/2020] [Accepted: 12/21/2020] [Indexed: 11/26/2022]
Abstract
PURPOSE The aim of this study was to investigate the use of spectral analysis (SA) for voxel-wise analysis of TSPO PET imaging studies. TSPO PET quantification is methodologically complicated by the heterogeneity of TSPO expression and its cell-dependent modulation during neuroinflammatory response. Compartmental models to account for this complexity exist, but they are unreliable at the high noise typical of voxel data. On the contrary, SA is noise-robust for parametric mapping and provides useful information about tracer kinetics with a free compartmental structure. PROCEDURES SA impulse response function (IRF) calculated at 90 min after tracer injection was used as main parameter of interest in 3 independent PET imaging studies to investigate its sensitivity to (1) a TSPO genetic polymorphism (rs6971) known to affect tracer binding in a cross-sectional analysis of healthy controls scanned with [11C]PBR28 PET; (2) TSPO density with [11C]PBR28 in a competitive blocking study with a TSPO blocker, XBD173; and (3) the higher affinity of a second radiotracer for TSPO, by using data from a head-to-head comparison between [11C]PBR28 and [11C]ER176 scans. RESULTS SA-IRF produced parametric maps of visually good quality. These were sensitive to TSPO genotype (mean relative difference between high- and mixed-affinity binders = 25 %) and TSPO availability (mean signal displacement after 90 mg oral administration of XBD173 = 39 %). Regional averages of voxel-wise IRF estimates were strongly associated with regional total distribution volume (VT) estimated with a 2-tissue compartmental model with vascular compartment (Pearson's r = 0.86 ± 0.11) but less strongly with standard 2TCM-VT (Pearson's r = 0.76 ± 0.32). Finally, SA-IRF estimates for [11C]ER176 were significantly higher than [11C]PBR28 ones, consistent with the higher amount of specific binding of the former tracer. CONCLUSIONS SA-IRF can be used for voxel-wise quantification of TSPO PET data because it generates high-quality parametric maps, it is sensitive to TSPO availability and genotype, and it accounts for the complexity of TSPO tracer kinetics with no additional assumptions.
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Affiliation(s)
- Mattia Veronese
- Department of Neuroimaging, IoPPN, King's College London, London, UK.
| | - Marcello Tuosto
- Department of Information Engineering, Padova University, Padova, Italy
| | - Tiago Reis Marques
- Department of Psychosis Studies, IoPPN, King's College London, London, UK
| | - Oliver Howes
- Department of Psychosis Studies, IoPPN, King's College London, London, UK
- MRC London Institute of Medical Sciences, Hammersmith Hospital, London, UK
- Institute of Clinical Sciences (ICS), Faculty of Medicine, Imperial College London, London, UK
| | - Belen Pascual
- Nantz National Alzheimer Center and Houston Methodist Research Neurological Institute, and Weill Cornell Medicine, 6670 Bertner Ave, Houston, TX, 77030, USA
| | - Meixiang Yu
- Nantz National Alzheimer Center and Houston Methodist Research Neurological Institute, and Weill Cornell Medicine, 6670 Bertner Ave, Houston, TX, 77030, USA
| | - Joseph C Masdeu
- Nantz National Alzheimer Center and Houston Methodist Research Neurological Institute, and Weill Cornell Medicine, 6670 Bertner Ave, Houston, TX, 77030, USA
| | | | - Alessandra Bertoldo
- Department of Information Engineering, Padova University, Padova, Italy
- Padova Neuroscience Centre, Padova University, Padova, Italy
| | - Paolo Zanotti-Fregonara
- Nantz National Alzheimer Center and Houston Methodist Research Neurological Institute, and Weill Cornell Medicine, 6670 Bertner Ave, Houston, TX, 77030, USA
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19
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Khodaii J, Araj-Khodaei M, Vafaee MS, Wong DF, Gjedde A. Relative strengths of three linearizations of receptor availability: Saturation, Inhibition, and Occupancy plots. J Nucl Med 2021; 63:294-301. [PMID: 34088774 DOI: 10.2967/jnumed.117.204453] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Revised: 04/23/2021] [Indexed: 11/16/2022] Open
Abstract
We derived three widely used linearizations from the definition of receptor availability in molecular imaging with Positron Emission Tomography. The purpose of the present research was to determine the convergence of the results of the three methods in terms of three parameters, occupancy (s), distribution volume of the non-displaceable binding compartment (VND), and binding potential of the radioligand (BPND), in the absence of a gold standard. We tested 104 cases culled from the literature and calculated the goodness of fit of each of the Least Squares (LSM) and Deming II (DM) methods of linear regression when applied to the determination of the three main parameters, s, VND, and BPND, using the goodness of fit parameters R2, coefficient of variation (RMSE), and ‖X‖_∞ with both regression methods. We observed superior convergence among the values of s, VND, and BPND for the Inhibition and Occupancy plots. The Inhibition Plot emerged as the plot with a slightly higher degree of convergence (based on R2, RMSE and ‖X‖_∞ value). With two regression methods, Least Squares (LSM) and Deming II (DM), the estimated values of s, VND, and BPND generally converged. The Inhibition and Occupancy plots yielded the best fits to the data, according to the goodness of fit parameters, due primarily to the absent commingling of the dependent and independent variables tested with the Saturation (original Lassen) plot. In the presence of noise, the Inhibition and Occupancy plots yielded higher convergence.
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Affiliation(s)
- Javad Khodaii
- Amirkabir university of technology (Tehran Polytechnic), Iran, Islamic Republic of
| | - Mostafa Araj-Khodaei
- Neurosciences Research Center (NSRC), Tabriz University of Medical Sciences ,Tabriz, Iran, Iran, Islamic Republic of
| | - Manouchehr S Vafaee
- Center of Neuroscience, University of Copenhagen, Copenhagen, Denmark, Denmark
| | - Dean F Wong
- Section of Nuclear Medicine, Department of Radiology and Radiological Science, Johns Hopkins Medical, United States
| | - Albert Gjedde
- Center of Neuroscience, University of Copenhagen, Copenhagen, Denmark, Denmark
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20
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Akerele MI, Zein SA, Pandya S, Nikolopoulou A, Gauthier SA, Raj A, Henchcliffe C, Mozley PD, Karakatsanis NA, Gupta A, Babich J, Nehmeh SA. Population-based input function for TSPO quantification and kinetic modeling with [ 11C]-DPA-713. EJNMMI Phys 2021; 8:39. [PMID: 33914185 PMCID: PMC8085191 DOI: 10.1186/s40658-021-00381-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2021] [Accepted: 03/29/2021] [Indexed: 11/23/2022] Open
Abstract
INTRODUCTION Quantitative positron emission tomography (PET) studies of neurodegenerative diseases typically require the measurement of arterial input functions (AIF), an invasive and risky procedure. This study aims to assess the reproducibility of [11C]DPA-713 PET kinetic analysis using population-based input function (PBIF). The final goal is to possibly eliminate the need for AIF. MATERIALS AND METHODS Eighteen subjects including six healthy volunteers (HV) and twelve Parkinson disease (PD) subjects from two [11C]-DPA-713 PET studies were included. Each subject underwent 90 min of dynamic PET imaging. Five healthy volunteers underwent a test-retest scan within the same day to assess the repeatability of the kinetic parameters. Kinetic modeling was carried out using the Logan total volume of distribution (VT) model. For each data set, kinetic analysis was performed using a patient-specific AIF (PSAIF, ground-truth standard) and then repeated using the PBIF. PBIF was generated using the leave-one-out method for each subject from the remaining 17 subjects and after normalizing the PSAIFs by 3 techniques: (a) Weightsubject×DoseInjected, (b) area under AIF curve (AUC), and (c) Weightsubject×AUC. The variability in the VT measured with PSAIF, in the test-retest study, was determined for selected brain regions (white matter, cerebellum, thalamus, caudate, putamen, pallidum, brainstem, hippocampus, and amygdala) using the Bland-Altman analysis and for each of the 3 normalization techniques. Similarly, for all subjects, the variabilities due to the use of PBIF were assessed. RESULTS Bland-Altman analysis showed systematic bias between test and retest studies. The corresponding mean bias and 95% limits of agreement (LOA) for the studied brain regions were 30% and ± 70%. Comparing PBIF- and PSAIF-based VT estimate for all subjects and all brain regions, a significant difference between the results generated by the three normalization techniques existed for all brain structures except for the brainstem (P-value = 0.095). The mean % difference and 95% LOA is -10% and ±45% for Weightsubject×DoseInjected; +8% and ±50% for AUC; and +2% and ± 38% for Weightsubject×AUC. In all cases, normalizing by Weightsubject×AUC yielded the smallest % bias and variability (% bias = ±2%; LOA = ±38% for all brain regions). Estimating the reproducibility of PBIF-kinetics to PSAIF based on disease groups (HV/PD) and genotype (MAB/HAB), the average VT values for all regions obtained from PBIF is insignificantly higher than PSAIF (%difference = 4.53%, P-value = 0.73 for HAB; and %difference = 0.73%, P-value = 0.96 for MAB). PBIF also tends to overestimate the difference between PD and HV for HAB (% difference = 32.33% versus 13.28%) and underestimate it in MAB (%difference = 6.84% versus 20.92%). CONCLUSIONS PSAIF kinetic results are reproducible with PBIF, with variability in VT within that obtained for the test-retest studies. Therefore, VT assessed using PBIF-based kinetic modeling is clinically feasible and can be an alternative to PSAIF.
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Affiliation(s)
- Mercy I Akerele
- Department of Radiology, Weill Cornell Medical College, New York, NY, 10021, USA.
| | - Sara A Zein
- Department of Radiology, Weill Cornell Medical College, New York, NY, 10021, USA
| | - Sneha Pandya
- Department of Radiology, Weill Cornell Medical College, New York, NY, 10021, USA
| | | | - Susan A Gauthier
- Department of Radiology, Weill Cornell Medical College, New York, NY, 10021, USA
- Department of Neurology, Weill Cornell Medical College, New York, NY, 10021, USA
- Feil Family Brain and Mind Institute, Weill Cornell Medical College, New York, NY, 10021, USA
| | - Ashish Raj
- Department of Radiology, Weill Cornell Medical College, New York, NY, 10021, USA
| | - Claire Henchcliffe
- Department of Radiology, Weill Cornell Medical College, New York, NY, 10021, USA
- Department of Neurology, Weill Cornell Medical College, New York, NY, 10021, USA
| | - P David Mozley
- Department of Radiology, Weill Cornell Medical College, New York, NY, 10021, USA
| | | | - Ajay Gupta
- Department of Radiology, Weill Cornell Medical College, New York, NY, 10021, USA
| | - John Babich
- Department of Radiology, Weill Cornell Medical College, New York, NY, 10021, USA
| | - Sadek A Nehmeh
- Department of Radiology, Weill Cornell Medical College, New York, NY, 10021, USA
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21
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Comparison of [11C]-PBR28 Binding Between Persons Living With HIV and HIV-Uninfected Individuals. J Acquir Immune Defic Syndr 2021; 85:244-251. [PMID: 32658129 DOI: 10.1097/qai.0000000000002435] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVE Despite combined antiretroviral therapy, neuroinflammation may persist in persons living with HIV (PLWH) and contribute to cognitive impairment in this population. Positron emission tomography (PET) imaging targeting 18 kDa translocator protein (TSPO) has been used to localize neuroinflammation. We aimed to use TSPO-PET imaging to evaluate neuroinflammation in PLWH. DESIGN Twenty-four virologically suppressed PLWH on combined antiretroviral therapy and 13 HIV-negative (HIV-) controls completed TSPO-PET imaging using the radiotracer [C]PBR28. Because of tracer complexity and differing procedures used in previous studies, we employed an expansive methodological approach, using binding potential (BP) and standard uptake value ratio and multiple different reference regions to estimate [C]PBR28 binding. METHODS [C]PBR28 binding was measured in 30 cortical and subcortical regions and compared between PLWH and HIV- controls. Pearson correlation evaluated the association between [C]PBR28 binding and cognition and clinical measures of HIV. RESULTS Analyses conducted using multiple reference regions and measures of tracer uptake revealed no significant differences between [C]PBR28 binding in PLWH compared with HIV- controls. In addition, [C]PBR28 binding in PLWH was not significantly associated with clinical measures of HIV or plasma biomarkers of inflammation. [C]PBR28 binding was not significantly elevated in cognitively impaired PLWH compared with unimpaired PLWH, but there were inverse relationships between cognitive performance (executive and global function) and [C]PBR28 binding in PLWH. CONCLUSIONS Our results suggest that neuroinflammation may play a role in cognitive deficits, but overall neuroinflammatory levels as measured by TSPO-PET imaging in PLWH are not significantly different from those seen in HIV- controls.
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22
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Schubert J, Tonietto M, Turkheimer F, Zanotti-Fregonara P, Veronese M. Supervised clustering for TSPO PET imaging. Eur J Nucl Med Mol Imaging 2021; 49:257-268. [PMID: 33779770 PMCID: PMC8712290 DOI: 10.1007/s00259-021-05309-z] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Accepted: 03/08/2021] [Indexed: 12/12/2022]
Abstract
Purpose This technical note seeks to act as a practical guide for implementing a supervised clustering algorithm (SVCA) reference region approach and to explain the main strengths and limitations of the technique in the context of 18-kilodalton translocator protein (TSPO) positron emission tomography (PET) studies in experimental medicine. Background TSPO PET is the most widely used imaging technique for studying neuroinflammation in vivo in humans. Quantifying neuroinflammation with PET can be a challenging and invasive procedure, especially in frail patients, because it often requires blood sampling from an arterial catheter. A widely used alternative to arterial sampling is SVCA, which identifies the voxels with minimal specific binding in the PET images, thus extracting a pseudo-reference region for non-invasive quantification. Unlike other reference region approaches, SVCA does not require specification of an anatomical reference region a priori, which alleviates the limitation of TSPO contamination in anatomically-defined reference regions in individuals with underlying inflammatory processes. Furthermore, SVCA can be applied to any TSPO PET tracer across different neurological and neuropsychiatric conditions, providing noninvasivequantification of TSPO expression. Methods We provide an overview of the development of SVCA as well as step-by-step instructions for implementing SVCA with suggestions for specific settings. We review the literature on SVCAapplications using first- and second- generation TSPO PET tracers and discuss potential clinically relevant limitations and applications. Conclusions The correct implementation of SVCA can provide robust and reproducible estimates of brain TSPO expression. This review encourages the standardisation of SVCA methodology in TSPO PET analysis, ultimately aiming to improve replicability and comparability across study sites.
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Affiliation(s)
- Julia Schubert
- Centre for Neuroimaging Sciences, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK.
| | - Matteo Tonietto
- Université Paris-Saclay, CEA, CNRS, Inserm, BioMaps, Service Hospitalier Frédéric Joliot, Orsay, France
| | - Federico Turkheimer
- Centre for Neuroimaging Sciences, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK
| | - Paolo Zanotti-Fregonara
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, MD, USA
| | - Mattia Veronese
- Centre for Neuroimaging Sciences, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK.
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23
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Identifying Musculoskeletal Pain Generators Using Molecular Imaging. Mol Imaging 2021. [DOI: 10.1016/b978-0-12-816386-3.00076-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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24
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Helo Y, Searle GE, Borghese F, Abraham S, Saleem A. Specificity of translocator protein-targeted positron emission tomography in inflammatory joint disease. EJNMMI Res 2020; 10:147. [PMID: 33284369 PMCID: PMC7721924 DOI: 10.1186/s13550-020-00736-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2020] [Accepted: 11/23/2020] [Indexed: 12/02/2022] Open
Abstract
Objective Expression of the translocator protein (TSPO) on inflammatory cells has facilitated imaging of synovitis with TSPO-targeted positron emission tomography (PET). We aimed to quantitatively assess the specificity of the second-generation TSPO PET radioligand, [11C]PBR28, and to generate simplified PET protocols in patients with inflammatory joint disease (IJD) in this pilot study. Methods Three IJD patients (two rheumatoid arthritis and one osteoarthritis) with knee involvement underwent dynamic [11C]PBR28-PET scans before and after administration of 90 mg of oral emapunil (XBD-173), a TSPO ligand the same day. Radial arterial blood sampling was performed throughout the scan, and total radioactivity and radioactive metabolites were obtained. A semi-automated method was used to generate regions of interest. Standardized uptake value (SUV) and SUV ratio corrected for activity in bone and blood between 50 and 70 min (SUVr50–70 bone, SUVr50–70 blood, respectively) and PET volume of distribution (VT) of the radioligand were calculated. Results A mean [11C]PBR28 radioactivity of 378 (range 362–389) MBq was administered. A significant decrease (p < 0.05) in VT, SUVr50–70 bone and SUVr50–70 blood observed after oral emapunil confirmed the TSPO specificity of [11C]PBR28. A decrease in SUV was not observed in the post-block scan. Conclusion [11C]PBR28 is TSPO-specific radioligand in IJD patients. Simplified PET protocols with static PET acquisition can be used in the management and evaluation of novel therapeutics that target TSPO overexpressing cells.
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Affiliation(s)
- Yusuf Helo
- Invicro, A Konica Minolta Company, Burlington Danes Building, Hammersmith Hospital, Du Cane Road, London, W12 0NN, UK
| | - Graham E Searle
- Invicro, A Konica Minolta Company, Burlington Danes Building, Hammersmith Hospital, Du Cane Road, London, W12 0NN, UK
| | - Federica Borghese
- Imperial College London, Hammersmith Hospital, Du Cane Road, London, W12 0NN, UK
| | - Sonya Abraham
- Imperial College London, Hammersmith Hospital, Du Cane Road, London, W12 0NN, UK
| | - Azeem Saleem
- Invicro, A Konica Minolta Company, Burlington Danes Building, Hammersmith Hospital, Du Cane Road, London, W12 0NN, UK. .,Hull York Medical School, Allam Medical Building, University of Hull, Cottingham Road, Hull, HU6 7RX, UK.
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25
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Yang T, Velagapudi R, Terrando N. Neuroinflammation after surgery: from mechanisms to therapeutic targets. Nat Immunol 2020; 21:1319-1326. [PMID: 33077953 DOI: 10.1038/s41590-020-00812-1] [Citation(s) in RCA: 109] [Impact Index Per Article: 27.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2020] [Accepted: 09/16/2020] [Indexed: 12/12/2022]
Abstract
Injury is a key driver of inflammation, a critical yet necessary response involving several mediators that is aimed at restoring tissue homeostasis. Inflammation in the central nervous system can be triggered by a variety of stimuli, some intrinsic to the brain and others arising from peripheral signals. Fine-tuned regulation of this response is crucial in a system that is vulnerable due to, for example, aging and ongoing neurodegeneration. In this context, seemingly harmless interventions like a common surgery to repair a broken limb can overwhelm the immune system and become the driver of further complications such as delirium and other perioperative neurocognitive disorders. Here, we discuss potential mechanisms by which the immune system affects the central nervous system after surgical trauma. Together, these neuroimmune interactions are becoming hallmarks of and potential therapeutic targets for multiple neurologic conditions, including those affecting the perioperative space.
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Affiliation(s)
- Ting Yang
- Department of Medicine, Division of Nephrology, Duke University Medical Center, Durham, NC, USA
| | | | - Niccolò Terrando
- Department of Anesthesiology, Duke University Medical Center, Durham, NC, USA. .,Department of Cell Biology, Duke University Medical Center, Durham, NC, USA.
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26
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Wright P, Veronese M, Mazibuko N, Turkheimer FE, Rabiner EA, Ballard CG, Williams SCR, Hari Narayanan AK, Osrah B, Williams R, Marques TR, Howes OD, Roncaroli F, O'Sullivan MJ. Patterns of Mitochondrial TSPO Binding in Cerebral Small Vessel Disease: An in vivo PET Study With Neuropathological Comparison. Front Neurol 2020; 11:541377. [PMID: 33178101 PMCID: PMC7596201 DOI: 10.3389/fneur.2020.541377] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2020] [Accepted: 08/20/2020] [Indexed: 12/11/2022] Open
Abstract
Small vessel disease (SVD) is associated with cognitive impairment in older age and be implicated in vascular dementia. Post-mortem studies show proliferation of activated microglia in the affected white matter. However, the role of inflammation in SVD pathogenesis is incompletely understood and better biomarkers are needed. We hypothesized that expression of the 18 kDa translocator protein (TSPO), a marker of microglial activation, would be higher in SVD. Positron emission tomography (PET) was performed with the second-generation TSPO ligand [11C]PBR28 in 11 participants with SVD. TSPO binding was evaluated by a two-tissue compartment model, with and without a vascular binding component, in white matter hyperintensities (WMH) and normal-appearing white matter (NAWM). In post-mortem tissue, in a separate cohort of individuals with SVD, immunohistochemistry was performed for TSPO and a pan-microglial marker Iba1. Kinetic modeling showed reduced tracer volume and blood volume fraction in WMH compared with NAWM, but a significant increase in vascular binding. Vascular [11C]PBR28 binding was also increased compared with normal-appearing white matter of healthy participants free of SVD. Immunohistochemistry showed a diffuse increase in microglial staining (with Iba1) in sampled tissue in SVD compared with control samples, but with only a subset of microglia staining positively for TSPO. Intense TSPO staining was observed in the vicinity of damaged small blood vessels, which included perivascular macrophages. The results suggest an altered phenotype of activated microglia, with reduced TSPO expression, in the areas of greatest white matter ischemia in SVD, with implications for the interpretation of TSPO PET studies in older individuals or those with vascular risk factors.
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Affiliation(s)
- Paul Wright
- Department of Neuroimaging, Institute of Psychiatry Psychology & Neuroscience, King's College London, London, United Kingdom
| | - Mattia Veronese
- Department of Neuroimaging, Institute of Psychiatry Psychology & Neuroscience, King's College London, London, United Kingdom
| | - Ndabezinhle Mazibuko
- Department of Neuroimaging, Institute of Psychiatry Psychology & Neuroscience, King's College London, London, United Kingdom
| | - Federico E. Turkheimer
- Department of Neuroimaging, Institute of Psychiatry Psychology & Neuroscience, King's College London, London, United Kingdom
| | - Eugenii A. Rabiner
- Department of Neuroimaging, Institute of Psychiatry Psychology & Neuroscience, King's College London, London, United Kingdom
- Invicro, London, United Kingdom
| | - Clive G. Ballard
- College of Medicine and Health, University of Exeter, Exeter, United Kingdom
| | - Steven C. R. Williams
- Department of Neuroimaging, Institute of Psychiatry Psychology & Neuroscience, King's College London, London, United Kingdom
| | - Avinash Kumar Hari Narayanan
- Division of Neuroscience and Experimental Psychology, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom
- Manchester Centre for Clinical Neuroscience, Salford Royal Foundation Trust, Salford, United Kingdom
| | - Bahiya Osrah
- Division of Neuroscience and Experimental Psychology, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom
- Manchester Centre for Clinical Neuroscience, Salford Royal Foundation Trust, Salford, United Kingdom
| | - Ricky Williams
- Division of Neuroscience and Experimental Psychology, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom
- Manchester Centre for Clinical Neuroscience, Salford Royal Foundation Trust, Salford, United Kingdom
| | - Tiago R. Marques
- Department of Psychosis Studies, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, United Kingdom
| | - Oliver D. Howes
- Department of Psychosis Studies, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, United Kingdom
| | - Federico Roncaroli
- Division of Neuroscience and Experimental Psychology, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom
- Manchester Centre for Clinical Neuroscience, Salford Royal Foundation Trust, Salford, United Kingdom
| | - Michael J. O'Sullivan
- Department of Neuroimaging, Institute of Psychiatry Psychology & Neuroscience, King's College London, London, United Kingdom
- University of Queensland Centre for Clinical Research, Brisbane, QLD, Australia
- Department of Neurology, The Royal Brisbane and Women's Hospital, Herston, QLD, Australia
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27
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Yoon D, Kogan F, Gold GE, Biswal S. Identifying Musculoskeletal Pain Generators Using Clinical PET. Semin Musculoskelet Radiol 2020; 24:441-450. [DOI: 10.1055/s-0040-1713607] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
AbstractIdentifying the source of a person's pain is a significant clinical challenge because the physical sensation of pain is believed to be subjective and difficult to quantify. The experience of pain is not only modulated by the individual's threshold to painful stimuli but also a product of the person's affective contributions, such as fear, anxiety, and previous experiences. Perhaps then to quantify pain is to examine the degree of nociception and pro-nociceptive inflammation, that is, the extent of cellular, chemical, and molecular changes that occur in pain-generating processes. Measuring changes in the local density of receptors, ion channels, mediators, and inflammatory/immune cells that are involved in the painful phenotype using targeted, highly sensitive, and specific positron emission tomography (PET) radiotracers is therefore a promising approach toward objectively identifying peripheral pain generators. Although several preclinical radiotracer candidates are being developed, a growing number of ongoing clinical PET imaging approaches can measure the degree of target concentration and thus serve as a readout for sites of pain generation. Further, when PET is combined with the spatial and contrast resolution afforded by magnetic resonance imaging, nuclear medicine physicians and radiologists can potentially identify pain drivers with greater accuracy and confidence. Clinical PET imaging approaches with fluorine-18 fluorodeoxyglucose, fluorine-18 sodium fluoride, and sigma-1 receptor PET radioligand and translocator protein radioligands to isolate the source of pain are described here.
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Affiliation(s)
- Daehyun Yoon
- Division of Musculoskeletal Radiology, Department of Radiology, Stanford University School of Medicine, Stanford, California
| | - Feliks Kogan
- Division of Musculoskeletal Radiology, Department of Radiology, Stanford University School of Medicine, Stanford, California
| | - Garry E. Gold
- Division of Musculoskeletal Radiology, Department of Radiology, Stanford University School of Medicine, Stanford, California
| | - Sandip Biswal
- Division of Musculoskeletal Radiology, Department of Radiology, Stanford University School of Medicine, Stanford, California
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28
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Laurell GL, Plavén-Sigray P, Jucaite A, Varrone A, Cosgrove KP, Svarer C, Knudsen GM, Ogden RT, Zanderigo F, Cervenka S, Hillmer AT, Schain M. Nondisplaceable Binding Is a Potential Confounding Factor in 11C-PBR28 Translocator Protein PET Studies. J Nucl Med 2020; 62:412-417. [PMID: 32680926 DOI: 10.2967/jnumed.120.243717] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2020] [Accepted: 06/23/2020] [Indexed: 01/08/2023] Open
Abstract
The PET ligand 11C-PBR28 (N-((2-(methoxy-11C)-phenyl)methyl)-N-(6-phenoxy-3-pyridinyl)acetamide) binds to the 18-kDa translocator protein (TSPO), a biomarker of glia. In clinical studies of TSPO, the ligand total distribution volume, VT, is frequently the reported outcome measure. Since VT is the sum of the ligand-specific distribution volume (VS) and the nondisplaceable-binding distribution volume (VND), differences in VND across subjects and groups will have an impact on VT Methods: Here, we used a recently developed method for simultaneous estimation of VND (SIME) to disentangle contributions from VND and VS Data from 4 previously published 11C-PBR28 PET studies were included: before and after a lipopolysaccharide challenge (8 subjects), in alcohol use disorder (14 patients, 15 controls), in first-episode psychosis (16 patients, 16 controls), and in Parkinson disease (16 patients, 16 controls). In each dataset, regional VT estimates were obtained with a standard 2-tissue-compartment model, and brain-wide VND was estimated with SIME. VS was then calculated as VT - VND VND and VS were then compared across groups, within each dataset. Results: A lower VND was found for individuals with alcohol-use disorder (34%, P = 0.00084) and Parkinson disease (34%, P = 0.0032) than in their corresponding controls. We found no difference in VND between first-episode psychosis patients and their controls, and the administration of lipopolysaccharide did not change VND Conclusion: Our findings suggest that in TSPO PET studies, nondisplaceable binding can differ between patient groups and conditions and should therefore be considered.
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Affiliation(s)
- Gjertrud L Laurell
- Neurobiology Research Unit, Copenhagen University Hospital Rigshospitalet, Copenhagen, Denmark
| | - Pontus Plavén-Sigray
- Neurobiology Research Unit, Copenhagen University Hospital Rigshospitalet, Copenhagen, Denmark.,Centre for Psychiatry Research, Department of Clinical Neuroscience, Karolinska Institutet, and Stockholm Health Care Services, Region Stockholm, Stockholm, Sweden
| | - Aurelija Jucaite
- Centre for Psychiatry Research, Department of Clinical Neuroscience, Karolinska Institutet, and Stockholm Health Care Services, Region Stockholm, Stockholm, Sweden.,PET Science Centre, Precision Medicine and Genomics, R&D, AstraZeneca, Stockholm, Sweden
| | - Andrea Varrone
- Centre for Psychiatry Research, Department of Clinical Neuroscience, Karolinska Institutet, and Stockholm Health Care Services, Region Stockholm, Stockholm, Sweden
| | - Kelly P Cosgrove
- PET Center, Department of Radiology and Biomedical Imaging, Yale University, New Haven, Connecticut.,Department of Psychiatry, Yale University, New Haven, Connecticut
| | - Claus Svarer
- Neurobiology Research Unit, Copenhagen University Hospital Rigshospitalet, Copenhagen, Denmark
| | - Gitte M Knudsen
- Neurobiology Research Unit, Copenhagen University Hospital Rigshospitalet, Copenhagen, Denmark.,Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | | | - R Todd Ogden
- Department of Biostatistics, Columbia University, New York, New York.,Molecular Imaging and Neuropathology Area, New York State Psychiatric Institute, New York, New York
| | - Francesca Zanderigo
- Department of Biostatistics, Columbia University, New York, New York.,Department of Psychiatry, Columbia University College of Physicians and Surgeons, New York, New York; and
| | - Simon Cervenka
- Centre for Psychiatry Research, Department of Clinical Neuroscience, Karolinska Institutet, and Stockholm Health Care Services, Region Stockholm, Stockholm, Sweden
| | - Ansel T Hillmer
- PET Center, Department of Radiology and Biomedical Imaging, Yale University, New Haven, Connecticut.,Department of Psychiatry, Yale University, New Haven, Connecticut.,Department of Radiology and Biomedical Imaging, Yale University School of Medicine, New Haven, Connecticut
| | - Martin Schain
- Neurobiology Research Unit, Copenhagen University Hospital Rigshospitalet, Copenhagen, Denmark
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Sridharan S, Raffel J, Nandoskar A, Record C, Brooks DJ, Owen D, Sharp D, Muraro PA, Gunn R, Nicholas R. Confirmation of Specific Binding of the 18-kDa Translocator Protein (TSPO) Radioligand [ 18F]GE-180: a Blocking Study Using XBD173 in Multiple Sclerosis Normal Appearing White and Grey Matter. Mol Imaging Biol 2020; 21:935-944. [PMID: 30796709 DOI: 10.1007/s11307-019-01323-8] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
PURPOSE Measurements of non-displaceable binding (VND) of positron emission tomography (PET) ligands are not often made in vivo in humans because they require ligands to displace binding to target receptors and there are few readily available, safe ones to use. A technique to measure VND for ligands for the 18-kDa translocator protein (TSPO) has recently been developed which compares the total volume of distribution (VT) before and after administration of the TSPO ligand XBD173. Here, we used XBD173 with an occupancy plot to quantify VND for two TSPO radiotracers, [18F]GE-180 and [11C]PBR28, in cohorts of people with multiple sclerosis (MS). Additionally, we compared plots of subjects carrying high (HAB) or mixed binding (MAB) affinity polymorphisms of TSPO to estimate VND without receptor blockade. PROCEDURES Twelve people with MS underwent baseline MRI and 90-min dynamic [18F]GE-180 PET or [11C]PBR28 PET (n = 6; three HAB, three MAB each). Arterial blood sampling was used to generate plasma input functions for the two-tissue compartment model. VND was calculated using two independent methods: the occupancy plot (by modelling the differences in signal post XBD173) and the polymorphism plot (by modelling the differences in signal across presence and absence of rs6971 genotypes). RESULTS Whole brain VT (mean ± standard deviation) was 0.29 ± 0.17 ml/cm3 for [18F]GE-180 and 5.01 ± 1.88 ml/cm3 for [11C]PBR28. Using the occupancy and polymorphism plots respectively, VND for [18F]GE-180 was 0.11 ml/cm3 (95 % CI = 0.02, 0.16) and 0.20 ml/cm3 (0.16, 0.34), accounting for, on average, 55 % of VT in the whole brain. For [11C]PBR28, these values were 3.81 ml/cm3 (3.02, 4.21) and 3.49 ml/cm3 (1.38, 4.27), accounting for 67 % of average whole brain VT. CONCLUSIONS Although VT for [18F]GE-180 is low, indicating low brain penetration, half the signal shown by MS subjects reflected specific TSPO binding. VT for [11C]PBR28 was higher and two thirds of the binding was non-specific. No brain ROIs were devoid of specific signal, further confirming that true reference tissue approaches are potentially problematic for estimating TSPO levels.
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Affiliation(s)
- Sujata Sridharan
- Division of Brain Sciences, Faculty of Medicine, Imperial College London, Hammersmith Hospital Campus, Burlington Danes Building, Du Cane Road, London, W12 0NN, UK.
| | - Joel Raffel
- Division of Brain Sciences, Faculty of Medicine, Imperial College London, Hammersmith Hospital Campus, Burlington Danes Building, Du Cane Road, London, W12 0NN, UK
| | - Ashwini Nandoskar
- Division of Brain Sciences, Faculty of Medicine, Imperial College London, Hammersmith Hospital Campus, Burlington Danes Building, Du Cane Road, London, W12 0NN, UK
| | - Chris Record
- Division of Brain Sciences, Faculty of Medicine, Imperial College London, Hammersmith Hospital Campus, Burlington Danes Building, Du Cane Road, London, W12 0NN, UK
| | - David J Brooks
- Division of Brain Sciences, Faculty of Medicine, Imperial College London, Hammersmith Hospital Campus, Burlington Danes Building, Du Cane Road, London, W12 0NN, UK.,Institute of Clinical Medicine, Aarhus University, Aarhus, Denmark.,Institute of Neuroscience, Newcastle upon Tyne University, Newcastle upon Tyne, UK
| | - David Owen
- Division of Brain Sciences, Faculty of Medicine, Imperial College London, Hammersmith Hospital Campus, Burlington Danes Building, Du Cane Road, London, W12 0NN, UK
| | - David Sharp
- Division of Brain Sciences, Faculty of Medicine, Imperial College London, Hammersmith Hospital Campus, Burlington Danes Building, Du Cane Road, London, W12 0NN, UK
| | - Paolo A Muraro
- Division of Brain Sciences, Faculty of Medicine, Imperial College London, Hammersmith Hospital Campus, Burlington Danes Building, Du Cane Road, London, W12 0NN, UK
| | | | - Richard Nicholas
- Division of Brain Sciences, Faculty of Medicine, Imperial College London, Hammersmith Hospital Campus, Burlington Danes Building, Du Cane Road, London, W12 0NN, UK
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30
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Bhatt S, Hillmer AT, Girgenti MJ, Rusowicz A, Kapinos M, Nabulsi N, Huang Y, Matuskey D, Angarita GA, Esterlis I, Davis MT, Southwick SM, Friedman MJ, Duman RS, Carson RE, Krystal JH, Pietrzak RH, Cosgrove KP. PTSD is associated with neuroimmune suppression: evidence from PET imaging and postmortem transcriptomic studies. Nat Commun 2020; 11:2360. [PMID: 32398677 PMCID: PMC7217830 DOI: 10.1038/s41467-020-15930-5] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2019] [Accepted: 03/31/2020] [Indexed: 12/22/2022] Open
Abstract
Despite well-known peripheral immune activation in posttraumatic stress disorder (PTSD), there are no studies of brain immunologic regulation in individuals with PTSD. [11C]PBR28 Positron Emission Tomography brain imaging of the 18-kDa translocator protein (TSPO), a microglial biomarker, was conducted in 23 individuals with PTSD and 26 healthy individuals-with or without trauma exposure. Prefrontal-limbic TSPO availability in the PTSD group was negatively associated with PTSD symptom severity and was significantly lower than in controls. Higher C-reactive protein levels were also associated with lower prefrontal-limbic TSPO availability and PTSD severity. An independent postmortem study found no differential gene expression in 22 PTSD vs. 22 controls, but showed lower relative expression of TSPO and microglia-associated genes TNFRSF14 and TSPOAP1 in a female PTSD subgroup. These findings suggest that peripheral immune activation in PTSD is associated with deficient brain microglial activation, challenging prevailing hypotheses positing neuroimmune activation as central to stress-related pathophysiology.
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Affiliation(s)
- Shivani Bhatt
- Interdepartmental Neuroscience Program, Yale University, New Haven, CT, 06510, USA
| | - Ansel T Hillmer
- Department of Radiology and Biomedical Imaging, Yale School of Medicine, New Haven, CT, 06520, USA
- Department of Psychiatry, Yale School of Medicine, New Haven, CT, 06511, USA
- Yale PET Center, Yale School of Medicine, New Haven, CT, 06519, USA
| | - Matthew J Girgenti
- Department of Psychiatry, Yale School of Medicine, New Haven, CT, 06511, USA
- U.S. Department of Veterans Affairs, National Center for Posttraumatic Stress Disorder, Clinical Neurosciences Division, VA Connecticut Healthcare System, West Haven, CT, 06516, USA
| | - Aleksandra Rusowicz
- Department of Psychiatry, Yale School of Medicine, New Haven, CT, 06511, USA
| | - Michael Kapinos
- Yale PET Center, Yale School of Medicine, New Haven, CT, 06519, USA
| | - Nabeel Nabulsi
- Department of Radiology and Biomedical Imaging, Yale School of Medicine, New Haven, CT, 06520, USA
- Yale PET Center, Yale School of Medicine, New Haven, CT, 06519, USA
| | - Yiyun Huang
- Department of Radiology and Biomedical Imaging, Yale School of Medicine, New Haven, CT, 06520, USA
- Yale PET Center, Yale School of Medicine, New Haven, CT, 06519, USA
| | - David Matuskey
- Department of Radiology and Biomedical Imaging, Yale School of Medicine, New Haven, CT, 06520, USA
- Department of Psychiatry, Yale School of Medicine, New Haven, CT, 06511, USA
- Yale PET Center, Yale School of Medicine, New Haven, CT, 06519, USA
| | - Gustavo A Angarita
- Department of Psychiatry, Yale School of Medicine, New Haven, CT, 06511, USA
- Yale PET Center, Yale School of Medicine, New Haven, CT, 06519, USA
| | - Irina Esterlis
- Interdepartmental Neuroscience Program, Yale University, New Haven, CT, 06510, USA
- Department of Psychiatry, Yale School of Medicine, New Haven, CT, 06511, USA
- Yale PET Center, Yale School of Medicine, New Haven, CT, 06519, USA
- U.S. Department of Veterans Affairs, National Center for Posttraumatic Stress Disorder, Clinical Neurosciences Division, VA Connecticut Healthcare System, West Haven, CT, 06516, USA
| | - Margaret T Davis
- Department of Psychiatry, Yale School of Medicine, New Haven, CT, 06511, USA
| | - Steven M Southwick
- Department of Psychiatry, Yale School of Medicine, New Haven, CT, 06511, USA
- U.S. Department of Veterans Affairs, National Center for Posttraumatic Stress Disorder, Clinical Neurosciences Division, VA Connecticut Healthcare System, West Haven, CT, 06516, USA
| | | | - Ronald S Duman
- Department of Psychiatry, Yale School of Medicine, New Haven, CT, 06511, USA
| | - Richard E Carson
- Department of Radiology and Biomedical Imaging, Yale School of Medicine, New Haven, CT, 06520, USA
- Yale PET Center, Yale School of Medicine, New Haven, CT, 06519, USA
| | - John H Krystal
- Department of Psychiatry, Yale School of Medicine, New Haven, CT, 06511, USA
- U.S. Department of Veterans Affairs, National Center for Posttraumatic Stress Disorder, Clinical Neurosciences Division, VA Connecticut Healthcare System, West Haven, CT, 06516, USA
| | - Robert H Pietrzak
- Department of Psychiatry, Yale School of Medicine, New Haven, CT, 06511, USA
- U.S. Department of Veterans Affairs, National Center for Posttraumatic Stress Disorder, Clinical Neurosciences Division, VA Connecticut Healthcare System, West Haven, CT, 06516, USA
| | - Kelly P Cosgrove
- Interdepartmental Neuroscience Program, Yale University, New Haven, CT, 06510, USA.
- Department of Radiology and Biomedical Imaging, Yale School of Medicine, New Haven, CT, 06520, USA.
- Department of Psychiatry, Yale School of Medicine, New Haven, CT, 06511, USA.
- Yale PET Center, Yale School of Medicine, New Haven, CT, 06519, USA.
- U.S. Department of Veterans Affairs, National Center for Posttraumatic Stress Disorder, Clinical Neurosciences Division, VA Connecticut Healthcare System, West Haven, CT, 06516, USA.
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Tong J, Williams B, Rusjan PM, Mizrahi R, Lacapère JJ, McCluskey T, Furukawa Y, Guttman M, Ang LC, Boileau I, Meyer JH, Kish SJ. Concentration, distribution, and influence of aging on the 18 kDa translocator protein in human brain: Implications for brain imaging studies. J Cereb Blood Flow Metab 2020; 40:1061-1076. [PMID: 31220997 PMCID: PMC7181090 DOI: 10.1177/0271678x19858003] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Positron emission tomography (PET) imaging of the translocator protein (TSPO) is widely used as a biomarker of microglial activation. However, TSPO protein concentration in human brain has not been optimally quantified nor has its regional distribution been compared to TSPO binding. We determined TSPO protein concentration, change with age, and regional distribution by quantitative immunoblotting in autopsied human brain. Brain TSPO protein concentration (>0.1 ng/µg protein) was higher than those reported by in vitro binding assays by at least 2 to 70 fold. TSPO protein distributed widely in both gray and white matter regions, with distribution in major gray matter areas ranked generally similar to that of PET binding in second-generation radiotracer studies. TSPO protein concentration in frontal cortex was high at birth, declined precipitously during the first three months, and increased modestly during adulthood/senescence (10%/decade; vs. 30% for comparison astrocytic marker GFAP). As expected, TSPO protein levels were significantly increased (+114%) in degenerating putamen in multiple system atrophy, providing further circumstantial support for TSPO as a gliosis marker. Overall, findings show some similarities between TSPO protein and PET binding characteristics in the human brain but also suggest that part of the TSPO protein pool might be less available for radioligand binding.
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Affiliation(s)
- Junchao Tong
- Preclinical Imaging, Research Imaging
Centre, Centre for Addiction and Mental Health, Toronto, Ontario, Canada
- Human Brain Laboratory, Research Imaging
Centre, Centre for Addiction and Mental Health, Toronto, Ontario, Canada
- Research Imaging Centre and Campbell
Family Mental Health Research Institute, Centre for Addiction and Mental Health,
Toronto, Ontario, Canada
- Junchao Tong, Preclinical Imaging, Centre
for Addiction and Mental Health, 250 College Street, Toronto, Ontario M5T 1R8,
Canada.
| | - Belinda Williams
- Human Brain Laboratory, Research Imaging
Centre, Centre for Addiction and Mental Health, Toronto, Ontario, Canada
- Addiction Imaging Research Group,
Research Imaging Centre, Centre for Addiction and Mental Health, Toronto, Ontario,
Canada
| | - Pablo M. Rusjan
- Research Imaging Centre and Campbell
Family Mental Health Research Institute, Centre for Addiction and Mental Health,
Toronto, Ontario, Canada
| | - Romina Mizrahi
- Research Imaging Centre and Campbell
Family Mental Health Research Institute, Centre for Addiction and Mental Health,
Toronto, Ontario, Canada
| | - Jean-Jacques Lacapère
- Sorbonne Universités-UPMC University of
Paris 06, Département de Chimie, École Normale Supérieure-PSL Research University,
Paris, France
| | - Tina McCluskey
- Human Brain Laboratory, Research Imaging
Centre, Centre for Addiction and Mental Health, Toronto, Ontario, Canada
- Research Imaging Centre and Campbell
Family Mental Health Research Institute, Centre for Addiction and Mental Health,
Toronto, Ontario, Canada
| | - Yoshiaki Furukawa
- Department of Neurology, Juntendo Tokyo
Koto Geriatric Medical Center, and Faculty of Medicine, University & Post
Graduate University of Juntendo, Tokyo, Japan
| | - Mark Guttman
- Centre for Movement Disorders, Toronto,
Ontario, Canada
| | - Lee-Cyn Ang
- Division of Neuropathology, London
Health Science Centre, University of Western Ontario, London, Ontario, Canada
| | - Isabelle Boileau
- Research Imaging Centre and Campbell
Family Mental Health Research Institute, Centre for Addiction and Mental Health,
Toronto, Ontario, Canada
- Addiction Imaging Research Group,
Research Imaging Centre, Centre for Addiction and Mental Health, Toronto, Ontario,
Canada
| | - Jeffrey H Meyer
- Research Imaging Centre and Campbell
Family Mental Health Research Institute, Centre for Addiction and Mental Health,
Toronto, Ontario, Canada
| | - Stephen J Kish
- Human Brain Laboratory, Research Imaging
Centre, Centre for Addiction and Mental Health, Toronto, Ontario, Canada
- Research Imaging Centre and Campbell
Family Mental Health Research Institute, Centre for Addiction and Mental Health,
Toronto, Ontario, Canada
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32
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Letter to the Editor re: Confirmation of Specific Binding of the 18-kDa Translocator Protein (TSPO) Radioligand [ 18F]GE-180: a Blocking Study Using XBD173 in Multiple Sclerosis Normal Appearing White and Grey Matter. Mol Imaging Biol 2020; 22:10-12. [PMID: 31641965 DOI: 10.1007/s11307-019-01433-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
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33
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Sharma AA, Szaflarski JP. In Vivo Imaging of Neuroinflammatory Targets in Treatment-Resistant Epilepsy. Curr Neurol Neurosci Rep 2020; 20:5. [PMID: 32166626 DOI: 10.1007/s11910-020-1025-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
PURPOSE OF REVIEW Recent evidence indicates that chronic, low-level neuroinflammation underlies epileptogenesis. Targeted imaging of key neuroinflammatory cells, receptors, and tissues may enable localizing epileptogenic onset zone, especially in those patients who are treatment-resistant and considered MRI-negative. Finding a specific, sensitive neuroimaging-based biomarker could aid surgical planning and improve overall prognosis in eligible patients. This article reviews recent research on in vivo imaging of neuroinflammatory targets in patients with treatment-resistant, non-lesional epilepsy. RECENT FINDINGS A number of advanced approaches based on imaging neuroinflammation are being implemented in order to assist localization of epileptogenic onset zone. The most exciting tools are based on radioligand-based nuclear imaging or revisiting of existing technology in novel ways. The greatest limitations stem from gaps in knowledge about the exact function of neuroinflammatory targets (e.g., neurotoxic or neuroprotective). Further, lingering questions about each approach's specificity, reliability, and sensitivity must be addressed, and clinical utility must be validated before any novel method is incorporated into mainstream clinical practice. Current applications of imaging neuroinflammation in humans are limited and underutilized, but offer hope for finding sensitive and specific neuroimaging-based biomarker(s). Future work necessitates appreciation of investigations to date, significant findings, and neuroinflammatory targets worth exploring further.
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Affiliation(s)
- Ayushe A Sharma
- Department of Psychology, University of Alabama at Birmingham, Birmingham, AL, USA. .,Department of Neurology, UAB Epilepsy Center, University of Alabama at Birmingham, 1719 6th Avenue South, CIRC 312, Birmingham, AL, 35249-0021, USA.
| | - Jerzy P Szaflarski
- Department of Neurology, UAB Epilepsy Center, University of Alabama at Birmingham, 1719 6th Avenue South, CIRC 312, Birmingham, AL, 35249-0021, USA.,University of Alabama at Birmingham Epilepsy Center, Birmingham, AL, USA
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34
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Hshieh TT, Vasunilashorn SM, D'Aquila ML, Arnold SE, Dickerson BC, Fong TG, Jones RN, Marcantonio ER, Schmitt EM, Xu G, Gou Y, Chen F, Kunze LJ, Vlassakov KV, Abdeen AR, Lange JK, Earp BE, Touroutoglou A, Carlyle BC, Kivisakk-Webb P, Travison TG, Dillon ST, Libermann TA, Inouye SK. The Role of Inflammation after Surgery for Elders (RISE) study: Study design, procedures, and cohort profile. ALZHEIMER'S & DEMENTIA: DIAGNOSIS, ASSESSMENT & DISEASE MONITORING 2019; 11:752-762. [PMID: 31737775 PMCID: PMC6849121 DOI: 10.1016/j.dadm.2019.09.004] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Introduction The Role of Inflammation after Surgery for Elders study correlates novel inflammatory markers measured in blood, cerebrospinal fluid (CSF) assays, and [11C]-PBR28 positron-emission tomography imaging. Methods This study involved a prospective cohort design with patients who underwent elective hip and knee arthroplasty under spinal anesthesia. Sixty-five adults participated with their family members. Inflammatory biomarker assays were measured preoperatively on day 1 and postoperatively at one month. Results On average, participants were 75 years old, and 72% were female. 54% underwent total knee arthroplasty, and 46% underwent total hip arthroplasty. The mean Modified Mini-Mental State (3MS) Examination score was 89.3; four patients (6%) scored ≤77 points. Plasma assays were completed in 63 (97%) participants, cerebrospinal fluid assays in 61 (94%), and PET imaging in 44 (68%). Discussion This complex study presents an innovative effort to correlate peripheral and central inflammatory biomarkers before and after major surgery in older adults. Strengths include collecting concurrent blood, cerebrospinal fluid, and positron-emission tomography with detailed clinical characterization of delirium, cognition, and functional status. We describe the methodology of the Role of Inflammation after Surgery for Elders Study. This is a prospective cohort of elective hip/knee arthroplasty patients 70 years or older. We examine inflammation in blood, cerebrospinal fluid and positron emission tomography. We collect novel biomarkers preoperatively and one-month postoperatively. There is clinical characterization of delirium, cognition and functional status.
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Affiliation(s)
- Tammy T Hshieh
- Division of Aging, Department of Medicine, Brigham and Women's Hospital, Boston, MA, USA.,Aging Brain Center, Marcus Institute for Aging Research, Hebrew SeniorLife, Boston, MA, USA.,Harvard Medical School, Boston, MA, USA
| | - Sarinnapha M Vasunilashorn
- Aging Brain Center, Marcus Institute for Aging Research, Hebrew SeniorLife, Boston, MA, USA.,Harvard Medical School, Boston, MA, USA.,Department of Medicine, Beth Israel Deaconess Medical Center, Boston, MA, USA
| | - Madeline L D'Aquila
- Aging Brain Center, Marcus Institute for Aging Research, Hebrew SeniorLife, Boston, MA, USA
| | - Steven E Arnold
- Harvard Medical School, Boston, MA, USA.,Department of Neurology, Massachusetts Alzheimer's Disease Research Center, Massachusetts General Hospital, Boston, MA, USA
| | - Bradford C Dickerson
- Harvard Medical School, Boston, MA, USA.,Department of Neurology, Massachusetts Alzheimer's Disease Research Center, Massachusetts General Hospital, Boston, MA, USA
| | - Tamara G Fong
- Aging Brain Center, Marcus Institute for Aging Research, Hebrew SeniorLife, Boston, MA, USA.,Harvard Medical School, Boston, MA, USA.,Department of Neurology, Beth Israel Deaconess Medical Center, Boston, MA, USA
| | - Richard N Jones
- Department of Psychiatry and Human Behavior, Brown University Warren Alpert Medical School, Providence, RI, USA.,Department of Neurology, Brown University Warren Alpert Medical School, Providence, RI, USA
| | - Edward R Marcantonio
- Aging Brain Center, Marcus Institute for Aging Research, Hebrew SeniorLife, Boston, MA, USA.,Harvard Medical School, Boston, MA, USA.,Department of Medicine, Beth Israel Deaconess Medical Center, Boston, MA, USA
| | - Eva M Schmitt
- Aging Brain Center, Marcus Institute for Aging Research, Hebrew SeniorLife, Boston, MA, USA.,Harvard Medical School, Boston, MA, USA
| | - Guoquan Xu
- Aging Brain Center, Marcus Institute for Aging Research, Hebrew SeniorLife, Boston, MA, USA.,Harvard Medical School, Boston, MA, USA
| | - Yun Gou
- Aging Brain Center, Marcus Institute for Aging Research, Hebrew SeniorLife, Boston, MA, USA
| | - Fan Chen
- Aging Brain Center, Marcus Institute for Aging Research, Hebrew SeniorLife, Boston, MA, USA
| | - Lisa J Kunze
- Harvard Medical School, Boston, MA, USA.,Department of Anesthesia, Critical Care and Pain Medicine, Beth Israel Deaconess Medical Center, Boston, MA, USA
| | - Kamen V Vlassakov
- Harvard Medical School, Boston, MA, USA.,Department of Anesthesiology, Perioperative and Pain Medicine, Brigham and Women's Hospital, Boston, MA, USA
| | - Ayesha R Abdeen
- Harvard Medical School, Boston, MA, USA.,Department of Orthopedic Surgery, Beth Israel Deaconess Medical Center, Boston, MA, USA
| | - Jeffrey K Lange
- Harvard Medical School, Boston, MA, USA.,Department of Orthopedic Surgery, Brigham and Women's Hospital, Boston, MA, USA
| | - Brandon E Earp
- Harvard Medical School, Boston, MA, USA.,Department of Orthopedic Surgery, Brigham and Women's Faulkner Hospital, Boston, MA, USA
| | - Alexandra Touroutoglou
- Harvard Medical School, Boston, MA, USA.,Department of Neurology, Massachusetts Alzheimer's Disease Research Center, Massachusetts General Hospital, Boston, MA, USA
| | - Becky C Carlyle
- Harvard Medical School, Boston, MA, USA.,Department of Neurology, Massachusetts Alzheimer's Disease Research Center, Massachusetts General Hospital, Boston, MA, USA
| | - Pia Kivisakk-Webb
- Department of Neurology, Massachusetts Alzheimer's Disease Research Center, Massachusetts General Hospital, Boston, MA, USA
| | - Thomas G Travison
- Aging Brain Center, Marcus Institute for Aging Research, Hebrew SeniorLife, Boston, MA, USA.,Harvard Medical School, Boston, MA, USA
| | - Simon T Dillon
- Harvard Medical School, Boston, MA, USA.,Department of Medicine, Beth Israel Deaconess Medical Center, Boston, MA, USA
| | - Towia A Libermann
- Harvard Medical School, Boston, MA, USA.,Genomics, Proteomics, Bioinformatics and Systems Biology Center, Beth Israel Deaconess Medical Center, Boston, MA, USA
| | - Sharon K Inouye
- Aging Brain Center, Marcus Institute for Aging Research, Hebrew SeniorLife, Boston, MA, USA.,Harvard Medical School, Boston, MA, USA.,Department of Medicine, Beth Israel Deaconess Medical Center, Boston, MA, USA
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Chronic inflammation in multiple sclerosis - seeing what was always there. Nat Rev Neurol 2019; 15:582-593. [PMID: 31420598 DOI: 10.1038/s41582-019-0240-y] [Citation(s) in RCA: 75] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/09/2019] [Indexed: 12/18/2022]
Abstract
Activation of innate immune cells and other compartmentalized inflammatory cells in the brains and spinal cords of people with relapsing-remitting multiple sclerosis (MS) and progressive MS has been well described histopathologically. However, conventional clinical MRI is largely insensitive to this inflammatory activity. The past two decades have seen the introduction of quantitative dynamic MRI scanning with contrast agents that are sensitive to the reduction in blood-brain barrier integrity associated with inflammation and to the trafficking of inflammatory myeloid cells. New MRI imaging sequences provide improved contrast for better detection of grey matter lesions. Quantitative lesion volume measures and magnetic resonance susceptibility imaging are sensitive to the activity of macrophages in the rims of white matter lesions. PET and magnetic resonance spectroscopy methods can also be used to detect contributions from innate immune activation in the brain and spinal cord. Some of these advanced research imaging methods for visualization of chronic inflammation are practical for relatively routine clinical applications. Observations made with the use of these techniques suggest ways of stratifying patients with MS to improve their care. The imaging methods also provide new tools to support the development of therapies for chronic inflammation in MS.
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Xu J, Sun J, Perrin RJ, Mach RH, Bales KR, Morris JC, Benzinger TLS, Holtzman DM. Translocator protein in late stage Alzheimer's disease and Dementia with Lewy bodies brains. Ann Clin Transl Neurol 2019; 6:1423-1434. [PMID: 31402620 PMCID: PMC6689696 DOI: 10.1002/acn3.50837] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2018] [Revised: 06/11/2019] [Accepted: 06/13/2019] [Indexed: 01/08/2023] Open
Abstract
OBJECTIVE Increased translocator protein (TSPO), previously known as the peripheral benzodiazepine receptor (PBR), in glial cells of the brain has been used as a neuroinflammation marker in the early and middle stages of neurodegenerative diseases, such as Alzheimer's disease (AD) and Dementia with Lewy Bodies (DLB). In this study, we investigated the changes in TSPO density with respect to late stage AD and DLB. METHODS TSPO density was measured in multiple regions of postmortem human brains in 20 different cases: seven late stage AD cases (Braak amyloid average: C; Braak tangle average: VI; Aged 74-88, mean: 83 ± 5 years), five DLB cases (Braak amyloid average: C; Braak tangle average: V; Aged 79-91, mean: 84 ± 4 years), and eight age-matched normal control cases (3 males, 5 females: aged 77-92 years; mean: 87 ± 6 years). Measurements were taken by quantitative autoradiography using [3 H]PK11195 and [3 H]PBR28. RESULTS No significant changes were found in TSPO density of the frontal cortex, striatum, thalamus, or red nucleus of the AD and DLB brains. A significant reduction in TSPO density was found in the substantia nigra (SN) of the AD and DLB brains compared to that of age-matched healthy controls. INTERPRETATION This distinct pattern of TSPO density change in late stage AD and DLB cases may imply the occurrence of microglia dystrophy in late stage neurodegeneration. Furthermore, TSPO may not only be a microglia activation marker in early stage AD and DLB, but TSPO may also be used to monitor microglia dysfunction in the late stage of these diseases.
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Affiliation(s)
- Jinbin Xu
- Department of RadiologyWashington University School of Medicine510 S. Kingshighway BlvdSt. LouisMissouri63110
| | - Jianjun Sun
- Department of RadiologyWashington University School of Medicine510 S. Kingshighway BlvdSt. LouisMissouri63110
| | - Richard J. Perrin
- Department of Pathology & ImmunologyWashington University School of Medicine510 S. Kingshighway BlvdSt. LouisMissouri63110
| | - Robert H. Mach
- Department of RadiologyUniversity of PennsylvaniaPhiladelphiaPennsylvania19104
| | | | - John C. Morris
- Department of NeurologyWashington University School of Medicine510 S. Kingshighway BlvdSt. LouisMissouri63110
| | - Tammie L. S. Benzinger
- Department of RadiologyWashington University School of Medicine510 S. Kingshighway BlvdSt. LouisMissouri63110
| | - David M. Holtzman
- Department of NeurologyWashington University School of Medicine510 S. Kingshighway BlvdSt. LouisMissouri63110
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Effects of age, BMI and sex on the glial cell marker TSPO - a multicentre [ 11C]PBR28 HRRT PET study. Eur J Nucl Med Mol Imaging 2019; 46:2329-2338. [PMID: 31363804 PMCID: PMC6717599 DOI: 10.1007/s00259-019-04403-7] [Citation(s) in RCA: 63] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2019] [Accepted: 06/14/2019] [Indexed: 01/25/2023]
Abstract
Purpose The purpose of this study was to investigate the effects of ageing, sex and body mass index (BMI) on translocator protein (TSPO) availability in healthy subjects using positron emission tomography (PET) and the radioligand [11C]PBR28. Methods [11C]PBR28 data from 140 healthy volunteers (72 males and 68 females; N = 78 with HAB and N = 62 MAB genotype; age range 19–80 years; BMI range 17.6–36.9) were acquired with High Resolution Research Tomograph at three centres: Karolinska Institutet (N = 53), Turku PET centre (N = 62) and Yale University PET Center (N = 25). The total volume of distribution (VT) was estimated in global grey matter, frontal, temporal, occipital and parietal cortices, hippocampus and thalamus using multilinear analysis 1. The effects of age, BMI and sex on TSPO availability were investigated using linear mixed effects model, with TSPO genotype and PET centre specified as random intercepts. Results There were significant positive correlations between age and VT in the frontal and temporal cortex. BMI showed a significant negative correlation with VT in all regions. Additionally, significant differences between males and females were observed in all regions, with females showing higher VT. A subgroup analysis revealed a positive correlation between VT and age in all regions in male subjects, whereas age showed no effect on TSPO levels in female subjects. Conclusion These findings provide evidence that individual biological properties may contribute significantly to the high variation shown in TSPO binding estimates, and suggest that age, BMI and sex can be confounding factors in clinical studies. Electronic supplementary material The online version of this article (10.1007/s00259-019-04403-7) contains supplementary material, which is available to authorized users.
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Dani M, Wood M, Mizoguchi R, Fan Z, Walker Z, Morgan R, Hinz R, Biju M, Kuruvilla T, Brooks DJ, Edison P. Microglial activation correlates in vivo with both tau and amyloid in Alzheimer's disease. Brain 2019; 141:2740-2754. [PMID: 30052812 DOI: 10.1093/brain/awy188] [Citation(s) in RCA: 88] [Impact Index Per Article: 17.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2017] [Accepted: 05/29/2018] [Indexed: 12/30/2022] Open
Abstract
Alzheimer's disease is characterized by the histopathological presence of amyloid-β plaques and tau-containing neurofibrillary tangles. Microglial activation is also a recognized pathological component. The relationship between microglial activation and protein aggregation is still debated. We investigated the relationship between amyloid plaques, tau tangles and activated microglia using PET imaging. Fifty-one subjects (19 healthy controls, 16 mild cognitive impairment and 16 Alzheimer's disease subjects) participated in the study. All subjects had neuropsychometric testing, MRI, amyloid (18F-flutemetamol), and microglial (11C-PBR28) PET. All subjects with mild cognitive impairment and Alzheimer's disease and eight of the controls had tau (18F-AV1451) PET. 11C-PBR28 PET was analysed using Logan graphical analysis with an arterial plasma input function, while 18F-flutemetamol and 18F-AV1451 PET were analysed as target:cerebellar ratios to create parametric standardized uptake value ratio maps. Biological parametric mapping in the Statistical Parametric Mapping platform was used to examine correlations between uptake of tracers at a voxel-level. There were significant widespread clusters of positive correlation between levels of microglial activation and tau aggregation in both the mild cognitive impairment (amyloid-positive and amyloid-negative) and Alzheimer's disease subjects. The correlations were stronger in Alzheimer's disease than in mild cognitive impairment, suggesting that these pathologies increase together as disease progresses. Levels of microglial activation and amyloid deposition were also correlated, although in a different spatial distribution; correlations were stronger in mild cognitive impairment than Alzheimer's subjects, in line with a plateauing of amyloid load with disease progression. Clusters of positive correlations between microglial activation and protein aggregation often targeted similar areas of association cortex, indicating that all three processes are present in specific vulnerable brain areas. For the first time using PET imaging, we show that microglial activation can correlate with both tau aggregation and amyloid deposition. This confirms the complex relationship between these processes. These results suggest that preventative treatment for Alzheimer's disease should target all three processes.
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Affiliation(s)
- Melanie Dani
- Neurology Imaging Unit, Department of Medicine, Imperial College London, Hammersmith Hospital, UK
| | - Melanie Wood
- Neurology Imaging Unit, Department of Medicine, Imperial College London, Hammersmith Hospital, UK
| | - Ruth Mizoguchi
- Neurology Imaging Unit, Department of Medicine, Imperial College London, Hammersmith Hospital, UK
| | - Zhen Fan
- Neurology Imaging Unit, Department of Medicine, Imperial College London, Hammersmith Hospital, UK
| | - Zuzana Walker
- Division of Psychiatry, University College London, UK.,Essex Partnership University NHS Foundation Trust, UK
| | | | - Rainer Hinz
- Wolfson Molecular Imaging Centre, University of Manchester, UK
| | - Maya Biju
- Gether NHS Foundation Trust, Gloucester, UK
| | | | - David J Brooks
- Neurology Imaging Unit, Department of Medicine, Imperial College London, Hammersmith Hospital, UK.,Department of Nuclear Medicine, Aarhus University, Denmark.,Institute of Neuroscience, University of Newcastle upon Tyne, UK
| | - Paul Edison
- Neurology Imaging Unit, Department of Medicine, Imperial College London, Hammersmith Hospital, UK
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Plavén-Sigray P, Cervenka S. Meta-analytic studies of the glial cell marker TSPO in psychosis - a question of apples and pears? Psychol Med 2019; 49:1624-1628. [PMID: 30739609 PMCID: PMC6601355 DOI: 10.1017/s003329171800421x] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- P Plavén-Sigray
- Department of Clinical Neuroscience,Centre for Psychiatry Research, Karolinska Institutet & Stockholm Health Care Services, Stockholm County Council, Karolinska University Hospital,SE-171 76 Stockholm,Sweden
| | - S Cervenka
- Department of Clinical Neuroscience,Centre for Psychiatry Research, Karolinska Institutet & Stockholm Health Care Services, Stockholm County Council, Karolinska University Hospital,SE-171 76 Stockholm,Sweden
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Paul S, Gallagher E, Liow JS, Mabins S, Henry K, Zoghbi SS, Gunn RN, Kreisl WC, Richards EM, Zanotti-Fregonara P, Morse CL, Hong J, Kowalski A, Pike VW, Innis RB, Fujita M. Building a database for brain 18 kDa translocator protein imaged using [ 11C]PBR28 in healthy subjects. J Cereb Blood Flow Metab 2019; 39:1138-1147. [PMID: 29749279 PMCID: PMC6547185 DOI: 10.1177/0271678x18771250] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Translocator protein 18 kDa (TSPO) has been widely imaged as a marker of neuroinflammation using several radioligands, including [11C]PBR28. In order to study the effects of age, sex, and obesity on TSPO binding and to determine whether this binding can be accurately assessed using fewer radio high-performance liquid chromatography (radio-HPLC) measurements of arterial blood samples, we created a database of 48 healthy subjects who had undergone [11C]PBR28 scans (23 high-affinity binders (HABs) and 25 mixed-affinity binders (MABs), 20 F/28 M, age: 40.6 ± 16.8 years). After analysis by Logan plot using 23 metabolite-corrected arterial samples, total distribution volume ( VT) was found to be 1.2-fold higher in HABs across all brain regions. Additionally, the polymorphism plot estimated nondisplaceable uptake ( VND) as 1.40 mL · cm-3, which generated a specific-to-nondisplaceable ratio ( BPND) of 1.6 ± 0.6 in HABs and 1.1 ± 0.6 in MABs. VT increased significantly with age in nearly all regions and was well estimated with radio-HPLC measurements from six arterial samples. However, VT did not correlate with body mass index and was not affected by sex. These results underscore which patient characteristics should be accounted for during [11C]PBR28 studies and suggest ways to perform such studies more easily and with fewer blood samples.
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Affiliation(s)
- Soumen Paul
- 1 Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, MD, USA
| | - Evan Gallagher
- 1 Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, MD, USA
| | - Jeih-San Liow
- 1 Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, MD, USA
| | - Sanche Mabins
- 1 Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, MD, USA
| | - Katharine Henry
- 1 Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, MD, USA
| | - Sami S Zoghbi
- 1 Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, MD, USA
| | - Roger N Gunn
- 2 Division of Brain Sciences, Department of Medicine, Imperial College London, London, UK; Imanova Centre for Imaging Sciences, London, UK
| | - William C Kreisl
- 3 Taub Institute, Columbia University Medical Center, New York, NY, USA
| | - Erica M Richards
- 1 Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, MD, USA
| | | | - Cheryl L Morse
- 1 Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, MD, USA
| | - Jinsoo Hong
- 1 Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, MD, USA
| | - Aneta Kowalski
- 1 Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, MD, USA
| | - Victor W Pike
- 1 Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, MD, USA
| | - Robert B Innis
- 1 Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, MD, USA
| | - Masahiro Fujita
- 1 Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, MD, USA
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Head-to-head comparison of 11C-PBR28 and 11C-ER176 for quantification of the translocator protein in the human brain. Eur J Nucl Med Mol Imaging 2019; 46:1822-1829. [DOI: 10.1007/s00259-019-04349-w] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2019] [Accepted: 04/29/2019] [Indexed: 10/26/2022]
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42
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Scott G, Zetterberg H, Jolly A, Cole JH, De Simoni S, Jenkins PO, Feeney C, Owen DR, Lingford-Hughes A, Howes O, Patel MC, Goldstone AP, Gunn RN, Blennow K, Matthews PM, Sharp DJ. Minocycline reduces chronic microglial activation after brain trauma but increases neurodegeneration. Brain 2019; 141:459-471. [PMID: 29272357 PMCID: PMC5837493 DOI: 10.1093/brain/awx339] [Citation(s) in RCA: 121] [Impact Index Per Article: 24.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2017] [Accepted: 10/19/2017] [Indexed: 12/12/2022] Open
Abstract
Survivors of a traumatic brain injury can deteriorate years later, developing brain atrophy and dementia. Traumatic brain injury triggers chronic microglial activation, but it is unclear whether this is harmful or beneficial. A successful chronic-phase treatment for traumatic brain injury might be to target microglia. In experimental models, the antibiotic minocycline inhibits microglial activation. We investigated the effect of minocycline on microglial activation and neurodegeneration using PET, MRI, and measurement of the axonal protein neurofilament light in plasma. Microglial activation was assessed using 11C-PBR28 PET. The relationships of microglial activation to measures of brain injury, and the effects of minocycline on disease progression, were assessed using structural and diffusion MRI, plasma neurofilament light, and cognitive assessment. Fifteen patients at least 6 months after a moderate-to-severe traumatic brain injury received either minocycline 100 mg orally twice daily or no drug, for 12 weeks. At baseline, 11C-PBR28 binding in patients was increased compared to controls in cerebral white matter and thalamus, and plasma neurofilament light levels were elevated. MRI measures of white matter damage were highest in areas of greater 11C-PBR28 binding. Minocycline reduced 11C-PBR28 binding (mean Δwhite matter binding = −23.30%, 95% confidence interval −40.9 to −5.64%, P = 0.018), but increased plasma neurofilament light levels. Faster rates of brain atrophy were found in patients with higher baseline neurofilament light levels. In this experimental medicine study, minocycline after traumatic brain injury reduced chronic microglial activation while increasing a marker of neurodegeneration. These findings suggest that microglial activation has a reparative effect in the chronic phase of traumatic brain injury.
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Affiliation(s)
- Gregory Scott
- Division of Brain Sciences, Department of Medicine, Imperial College London, UK
| | - Henrik Zetterberg
- Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, the Sahlgrenska Academy at the University of Gothenburg, Mölndal, Sweden.,Clinical Neurochemistry Laboratory, Sahlgrenska University Hospital, Mölndal, Sweden.,Department of Molecular Neuroscience, UCL Institute of Neurology, London, UK
| | - Amy Jolly
- Division of Brain Sciences, Department of Medicine, Imperial College London, UK
| | - James H Cole
- Division of Brain Sciences, Department of Medicine, Imperial College London, UK
| | - Sara De Simoni
- Division of Brain Sciences, Department of Medicine, Imperial College London, UK
| | - Peter O Jenkins
- Division of Brain Sciences, Department of Medicine, Imperial College London, UK
| | - Claire Feeney
- Division of Brain Sciences, Department of Medicine, Imperial College London, UK
| | - David R Owen
- Division of Brain Sciences, Department of Medicine, Imperial College London, UK
| | | | - Oliver Howes
- Division of Brain Sciences, Department of Medicine, Imperial College London, UK
| | - Maneesh C Patel
- Charing Cross Hospital, Imperial College Healthcare NHS Trust, London, UK
| | - Anthony P Goldstone
- Division of Brain Sciences, Department of Medicine, Imperial College London, UK
| | | | - Kaj Blennow
- Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, the Sahlgrenska Academy at the University of Gothenburg, Mölndal, Sweden.,Clinical Neurochemistry Laboratory, Sahlgrenska University Hospital, Mölndal, Sweden
| | - Paul M Matthews
- Division of Brain Sciences, Department of Medicine, Imperial College London, UK
| | - David J Sharp
- Division of Brain Sciences, Department of Medicine, Imperial College London, UK
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Woodcock EA, Hillmer AT, Mason GF, Cosgrove KP. Imaging Biomarkers of the Neuroimmune System among Substance Use Disorders: A Systematic Review. MOLECULAR NEUROPSYCHIATRY 2019; 5:125-146. [PMID: 31312635 DOI: 10.1159/000499621] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/20/2018] [Accepted: 03/13/2019] [Indexed: 12/14/2022]
Abstract
There is tremendous interest in the role of the neuroimmune system and inflammatory processes in substance use disorders (SUDs). Imaging biomarkers of the neuroimmune system in vivo provide a vital translational bridge between preclinical and clinical research. Herein, we examine two imaging techniques that measure putative indices of the neuroimmune system and review their application among SUDs. Positron emission tomography (PET) imaging of 18 kDa translocator protein availability is a marker associated with microglia. Proton magnetic resonance spectroscopy quantification of myo-inositol levels is a putative glial marker found in astrocytes. Neuroinflammatory responses are initiated and maintained by microglia and astrocytes, and thus represent important imaging markers. The goal of this review is to summarize neuroimaging findings from the substance use literature that report data using these markers and discuss possible mechanisms of action. The extant literature indicates abused substances exert diverse and complex neuroimmune effects. Moreover, drug effects may change across addiction stages, i.e. the neuroimmune effects of acute drug administration may differ from chronic use. This burgeoning field has considerable potential to improve our understanding and treatment of SUDs. Future research is needed to determine how targeting the neuroimmune system may improve treatment outcomes.
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Affiliation(s)
- Eric A Woodcock
- Departments of Psychiatry, and of Radiology and Biomedical Imaging, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Ansel T Hillmer
- Departments of Psychiatry, and of Radiology and Biomedical Imaging, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Graeme F Mason
- Departments of Psychiatry, and of Radiology and Biomedical Imaging, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Kelly P Cosgrove
- Departments of Psychiatry, and of Radiology and Biomedical Imaging, Yale University School of Medicine, New Haven, Connecticut, USA
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Tonietto M, Rizzo G, Veronese M, Borgan F, Bloomfield PS, Howes O, Bertoldo A. A Unified Framework for Plasma Data Modeling in Dynamic Positron Emission Tomography Studies. IEEE Trans Biomed Eng 2019; 66:1447-1455. [DOI: 10.1109/tbme.2018.2874308] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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45
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Bauckneht M, Capitanio S, Raffa S, Roccatagliata L, Pardini M, Lapucci C, Marini C, Sambuceti G, Inglese M, Gallo P, Cecchin D, Nobili F, Morbelli S. Molecular imaging of multiple sclerosis: from the clinical demand to novel radiotracers. EJNMMI Radiopharm Chem 2019; 4:6. [PMID: 31659498 PMCID: PMC6453990 DOI: 10.1186/s41181-019-0058-3] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2019] [Accepted: 03/21/2019] [Indexed: 12/13/2022] Open
Abstract
Background Brain PET imaging with different tracers is mainly clinically used in the field of neurodegenerative diseases and brain tumors. In recent years, the potential usefulness of PET has also gained attention in the field of MS. In fact, MS is a complex disease and several processes can be selected as a target for PET imaging. The use of PET with several different tracers has been mainly evaluated in the research setting to investigate disease pathophysiology (i.e. phenotypes, monitoring of progression) or to explore its use a surrogate end-point in clinical trials. Results We have reviewed PET imaging studies in MS in humans and animal models. Tracers have been grouped according to their pathophysiological targets (ie. tracers for myelin kinetic, neuroinflammation, and neurodegeneration). The emerging clinical indication for brain PET imaging in the differential diagnosis of suspected tumefactive demyelinated plaques as well as the clinical potential provided by PET images in view of the recent introduction of PET/MR technology are also addressed. Conclusion While several preclinical and fewer clinical studies have shown results, full-scale clinical development programs are needed to translate molecular imaging technologies into a clinical reality that could ideally fit into current precision medicine perspectives.
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Affiliation(s)
- Matteo Bauckneht
- Nuclear Medicine Unit, IRCCS Ospedale Policlinico San Martino, Largo R. Benzi 10, 16132, Genoa, Italy.
| | - Selene Capitanio
- Nuclear Medicine Unit, IRCCS Ospedale Policlinico San Martino, Largo R. Benzi 10, 16132, Genoa, Italy
| | - Stefano Raffa
- Department of Health Sciences (DISSAL), University of Genova, Genoa, Italy
| | - Luca Roccatagliata
- Department of Health Sciences (DISSAL), University of Genova, Genoa, Italy.,Neuroradiology, IRCCS Ospedale Policlinico San Martino, Genoa, Italy
| | - Matteo Pardini
- Clinical Neurology, Department of Neuroscience (DINOGMI), University of Genoa, Genoa, Italy.,Clinica Neurologica, IRCCS Ospedale Policlinico, San Martino, Genoa, Italy
| | - Caterina Lapucci
- Clinical Neurology, Department of Neuroscience (DINOGMI), University of Genoa, Genoa, Italy
| | - Cecilia Marini
- Nuclear Medicine Unit, IRCCS Ospedale Policlinico San Martino, Largo R. Benzi 10, 16132, Genoa, Italy.,CNR Institute of Molecular Bioimaging and Physiology, Milan, Italy
| | - Gianmario Sambuceti
- Nuclear Medicine Unit, IRCCS Ospedale Policlinico San Martino, Largo R. Benzi 10, 16132, Genoa, Italy.,Department of Health Sciences (DISSAL), University of Genova, Genoa, Italy
| | - Matilde Inglese
- Clinical Neurology, Department of Neuroscience (DINOGMI), University of Genoa, Genoa, Italy.,Clinica Neurologica, IRCCS Ospedale Policlinico, San Martino, Genoa, Italy
| | - Paolo Gallo
- Multiple Sclerosis Centre of the Veneto Region, Department of Neurosciences DNS, University of Padua, Padua, Italy
| | - Diego Cecchin
- Nuclear Medicine Unit, Department of Medicine-DIMED, Padova University Hospital, Padua, Italy.,Padua Neuroscience Center, University of Padua, Padua, Italy
| | - Flavio Nobili
- Clinical Neurology, Department of Neuroscience (DINOGMI), University of Genoa, Genoa, Italy.,Clinica Neurologica, IRCCS Ospedale Policlinico, San Martino, Genoa, Italy
| | - Silvia Morbelli
- Nuclear Medicine Unit, IRCCS Ospedale Policlinico San Martino, Largo R. Benzi 10, 16132, Genoa, Italy.,Department of Health Sciences (DISSAL), University of Genova, Genoa, Italy
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Translocator Protein Ligand Protects against Neurodegeneration in the MPTP Mouse Model of Parkinsonism. J Neurosci 2019; 39:3752-3769. [PMID: 30796158 DOI: 10.1523/jneurosci.2070-18.2019] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2018] [Revised: 01/11/2019] [Accepted: 01/15/2019] [Indexed: 12/18/2022] Open
Abstract
Parkinson's disease is the second most common neurodegenerative disease, after Alzheimer's disease. Parkinson's disease is a movement disorder with characteristic motor features that arise due to the loss of dopaminergic neurons from the substantia nigra. Although symptomatic treatment by the dopamine precursor levodopa and dopamine agonists can improve motor symptoms, no disease-modifying therapy exists yet. Here, we show that Emapunil (AC-5216, XBD-173), a synthetic ligand of the translocator protein 18, ameliorates degeneration of dopaminergic neurons, preserves striatal dopamine metabolism, and prevents motor dysfunction in female mice treated with the MPTP, as a model of parkinsonism. We found that Emapunil modulates the inositol requiring kinase 1α (IRE α)/X-box binding protein 1 (XBP1) unfolded protein response pathway and induces a shift from pro-inflammatory toward anti-inflammatory microglia activation. Previously, Emapunil was shown to cross the blood-brain barrier and to be safe and well tolerated in a Phase II clinical trial. Therefore, our data suggest that Emapunil may be a promising approach in the treatment of Parkinson's disease.SIGNIFICANCE STATEMENT Our study reveals a beneficial effect of Emapunil on dopaminergic neuron survival, dopamine metabolism, and motor phenotype in the MPTP mouse model of parkinsonism. In addition, our work uncovers molecular networks which mediate neuroprotective effects of Emapunil, including microglial activation state and unfolded protein response pathways. These findings not only contribute to our understanding of biological mechanisms of translocator protein 18 (TSPO) function but also indicate that translocator protein 18 may be a promising therapeutic target. We thus propose to further validate Emapunil in other Parkinson's disease mouse models and subsequently in clinical trials to treat Parkinson's disease.
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Kohno M, Link J, Dennis LE, McCready H, Huckans M, Hoffman WF, Loftis JM. Neuroinflammation in addiction: A review of neuroimaging studies and potential immunotherapies. Pharmacol Biochem Behav 2019; 179:34-42. [PMID: 30695700 DOI: 10.1016/j.pbb.2019.01.007] [Citation(s) in RCA: 92] [Impact Index Per Article: 18.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/06/2018] [Revised: 01/22/2019] [Accepted: 01/25/2019] [Indexed: 12/29/2022]
Abstract
Addiction is a worldwide public health problem and this article reviews scientific advances in identifying the role of neuroinflammation in the genesis, maintenance, and treatment of substance use disorders. With an emphasis on neuroimaging techniques, this review examines human studies of addiction using positron emission tomography to identify binding of translocator protein (TSPO), which is upregulated in reactive glial cells and activated microglia during pathological states. High TSPO levels have been shown in methamphetamine use but exhibits variable patterns in cocaine use. Alcohol and nicotine use, however, are associated with lower TSPO levels. We discuss how mechanistic differences at the neurotransmitter and circuit level in the neural effects of these agents and subsequent immune response may explain these observations. Finally, we review the potential of anti-inflammatory drugs, including ibudilast, minocycline, and pioglitazone, to ameliorate the behavioral and cognitive consequences of addiction.
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Affiliation(s)
- Milky Kohno
- Research & Development Service, Veterans Affairs Portland Health Care System, 3710 SW US Veterans Hospital Road, Portland, OR, USA; Department of Psychiatry, Oregon Health & Science University, 3181 SW Sam Jackson Park Road, Portland, OR, USA; Methamphetamine Abuse Research Center, Oregon Health & Science University and Veterans Affairs Portland Health Care System, Portland, OR, USA
| | - Jeanne Link
- Center for Radiochemistry Research, Knight Cardiovascular Institute, Oregon Health & Science University, 3181 SW Sam Jackson Park Road, Portland, OR, USA
| | - Laura E Dennis
- Research & Development Service, Veterans Affairs Portland Health Care System, 3710 SW US Veterans Hospital Road, Portland, OR, USA; Methamphetamine Abuse Research Center, Oregon Health & Science University and Veterans Affairs Portland Health Care System, Portland, OR, USA
| | - Holly McCready
- Research & Development Service, Veterans Affairs Portland Health Care System, 3710 SW US Veterans Hospital Road, Portland, OR, USA; Methamphetamine Abuse Research Center, Oregon Health & Science University and Veterans Affairs Portland Health Care System, Portland, OR, USA
| | - Marilyn Huckans
- Department of Psychiatry, Oregon Health & Science University, 3181 SW Sam Jackson Park Road, Portland, OR, USA; Mental Health and Clinical Neurosciences Division, Veterans Affairs Portland Health Care System, 3710 SW US Veterans Hospital Road, Portland, OR, USA; Methamphetamine Abuse Research Center, Oregon Health & Science University and Veterans Affairs Portland Health Care System, Portland, OR, USA
| | - William F Hoffman
- Research & Development Service, Veterans Affairs Portland Health Care System, 3710 SW US Veterans Hospital Road, Portland, OR, USA; Department of Psychiatry, Oregon Health & Science University, 3181 SW Sam Jackson Park Road, Portland, OR, USA; Department of Behavioral Neuroscience, Oregon Health & Science University, 3181 SW Sam Jackson Park Road, Portland, OR, USA; Mental Health and Clinical Neurosciences Division, Veterans Affairs Portland Health Care System, 3710 SW US Veterans Hospital Road, Portland, OR, USA; Methamphetamine Abuse Research Center, Oregon Health & Science University and Veterans Affairs Portland Health Care System, Portland, OR, USA
| | - Jennifer M Loftis
- Research & Development Service, Veterans Affairs Portland Health Care System, 3710 SW US Veterans Hospital Road, Portland, OR, USA; Department of Psychiatry, Oregon Health & Science University, 3181 SW Sam Jackson Park Road, Portland, OR, USA; Methamphetamine Abuse Research Center, Oregon Health & Science University and Veterans Affairs Portland Health Care System, Portland, OR, USA.
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Boerwinkle A, Ances BM. Molecular Imaging of Neuroinflammation in HIV. J Neuroimmune Pharmacol 2018; 14:9-15. [PMID: 30515624 DOI: 10.1007/s11481-018-9823-4] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2018] [Accepted: 11/12/2018] [Indexed: 02/05/2023]
Abstract
The development of combined antiretroviral therapy (cART) has increased the lifespan of persons living with HIV (PLWH), with most PLWH having a normal life expectancy. While significant progress has occurred, PLWH continue to have multiple health complications, including HIV associated neurocognitive disorders (HAND). While the exact cause of HAND is not known, persistent neuroinflammation is hypothesized to be an important potential contributor. Molecular imaging using positron emission tomography (PET) can non-invasively evaluate neuroinflammation. PET radiotracers specific for increased expression of the translocator protein18kDa (TSPO) on activated microglia can detect the presence of neuroinflammation in PLWH. However, results from these studies have been inconsistent and inconclusive. Future studies are needed to address key limitations that continue to persist with these techniques before accurate conclusions can be drawn regarding the role of persistent neuroinflammation in PLWH.
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Affiliation(s)
- Anna Boerwinkle
- Department of Neurology, Washington University in Saint Louis, Box 8111, 660 South Euclid Ave, St. Louis, MO, 63110, USA
| | - Beau M Ances
- Department of Neurology, Washington University in Saint Louis, Box 8111, 660 South Euclid Ave, St. Louis, MO, 63110, USA. .,Hope Center for Neurological Disorders, Washington University in St. Louis, St. Louis, MO, 63110, USA.
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Plavén-Sigray P, Schain M, Zanderigo F, Rabiner EA, Gunn RN, Ogden RT, Cervenka S. Accuracy and reliability of [ 11C]PBR28 specific binding estimated without the use of a reference region. Neuroimage 2018; 188:102-110. [PMID: 30500425 DOI: 10.1016/j.neuroimage.2018.11.020] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2018] [Revised: 11/06/2018] [Accepted: 11/16/2018] [Indexed: 12/22/2022] Open
Abstract
[11C]PBR28 is a positron emission tomography radioligand used to examine the expression of the 18 kDa translocator protein (TSPO). TSPO is located in glial cells and can function as a marker for immune activation. Since TSPO is expressed throughout the brain, no true reference region exists. For this reason, an arterial input function is required for accurate quantification of [11C]PBR28 binding and the most common outcome measure is the total distribution volume (VT). Notably, VT reflects both specific binding and non-displaceable binding. Therefore, estimates of specific binding, such as binding potential (e.g. BPND) and specific distribution volume (VS) should theoretically be more sensitive to underlying differences in TSPO expression. It is unknown, however, if unbiased and accurate estimates of these outcome measures are obtainable for [11C]PBR28. The Simultaneous Estimation (SIME) method uses time-activity-curves from multiple brain regions with the aim to obtain a brain-wide estimate of the non-displaceable distribution volume (VND), which can subsequently be used to improve the estimation of BPND and VS. In this study we evaluated the accuracy of SIME-derived VND, and the reliability of resulting estimates of specific binding for [11C]PBR28, using a combination of simulation experiments and in vivo studies in healthy humans. The simulation experiments, based on data from 54 unique [11C]PBR28 examinations, showed that VND values estimated using SIME were both precise and accurate. Data from a pharmacological competition challenge (n = 5) showed that SIME provided VND values that were on average 19% lower than those obtained using the Lassen plot, but similar to values obtained using the Likelihood-Estimation of Occupancy technique. Test-retest data (n = 11) showed that SIME-derived VS values exhibited good reliability and precision, while larger variability was observed in SIME-derived BPND values. The results support the use of SIME for quantifying specific binding of [11C]PBR28, and suggest that VS can be used in complement to the conventional outcome measure VT. Additional studies in patient cohorts are warranted.
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Affiliation(s)
- Pontus Plavén-Sigray
- Centre for Psychiatry Research, Department of Clinical Neuroscience, Karolinska Institutet, & Stockholm Health Care Services, Stockholm County Council, Karolinska University Hospital, SE-171 76 Stockholm, Sweden.
| | - Martin Schain
- Neurobiology Research Unit, Copenhagen University Hospital, Copenhagen, Denmark
| | - Francesca Zanderigo
- Department of Psychiatry, Columbia University, New York, NY, USA; Molecular Imaging and Neuropathology Division, New York State Psychiatric Institute, New York, USA
| | | | | | - Roger N Gunn
- Invicro LLC, London, UK; Division of Brain Sciences, Imperial College London, London, UK
| | - R Todd Ogden
- Department of Psychiatry, Columbia University, New York, NY, USA; Molecular Imaging and Neuropathology Division, New York State Psychiatric Institute, New York, USA; Department of Biostatistics, Mailman School of Public Health, Columbia University, New York, USA
| | - Simon Cervenka
- Centre for Psychiatry Research, Department of Clinical Neuroscience, Karolinska Institutet, & Stockholm Health Care Services, Stockholm County Council, Karolinska University Hospital, SE-171 76 Stockholm, Sweden
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Plavén-Sigray P, Matheson GJ, Collste K, Ashok AH, Coughlin JM, Howes OD, Mizrahi R, Pomper MG, Rusjan P, Veronese M, Wang Y, Cervenka S. Positron Emission Tomography Studies of the Glial Cell Marker Translocator Protein in Patients With Psychosis: A Meta-analysis Using Individual Participant Data. Biol Psychiatry 2018; 84:433-442. [PMID: 29653835 PMCID: PMC7893597 DOI: 10.1016/j.biopsych.2018.02.1171] [Citation(s) in RCA: 90] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/08/2017] [Revised: 02/13/2018] [Accepted: 02/20/2018] [Indexed: 12/20/2022]
Abstract
BACKGROUND Accumulating evidence suggests that the immune system may be an important target for new treatment approaches in schizophrenia. Positron emission tomography and radioligands binding to the translocator protein (TSPO), which is expressed in glial cells in the brain including immune cells, represents a potential method for patient stratification and treatment monitoring. This study examined whether patients with first-episode psychosis and schizophrenia had altered TSPO levels compared with healthy control subjects. METHODS PubMed was searched for studies comparing patients with psychosis with healthy control subjects using second-generation TSPO radioligands. The outcome measure was total distribution volume (VT), an index of TSPO levels, in frontal cortex, temporal cortex, and hippocampus. Bayes factors (BFs) were applied to examine the relative support for higher, lower, or no difference in patients' TSPO levels compared with healthy control subjects. RESULTS Five studies, with 75 participants with first-episode psychosis or schizophrenia and 77 healthy control subjects, were included. BFs showed strong support for lower VT in patients relative to no difference (all BFs > 32), or relative to higher VT (all BFs > 422), in all brain regions. From the posterior distributions, mean patient-control differences in standardized VT values were -0.48 for frontal cortex (95% credible interval [CredInt] = -0.88 to 0.09), -0.47 for temporal cortex (CredInt = -0.87 to -0.07), and -0.63 for hippocampus (CredInt = -1.00 to -0.25). CONCLUSIONS The lower levels of TSPO observed in patients may correspond to altered function or lower density of brain immune cells. Future studies should focus on investigating the underlying biological mechanisms and their relevance for treatment.
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Affiliation(s)
- Pontus Plavén-Sigray
- Centre for Psychiatry Research, Department of Clinical Neuroscience, Karolinska Institutet and Stockholm Health Care Services, Stockholm County Council, Stockholm, Sweden.
| | - Granville J Matheson
- Centre for Psychiatry Research, Department of Clinical Neuroscience, Karolinska Institutet and Stockholm Health Care Services, Stockholm County Council, Stockholm, Sweden
| | - Karin Collste
- Centre for Psychiatry Research, Department of Clinical Neuroscience, Karolinska Institutet and Stockholm Health Care Services, Stockholm County Council, Stockholm, Sweden
| | - Abhishekh H Ashok
- Institute of Psychiatry, Psychology, & Neuroscience, King's College London, London, United Kingdom; Medical Research Council London Institute of Medical Sciences, Hammersmith Hospital, London, United Kingdom; Institute of Clinical Sciences, Faculty of Medicine, Imperial College London, London, United Kingdom
| | - Jennifer M Coughlin
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins Medical Institutions, Baltimore, Maryland; Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins Medical Institutions, Baltimore, Maryland
| | - Oliver D Howes
- Institute of Psychiatry, Psychology, & Neuroscience, King's College London, London, United Kingdom; Medical Research Council London Institute of Medical Sciences, Hammersmith Hospital, London, United Kingdom; Institute of Clinical Sciences, Faculty of Medicine, Imperial College London, London, United Kingdom
| | - Romina Mizrahi
- Department of Psychiatry, University of Toronto, Toronto, Ontario, Canada
| | - Martin G Pomper
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins Medical Institutions, Baltimore, Maryland; Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins Medical Institutions, Baltimore, Maryland
| | - Pablo Rusjan
- Department of Psychiatry, University of Toronto, Toronto, Ontario, Canada
| | - Mattia Veronese
- Department of Neuroimaging, Institute of Psychiatry, Psychology, & Neuroscience, King's College London, London, United Kingdom
| | - Yuchuan Wang
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins Medical Institutions, Baltimore, Maryland
| | - Simon Cervenka
- Centre for Psychiatry Research, Department of Clinical Neuroscience, Karolinska Institutet and Stockholm Health Care Services, Stockholm County Council, Stockholm, Sweden
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