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Varlow C, Mathis CA, Vasdev N. In vitro evaluation of [ 3H] PI-2620 and structural derivatives in non-Alzheimer's tauopathies. Nucl Med Biol 2024; 130-131:108891. [PMID: 38458074 DOI: 10.1016/j.nucmedbio.2024.108891] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2023] [Revised: 01/28/2024] [Accepted: 02/16/2024] [Indexed: 03/10/2024]
Abstract
Alzheimer's disease (AD) and non-AD tauopathies such as chronic traumatic encephalopathy (CTE), progressive supranuclear palsy (PSP), and corticobasal degeneration (CBD) are characterized by the abnormal aggregation of three-repeat (3R) and/or four-repeat (4R) tau isoforms. Several tau-PET tracers have been applied for human imaging of AD and non-AD tauopathies including [18F]PI-2620. Our objective is to evaluate [3H]PI-2620 and two promising structural derivatives, [3H]PI-2014 and [3H]F-4, using in vitro saturation assays and competitive binding assays against new chemical entities based on this scaffold in human AD tissues for comparison with PSP, CBD and CTE tissues. Thin section autoradiography was employed to assess specific binding and distribution of [3H]PI-2620 and [3H]F-4 in fresh-frozen human post-mortem AD, PSP, CBD and CTE tissues. Immunohistochemistry was performed for phospho-tau (AT8) and 4R-tau (RD4). Homogenate filtration binding assays were performed for saturation analysis and competitive binding studies against [3H]PI-2620. All compounds bound with high affinity in AD tissue. In PSP tissue [3H]PI-2620 demonstrated the highest affinity (5.3 nM) and in CBD tissue [3H]F-4 bound with the highest affinity (9.4 nM). Over 40 fluorinated derivatives based on PI-2620 and F-4 were screened in AD and PSP tissue. Notably, compound 2 was the most potent derivative in PSP tissue (Ki = 7.3 nM). By autoradiography, [3H]PI-2620 and [3H]F-4 demonstrated positive signals similar in intensity in AD, PSP and CTE tissues that were displaced by homologous blockade. Binding of both radiotracers aligned with immunostaining for 4R-tau. This work demonstrates that [3H]PI-2620 and [3H]F-4 show promise for imaging 4R-tau aggregates in non-AD tauopathies. PI-2620 continues to serve as a structural scaffold for PET radiotracers with higher affinity for non-AD tau over AD tau.
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Affiliation(s)
- Cassis Varlow
- Institute of Medical Science, University of Toronto, ON M5S 1A8, Canada; Brain Health Imaging Centre, Centre for Addiction and Mental Health, Toronto, ON M5T 1R8, Canada.
| | - Chester A Mathis
- Department of Radiology, University of Pittsburgh, PA 15213, USA
| | - Neil Vasdev
- Institute of Medical Science, University of Toronto, ON M5S 1A8, Canada; Brain Health Imaging Centre, Centre for Addiction and Mental Health, Toronto, ON M5T 1R8, Canada.
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2
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Rueb M, Rauen K, Koerte IK, Gersing A, Zetterberg H, Simrén J, Brendel M, Adorjan K. Traumatic Encephalopathy Syndrome and Tauopathy in a 19-Year-Old With Child Abuse. Neurotrauma Rep 2023; 4:857-862. [PMID: 38156074 PMCID: PMC10754342 DOI: 10.1089/neur.2023.0078] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2023] Open
Abstract
The majority of traumatic encephalopathy syndrome (TES) cases have been reported in former contact sport athletes. This is the first case with TES in a 19-year-old male patient with progressive cognitive decline after daily domestic physical violence through repeated hits to the head for 15 years. The patient presented with a moderate depressive episode and progressive cognitive decline. Tau positron emission tomography (PET) with 220 MBq of [18F]PI-2620 revealed increased focal signal at the frontal and parietal white/gray matter border. Brain magnetic resonance imaging (MRI) showed a cavum septum pellucidum, reduced left-sided hippocampal volume, and a left midbrain lesion. Cerebrospinal fluid results showed elevated total and p-tau. Neurocognitive testing at admission showed memory deficits clearly below average, and hampered dysfunctions according to the slow processing speed with a low mistake rate, indicating the acquired, thus secondary, attentional deficits. We diagnosed the patient with a TES suggestive of chronic traumatic encephalopathy and classified him as having subtle/mild functional limitation with a most likely transition to mild dementia within the TES criteria. This report underlines child abuse as a relevant criterion in diagnosing TES in cases with repetitive hits to the head. In addition to clinical markers, we show the relevance of fluid tau biomarkers and tau-PET to support the diagnosis of TES according to the recently published diagnosis criteria for TES.
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Affiliation(s)
- Mike Rueb
- Department of Psychiatry and Psychotherapy, LMU University Hospital, Munich, Germany
- Pettenkofer School of Public Health, Munich, Germany
- Institute for Medical Information Processing, Biometry and Epidemiology, LMU University Hospital, LMU Munich, Munich, Germany
- Center for International Health (CIH LMU), LMU University Hospital, LMU Munich, Munich, Germany
| | - Katrin Rauen
- Department of Geriatric Psychiatry, Psychiatric Hospital Zurich, University of Zurich, Zurich, Switzerland
- Institute for Stroke and Dementia Research (ISD), LMU University Hospital, LMU Munich, Munich, Germany
| | - Inga Katharina Koerte
- Psychiatric Neuroimaging Laboratory, Brigham and Women's Hospital, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, USA
- Department of Child and Adolescent Psychiatry, Psychosomatic, and Psychotherapy, LMU University Hospital, Munich, Germany
- Department of Psychiatry, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Alexandra Gersing
- Department of Neuroradiology, LMU University Hospital, LMU Munich, Munich, Germany
| | - 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 Neurodegenerative Disease, Institute of Neurology, University College London, London, United Kingdom
- UK Dementia Research Institute, University College London, London, United Kingdom
- Hong Kong Center for Neurodegenerative Diseases, Hong Kong, China
- Wisconsin Alzheimer's Disease Research Center, University of Wisconsin School of Medicine and Public Health, University of Wisconsin–Madison, Madison, Wisconsin, USA
| | - Joel Simrén
- 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
| | - Matthias Brendel
- Department of Nuclear Medicine, LMU University Hospital, LMU Munich, Munich, Germany
- German Center for Neurodegenerative Diseases (DZNE) Munich, Germany
- Munich Cluster for Systems Neurology (SyNergy), Munich, Germany
| | - Kristina Adorjan
- Department of Psychiatry and Psychotherapy, LMU University Hospital, Munich, Germany
- Center for International Health (CIH LMU), LMU University Hospital, LMU Munich, Munich, Germany
- Institute of Psychiatric Phenomics and Genomics, LMU University Hospital, Munich, Germany
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3
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Künze G, Kümpfel R, Rullmann M, Barthel H, Brendel M, Patt M, Sabri O. Molecular Simulations Reveal Distinct Energetic and Kinetic Binding Properties of [ 18F] PI-2620 on Tau Filaments from 3R/4R and 4R Tauopathies. ACS Chem Neurosci 2022; 13:2222-2234. [PMID: 35762647 DOI: 10.1021/acschemneuro.2c00291] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
Tauopathies are a class of neurodegenerative disorders characterized by the accumulation of tau protein filaments in the brain. On the basis of isoforms with three or four microtubule-binding repeats (3R or 4R) that constitute tau filaments, tauopathies can be divided into 3R, 4R, and 3R/4R tauopathies. [18F]PI-2620 is a tau-positron emission tomography (PET) tracer that detects tau filaments in the 3R/4R tauopathy Alzheimer's disease (AD) and the 4R tauopathies corticobasal degeneration (CBD) and progressive supranuclear palsy (PSP) with differential binding characteristics. A multiscale simulation workflow, including molecular docking, molecular dynamics simulation, metadynamics, and Brownian dynamics, was applied to uncover the molecular basis for the different binding properties of [18F]PI-2620 in these tauopathies. The energetically best binding sites of [18F]PI-2620 in the AD-tau filament are located in the C-shaped groove of the filament core structure that is accessible to the outside. The most favorable binding sites in CBD-tau and PSP-tau filaments are localized to cavities in the inner filament core. Sites on the outer surface have higher binding free energies, and interaction of [18F]PI-2620 at these sites was short-lived in the molecular dynamics simulations. Computationally predicted associated rates of [18F]PI-2620 with the groove sites in the AD-tau filament were higher than association rates with the cavity sites in the CBD- and PSP-tau filaments. The results indicate that tau filaments in AD combine favorable energetic and kinetic properties with regard to tracer binding, while the binding of [18F]PI-2620 to filaments in CBD and PSP is kinetically restricted. Our findings reveal that distinct structural, energetic, and kinetic properties of tau filaments from AD, CBD, and PSP govern their interaction with PET tracers, which highlights the possibility to achieve tau isoform specificity in future tracer developments.
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Affiliation(s)
- Georg Künze
- Institute for Drug Discovery, University of Leipzig, 04103 Leipzig, Germany
| | - Richy Kümpfel
- Institute for Drug Discovery, University of Leipzig, 04103 Leipzig, Germany
| | - Michael Rullmann
- Department of Nuclear Medicine, University of Leipzig, Leipzig 04103, Germany
| | - Henryk Barthel
- Department of Nuclear Medicine, University of Leipzig, Leipzig 04103, Germany
| | - Matthias Brendel
- Department of Nuclear Medicine, University Hospital of Munich, LMU Munich, 81377 Munich, Germany.,German Center for Neurodegenerative Diseases (DZNE), Munich 81377, Germany.,Munich Cluster for Systems Neurology (SyNergy), Munich 81377, Germany
| | - Marianne Patt
- Department of Nuclear Medicine, University of Leipzig, Leipzig 04103, Germany
| | - Osama Sabri
- Department of Nuclear Medicine, University of Leipzig, Leipzig 04103, Germany
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4
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Song M, Beyer L, Kaiser L, Barthel H, van Eimeren T, Marek K, Nitschmann A, Scheifele M, Palleis C, Respondek G, Kern M, Biechele G, Hammes J, Bischof G, Barbe M, Onur Ö, Jessen F, Saur D, Schroeter ML, Rumpf JJ, Rullmann M, Schildan A, Patt M, Neumaier B, Barret O, Madonia J, Russell DS, Stephens AW, Mueller A, Roeber S, Herms J, Bötzel K, Danek A, Levin J, Classen J, Höglinger GU, Bartenstein P, Villemagne V, Drzezga A, Seibyl J, Sabri O, Boening G, Ziegler S, Brendel M. Binding characteristics of [ 18F] PI-2620 distinguish the clinically predicted tau isoform in different tauopathies by PET. J Cereb Blood Flow Metab 2021; 41:2957-2972. [PMID: 34044665 PMCID: PMC8545042 DOI: 10.1177/0271678x211018904] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
The novel tau-PET tracer [18F]PI-2620 detects the 3/4-repeat-(R)-tauopathy Alzheimer's disease (AD) and the 4R-tauopathies corticobasal syndrome (CBS) and progressive supranuclear palsy (PSP). We determined whether [18F]PI-2620 binding characteristics deriving from non-invasive reference tissue modelling differentiate 3/4R- and 4R-tauopathies. Ten patients with a 3/4R tauopathy (AD continuum) and 29 patients with a 4R tauopathy (CBS, PSP) were evaluated. [18F]PI-2620 PET scans were acquired 0-60 min p.i. and the distribution volume ratio (DVR) was calculated. [18F]PI-2620-positive clusters (DVR ≥ 2.5 SD vs. 11 healthy controls) were evaluated by non-invasive kinetic modelling. R1 (delivery), k2 & k2a (efflux), DVR, 30-60 min standardized-uptake-value-ratios (SUVR30-60) and the linear slope of post-perfusion phase SUVR (9-60 min p.i.) were compared between 3/4R- and 4R-tauopathies. Cortical clusters of 4R-tau cases indicated higher delivery (R1SRTM: 0.92 ± 0.21 vs. 0.83 ± 0.10, p = 0.0007), higher efflux (k2SRTM: 0.17/min ±0.21/min vs. 0.06/min ± 0.07/min, p < 0.0001), lower DVR (1.1 ± 0.1 vs. 1.4 ± 0.2, p < 0.0001), lower SUVR30-60 (1.3 ± 0.2 vs. 1.8 ± 0.3, p < 0.0001) and flatter slopes of the post-perfusion phase (slope9-60: 0.006/min ± 0.007/min vs. 0.016/min ± 0.008/min, p < 0.0001) when compared to 3/4R-tau cases. [18F]PI-2620 binding characteristics in cortical regions differentiate 3/4R- and 4R-tauopathies. Higher tracer clearance indicates less stable binding in 4R tauopathies when compared to 3/4R-tauopathies.
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Affiliation(s)
- Mengmeng Song
- Department of Nuclear Medicine, University Hospital of Munich, LMU Munich, Munich, Germany
| | - Leonie Beyer
- Department of Nuclear Medicine, University Hospital of Munich, LMU Munich, Munich, Germany
| | - Lena Kaiser
- Department of Nuclear Medicine, University Hospital of Munich, LMU Munich, Munich, Germany
| | - Henryk Barthel
- Department of Nuclear Medicine, University of Leipzig, Leipzig, Germany
| | - Thilo van Eimeren
- Cognitive Neuroscience, Institute for Neuroscience and Medicine (INM-3), Research Centre Juelich, Juelich, Germany.,Department of Nuclear Medicine, University Hospital Cologne, Cologne, Germany.,Department of Neurology, University Hospital Cologne, Cologne, Germany.,German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany
| | - Ken Marek
- InviCRO, LLC, Boston, MA, USA.,Molecular Neuroimaging, A Division of inviCRO, New Haven, CT, USA
| | - Alexander Nitschmann
- Department of Nuclear Medicine, University Hospital of Munich, LMU Munich, Munich, Germany
| | - Maximilian Scheifele
- Department of Nuclear Medicine, University Hospital of Munich, LMU Munich, Munich, Germany
| | - Carla Palleis
- Department of Neurology, University Hospital of Munich, LMU Munich, Munich, Germany
| | - Gesine Respondek
- Department of Neurology, Medizinische Hochschule Hannover, Hannover, Germany
| | - Maike Kern
- Department of Nuclear Medicine, University Hospital of Munich, LMU Munich, Munich, Germany
| | - Gloria Biechele
- Department of Nuclear Medicine, University Hospital of Munich, LMU Munich, Munich, Germany
| | - Jochen Hammes
- Department of Nuclear Medicine, University Hospital Cologne, Cologne, Germany
| | - Gèrard Bischof
- Department of Nuclear Medicine, University Hospital Cologne, Cologne, Germany
| | - Michael Barbe
- Department of Neurology, University Hospital Cologne, Cologne, Germany
| | - Özgür Onur
- Department of Neurology, University Hospital Cologne, Cologne, Germany
| | - Frank Jessen
- German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany.,Department of Psychiatry, University Hospital Cologne, Cologne, Germany.,Center for Memory Disorders, University Hospital Cologne, Cologne, Germany
| | - Dorothee Saur
- Department of Neurology, University of Leipzig, Leipzig, Germany
| | - Matthias L Schroeter
- Clinic for Cognitive Neurology, University of Leipzig, Leipzig, Germany.,LIFE - Leipzig Research Center for Civilization Diseases, University of Leipzig, Leipzig, Germany.,Max- Planck-Institute of Human Cognitive and Brain Sciences, Leipzig, Germany.,FTLD Consortium Germany, Ulm, Germany
| | | | - Michael Rullmann
- Department of Nuclear Medicine, University of Leipzig, Leipzig, Germany
| | - Andreas Schildan
- Department of Nuclear Medicine, University of Leipzig, Leipzig, Germany
| | - Marianne Patt
- Department of Nuclear Medicine, University of Leipzig, Leipzig, Germany
| | - Bernd Neumaier
- Cognitive Neuroscience, Institute for Neuroscience and Medicine (INM-3), Research Centre Juelich, Juelich, Germany.,Department of Nuclear Medicine, University Hospital Cologne, Cologne, Germany
| | - Olivier Barret
- InviCRO, LLC, Boston, MA, USA.,Molecular Neuroimaging, A Division of inviCRO, New Haven, CT, USA.,Laboratoire des Maladies Neurodégénératives, Université Paris-Saclay, CEA, CNRS, MIRCen, Fontenay-aux-Roses, France
| | - Jennifer Madonia
- InviCRO, LLC, Boston, MA, USA.,Molecular Neuroimaging, A Division of inviCRO, New Haven, CT, USA
| | - David S Russell
- InviCRO, LLC, Boston, MA, USA.,Molecular Neuroimaging, A Division of inviCRO, New Haven, CT, USA
| | | | | | - Sigrun Roeber
- Center for Neuropathology and Prion Research, University Hospital of Munich, LMU Munich, Munich, Germany
| | - Jochen Herms
- German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany.,Center for Neuropathology and Prion Research, University Hospital of Munich, LMU Munich, Munich, Germany
| | - Kai Bötzel
- Department of Neurology, University Hospital of Munich, LMU Munich, Munich, Germany
| | - Adrian Danek
- Department of Neurology, University Hospital of Munich, LMU Munich, Munich, Germany
| | - Johannes Levin
- Department of Neurology, University Hospital of Munich, LMU Munich, Munich, Germany.,German Center for Neurodegenerative Diseases (DZNE), Munich, Germany.,Munich Cluster for Systems Neurology (SyNergy), Munich, Germany
| | - Joseph Classen
- Department of Neurology, University of Leipzig, Leipzig, Germany
| | - Günter U Höglinger
- Department of Neurology, Medizinische Hochschule Hannover, Hannover, Germany.,German Center for Neurodegenerative Diseases (DZNE), Munich, Germany.,Department of Neurology, Technical University Munich, Munich, Germany
| | - Peter Bartenstein
- Department of Nuclear Medicine, University Hospital of Munich, LMU Munich, Munich, Germany.,Munich Cluster for Systems Neurology (SyNergy), Munich, Germany
| | - Victor Villemagne
- Department of Molecular Imaging & Therapy, Austin Health, Heidelberg, VIC, Australia.,The Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Melbourne, VIC, Australia.,Department of Medicine, Austin Health, The University of Melbourne, Melbourne, VIC, Australia
| | - Alexander Drzezga
- Department of Nuclear Medicine, University Hospital Cologne, Cologne, Germany.,German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany
| | - John Seibyl
- InviCRO, LLC, Boston, MA, USA.,Molecular Neuroimaging, A Division of inviCRO, New Haven, CT, USA
| | - Osama Sabri
- Department of Nuclear Medicine, University of Leipzig, Leipzig, Germany
| | - Guido Boening
- Department of Nuclear Medicine, University Hospital of Munich, LMU Munich, Munich, Germany
| | - Sibylle Ziegler
- Department of Nuclear Medicine, University Hospital of Munich, LMU Munich, Munich, Germany
| | - Matthias Brendel
- Department of Nuclear Medicine, University Hospital of Munich, LMU Munich, Munich, Germany.,Munich Cluster for Systems Neurology (SyNergy), Munich, Germany
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5
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Willroider M, Roeber S, Horn AKE, Arzberger T, Scheifele M, Respondek G, Sabri O, Barthel H, Patt M, Mishchenko O, Schildan A, Mueller A, Koglin N, Stephens A, Levin J, Höglinger GU, Bartenstein P, Herms J, Brendel M, Beyer L. Superiority of Formalin-Fixed Paraffin-Embedded Brain Tissue for in vitro Assessment of Progressive Supranuclear Palsy Tau Pathology With [ 18 F] PI-2620. Front Neurol 2021; 12:684523. [PMID: 34276540 PMCID: PMC8282895 DOI: 10.3389/fneur.2021.684523] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2021] [Accepted: 05/25/2021] [Indexed: 11/13/2022] Open
Abstract
Objectives: Autoradiography on brain tissue is used to validate binding targets of newly discovered radiotracers. The purpose of this study was to correlate quantification of autoradiography signal using the novel next-generation tau positron emission tomography (PET) radiotracer [18F]PI-2620 with immunohistochemically determined tau-protein load in both formalin-fixed paraffin-embedded (FFPE) and frozen tissue samples of patients with Alzheimer's disease (AD) and Progressive Supranuclear Palsy (PSP). Methods: We applied [18F]PI-2620 autoradiography to postmortem cortical brain samples of six patients with AD, five patients with PSP and five healthy controls, respectively. Binding intensity was compared between both tissue types and different disease entities. Autoradiography signal quantification (CWMR = cortex to white matter ratio) was correlated with the immunohistochemically assessed tau load (AT8-staining, %-area) for FFPE and frozen tissue samples in the different disease entities. Results: In AD tissue, relative cortical tracer binding was higher in frozen samples when compared to FFPE samples (CWMRfrozen vs. CWMRFFPE: 2.5-fold, p < 0.001), whereas the opposite was observed in PSP tissue (CWMRfrozen vs. CWMRFFPE: 0.8-fold, p = 0.004). In FFPE samples, [18F]PI-2620 autoradiography tracer binding and immunohistochemical tau load correlated significantly for both PSP (R = 0.641, p < 0.001) and AD tissue (R = 0.435, p = 0.016), indicating a high agreement of relative tracer binding with underlying pathology. In frozen tissue, the correlation between autoradiography and immunohistochemistry was only present in AD (R = 0.417, p = 0.014) but not in PSP tissue (R = -0.115, p = n.s.). Conclusion: Our head-to-head comparison indicates that FFPE samples show superiority over frozen samples for autoradiography assessment of PSP tau pathology by [18F]PI-2620. The [18F]PI-2620 autoradiography signal in FFPE samples reflects AT8 positive tau in samples of both PSP and AD patients.
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Affiliation(s)
- Marie Willroider
- Department of Nuclear Medicine, University Hospital of Munich, LMU Munich, Munich, Germany
| | - Sigrun Roeber
- Center for Neuropathology and Prion Research, LMU Munich, Munich, Germany
| | - Anja K E Horn
- Institute of Anatomy and Cell Biology, LMU Munich, Munich, Germany
| | - Thomas Arzberger
- Center for Neuropathology and Prion Research, LMU Munich, Munich, Germany.,German Center for Neurodegenerative Diseases (DZNE), Munich, Germany
| | - Maximilian Scheifele
- Department of Nuclear Medicine, University Hospital of Munich, LMU Munich, Munich, Germany
| | - Gesine Respondek
- Department of Neurology, Hannover Medical School, Hanover, Germany
| | - Osama Sabri
- Department of Nuclear Medicine, University Hospital Leipzig, Leipzig, Germany
| | - Henryk Barthel
- Department of Nuclear Medicine, University Hospital Leipzig, Leipzig, Germany
| | - Marianne Patt
- Department of Nuclear Medicine, University Hospital Leipzig, Leipzig, Germany
| | - Olena Mishchenko
- Department of Nuclear Medicine, University Hospital Leipzig, Leipzig, Germany
| | - Andreas Schildan
- Department of Nuclear Medicine, University Hospital Leipzig, Leipzig, Germany
| | | | | | | | - Johannes Levin
- German Center for Neurodegenerative Diseases (DZNE), Munich, Germany.,Department of Neurology, University Hospital Munich, LMU Munich, Munich, Germany.,Munich Cluster for Systems Neurology (SyNergy), Munich, Germany
| | - Günter U Höglinger
- German Center for Neurodegenerative Diseases (DZNE), Munich, Germany.,Department of Neurology, Hannover Medical School, Hanover, Germany.,Munich Cluster for Systems Neurology (SyNergy), Munich, Germany.,Department of Neurology, Technical University Munich, Munich, Germany
| | - Peter Bartenstein
- Department of Nuclear Medicine, University Hospital of Munich, LMU Munich, Munich, Germany.,Munich Cluster for Systems Neurology (SyNergy), Munich, Germany
| | - Jochen Herms
- Center for Neuropathology and Prion Research, LMU Munich, Munich, Germany.,German Center for Neurodegenerative Diseases (DZNE), Munich, Germany
| | - Matthias Brendel
- Department of Nuclear Medicine, University Hospital of Munich, LMU Munich, Munich, Germany.,Munich Cluster for Systems Neurology (SyNergy), Munich, Germany
| | - Leonie Beyer
- Department of Nuclear Medicine, University Hospital of Munich, LMU Munich, Munich, Germany.,Center for Neuropathology and Prion Research, LMU Munich, Munich, Germany
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6
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Nuebling GS, Prix C, Brendel M, Beyer L, Wlasich E, Loosli SV, Barthel H, Sabri O, Bartenstein P, Vöglein J, Danek A, Rominger A, Edbauer D, Haass C, Levin J. Low-degree trisomy 21 mosaicism promotes early-onset Alzheimer disease. Neurobiol Aging 2021; 103:147.e1-147.e5. [PMID: 33789815 DOI: 10.1016/j.neurobiolaging.2021.02.021] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2020] [Revised: 01/31/2021] [Accepted: 02/25/2021] [Indexed: 11/15/2022]
Abstract
Trisomy-21 mosaicism (mT21) with subclinical intellectual development disorder or physical phenotype has very rarely been associated with early-onset cognitive decline. Notably, early-onset Alzheimer's disease (EOAD) patients' family histories frequently suggest genetic causes other than autosomal-dominant APP/PSEN-1/2 mutations. We present an EOAD patient in his late fifties newly diagnosed with low-degree mT21 (13%/21% blood lymphocytes/ectodermal cells). We applied fluorescence in-situ hybridization to confirm a diagnosis of mT21. Multimodal positron-emission-tomography applying 18F-fluodesoxyglucose (metabolism), 18F-florbetaben (amyloid-β deposits) and 18F-PI-2620 (tau-deposits) tracers was used to confirm a diagnosis of EOAD according to the ATN-criteria of AD. Initial PET-studies revealed marked cerebral amyloid-β- and tau-pathology and parietotemporal hypometabolism, confirming EOAD according to the ATN-criteria of AD. A marked cognitive decline was accompanied by an increase in tau pathology in follow-up studies. This is the first case demonstrating that a low-degree APP gene-dose increase suffices to cause EOAD with prominent amyloid-β/tau pathology.
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Affiliation(s)
- Georg S Nuebling
- Department of Neurology, Klinikum der Universität München, Ludwig-Maximilians-University, Munich, Germany; Department of Palliative Medicine, Klinikum der Universität München, Ludwig-Maximilians-University Munich, Germany
| | - Catharina Prix
- Department of Neurology, Klinikum der Universität München, Ludwig-Maximilians-University, Munich, Germany; German Center for Neurodegenerative Diseases (DZNE), Munich, Germany
| | - Matthias Brendel
- Department of Nuclear medicine, Klinikum der Universität München, Ludwig-Maximilians-University, Munich, Germany
| | - Leonie Beyer
- Department of Nuclear medicine, Klinikum der Universität München, Ludwig-Maximilians-University, Munich, Germany
| | - Elisabeth Wlasich
- Department of Neurology, Klinikum der Universität München, Ludwig-Maximilians-University, Munich, Germany
| | - Sandra V Loosli
- Department of Neurology, Klinikum der Universität München, Ludwig-Maximilians-University, Munich, Germany
| | - Henryk Barthel
- Department of Nuclear medicine, University Hospital Leipzig, Leipzig, Germany
| | - Osama Sabri
- Department of Nuclear medicine, Klinikum der Universität München, Ludwig-Maximilians-University, Munich, Germany
| | - Peter Bartenstein
- Department of Nuclear medicine, Klinikum der Universität München, Ludwig-Maximilians-University, Munich, Germany
| | - Jonathan Vöglein
- Department of Neurology, Klinikum der Universität München, Ludwig-Maximilians-University, Munich, Germany; German Center for Neurodegenerative Diseases (DZNE), Munich, Germany
| | - Adrian Danek
- Department of Neurology, Klinikum der Universität München, Ludwig-Maximilians-University, Munich, Germany
| | - Axel Rominger
- Department of Nuclear medicine, Inselspital Bern, Bern, Switzerland
| | - Dieter Edbauer
- German Center for Neurodegenerative Diseases (DZNE), Munich, Germany
| | - Christian Haass
- German Center for Neurodegenerative Diseases (DZNE), Munich, Germany; Munich Cluster for Systems Neurology, Munich, Germany; Metabolic Biochemistry, Biomedical Center (BMC), Faculty of Medicine, Ludwig-Maximilians-University Munich, Germany
| | - Johannes Levin
- Department of Neurology, Klinikum der Universität München, Ludwig-Maximilians-University, Munich, Germany; German Center for Neurodegenerative Diseases (DZNE), Munich, Germany; Munich Cluster for Systems Neurology, Munich, Germany.
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Mueller A, Bullich S, Barret O, Madonia J, Berndt M, Papin C, Perrotin A, Koglin N, Kroth H, Pfeifer A, Tamagnan G, Seibyl JP, Marek K, De Santi S, Dinkelborg LM, Stephens AW. Tau PET imaging with 18F- PI-2620 in Patients with Alzheimer Disease and Healthy Controls: A First-in-Humans Study. J Nucl Med 2019; 61:911-919. [PMID: 31712323 DOI: 10.2967/jnumed.119.236224] [Citation(s) in RCA: 77] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2019] [Accepted: 11/04/2019] [Indexed: 12/15/2022] Open
Abstract
18F-PI-2620 is a PET tracer with high binding affinity for aggregated tau, a key pathologic feature of Alzheimer disease (AD) and other neurodegenerative disorders. Preclinically, 18F-PI-2620 binds to both 3-repeat and 4-repeat tau isoforms. The purpose of this first-in-humans study was to evaluate the ability of 18F-PI-2620 to detect tau pathology in AD patients using PET imaging, as well as to assess the safety and tolerability of this new tau PET tracer. Methods: Participants with a clinical diagnosis of probable AD and healthy controls (HCs) underwent dynamic 18F-PI-2620 PET imaging for 180 min. 18F-PI-2620 binding was assessed visually and quantitatively using distribution volume ratios (DVR) estimated from noninvasive tracer kinetics and SUV ratio (SUVR) measured at different time points after injection, with the cerebellar cortex as the reference region. Time-activity curves and SUVR were assessed in AD and HC subjects, as well as DVR and SUVR correlations and effect size (Cohen's d) over time. Results: 18F-PI-2620 showed peak brain uptake around 5 min after injection and fast washout from nontarget regions. In AD subjects, focal asymmetric uptake was evident in temporal and parietal lobes, precuneus, and posterior cingulate cortex. DVR and SUVR in these regions were significantly higher in AD subjects than in HCs. Very low background signal was observed in HCs. 18F-PI-2620 administration was safe and well tolerated. SUVR time-activity curves in most regions and subjects achieved a secular equilibrium after 40 min after injection. A strong correlation (R 2 > 0.93) was found between noninvasive DVR and SUVR for all imaging windows starting at more than 30 min after injection. Similar effect sizes between AD and HC groups were obtained across the different imaging windows. 18F-PI-2620 uptake in neocortical regions significantly correlated with the degree of cognitive impairment. Conclusion: Initial clinical data obtained in AD and HC subjects demonstrated a high image quality and excellent signal-to-noise ratio of 18F-PI-2620 PET for imaging tau deposition in AD subjects. Noninvasive quantification using DVR and SUVR for 30-min imaging windows between 30 and 90 min after injection-for example, 45-75 min-provides robust and significant discrimination between AD and HC subjects. 18F-PI-2620 uptake in expected regions correlates strongly with neurocognitive performance.
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Affiliation(s)
| | | | | | | | | | - Caroline Papin
- Life Molecular Imaging GmbH, Berlin, Germany.,Invicro, New Haven, Connecticut
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Bullich S, Barret O, Constantinescu C, Sandiego C, Mueller A, Berndt M, Papin C, Perrotin A, Koglin N, Kroth H, Pfeifer A, Tamagnan G, Madonia J, Seibyl JP, Marek K, De Santi S, Dinkelborg LM, Stephens AW. Evaluation of Dosimetry, Quantitative Methods, and Test-Retest Variability of 18F- PI-2620 PET for the Assessment of Tau Deposits in the Human Brain. J Nucl Med 2019; 61:920-927. [PMID: 31712324 DOI: 10.2967/jnumed.119.236240] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2019] [Accepted: 11/04/2019] [Indexed: 02/01/2023] Open
Abstract
18F-PI-2620 is a next-generation tau PET tracer that has demonstrated ability to image the spatial distribution of suspected tau pathology. The objective of this study was to assess the tracer biodistribution, dosimetry, and quantitative methods of 18F-PI-2620 in the human brain. Full kinetic modeling to quantify tau load was investigated. Noninvasive kinetic modeling and semiquantitative methods were evaluated against the full tracer kinetics. Finally, the reproducibility of PET measurements from test and retest scans was assessed. Methods: Three healthy controls (HCs) and 4 Alzheimer disease (AD) subjects underwent 2 dynamic PET scans, including arterial sampling. Distribution volume ratio (DVR) was estimated using full tracer kinetics (reversible 2-tissue-compartment [2TC] model and Logan graphical analysis [LGA]) and noninvasive kinetic models (noninvasive LGA [NI-LGA] and the multilinear reference tissue model [MRTM2]). SUV ratio (SUVR) was determined at different imaging windows after injection. The correlation between DVR and SUVR, effect size (Cohen's d), and test-retest variability (TRV) were evaluated. Additionally, 6 HCs received 1 tracer administration and underwent whole-body PET for dosimetry calculation. Organ doses and the whole-body effective dose were calculated using OLINDA 2.0. Results: A strong correlation was found across different kinetic models (R 2 > 0.97) and between DVR(2TC) and SUVR between 30 and 90 min, with an R 2 of more than 0.95. Secular equilibrium was reached at around 40 min after injection in most regions and subjects. TRV and effect size for SUVR across different regions were similar at 30-60 min (TRV, 3.8%; Cohen's d, 3.80), 45-75 min (TRV, 4.3%; Cohen's d, 3.77) and 60-90 min (TRV, 4.9%; Cohen's d, 3.73) and increased at later time points. Elimination was via the hepatobiliary and urinary systems. The whole-body effective dose was 33.3 ± 2.1 μSv/MBq for an adult female and 33.1 ± 1.4 μSv/MBq for an adult male, with a 1.5-h urinary bladder voiding interval. Conclusion: 18F-PI-2620 exhibits fast kinetics, suitable dosimetry, and low TRV. DVR measured using the 2TC model with arterial sampling correlated strongly with DVR measured by NI-LGA, MRTM2, and SUVR. SUVR can be used for 18F-PI-2620 PET quantification of tau deposits, avoiding arterial blood sampling. Static 18F-PI-2620 PET scans between 45 and 75 min after injection provide excellent quantification accuracy, a large effect size, and low TRV.
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Affiliation(s)
| | | | | | | | | | | | - Caroline Papin
- Life Molecular Imaging GmbH, Berlin, Germany.,Invicro, New Haven, Connecticut
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Kroth H, Oden F, Molette J, Schieferstein H, Capotosti F, Mueller A, Berndt M, Schmitt-Willich H, Darmency V, Gabellieri E, Boudou C, Juergens T, Varisco Y, Vokali E, Hickman DT, Tamagnan G, Pfeifer A, Dinkelborg L, Muhs A, Stephens A. Discovery and preclinical characterization of [ 18F] PI-2620, a next-generation tau PET tracer for the assessment of tau pathology in Alzheimer's disease and other tauopathies. Eur J Nucl Med Mol Imaging 2019; 46:2178-2189. [PMID: 31264169 PMCID: PMC6667408 DOI: 10.1007/s00259-019-04397-2] [Citation(s) in RCA: 118] [Impact Index Per Article: 23.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2018] [Accepted: 06/10/2019] [Indexed: 01/11/2023]
Abstract
PURPOSE Tau deposition is a key pathological feature of Alzheimer's disease (AD) and other neurodegenerative disorders. The spreading of tau neurofibrillary tangles across defined brain regions corresponds to the observed level of cognitive decline in AD. Positron-emission tomography (PET) has proved to be an important tool for the detection of amyloid-beta (Aβ) aggregates in the brain, and is currently being explored for detection of pathological misfolded tau in AD and other non-AD tauopathies. Several PET tracers targeting tau deposits have been discovered and tested in humans. Limitations have been reported, especially regarding their selectivity. METHODS In our screening campaign we identified pyrrolo[2,3-b:4,5-c']dipyridine core structures with high affinity for aggregated tau. Further characterization showed that compounds containing this moiety had significantly reduced monoamine oxidase A (MAO-A) binding compared to pyrido[4,3-b]indole derivatives such as AV-1451. RESULTS Here we present preclinical data of all ten fluoropyridine regioisomers attached to the pyrrolo[2,3-b:4,5-c']dipyridine scaffold, revealing compounds 4 and 7 with superior properties. The lead candidate [18F]PI-2620 (compound 7) displayed high affinity for tau deposits in AD brain homogenate competition assays. Specific binding to pathological misfolded tau was further demonstrated by autoradiography on AD brain sections (Braak I-VI), Pick's disease and progressive supranuclear palsy (PSP) pathology, whereas no specific tracer binding was detected on brain slices from non-demented donors. In addition to its high affinity binding to tau aggregates, the compound showed excellent selectivity with no off-target binding to Aβ or MAO-A/B. Good brain uptake and fast washout were observed in healthy mice and non-human primates. CONCLUSIONS Therefore, [18F]PI-2620 was selected for clinical validation.
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Affiliation(s)
| | - Felix Oden
- Life Molecular Imaging, GmbH, Berlin, Germany
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