A consensus protocol for the standardization of cerebrospinal fluid collection and biobanking

Insights into the human brain proteome: Disclosing the biological meaning of protein networks in cerebrospinal fluid

Cerebrospinal fluid (CSF) is an excellent source of biological information regarding the nervous system, once it is in close contact and accurately reflects alterations in this system. Several studies have analyzed differential protein profiles of CSF samples between healthy and diseased human subjects. However, the pathophysiological mechanisms and how CSF proteins relate to diseases are still poorly known. By applying bioinformatics tools, we attempted to provide new insights on the biological and functional meaning of proteomics data envisioning the identification of putative disease biomarkers. Bioinformatics analysis of data retrieved from 99 mass spectrometry (MS)-based studies on CSF profiling highlighted 1985 differentially expressed proteins across 49 diseases. A large percentage of the modulated proteins originate from exosome vesicles, and the majority are involved in either neuronal cell growth, development, maturation, migration, or neurotransmitter-mediated cellular communication. Nevertheless, some diseases present a unique CSF proteome profile, which were critically analyzed in the present study. For instance, 48 proteins were found exclusively upregulated in the CSF of patients with Alzheimer's disease and are mainly involved in steroid esterification and protein activation cascade processes. A higher number of exclusively upregulated proteins were found in the CSF of patients with multiple sclerosis (76 proteins) and with bacterial meningitis (70 proteins). Whereas in multiple sclerosis, these proteins are mostly involved in the regulation of RNA metabolism and apoptosis, in bacterial meningitis the exclusively upregulated proteins participate in inflammation and antibacterial humoral response, reflecting disease pathogenesis. The exploration of the contribution of exclusively upregulated proteins to disease pathogenesis will certainly help to envision potential biomarkers in the CSF for the clinical management of nervous system diseases.

Cerebrospinal fluid mtDNA concentration is elevated in multiple sclerosis disease and responds to treatment

BACKGROUND

Mitochondrial dysfunction is increasingly recognized as an important feature of multiple sclerosis (MS) pathology and may be relevant for clinical disease progression. However, it is unknown whether mitochondrial DNA (mtDNA) levels in the cerebrospinal fluid (CSF) associate with disease progression and therapeutic response.

OBJECTIVES

To evaluate whether CSF concentrations of mtDNA in MS patients can serve as a marker of ongoing neuropathology and may be helpful to differentiate between MS disease subtypes. To explore the effect of disease-modifying therapies on mtDNA levels in the CSF.

METHODS

CSF mtDNA was measured using a digital polymerase chain reaction (PCR) CSF mtDNA in two independent MS cohorts. The cohorts included 92 relapsing-remitting multiple sclerosis (RRMS) patients, 40 progressive multiple sclerosis (PMS) patients (27 secondary progressive and 13 primary progressive), 50 various neurologic disease controls, and 5 healthy controls.

RESULTS

Patients with PMS showed a significant increase in CSF mtDNA compared to non-inflammatory neurologic disease controls. Patients with higher T2 lesion volumes and lower normalized brain volumes showed increased concentration of mtDNA. Patients treated with fingolimod had significantly lower mtDNA copy levels at follow-up compared to baseline.

CONCLUSION

Our results showed a non-specific elevation of concentration of mtDNA in PMS patients. mtDNA concentrations respond to fingolimod and may be used to monitor biological effect of this treatment.

High Interferon-γ Uniquely in Vδ1 T Cells Correlates with Markers of Inflammation and Axonal Damage in Early Multiple Sclerosis

We have identified a population of T lymphocytes in peripheral blood, Vδ1 TCRγδ T lymphocytes, which unexpectedly was uniquely expressing high production of interferon-γ in newly diagnosed, untreated multiple sclerosis (MS) patients. IFN-γ production in this population distinctly correlated to parameters of clinical disease activity, inflammation, and neuronal damage. These Vδ1 T lymphocytes belong to a population of innate T lymphocytes that recognize antigen in the context of CD1d/CD1c and which include reactivity to the myelin glycosphingolipid sulfatide. Importantly, patients treated with natalizumab, blocking leukocyte transmigration to central nervous system, had completely normalized levels of interferon-γ-producing Vδ1 T lymphocytes. A biomarker and early sign of demyelinating disease in MS is much warranted and would help identify immunopathogenesis and prognosis of disease as well as monitor success with adequate treatment. The present study identifies the Vδ1 T lymphocytes as an early marker of MS and a possible link to understanding the disease etiology.

Comparison of three analytical platforms for quantification of the neurofilament light chain in blood samples: ELISA, electrochemiluminescence immunoassay and Simoa

BACKGROUND

Neuronal damage is the morphological substrate of persisting neurological disability. Neurofilaments (Nf) are specific cytoskeletal proteins of neurons and their quantification has shown encouraging results as a biomarker for axonal injury.

METHODS

We aimed at comparing a widely used conventional ELISA for Nf light chain (NfL) with an electrochemiluminescence-based method (ECL assay) and a newly developed single-molecule array (Simoa) method in clinically relevant cerebrospinal fluid (CSF) and serum samples.

RESULTS

Analytical sensitivity was 0.62 pg/mL for Simoa, 15.6 pg/mL for the ECL assay, and 78.0 pg/mL for the ELISA. Correlations between paired CSF and serum samples were strongest for Simoa (r=0.88, p<0.001) and the ECL assay (r=0.78, p<0.001) and weaker for ELISA measurements (r=0.38, p=0.030). CSF NfL measurements between the platforms were highly correlated (r=1.0, p<0.001). Serum NfL levels were highly related between ECL assay and Simoa (r=0.86, p<0.001), and this was less visible between ELISA-ECL assay (r=0.41, p=0.018) and ELISA-Simoa (r=0.43, p=0.013). Multiple sclerosis (MS) patients had significantly higher serum NfL levels than controls when measured with Simoa (p=0.001) but not with the other platforms.

CONCLUSIONS

We found Simoa to be more sensitive than ELISA or the ECL assay. Our results support the feasibility of quantifying NfL in serum; the results correlate with the more-established CSF NfL test. The highly sensitive Simoa technology deserves further studies in larger patient cohorts to clarify whether serum NfL could be used in the future to measure disease severity and determine prognosis or response to treatment interventions in neurological diseases.

Landscape of MS patient cohorts and registries: Recommendations for maximizing impact

BACKGROUND

There is a growing number of cohorts and registries collecting phenotypic and genotypic data from groups of multiple sclerosis patients. Improved awareness and better coordination of these efforts is needed.

OBJECTIVE

The purpose of this report is to provide a global landscape of the major longitudinal MS patient data collection efforts and share recommendations for increasing their impact.

METHODS

A workshop that included over 50 MS research and clinical experts from both academia and industry was convened to evaluate how current and future MS cohorts could be better used to provide answers to urgent questions about progressive MS.

RESULTS

The landscape analysis revealed a significant number of largely uncoordinated parallel studies. Strategic oversight and direction is needed to streamline and leverage existing and future efforts. A number of recommendations for enhancing these efforts were developed.

CONCLUSIONS

Better coordination, increased leverage of evolving technology, cohort designs that focus on the most important unanswered questions, improved access, and more sustained funding will be needed to close the gaps in our understanding of progressive MS and accelerate the development of effective therapies.

Biochemical changes in the injured brain

Brain metabolism is an energy intensive phenomenon involving a wide spectrum of chemical intermediaries. Various injury states have a detrimental effect on the biochemical processes involved in the homeostatic and electrophysiological properties of the brain. The biochemical markers of brain injury are a recent addition in the armamentarium of neuro-clinicians and are being increasingly used in the routine management of neuro-pathological entities such as traumatic brain injury, stroke, subarachnoid haemorrhage and intracranial space occupying lesions. These markers are increasingly being used in assessing severity as well as in predicting the prognostic course of neuro-pathological lesions. S-100 protein, neuron specific enolase, creatinine phosphokinase isoenzyme BB and myelin basic protein are some of the biochemical markers which have been proven to have prognostic and clinical value in the brain injury. While S-100, glial fibrillary acidic protein and ubiquitin C terminal hydrolase are early biomarkers of neuronal injury and have the potential to aid in clinical decision-making in the initial management of patients presenting with an acute neuronal crisis, the other biomarkers are of value in predicting long-term complications and prognosis in such patients. In recent times cerebral microdialysis has established itself as a novel way of monitoring brain tissue biochemical metabolites such as glucose, lactate, pyruvate, glutamate and glycerol while small non-coding RNAs have presented themselves as potential markers of brain injury for future.

Stability of Progranulin Under Pre-Analytical Conditions in Serum and Cerebrospinal Fluid

Progranulin (PGRN) levels in blood and cerebrospinal fluid (CSF) are increasingly studied as potential markers for neurodegenerative disorders. We aimed to 1) characterize two commercially available PGRN ELISAs on several assay validation parameters, 2) assess the stability of PGRN in serum and CSF under pre-analytical conditions, and 3) compare stability in the two assays. Intra- and inter-assay variation, inter-lot variation, linearity, lower limit of detection, and kit correlations were assessed for the Adipogen and R&D PGRN ELISA kits. Blood and serum samples were experimentally exposed to ≤9 freeze/thaw cycles, delayed processing for ≤24 h at room temperature and 4°C, and to temperature stability tests for ≤3 weeks at -20°C, 4°C, room temperature, and 37°C. Both commercial PGRN ELISA kits showed acceptable ranges for intra- and inter-assay variation, where the R&D kit performed more accurate than the Adipogen kit, especially for inter-assay variation (intra-assay serum: 6.7 and 8.3%, respectively; inter-assay serum: 9.2 and 21.0%; intra-assay CSF: 3.6 and 12.0%; inter-assay CSF: 16.0 and 44.5%). Absolute serum PGRN concentrations were 1.9-fold higher in Adipogen than R&D (p < 0.001) and strongly correlated between both kits (ρ= 0.86, p < 0.0001) and CSF PGRN levels were on the borderline of detection in both kits. PGRN was typically stable under all pre-analytical conditions addressed, although two weeks at 37°C resulted in decreased PGRN concentrations in CSF, only when using the Adipogen kit. These results support further examination of PGRN as a potential marker in neurodegenerative diseases, since PGRN is stable in serum and CSF and can be measured using ELISA kits from several providers.

The MRZ reaction in primary progressive multiple sclerosis

Background

The MRZ reaction (MRZR), composed of the three antibody indices (AI) against measles, rubella and varicella zoster virus and found positive in the majority of relapsing-remitting multiple sclerosis (RRMS) patients, is absent in other inflammatory neurological diseases (OIND). So far, it has been uncertain whether its differential diagnostic promise extends to patients with primary-progressive multiple sclerosis (PPMS).

Objective

To investigate the prevalence of MRZR in PPMS compared to RRMS and OIND patients.

Methods

MRZR was assessed in patients with PPMS (n = 103), RRMS (n = 100) and OIND (n = 48). Both stringency levels for MRZR testing, MRZR-1 (≥1 AI positive) and MRZR-2 (≥2 AI positive), were applied.

Results

Prevalence of positive MRZR-1 was 83.5% in PPMS and 67.8% in RRMS (p < 0.05). A positive MRZR-2 was found in 54.4% of PPMS and in 43.0% of RRMS patients (not significant). Compared to both MS subgroups, OIND patients exhibit lower frequencies of positive MRZR (MRZR-1: 22.9%, MRZR-2: 8.3%; p < 0.0001 each).

Conclusion

Positive MRZR was at least as frequent in PPMS as in RRMS and much less frequent in OIND, confirming its promise as a potentially useful diagnostic tool for distinguishing both MS course types from OIND.

Increased levels of CSF total but not oligomeric or phosphorylated forms of alpha-synuclein in patients diagnosed with probable Alzheimer's disease

Several studies reported an association between CSF alpha-synuclein (α-syn) and tau in Alzheimer's disease (AD), and demonstrated the significance of α-syn in improving the diagnostic sensitivity/specificity of classical AD CSF biomarkers. In the current study, we measured CSF levels of different α-syn species in a cohort of AD patients (n = 225) who showed a CSF profile typical of AD at baseline as well as in cognitively intact controls (n = 68). CSF total α-syn (t-α-syn) significantly increased in the AD group (p < 0.0001) compared to controls, while oligomeric- and phosphorylated-Ser129-α-syn did not change significantly. ROC analysis showed a sensitivity of 85% and a specificity of 84% (AUC = 0.88) in distinguishing AD from controls. T-α-syn levels correlated positively with tau species in AD group and negatively with baseline MMSE score. Our data support the added value of measurement of CSF α-syn species for further characterization of the CSF AD profile.

Cerebrospinal fluid biomarkers for Parkinson's disease - a systematic review

Diagnosis of Parkinson's disease (PD) relies on clinical history and physical examination, but misdiagnosis is common in early stages. Identification of biomarkers for PD may allow early and more precise diagnosis and monitoring of dopamine replacement strategies and disease modifying treatments. Developments in analytical chemistry allow the detection of large numbers of molecules in plasma or cerebrospinal fluid, associated with the pathophysiology or pathogenesis of PD. This systematic review includes cerebrospinal fluid biomarker studies focusing on different disease pathways: oxidative stress, neuroinflammation, lysosomal dysfunction and proteins involved in PD and other neurodegenerative disorders, focusing on four clinical domains: their ability to (1) distinguish PD from healthy subjects and other neurodegenerative disorders as well as their relation to (2) disease duration after initial diagnosis, (3) severity of disease (motor symptoms) and (4) cognitive dysfunction. Oligomeric alpha-synuclein might be helpful in the separation of PD from controls. Through metabolomics, changes in purine and tryptophan metabolism have been discovered in patients with PD. Neurofilament light chain (NfL) has a significant role in distinguishing PD from other neurodegenerative diseases. Several oxidative stress markers are related to disease severity, with the antioxidant urate also having a prognostic value in terms of disease severity. Increased levels of amyloid and tau-proteins correlate with cognitive decline and may have prognostic value for cognitive deficits in PD. In the future, larger longitudinal studies, corroborating previous research on viable biomarker candidates or using metabolomics identifying a vast amount of potential biomarkers, could be a good approach.

Hydroxycholesterol Levels in the Serum and Cerebrospinal Fluid of Patients with Neuromyelitis Optica Revealed by LC-Ag+CIS/MS/MS and LC-ESI/MS/MS with Picolinic Derivatization: Increased Levels and Association with Disability during Acute Attack

Neuromyelitis optica (NMO) is an inflammatory demyelinating disease of the central nervous system (CNS). Hydroxycholesterols (OHCs), metabolites of CNS cholesterol, are involved in diverse cellular responses to inflammation and demyelination, and may also be involved in the pathogenesis of NMO. We aimed to develop a sensitive and reliable method for the quantitative analysis of three major OHCs (24S-, 25-, and 27-OHCs), and to evaluate their concentration in the cerebrospinal fluid (CSF) and serum of patients with NMO. The levels of the three OHCs in the serum and CSF were measured using liquid chromatography-silver ion coordination ionspray tandem mass spectrometry and liquid chromatography-electrospray ionization tandem mass spectrometry with picolinyl ester derivatization, respectively. The linear range was 5–250 ng/mL for 24S- and 27-OHC, and 0.5–25 ng/mL for 25-OHC in serum, and was 0.1–5 ng/mL for 24S- and 27-OHC, and 0.03–1 ng/mL for 25-OHC in CSF. Precision and accuracy were 0.5%–14.7% and 92.5%–109.7%, respectively, in serum, and were 0.8%–7.7% and 94.5%–119.2%, respectively, in CSF. Extraction recovery was 82.7%–90.7% in serum and 68.4%–105.0% in CSF. When analyzed in 26 NMO patients and 23 control patients, the 25-OHC (0.54 ± 0.96 ng/mL vs. 0.09 ± 0.04 ng/mL, p = 0.032) and 27-OHC (2.68 ± 3.18 ng/mL vs. 0.68 ± 0.25 ng/mL, p = 0.005) were increased in the CSF from NMO patients. When we measured the OHC_CSF index that controls the effects of blood–brain barrier disruption on the level of OHC in the CSF, the 27-OHC_CSF index was associated with disability (0.723; 95% confidence interval (CI)– 0.181, 0.620; p = 0.002), while the 24-OHC_CSF index (0.518; 95% CI– 1.070, 38.121; p = 0.040) and 25-OHC_CSF index (0.677; 95% CI– 4.313, 18.532; p = 0.004) were associated with the number of white blood cells in the CSF of NMO patients. Our results imply that OHCs in the CNS could play a role in the pathogenesis of NMO.

Importance of cerebrospinal fluid analysis in the era of McDonald 2010 criteria: a German-Austrian retrospective multicenter study in patients with a clinically isolated syndrome

The majority of patients presenting with a first clinical symptom suggestive of multiple sclerosis (MS) do not fulfill the MRI criteria for dissemination in space and time according to the 2010 revision of the McDonald diagnostic criteria for MS and are thus classified as clinically isolated syndrome (CIS). To re-evaluate the utility of cerebrospinal fluid (CSF) analysis in the context of the revised McDonald criteria from 2010, we conducted a retrospective multicenter study aimed at determining the prevalence and predictive value of oligoclonal IgG bands (OCBs) in patients with CIS. Patients were recruited from ten specialized MS centers in Germany and Austria. We collected data from 406 patients; at disease onset, 44/406 (11 %) fulfilled the McDonald 2010 criteria for MS. Intrathecal IgG OCBs were detected in 310/362 (86 %) of CIS patients. Those patients were twice as likely to convert to MS according to McDonald 2010 criteria as OCB-negative individuals (hazard ratio = 2.1, p = 0.0014) and in a shorter time period of 25 months (95 % CI 21-34) compared to 47 months in OCB-negative individuals (95 % CI 36-85). In patients without brain lesions at first attack and presence of intrathecal OCBs (30/44), conversion rate to MS was 60 % (18/30), whereas it was only 21 % (3/14) in those without OCBs. Our data confirm that in patients with CIS the risk of conversion to MS substantially increases if OCBs are present at onset. CSF analysis definitely helps to evaluate the prognosis in patients who do not have MS according to the revised McDonald criteria.

Prognostic value of free light chains lambda and kappa in early multiple sclerosis

Background:

Cerebrospinal fluid (CSF) immunoglobulin free light chains (FLC) have been suggested as quantitative alternative to oligoclonal bands (OCB) in the diagnosis of multiple sclerosis (MS). However, little is known on their role in predicting clinical and paraclinical disease progression, particularly in early stages.

Objective:

To assess the prognostic value of FLC in OCB-positive patients with clinically isolated syndrome (CIS) suggestive of MS and early MS.

Methods:

We determined FLC kappa (KFLC) and lambda (LFLC) in CSF and serum by nephelometry in 61 patients (CIS ( n = 48), relapsing-remitting multiple sclerosis ( n = 13)) and 60 non-inflammatory neurological controls. Median clinical follow-up time in CIS was 4.8 years (interquartile range (IQR), 1.5–6.5 years). Patients underwent 3T magnetic resonance imaging (MRI) at baseline and follow-up (median time interval, 2.2 years; IQR, 1.0–3.7 years) to determine T2 lesion load (T2LL) and percent brain volume change (PBVC).

Results:

CSF FLC were significantly increased in CIS/MS compared to controls (all p < 0.001). A lower KFLC/LFLC CSF ratio was associated with CIS-clinically definite multiple sclerosis (CDMS) conversion (hazard ratio (HR) = 2.89; 95% confidence interval (CI) = 1.17–7.14; p < 0.05). No correlations were found for FLC variables with T2LL or PBVC.

Conclusion:

Our study confirms increased intrathecal synthesis of FLC in CIS/MS which supports their diagnostic contribution. The KFLC/LFLC CSF ratio appears to have a prognostic value in CIS beyond OCB.

CSF-PR 2.0: An Interactive Literature Guide to Quantitative Cerebrospinal Fluid Mass Spectrometry Data from Neurodegenerative Disorders

The rapidly growing number of biomedical studies supported by mass spectrometry based quantitative proteomics data has made it increasingly difficult to obtain an overview of the current status of the research field. A better way of organizing the biomedical proteomics information from these studies and making it available to the research community is therefore called for. In the presented work, we have investigated scientific publications describing the analysis of the cerebrospinal fluid proteome in relation to multiple sclerosis, Parkinson's disease and Alzheimer's disease. Based on a detailed set of filtering criteria we extracted 85 data sets containing quantitative information for close to 2000 proteins. This information was made available in CSF-PR 2.0 (http://probe.uib.no/csf-pr-2.0), which includes novel approaches for filtering, visualizing and comparing quantitative proteomics information in an interactive and user-friendly environment. CSF-PR 2.0 will be an invaluable resource for anyone interested in quantitative proteomics on cerebrospinal fluid.

In-Depth Cerebrospinal Fluid Quantitative Proteome and Deglycoproteome Analysis: Presenting a Comprehensive Picture of Pathways and Processes Affected by Multiple Sclerosis

In the current study, we conducted a quantitative in-depth proteome and deglycoproteome analysis of cerebrospinal fluid (CSF) from relapsing-remitting multiple sclerosis (RRMS) and neurological controls using mass spectrometry and pathway analysis. More than 2000 proteins and 1700 deglycopeptides were quantified, with 484 proteins and 180 deglycopeptides significantly changed between pools of RRMS and pools of controls. Approximately 300 of the significantly changed proteins were assigned to various biological processes including inflammation, extracellular matrix organization, cell adhesion, immune response, and neuron development. Ninety-six significantly changed deglycopeptides mapped to proteins that were not found changed in the global protein study. In addition, four mapped to the proteins oligo-myelin glycoprotein and noelin, which were found oppositely changed in the global study. Both are ligands to the nogo receptor, and the glycosylation of these proteins appears to be affected by RRMS. Our study gives the most extensive overview of the RRMS affected processes observed from the CSF proteome to date, and the list of differential proteins will have great value for selection of biomarker candidates for further verification.

Laboratory testing of extravascular body fluids in Croatia: a survey of the Working group for extravascular body fluids of the Croatian Society of Medical Biochemistry and Laboratory Medicine

INTRODUCTION

We hypothesized that extravascular body fluid (EBF) analysis in Croatia is not harmonized and aimed to investigate preanalytical, analytical and postanalytical procedures used in EBF analysis in order to identify key aspects that should be addressed in future harmonization attempts.

MATERIALS AND METHODS

An anonymous online survey created to explore laboratory testing of EBF was sent to secondary, tertiary and private health care Medical Biochemistry Laboratories (MBLs) in Croatia. Statements were designed to address preanalytical, analytical and postanalytical procedures of cerebrospinal, pleural, peritoneal (ascites), pericardial, seminal, synovial, amniotic fluid and sweat. Participants were asked to declare the strength of agreement with proposed statements using a Likert scale. Mean scores for corresponding separate statements divided according to health care setting were calculated and compared.

RESULTS

The survey response rate was 0.64 (58 / 90). None of the participating private MBLs declared to analyse EBF. We report a mean score of 3.45 obtained for all statements evaluated. Deviations from desirable procedures were demonstrated in all EBF testing phases. Minor differences in procedures used for EBF analysis comparing secondary and tertiary health care MBLs were found. The lowest scores were obtained for statements regarding quality control procedures in EBF analysis, participation in proficiency testing programmes and provision of interpretative comments on EBF's test reports.

CONCLUSIONS

Although good laboratory EBF practice is present in Croatia, procedures for EBF analysis should be further harmonized to improve the quality of EBF testing and patient safety.

No diurnal variation of classical and candidate biomarkers of Alzheimer's disease in CSF

Background

Cerebrospinal fluid (CSF) biomarkers have gained increasing importance in the diagnostic work-up of Alzheimer’s disease (AD). The core CSF biomarkers related to AD pathology (Aβ42, t-tau and p-tau) are currently used in CSF diagnostics, while candidate markers of amyloid metabolism (Aβ38, Aβ40, sAPPα, sAPPβ), synaptic loss (neurogranin), neuroinflammation (YKL-40), neuronal damage (VILIP-1) and genetic risk (apolipoprotein E) are undergoing evaluation. Diurnal fluctuation in the concentration of CSF biomarkers has been reported and may represent a preanalytical confounding factor in the laboratory diagnosis of AD. The aim of the present study was to investigate the diurnal variability of classical and candidate CSF biomarkers in a cohort of neurosurgical patients carrying a CSF drainage.

Method

Samples were collected from a cohort of 13 neurosurgical patients from either ventricular (n = 6) or lumbar (n = 7) CSF drainage at six time points during the day, 1–7 days following the neurosurgical intervention. Concentrations of the core biomarkers were determined by immunoassays.

Results

Although absolute values largely varied among subjects, none of the biomarkers showed significant diurnal variation. Site of drainage (lumbar vs. ventricular) did not influence this result. The different immunoassays used for tau and Aβ markers provided similar results.

Conclusion

Time of day at CSF collection does not ultimately affect the concentration levels of classical and candidate AD biomarkers. Similar trends were found when using different immunoassays, thus corroborating the consistency of the data.

Electronic supplementary material

The online version of this article (doi:10.1186/s13024-016-0130-3) contains supplementary material, which is available to authorized users.

Immunosensors for Biomarker Detection in Autoimmune Diseases

Autoimmune diseases occur when the immune system generates proinflammatory molecules and autoantibodies that mistakenly attack their own body. Traditional diagnosis of autoimmune disease is primarily based on physician assessment combined with core laboratory tests. However, these tests are not sensitive enough to detect early molecular events, and quite often, it is too late to control these autoimmune diseases and reverse tissue damage when conventional tests show positivity for disease. It is fortunate that during the past decade, research in nanotechnology has provided enormous opportunities for the development of ultrasensitive biosensors in detecting early biomarkers with high sensitivity. Biosensors consist of a biorecognition element and a transducer which are able to facilitate an accurate detection of proinflammatory molecules, autoantibodies and other disease-causing molecules. Apparently, novel biosensors could be superior to traditional metrics in assessing the drug efficacy in clinical trials, especially when specific biomarkers are indicative of the pathogenesis of disease. Furthermore, the portability of a biosensor enables the development of point-of-care devices. In this review, various types of biomolecule sensing systems, including electrochemical, optical and mechanical sensors, and their applications and future potentials in autoimmune disease treatment were discussed.

Cerebrospinal Fluid Alzheimer's Disease Biomarkers Across the Spectrum of Lewy Body Diseases: Results from a Large Multicenter Cohort

BACKGROUND

Concomitant Alzheimer's disease (AD) pathology is observed in Lewy body diseases (LBD), but the clinical impact is unknown. Only a few biomarker studies in LBD exist and have included small cohorts from single centers.

OBJECTIVE

We aimed to evaluate the prevalence of abnormal cerebrospinal fluid (CSF) AD biomarkers across the spectrum of LBD in a large multicenter cohort and to assess whether an AD biomarker profile was associated with demographic and clinical differences in dementia with Lewy bodies (DLB).

METHODS

We included 375 DLB patients, 164 Parkinson's disease (PD) patients without dementia, and 55 PD patients with dementia (PDD) from 10 centers. CSF amyloid-beta42 (Aβ42), total tau (t-tau), and phosphorylated tau (p-tau) values were dichotomized as abnormal or normal according to locally available cut-off values. A CSF AD profile was defined as abnormal Aβ42 combined with abnormal t-tau and/or p-tau.

RESULTS

A substantial proportion of DLB patients had abnormal values for CSF Aβ42, t-tau, and p-tau, while abnormal values were uncommon in PD without dementia. Patients with PDD had values in between. A CSF AD profile was observed in 25% of DLB patients, compared with only 9% of PDD and 3% of PD without dementia. Within DLB, patients with a CSF AD profile were older, more often female, performed worse on the Mini-Mental State Examination, and had shorter disease duration compared with patients with normal CSF.

CONCLUSION

A CSF AD profile is more common in DLB compared with PDD and PD, and is associated with more severe cognitive impairment in DLB.

Retracted: Consensus Guidelines for CSF and Blood Biobanking for CNS Biomarker Studies

[This retracts the article DOI: 10.1155/2011/246412.].

Cerebrospinal fluid biomarkers of inflammation and degeneration as measures of fingolimod efficacy in multiple sclerosis

BACKGROUND

The disease-modifying therapies (DMTs) in relapsing-remitting multiple sclerosis (RRMS) vary in their mode of action and when therapies are changed, the consequences on inflammatory and degenerative processes are largely unknown.

OBJECTIVE

We investigated the effect of switching from other DMTs to fingolimod on cerebrospinal fluid (CSF) biomarkers.

METHODS

43 RRMS patients were followed up after 4-12 months of fingolimod treatment. Concentrations of C-X-C motif chemokine 13 (CXCL13), chemokine (C-C motif) ligand 2 (CCL2), chitinase-3-like protein 1 (CHI3L1), glial fibrillary acidic protein (GFAP), neurofilament light protein (NFL), and neurogranin (NGRN) were analyzed by enzyme-linked immunosorbent assay (ELISA), while chitotriosidase (CHIT1) was analyzed by spectrofluorometry.

RESULTS

The levels of NFL, CXCL13, and CHI3L1 decreased ( p < 0.05) after fingolimod treatment. Subgroup analysis revealed a reduction in NFL ( p < 0.001), CXCL13 ( p = 0.001), CHI3L1 ( p < 0.001), and CHIT1 ( p = 0.002) in patients previously treated with first-line therapies. In contrast, the levels of all analyzed biomarkers were essentially unchanged in patients switching from natalizumab.

CONCLUSION

We found reduced inflammatory activity (CXCL13, CHI3L1, and CHIT1) and reduced axonal damage (NFL) in patients switching from first-line DMTs to fingolimod. Biomarker levels in patients switching from natalizumab indicate similar effects on inflammatory and degenerative processes. The CSF biomarkers provide an additional measure of treatment efficacy.

Cerebrospinal fluid lipocalin 2 in patients with clinically isolated syndromes and early multiple sclerosis

Background:

Lipocalin 2 (LCN2) may be involved in the immunopathogenesis of multiple sclerosis (MS) and might further impact on iron homoeostasis. Brain iron accumulates in MS; however, the association to iron-related proteins is still unsolved.

Objective:

To investigate cerebrospinal fluid (CSF) and serum LCN2, transferrin (Trf) and ferritin in early MS in relation to disease evolution and longitudinal brain iron accumulation.

Methods:

We analysed CSF and serum LCN2 by enzyme-linked immunosorbent assay (ELISA) and Trf and ferritin by nephelometry in 55 patients (45 clinically isolated syndrome (CIS), 10 MS, median clinical follow-up 4.8 years) and 63 controls. In patients, we assessed sub-cortical grey matter iron by 3T magnetic resonance imaging (MRI) R2* relaxometry (median imaging follow-up 2.2 years).

Results:

Compared to controls serum ( p < 0.01), CSF ( p < 0.001) LCN2 and CSF Trf ( p < 0.001) levels were reduced in the patients. CSF LCN2 correlated with CSF Trf ( r = 0.5, p < 0.001). In clinically stable patients, CSF LCN2 levels correlated with basal ganglia iron accumulation ( r = 0.5, p < 0.05). In CIS, higher CSF LCN2 levels were associated with conversion to clinically definite MS ( p < 0.05).

Conclusion:

We demonstrate altered LCN2 regulation in early MS and provide first evidence for this to be possibly linked to both clinical MS activity and iron accumulation in the basal ganglia.

The γ-Secretase Modulator, BMS-932481, Modulates Aβ Peptides in the Plasma and Cerebrospinal Fluid of Healthy Volunteers

The pharmacokinetics, pharmacodynamics, safety, and tolerability of BMS-932481, a γ-secretase modulator (GSM), were tested in healthy young and elderly volunteers after single and multiple doses. BMS-932481 was orally absorbed, showed dose proportionality after a single dose administration, and had approximately 3-fold accumulation after multiple dosing. High-fat/caloric meals doubled the Cmax and area under the curve and prolonged Tmax by 1.5 hours. Consistent with the preclinical pharmacology of GSMs, BMS-932481 decreased cerebrospinal fluid (CSF) Aβ39, Aβ40, and Aβ42 while increasing Aβ37 and Aβ38, thereby providing evidence of γ-secretase enzyme modulation rather than inhibition. In plasma, reductions in Aβ40 and Aβ42 were observed with no change in total Aβ; in CSF, modest decreases in total Aβ were observed at higher dose levels. Increases in liver enzymes were observed at exposures associated with greater than 70% CSF Aβ42 lowering after multiple dosing. Although further development was halted due to an insufficient safety margin to test the hypothesis for efficacy of Aβ lowering in Alzheimer's disease, this study demonstrates that γ-secretase modulation is achievable in healthy human volunteers and supports further efforts to discover well tolerated GSMs for testing in Alzheimer's disease and other indications.

Systemic inflammatory response and neuromuscular involvement in amyotrophic lateral sclerosis

Objective:

To evaluate the combined blood expression of neuromuscular and inflammatory biomarkers as predictors of disease progression and prognosis in amyotrophic lateral sclerosis (ALS).

Methods:

Logistic regression adjusted for markers of the systemic inflammatory state and principal component analysis were carried out on plasma levels of creatine kinase (CK), ferritin, and 11 cytokines measured in 95 patients with ALS and 88 healthy controls. Levels of circulating biomarkers were used to study survival by Cox regression analysis and correlated with disease progression and neurofilament light chain (NfL) levels available from a previous study. Cytokines expression was also tested in blood samples longitudinally collected for up to 4 years from 59 patients with ALS.

Results:

Significantly higher levels of CK, ferritin, tumor necrosis factor (TNF)–α, and interleukin (IL)–1β, IL-2, IL-8, IL-12p70, IL-4, IL-5, IL-10, and IL-13 and lower levels of interferon (IFN)–γ were found in plasma samples from patients with ALS compared to controls. IL-6, TNF-α, and IFN-γ were the most highly regulated markers when all explanatory variables were jointly analyzed. High ferritin and IL-2 levels were predictors of poor survival. IL-5 levels were positively correlated with CK, as was TNF-α with NfL. IL-6 was strongly associated with CRP levels and was the only marker showing increasing expression towards end-stage disease in the longitudinal analysis.

Conclusions:

Neuromuscular pathology in ALS involves the systemic regulation of inflammatory markers mostly active on T-cell immune responses. Disease stratification based on the prognostic value of circulating inflammatory markers could improve clinical trials design in ALS.

Circulating miR-150 in CSF is a novel candidate biomarker for multiple sclerosis

Objective:

To explore circulating microRNAs (miRNAs) in cell-free CSF as novel biomarkers for multiple sclerosis (MS).

Methods:

Profiling of miRNAs in CSF of pooled patients with clinically isolated syndrome (CIS), patients with relapsing-remitting MS, and inflammatory and noninflammatory neurologic disease controls was performed using TaqMan miRNA arrays. Two independent patient cohorts (n = 142 and n = 430) were used for validation with real-time PCR.

Results:

We reliably detected 88 CSF miRNAs in the exploratory cohort. Subsequent validation in 2 cohorts demonstrated significantly higher levels of miR-150 in patients with MS. Higher miR-150 levels were also observed in patients with CIS who converted to MS compared to nonconverters, and in patients initiating natalizumab treatment. Levels of miR-150 correlated with immunologic parameters including CSF cell count, immunoglobulin G index, and presence of oligoclonal bands, and with candidate protein biomarkers C-X-C motif chemokine 13, matrix metallopeptidase 9, and osteopontin. Correlation with neurofilament light chain (NFL) was observed only when NFL was adjusted for age using a method that requires further validation. Additionally, miR-150 discriminated MS from controls and CIS converters from nonconverters equally well as the most informative protein biomarkers. Following treatment with natalizumab, but not fingolimod, CSF levels of miR-150 decreased, while plasma levels increased with natalizumab and decreased with fingolimod, suggesting immune cells as a source of miR-150.

Conclusions:

Our findings demonstrate miR-150 as a putative novel biomarker of inflammatory active disease with the potential to be used for early diagnosis of MS.

Classification of evidence:

This study provides Class II evidence that CSF miR-150 distinguishes patients with MS from patients with other neurologic conditions.

The Swiss Multiple Sclerosis Cohort-Study (SMSC): A Prospective Swiss Wide Investigation of Key Phases in Disease Evolution and New Treatment Options

The mechanisms leading to disability and the long-term efficacy and safety of disease modifying drugs (DMDs) in multiple sclerosis (MS) are unclear. We aimed at building a prospective cohort of MS patients with standardized collection of demographic, clinical, MRI data and body fluids that can be used to develop prognostic indicators and biomarkers of disease evolution and therapeutic response. The Swiss MS Cohort (SMSC) is a prospective observational study performed across seven Swiss MS centers including patients with MS, clinically isolated syndrome (CIS), radiologically isolated syndrome or neuromyelitis optica. Neurological and radiological assessments and biological samples are collected every 6-12 months. We recruited 872 patients (clinically isolated syndrome [CIS] 5.5%, relapsing-remitting MS [RRMS] 85.8%, primary progressive MS [PPMS] 3.5%, secondary progressive MS [SPMS] 5.2%) between June 2012 and July 2015. We performed 2,286 visits (median follow-up 398 days) and collected 2,274 serum, plasma and blood samples, 152 cerebrospinal fluid samples and 1,276 brain MRI scans. 158 relapses occurred and expanded disability status scale (EDSS) scores increased in PPMS, SPMS and RRMS patients experiencing relapses. Most RRMS patients were treated with fingolimod (33.4%), natalizumab (24.5%) or injectable DMDs (13.6%). The SMSC will provide relevant information regarding DMDs efficacy and safety and will serve as a comprehensive infrastructure available for nested research projects.

Cytokine Profile in Patients with Progressive Multiple Sclerosis and Its Association with Disease Progression and Disability

Inflammation is the driving force for brain injury in patients with multiple sclerosis (MS). The objective of the present study is to delineate the serum cytokine profile in patients with progressive MS in a Southern Brazilian population compared with healthy controls and patients with relapsing-remitting MS (RRMS) and its associations with disease progression and disability. We included 32 patients with progressive MS, 126 with RRMS, and 40 healthy controls. The patients were evaluated using the Expanded Disability Status Scale (EDSS) and magnetic resonance imaging (MRI) with gadolinium. Serum interleukin (IL)-1β, IL-6, IL-12, tumor necrosis factor (TNF)-α, interferon (IFN)-γ, IL-10, IL-4, and IL-17 levels were assessed using an enzyme-linked immunosorbent assay. IL-1β, IL-6, TNF-α, IFN-γ, IL-17, IL-4, and IL-10 levels were higher in progressive MS than in controls. Increased IL-1β and IFN-γ and decreased IL-12 and IL-4 levels were found in progressive MS compared with RRMS. Patients with progressive MS with disease progression presented higher TNF-α, IFN-γ, and IL-10 levels than those without disease progression. Patients with progressive MS with disease progression showed a higher frequency of positive gadolinium-enhanced lesions in MRI; higher TNF-α, IFN-γ, and IL-17 levels; and decreased IL-12 levels compared with RRMS patients with progression. There was a significant inverse correlation between IL-10 levels and EDSS score in patients with progressive MS. The results underscore the complex cytokine network imbalance exhibited by progressive MS patients and show the important involvement of TNF-α, IFN-γ, and IL-17 in the pathophysiology and progression of the disease. Moreover, serum IL-10 levels were inversely associated with disability in patients with progressive MS.

Analysis of the Cerebrospinal Fluid Proteome in Alzheimer's Disease

Alzheimer’s disease is a neurodegenerative disorder accounting for more than 50% of cases of dementia. Diagnosis of Alzheimer’s disease relies on cognitive tests and analysis of amyloid beta, protein tau, and hyperphosphorylated tau in cerebrospinal fluid. Although these markers provide relatively high sensitivity and specificity for early disease detection, they are not suitable for monitor of disease progression. In the present study, we used label-free shotgun mass spectrometry to analyse the cerebrospinal fluid proteome of Alzheimer’s disease patients and non-demented controls to identify potential biomarkers for Alzheimer’s disease. We processed the data using five programs (DecyderMS, Maxquant, OpenMS, PEAKS, and Sieve) and compared their results by means of reproducibility and peptide identification, including three different normalization methods. After depletion of high abundant proteins we found that Alzheimer’s disease patients had lower fraction of low-abundance proteins in cerebrospinal fluid compared to healthy controls (p<0.05). Consequently, global normalization was found to be less accurate compared to using spiked-in chicken ovalbumin for normalization. In addition, we determined that Sieve and OpenMS resulted in the highest reproducibility and PEAKS was the programs with the highest identification performance. Finally, we successfully verified significantly lower levels (p<0.05) of eight proteins (A2GL, APOM, C1QB, C1QC, C1S, FBLN3, PTPRZ, and SEZ6) in Alzheimer’s disease compared to controls using an antibody-based detection method. These proteins are involved in different biological roles spanning from cell adhesion and migration, to regulation of the synapse and the immune system.

Novel diagnostic cerebrospinal fluid biomarkers for pathologic subtypes of frontotemporal dementia identified by proteomics

Introduction

Reliable cerebrospinal fluid (CSF) biomarkers enabling identification of frontotemporal dementia (FTD) and its pathologic subtypes are lacking.

Methods

Unbiased high-resolution mass spectrometry–based proteomics was applied on CSF of FTD patients with TAR DNA-binding protein 43 (TDP-43, FTD-TDP, n = 12) or tau pathology (FTD-tau, n = 8), and individuals with subjective memory complaints (SMC, n = 10). Validation was performed by applying enzyme-linked immunosorbent assay (ELISA) or enzymatic assays, when available, in a larger cohort (FTLD-TDP, n = 21, FTLD-tau, n = 10, SMC, n = 23) and in Alzheimer's disease (n = 20), dementia with Lewy bodies (DLB, n = 20), and vascular dementia (VaD, n = 18).

Results

Of 1914 identified CSF proteins, 56 proteins were differentially regulated (fold change >1.2, P < .05) between the different patient groups: either between the two pathologic subtypes (10 proteins), or between at least one of these FTD subtypes and SMC (47 proteins). We confirmed the differential expression of YKL-40 by ELISA in a partly independent cohort. Furthermore, enzyme activity of catalase was decreased in FTD subtypes compared with SMC. Further validation in a larger cohort showed that the level of YKL-40 was twofold increased in both FTD pathologic subtypes compared with SMC and that the levels in FTLD-tau were higher compared to Alzheimer's dementia (AD), DLB, and VaD patients. Clinical validation furthermore showed that the catalase enzyme activity was decreased in the FTD subtypes compared to SMC, AD and DLB.

Discussion

We identified promising CSF biomarkers for both FTD differential diagnosis and pathologic subtyping. YKL-40 and catalase enzyme activity should be validated further in similar pathology defined patient cohorts for their use for FTD diagnosis or treatment development.

Soluble TREM-2 in cerebrospinal fluid from patients with multiple sclerosis treated with natalizumab or mitoxantrone

BACKGROUND

Microglia-mediated proteolysis of the triggering receptor expressed on myeloid cells-2 (TREM-2) produces soluble TREM-2 (sTREM-2) that can be measured in cerebrospinal fluid (CSF) samples. Loss-of-function mutations in TREM2 or in the gene encoding its adaptor protein cause the rare Nasu-Hakola disease (NHD). Multiple sclerosis (MS) is an autoimmune disease that in common with NHD is characterized by demyelination and microglial activation.

OBJECTIVE

To investigate the potential utility of sTREM-2 as a biomarker for MS and to follow treatment effects.

METHODS

sTREM-2 was analyzed in CSF samples from subjects with MS (N = 59); relapsing-remitting MS (RRMS) (N = 36), secondary progressive MS (SPMS) (N = 20) and primary progressive MS (PPMS) (N = 3), and controls (N = 27). CSF levels of sTREM-2 were also assessed before and after treatment of patients with natalizumab or mitoxantrone.

RESULTS

CSF levels of sTREM-2 were significantly increased in patients with RRMS, SPMS, and PPMS compared with controls. After natalizumab treatment, the levels of sTREM-2 were normalized to control levels. The levels of sTREM-2 were also reduced after mitoxantrone treatment.

CONCLUSION

Increased CSF levels of sTREM-2, a new marker of microglial activation, in MS and normalization upon treatment with either natalizumab or mitoxantrone support a role for microglial activation in active MS.

Genetic, Immune-Inflammatory, and Oxidative Stress Biomarkers as Predictors for Disability and Disease Progression in Multiple Sclerosis

The aim of this study was to evaluate the TNFβ NcoI polymorphism (rs909253) and immune-inflammatory, oxidative, and nitrosative stress (IO&NS) biomarkers as predictors of disease progression in multiple sclerosis (MS). We included 212 MS patients (150 female, 62 male, mean (±standard deviation (SD)) age = 42.7 ± 13.8 years) and 249 healthy controls (177 female, 72 male, 36.8 ± 11 years). The disability was measured the Expanded Disability Status Scale (EDSS) in 2006 and 2011. We determined the TNFβ NcoI polymorphism and serum levels of interleukin (IL)-6, tumor necrosis factor (TNF)-α, interferon (IFN)-γ, IL-4, IL-10, and IL-17, albumin, ferritin, and plasma levels of lipid hydroperoxides (CL-LOOH), carbonyl protein, advanced oxidation protein products (AOPPs), nitric oxide metabolites (NOx), and total radical-trapping antioxidant parameter (TRAP). The mean EDSS (±SD) in 2006 was 1.62 ± 2.01 and in 2011 3.16 ± 2.29, and disease duration was 7.34 ± 7.0 years. IL-10, TNF-α, IFN-γ, AOPP, and NOx levels were significantly higher and IL-4 lower in MS patients with a higher 2011 EDSS scores (≥3) as compared with those with EDSS < 3. The actual increases in EDSS from 2006 to 2011 were positively associated with TNF-α and IFN-γ. Increased IFN-γ values were associated with higher pyramidal symptoms and increased IL-6 with sensitive symptoms. Increased carbonyl protein and IL-10 but lowered albumin levels predicted cerebellar symptoms. The TNFB1/B2 genotype decreased risk towards progression of pyramidal symptoms. Treatments with IFN-β and glatiramer acetate significantly reduced TNF-α but did not affect the other IO&NS biomarkers or disease progression. Taken together, IO&NS biomarkers and NcoI TNFβ genotypes predict high disability in MS and are associated with different aspects of disease progression. New drugs to treat MS should also target oxidative stress pathways.

Developing Biomarkers for MS

Existing clinical outcomes of disease activity, including relapse rates, are inherently insensitive to the underlying pathological process in MS. Moreover, it is extremely difficult to measure clinical disability in patients, which is often a retrospective assessment, and definitely not within the time frame of a clinical trial. Biomarkers , conversely are more specific for a pathologic process and if used correctly can prove invaluable in the diagnosis, stratification and monitoring of disease activity, including any subclinical activity which is not visible to the naked eye. In this chapter, we discuss the development of neurofilaments as surrogate outcomes of disability in MS. The validation and qualification are vital steps in biomarker development and to gaining acceptance in scientific community, and the pitfalls leading up to this are also discussed.

The intrathecal, polyspecific antiviral immune response in neurosarcoidosis, acute disseminated encephalomyelitis and autoimmune encephalitis compared to multiple sclerosis in a tertiary hospital cohort

Background

A polyspecific, intrathecal humoral immune response against the neurotropic viruses, measles, rubella and varicella zoster virus, called “MRZ reaction” (MRZR), is present in the majority of patients with multiple sclerosis (MS). Neurosarcoidosis (NS) and acute disseminated encephalomyelitis (ADEM) are important clinical differential diagnoses of MS. Autoimmune encephalitis (AIE) represents a well characterized autoimmune CNS disorder with intrathecal antibody synthesis. The aim of this study was to investigate the specificity of MRZR for MS in patients with NS, ADEM and AIE for the first time, and to compare it with the diagnostic value of oligoclonal bands (OCB).

Patients and methods

Twenty-two patients with NS, 17 with AIE, 8 with ADEM and 33 with MS serving as controls were analyzed for OCB and MRZR by calculation of the antibody index (AI) for each virus. MRZR was considered as positive if at least two AIs were ≥1.5.

Results

A positive MRZR was statistically significantly less frequent in NS (9 %), AIE (11 %) and ADEM (0 %) compared to MS patients (70 %; p < 0.001 each). The specificity of MRZR for MS was 92 % in the study cohort. In comparison to MRZR, the OCB showed a higher sensitivity (100 %), but a lower specificity (69 %) for MS.

Conclusion

These results indicate that MRZR seems to be the most specific available CSF marker of MS.

Reduced cerebrospinal fluid mitochondrial DNA is a biomarker for early-stage Parkinson's disease

The identification of cell-free circulating mitochondrial DNA (ccf-mtDNA) in early-stage Alzheimer's disease (AD) raised the possibility that the same neurodegenerative effect could be observed in Parkinson's disease (PD). Here, and for the first time, we investigated the role of ccf-mtDNA in PD, identifying a significant reduction of ccf-mtDNA in PD patient cerebrospinal fluid (CSF) when compared to controls. Our data demonstrates that CSF ccf-mtDNA is not only a powerful biomarker for PD, but, given that the effect is also observed in AD, is likely a biomarker for neurodegeneration.

Deregulation of microRNA-181c in cerebrospinal fluid of patients with clinically isolated syndrome is associated with early conversion to relapsing-remitting multiple sclerosis

BACKGROUND

MiRNA-181c, miRNA-633 and miRNA-922 have been reported to be deregulated in multiple sclerosis.

OBJECTIVES

To investigate the association between miRNA-181c, miRNA-633 and miRNA-922 and conversion from clinically isolated syndrome (CIS) to relapsing-remitting multiple sclerosis (RRMS); and to compare microRNAs in cerebrospinal fluid (CSF) and serum with regard to dysfunction of the blood-CSF barrier.

METHODS

CSF and serum miRNA-181c, miRNA-633 and miRNA-922 were retrospectively determined by quantitative real-time polymerase chain reaction in CIS patients with (CIS-RRMS) and without (CIS-CIS) conversion to RRMS within 1 year.

RESULTS

Thirty of 58 CIS patients developed RRMS. Cerebrospinal fluid miRNA-922, serum miRNA-922 and cerebrospinal fluid miRNA-181c were significantly higher in CIS-RRMS compared to CIS-CIS (P=0.027, P=0.048, P=0.029, respectively). High levels of cerebrospinal fluid miRNA-181c were independently associated with conversion from CIS to RRMS in multivariate Cox regression analysis (hazard ratio 2.99, 95% confidence interval 1.41-6.34, P=0.005). A combination of high cerebrospinal fluid miRNA-181c, younger age and more than nine lesions on magnetic resonance imaging showed the highest specificity (96%) and positive predictive value (94%) for conversion from CIS to RRMS. MiRNA-181c was higher in serum than in cerebrospinal fluid (P <0.001), while miRNA-633 and miRNA-922 were no different in cerebrospinal fluid and serum. Cerebrospinal fluid/serum albumin quotients did not correlate with microRNAs in cerebrospinal fluid (all P>0.711).

CONCLUSIONS

Cerebrospinal fluid miRNA-181c might serve as a biomarker for early conversion to RRMS. Moreover, our data suggest an intrathecal origin of microRNAs detected in the cerebrospinal fluid.

Antibodies to MOG in adults with inflammatory demyelinating disease of the CNS

OBJECTIVE

To evaluate the clinical relevance of myelin oligodendrocyte glycoprotein antibody (MOG-Ab) in a cohort of adults with inflammatory demyelinating disease (IDD) of the CNS.

METHODS

Live cell-based assays for MOG-Ab (IgG1 subset) and antibody to aquaporin-4 (AQP4-Ab) were performed in a cohort of 270 adult patients with IDD and 72 controls. Patients were first grouped by positive antibody result as MOG-Ab or AQP4-Ab, and the remainder were grouped by published diagnostic criteria.

RESULTS

Seventeen patients with IDD (6.3%) had MOG-Abs and 49 patients (18.1%) had AQP4-Abs; none had both antibodies. The MOG-Ab patients predominantly manifested with isolated symptoms of optic neuritis (83%). One-third of these patients experienced relapses, which involved only the optic nerve, and all relapsed within 1 year of disease onset. At onset, MRI in the MOG-Ab group uniquely demonstrated perineural enhancement, extending to the soft tissues around the optic nerves (33%). Although about 30% of MOG-Ab patients had brain MRI lesions, they had fewer periventricular lesions than the 26 patients with relapsing-remitting multiple sclerosis (MS); none of these lesions were ovoid or perpendicular to the ventricle. Moreover, MOG-Ab patients did not meet the diagnostic criteria for definite neuromyelitis optica (NMO) and had less spinal cord involvement than the AQP4-Ab group. Four patients (23.5%) had poor visual outcomes (<0.2) or paraplegia.

CONCLUSIONS

MOG-Abs may be a disease-specific biomarker in adult patients with IDD who have a disease distinct from NMO or MS. The radiologic as well as clinical manifestations of MOG-Ab patients can be useful in their differential diagnosis.

The Central Biobank and Virtual Biobank of BIOMARKAPD: A Resource for Studies on Neurodegenerative Diseases

Biobanks are important resources for biomarker discovery and assay development. Biomarkers for Alzheimer’s and Parkinson’s disease (BIOMARKAPD) is a European multicenter study, funded by the EU Joint Programme-Neurodegenerative Disease Research, which aims to improve the clinical use of body fluid markers for the diagnosis and prognosis of Alzheimer’s disease (AD) and Parkinson’s disease (PD). The objective was to standardize the assessment of existing assays and to validate novel fluid biomarkers for AD and PD. To support the validation of novel biomarkers and assays, a central and a virtual biobank for body fluids and associated data from subjects with neurodegenerative diseases have been established. In the central biobank, cerebrospinal fluid (CSF) and blood samples were collected according to the BIOMARKAPD standardized pre-analytical procedures and stored at Integrated BioBank of Luxembourg. The virtual biobank provides an overview of available CSF, plasma, serum, and DNA samples at each site. Currently, at the central biobank of BIOMARKAPD samples are available from over 400 subjects with normal cognition, mild cognitive impairment (MCI), AD, frontotemporal dementia (FTD), vascular dementia, multiple system atrophy, progressive supranuclear palsy, PD, PD with dementia, and dementia with Lewy bodies. The virtual biobank contains information on over 8,600 subjects with varying diagnoses from 21 local biobanks. A website has been launched to enable sample requests from the central biobank and virtual biobank.

Gray matter-related proteins are associated with childhood-onset multiple sclerosis

Objective:

To identify CSF biomarkers for multiple sclerosis (MS) in children with an initial acquired CNS demyelinating syndrome (ADS).

Methods:

CSF was collected from a cohort of 39 children with initial ADS, 18 of whom were diagnosed with MS and 21 of whom had a monophasic disease course. Proteomic analysis of trypsinized CSF (20 μL) was performed by nano-liquid chromatography Orbitrap mass spectrometry. Univariate statistical analysis was used to identify differentially abundant proteins between childhood-onset MS and monophasic ADS.

Results:

A total of 2,260 peptides corresponding to 318 proteins were identified in the total set of samples. Of these 2,260 peptides, 88 were identified as being most distinctive between MS and ADS. Fifty-three peptides, corresponding to 14 proteins, had higher abundance in children with MS compared to children with monophasic ADS. Twelve of these 14 proteins were linked to neuronal functions and structures, such as synapses, axons, and CNS proteases (e.g., neurofascin, carboxypeptidase E, brevican core protein, and contactin-2). The other 2 were functionally related to immune function. The 35 peptides identified with decreased abundance in children with MS corresponded to 7 proteins. Six of them were linked to innate immune function (e.g., haptoglobin, haptoglobin-related protein, C4b-binding protein alpha chain, and monocyte differentiation antigen CD14) and 1 was linked to cellular adhesion (protein diaphanous homolog 1).

Conclusion:

At first onset of ADS, CSF of children diagnosed with MS showed increased abundance of CNS gray matter–related proteins, whereas CSF of children with a monophasic disease course showed increased abundance of innate immunity–related proteins.

Body fluid biomarkers for multiple sclerosis--the long road to clinical application

There is a strong unmet clinical need for objective body fluid biomarkers to assist early diagnosis and estimate long-term prognosis, monitor treatment response and predict potential adverse effects in multiple sclerosis (MS). Here, we review recent studies (focusing on 2012 to early 2015) on body fluid markers in MS from the perspective of their clinical utility. Because the first step towards clinical implementation of a newly discovered biomarker is independent replication, we focus on biomarkers that have been validated in at least two independent cohorts. We also discuss recent data challenging earlier findings, and biomarkers for which new clinical uses are suggested. For early MS diagnosis and prediction of conversion from clinically isolated syndrome to MS, several new B-cell-associated candidate blood biomarkers have emerged. For prognosis, several novel axonal damage markers should be adopted to biomarker panels. The number of disease-modifying treatments for MS has increased sharply, but biomarkers for treatment response monitoring and adverse effect prediction are scarce, and markers for subtyping and staging of MS are still lacking. In view of the availability and implementation of several standardized protocols to optimize biomarker studies, we expect biomarker development for MS to be improved and accelerated, with clinical implementation in the near future.