Determination of chitinase 3-like 1 in cerebrospinal fluid in multiple sclerosis and other neurological diseases

Alzheimer's disease CSF biomarkers correlate with early pathology and alterations in neuronal and glial gene expression

INTRODUCTION

Normal pressure hydrocephalus (NPH) patients undergoing cortical shunting frequently show early AD pathology on cortical biopsy, which is predictive of progression to clinical AD. The objective of this study was to use samples from this cohort to identify CSF biomarkers for AD-related CNS pathophysiologic changes using tissue and fluids with early pathology, free of post-mortem artifact.

METHODS

We analyzed Simoa, proteomic, and metabolomic CSF data from 81 patients with previously documented pathologic and transcriptomic changes.

RESULTS

AD pathology on biopsy correlates with CSF β-amyloid-40/42, neurofilament light chain (NfL), and phospho-tau-181(p-tau181)/β-amyloid-42, while several gene expression modules correlate with NfL. Proteomic analysis highlights 7 core proteins that correlate with pathology and gene expression changes on biopsy, and metabolomic analysis of CSF identifies disease-relevant groups that correlate with biopsy data..

DISCUSSION

As additional biomarkers are added to AD diagnostic panels, our work provides insight into the CNS pathophysiology these markers are tracking.

Chitinases: expanding the boundaries of knowledge beyond routinized chitin degradation

Chitinases, enzymes that degrade chitin, have long been studied for their role in various biological processes. They play crucial roles in the moulting process of invertebrates, the digestion of chitinous food, and defense against chitin-bearing pathogens. Additionally, chitinases are involved in physiological functions in crustaceans, such as chitinous food digestion, moulting, and stress response. Moreover, chitinases are universally distributed in organisms from viruses to mammals and have diverse functions including tissue degradation and remodeling, nutrition uptake, pathogen invasion, and immune response regulation. The discovery of these diverse functions expands our understanding of the biological significance and potential applications of chitinases. However, recent research has shown that chitinases possess several other functions beyond just chitin degradation. Their potential as biopesticides, therapeutic agents, and tools for bioremediation underscores their significance in addressing global challenges. More importantly, we noted that they may be applied as bioweapons if ethical regulations regarding production, engineering and application are overlooked.

CD138 as a Specific CSF Biomarker of Multiple Sclerosis

BACKGROUND AND OBJECTIVES

The aim of this study was to identify novel biomarkers for multiple sclerosis (MS) diagnosis and prognosis, addressing the critical need for specific and prognostically valuable markers in the field.

METHODS

We conducted an extensive proteomic investigation, combining analysis of (1) CSF proteome from symptomatic controls, fast and slow converters after clinically isolated syndromes, and patients with relapsing-remitting MS (n = 10 per group) using label-free quantitative proteomics and (2) oligodendrocyte secretome changes under proinflammatory or proapoptotic conditions using stable isotope labeling by amino acids in cell culture. Proteins exhibiting differential abundance in both proteomic analyses were combined with other putative MS biomarkers, yielding a comprehensive list of 87 proteins that underwent quantification through parallel reaction monitoring (PRM) in a novel cohort, comprising symptomatic controls, inflammatory neurologic disease controls, and patients with MS at various disease stages (n = 10 per group). The 11 proteins that passed this qualification step were subjected to a new PRM assay within an expanded cohort comprising 158 patients with either MS at different disease stages or other inflammatory or noninflammatory neurologic disease controls.

RESULTS

This study unveiled a promising biomarker signature for MS, including previously established candidates, such as chitinase 3-like protein 1, chitinase 3-like protein 2, chitotriosidase, immunoglobulin kappa chain region C, neutrophil gelatinase-associated lipocalin, and CD27. In addition, we identified novel markers, namely cat eye syndrome critical region protein 1 (adenosine deaminase 2, a therapeutic target in multiple sclerosis) and syndecan-1, a proteoglycan, also known as plasma cell surface marker CD138 and acting as chitinase 3-like protein 1 receptor implicated in inflammation and cancer signaling. CD138 exhibited good diagnostic accuracy in distinguishing MS from inflammatory neurologic disorders (area under the curve [AUC] = 0.85, CI 0.75-0.95). CD138 immunostaining was also observed in the brains of patients with MS and cultured oligodendrocyte precursor cells but was absent in astrocytes.

DISCUSSION

These findings identify CD138 as a specific CSF biomarker for MS and suggest the selective activation of the chitinase 3-like protein 1/CD138 pathway within the oligodendrocyte lineage in MS. They offer promising prospects for improving MS diagnosis and prognosis by providing much-needed specificity and clinical utility.

CLASSIFICATION OF EVIDENCE

This study provides Class II evidence that CD138 distinguishes multiple sclerosis from other inflammatory neurologic disorders with an AUC of 0.85 (95% CI 0.75-0.95).

Body fluid markers for multiple sclerosis and differential diagnosis from atypical demyelinating disorders

INTRODUCTION

Body fluid markers could be helpful to predict the conversion into clinically definite multiple sclerosis (MS) in people with a first demyelinating event of the central nervous system (CNS). Consequently, biomarkers such as oligoclonal bands, which are integrated in the current MS diagnostic criteria, could assist early MS diagnosis.

AREAS COVERED

This review examines existing knowledge on a broad spectrum of body fluid markers in people with a first CNS demyelinating event, explores their potential to predict conversion to MS, to assess MS disease activity, as well as their utility to differentiate MS from atypical demyelinating disorders such as neuromyelitis optica spectrum disorder and myelin oligodendrocyte glycoprotein associated disease.

EXPERT OPINION

This field of research has shown a dramatic increase of evidence, especially in the last decade. Some biomarkers are already established in clinical routine (e.g. oligoclonal bands) while others are currently implemented (e.g. kappa free light chains) or considered as breakthroughs (e.g. neurofilament light). Determination of biomarkers poses challenges for continuous monitoring, especially if exclusively detectable in cerebrospinal fluid. A handful of biomarkers are measurable in blood which holds a significant potential.

Chitinase-3-like 1-protein in CSF: a novel biomarker for progression in patients with multiple sclerosis

BACKGROUND

Chitinase -3-like 1-protein (CHI3L1) is a glycoside secreted by monocytes, microglia, and activated astrocytes. Its distribution in inflammatory lesions denotes its role in astrocytic response to modulate CNS inflammation. In multiple sclerosis (MS), CHI3L1 levels have been found to be influenced by disease severity, activity, and progression. We aimed to measure CSF level of CHI3L1 in patients with MS and correlate its level with disability measures for a possible role as a biomarker for disease progression.

METHODS

Fifty-two MS patients (30 relapsing-remitting MS and 22 progressive MS) and thirty-five age and sex-matched healthy controls were included. They all underwent full clinical assessment (including disability and cognitive scales), radiological assessment, and CSF level of CHI3L1.

RESULTS

Patients with MS had higher CSF level of CHI3L1 than controls. Patients with progressive forms had higher levels than relapsing forms. There were positive correlations between disease duration, number of attacks, total EDSS, and CSF level of CHI3L1. Patients who had higher level of CSF CHI3L1 showed worse performance in MMSE and BICAMS and more lesions in T2 MRI brain. A cut off value of 154 ng/mL was found between patients with RRMS and PMS patients.

CONCLUSION

CHI3L1 can be considered as a biomarker of disease progression. CHI3L1 level increases in progressive MS more than RRMS. Also, high CSF level of CHI3L1 was associated with more disability including motor, cognitive, and radiological aspects.

Biochemical biomarkers for multiple sclerosis

INTRODUCTION

Multiple sclerosis (MS) is the most frequent demyelinating disease of the central nervous system. Although there is currently no definite cure for MS, new therapies have recently been developed based on a continuous search for new biomarkers.

DEVELOPMENT

MS diagnosis relies on the integration of clinical, imaging and laboratory findings as there is still no singlepathognomonicclinical feature or diagnostic laboratory biomarker. The most commonly laboratory test used is the presence of immunoglobulin G oligoclonal bands (OCB) in cerebrospinal fluid of MS patients. This test is now included in the 2017 McDonald criteria as a biomarker of dissemination in time. Nevertheless, there are other biomarkers currently in use such as kappa free light chain, which has shown higher sensitivity and specificity for MS diagnosis than OCB. In addition, other potential laboratory tests involved in neuronal damage, demyelination and/or inflammation could be used for detecting MS.

CONCLUSIONS

CSF and serum biomarkers have been reviewed for their use in MS diagnosis and prognosis to stablish an accurate and prompt MS diagnosis, crucial to implement an adequate treatment and to optimize clinical outcomes over time.

The Heterogeneous Multiple Sclerosis Lesion: How Can We Assess and Modify a Degenerating Lesion?

Multiple sclerosis (MS) is a heterogeneous disease of the central nervous system that is governed by neural tissue loss and dystrophy during its progressive phase, with complex reactive pathological cellular changes. The immune-mediated mechanisms that promulgate the demyelinating lesions during relapses of acute episodes are not characteristic of chronic lesions during progressive MS. This has limited our capacity to target the disease effectively as it evolves within the central nervous system white and gray matter, thereby leaving neurologists without effective options to manage individuals as they transition to a secondary progressive phase. The current review highlights the molecular and cellular sequelae that have been identified as cooperating with and/or contributing to neurodegeneration that characterizes individuals with progressive forms of MS. We emphasize the need for appropriate monitoring via known and novel molecular and imaging biomarkers that can accurately detect and predict progression for the purposes of newly designed clinical trials that can demonstrate the efficacy of neuroprotection and potentially neurorepair. To achieve neurorepair, we focus on the modifications required in the reactive cellular and extracellular milieu in order to enable endogenous cell growth as well as transplanted cells that can integrate and/or renew the degenerative MS plaque.

Astrocytic Chitinase-3-like protein 1 in neurological diseases: Potential roles and future perspectives

Chitinase-3-like protein 1 (CHI3L1) is a secreted glycoprotein characterized by its ability to regulate multiple biological processes, such as the inflammatory response and gene transcriptional signaling activation. Abnormal CHI3L1 expression has been associated with multiple neurological disorders and serves as a biomarker for the early detection of several neurodegenerative diseases. Aberrant CHI3L1 expression is also reportedly associated with brain tumor migration and metastasis, as well as contributions to immune escape, playing important roles in brain tumor progression. CHI3L1 is synthesized and secreted mainly by reactive astrocytes in the central nervous system. Thus, targeting astrocytic CHI3L1 could be a promising approach for the treatment of neurological diseases, such as traumatic brain injury, ischemic stroke, Alzheimer's disease, Parkinson's disease, multiple sclerosis, amyotrophic lateral sclerosis, and glioma. Based on current knowledge of CHI3L1, we assume that it acts as a molecule mediating several signaling pathways driving the initiation and progression of neurological disorders. This narrative review is the first to introduce the potential roles of astrocytic CHI3L1 in neurological disorders. We also equally explore astrocytic CHI3L1 mRNA expression under physiological and pathological conditions. Inhibiting CHI3L1 and disrupting its interaction with its receptors through multiple mechanisms of action are briefly discussed. These endeavors highlight the pivotal roles of astrocytic CHI3L1 in neurological disorders and could contribute to the development of effective inhibitors based on the strategy of structure-based drug discovery, which could be an attractive therapeutic approach for neurological disease treatment.

Magnetic transferrin nanoparticles (MTNs) assay as a novel isolation approach for exosomal biomarkers in neurological diseases

BACKGROUND

Brain-derived exosomes released into the blood are considered a liquid biopsy to investigate the pathophysiological state, reflecting the aberrant heterogeneous pathways of pathological progression of the brain in neurological diseases. Brain-derived blood exosomes provide promising prospects for the diagnosis of neurological diseases, with exciting possibilities for the early and sensitive diagnosis of such diseases. However, the capability of traditional exosome isolation assays to specifically isolate blood exosomes and to characterize the brain-derived blood exosomal proteins by high-throughput proteomics for clinical specimens from patients with neurological diseases cannot be assured. We report a magnetic transferrin nanoparticles (MTNs) assay, which combined transferrin and magnetic nanoparticles to isolate brain-derived blood exosomes from clinical samples.

METHODS

The principle of the MTNs assay is a ligand-receptor interaction through transferrin on MTNs and transferrin receptor on exosomes, and electrostatic interaction via positively charged MTNs and negatively charged exosomes to isolate brain-derived blood exosomes. In addition, the MTNs assay is simple and rapid (< 35 min) and does not require any large instrument. We confirmed that the MTNs assay accurately and efficiently isolated exosomes from serum samples of humans with neurodegenerative diseases, such as dementia, Parkinson's disease (PD), and multiple sclerosis (MS). Moreover, we isolated exosomes from serum samples of 30 patients with three distinct neurodegenerative diseases and performed unbiased proteomic analysis to explore the pilot value of brain-derived blood protein profiles as biomarkers.

RESULTS

Using comparative statistical analysis, we found 21 candidate protein biomarkers that were significantly different among three groups of neurodegenerative diseases.

CONCLUSION

The MTNs assay is a convenient approach for the specific and affordable isolation of extracellular vesicles from body fluids for minimally-invasive diagnosis of neurological diseases.

Cerebrospinal Fluid Biomarkers in Differential Diagnosis of Multiple Sclerosis and Systemic Inflammatory Diseases with Central Nervous System Involvement

BACKGROUND

Diagnosis of multiple sclerosis (MS) is established on criteria according to clinical and radiological manifestation. Cerebrospinal fluid (CSF) analysis is an important part of differential diagnosis of MS and other inflammatory processes in the central nervous system (CNS).

METHODS

In total, 242 CSF samples were collected from patients undergoing differential MS diagnosis because of the presence of T2-hyperintensive lesions on brain MRI. The non-MS patients were subdivided into systemic inflammatory diseases with CNS involvement (SID) or cerebrovascular diseases (CVD) or other non-inflammatory diseases (NID). All samples were analyzed for the presence of oligoclonal bands and ELISA was performed for detection of: INF gamma, IL-6, neurofilaments light chain (NF-L), GFAP, CHI3L1, CXCL13, and osteopontin.

RESULTS

The level of IL-6 (p = 0.024), osteopontin (p = 0.0002), and NF-L (p = 0.002) was significantly different among groups. IL-6 (p = 0.0350) and NF-L (p = 0.0015) level was significantly higher in SID compared to NID patients. A significantly higher level of osteopontin (p = 0.00026) and NF-L (p = 0.002) in MS compared to NID population was noted. ROC analysis found weak diagnostic power for osteopontin and NFL-L.

CONCLUSIONS

The classical and non-standard markers of inflammatory process and neurodegeneration do not allow for sufficient differentiation between MS and non-MS inflammatory CNS disorders. Weak diagnostic power observed for the osteopontin and NF-L needs to be further investigated.

Identification of cerebral spinal fluid protein biomarkers in Niemann-Pick disease, type C1

BACKGROUND

Niemann-Pick disease, type C1 (NPC1) is an ultrarare, recessive, lethal, lysosomal disease characterized by progressive cerebellar ataxia and cognitive impairment. Although the NPC1 phenotype is heterogeneous with variable age of onset, classical NPC1 is a pediatric disorder. Currently there are no therapies approved by the FDA and therapeutics trials for NPC1 are complicated by disease rarity, heterogeneity, and the relatively slow rate of neurological decline. Thus, identification of disease relevant biomarkers is necessary to provide tools that can support drug development efforts for this devastating neurological disease.

METHODS

Proximal extension assays (O-link® Explore 1536) were used to compare cerebrospinal fluid (CSF) samples from individuals with NPC1 enrolled in a natural history study and non-NPC1 comparison samples. Relative expression levels of 1467 proteins were determined, and candidate protein biomarkers were identified by evaluating fold-change and adjusted Kruskal-Wallis test p-values. Selected proteins were orthogonally confirmed using ELISA. To gain insight into disease progression and severity we evaluated the altered protein expression with respect to clinically relevant phenotypic aspects: NPC Neurological Severity Score (NPC1 NSS), Annual Severity Increment Score (ASIS) and age of neurological onset.

RESULTS

This study identified multiple proteins with altered levels in CSF from individuals with NPC1 compared to non-NPC1 samples. These included proteins previously shown to be elevated in NPC1 (NEFL, MAPT, CHIT1, CALB1) and additional proteins confirmed by orthogonal assays (PARK7, CALB2/calretinin, CHI3L1/YKL-40, MIF, CCL18 and ENO2). Correlations with clinically relevant phenotypic parameters demonstrated moderate negative (p = 0.0210, r = -0.41) and possible moderate positive (p = 0.0631, r = 0.33) correlation of CSF CALB2 levels with age of neurological onset and ASIS, respectively. CSF CHI3L1 levels showed a moderate positive (p = 0.0183, r = 0.40) correlation with the concurrent NPC1 NSS. A strong negative correlation (p = 0.0016, r = -0.648) was observed between CSF CCL18 and age of neurological onset for childhood/adolescent cases. CSF CCL18 levels also showed a strong positive correlation (p = 0.0017, r = 0.61) with ASIS.

CONCLUSION

Our study identified and validated multiple proteins in CSF from individuals with NPC1 that are candidates for further investigation in a larger cohort. These analytes may prove to be useful as supportive data in therapeutic trials.

TRIAL REGISTRATIONS

NCT00344331, NCT00001721, NCT02931682.

An Update on Diagnostic Laboratory Biomarkers for Multiple Sclerosis

PURPOSE

For many patients, the multiple sclerosis (MS) diagnostic process can be lengthy, costly, and fraught with error. Recent research aims to address the unmet need for an accurate and simple diagnostic process through discovery of novel diagnostic biomarkers. This review summarizes recent studies on MS diagnostic fluid biomarkers, with a focus on blood biomarkers, and includes discussion of technical limitations and practical applicability.

RECENT FINDINGS

This line of research is in its early days. Accurate and easily obtainable biomarkers for MS have not yet been identified and validated, but several approaches to uncover them are underway. Continue efforts to define laboratory diagnostic biomarkers are likely to play an increasingly important role in defining MS at the earliest stages, leading to better long-term clinical outcomes.

Role of Chitinase 3-like 1 as a Biomarker in Multiple Sclerosis: A Systematic Review and Meta-analysis

BACKGROUND AND OBJECTIVES

Multiple sclerosis (MS) is an autoimmune disease confined in the CNS, and its course is frequently subtle and variable. Therefore, predictive biomarkers are needed. In this scenario, we conducted a systematic review and meta-analysis to evaluate the reliability of chitinase 3-like 1 as a biomarker of MS.

METHODS

Research through the main scientific databases (PubMed, Scopus, Web of Science, and Cochrane Library) published from January 2010 to December 2020 was performed using the following keywords: "chitinase 3-like 1 and multiple sclerosis" and "YKL40 and multiple sclerosis." Articles were selected according to the 2020 updated Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines by 2 authors independently, and data were extracted; 20 of the 90 studies screened were included in the meta-analysis. The main efficacy measure was represented by the standardized mean difference of CSF and blood CHI3L1 levels; Review Manager version 5.4 and R software applications were used for analysis.

RESULTS

Higher levels of CHI3L1 were found in CSF of 673 patients with MS compared with 336 healthy controls (size-weighted mean difference [SMD] 50.88; 95% CI = 44.98-56.79; p < 0.00001) and in 461 patients with MS than 283 patients with clinically isolated syndrome (CIS) (SMD 28.18; 95% CI = 23.59-32.76; p < 0.00001). Mean CSF CHI3L1 levels were significantly higher in 561 converting than 445 nonconverting CIS (SMD 30.6; 95% CI = 28.31-32.93; p < 0.00001). CSF CHI3L1 levels were significantly higher in patients with primary progressive MS (PPMS) than in patients with relapsing-remitting MS (RRMS) (SMD 43.15; 95% CI = 24.41-61.90; p < 0.00001) and in patients with secondary progressive MS (SMD 41.86 with 95% CI = 32.39-51.33; p < 0.00001). CSF CHI3L1 levels in 407 patients with MS during remission phase of disease were significantly higher than those in 395 patients with MS with acute relapse (SMD 10.48; 95% CI = 08.51-12.44; p < 0.00001). The performances of CHI3L1 in blood for differentiating patients with MS from healthy controls were not significant (SMD 0.48; 95% CI = -1.18 to 2.14; p: 0.57).

DISCUSSION

CSF levels of CHI3L1 have a strong correlation with the MS pathologic course, in particular with the mechanism of progression of the disease; it helps to distinguish the PPMS from the RRMS. The potential role of CHI3L1 in serum needs to be further studied in the future.

FastCAT Accelerates Absolute Quantification of Proteins Using Multiple Short Nonpurified Chimeric Standards

Absolute (molar) quantification of clinically relevant proteins determines their reference values in liquid and solid biopsies. The FastCAT (for Fast-track QconCAT) method employs multiple short (<50 kDa), stable-isotope labeled chimeric proteins (CPs) composed of concatenated quantotypic (Q)-peptides representing the quantified proteins. Each CP also comprises scrambled sequences of reference (R)-peptides that relate its abundance to a single protein standard (bovine serum albumin, BSA). FastCAT not only alleviates the need to purify CP or use sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) but also improves the accuracy, precision, and dynamic range of the absolute quantification by grouping Q-peptides according to the expected abundance of the target proteins. We benchmarked FastCAT against the reference method of MS Western and tested it in the direct molar quantification of neurological markers in human cerebrospinal fluid at the low ng/mL level.

Effects of age, amyloid, sex, and APOE ε4 on the CSF proteome in normal cognition

Introduction

It is important to understand which biological processes change with aging, and how such changes are associated with increased Alzheimer's disease (AD) risk. We studied how cerebrospinal fluid (CSF) proteomics changed with age and tested if associations depended on amyloid status, sex, and apolipoprotein E Ɛ4 genotype.

Methods

We included 277 cognitively intact individuals aged 46 to 89 years from Alzheimer's Disease Neuroimaging Initiative, European Medical Information Framework for Alzheimer's Disease Multimodal Biomarker Discovery, and Metabolic Syndrome in Men. In total, 1149 proteins were measured with liquid chromatography mass spectrometry with multiple reaction monitoring/Rules-Based Medicine, tandem mass tag mass spectrometry, and SOMAscan. We tested associations between age and protein levels in linear models and tested enrichment for Reactome pathways.

Results

Levels of 252 proteins increased with age independently of amyloid status. These proteins were associated with immune and signaling processes. Levels of 21 proteins decreased with older age exclusively in amyloid abnormal participants and these were enriched for extracellular matrix organization.

Discussion

We found amyloid-independent and -dependent CSF proteome changes with older age, perhaps representing physiological aging and early AD pathology.

The Neuroimmunology of Multiple Sclerosis: Fictions and Facts

There have been tremendous advances in the neuroimmunology of multiple sclerosis over the past five decades, which have led to improved diagnosis and therapy in the clinic. However, further advances must take into account an understanding of some of the complex issues in the field, particularly an appreciation of “facts” and “fiction.” Not surprisingly given the incredible complexity of both the nervous and immune systems, our understanding of the basic biology of the disease is very incomplete. This lack of understanding has led to many controversies in the field. This review identifies some of these controversies and facts/fictions with relation to the basic neuroimmunology of the disease (cells and molecules), and important clinical issues. Fortunately, the field is in a healthy transition from excessive reliance on animal models to a broader understanding of the disease in humans, which will likely lead to many improved treatments especially of the neurodegeneration in multiple sclerosis (MS).

Diagnostic biomarkers from proteomic characterization of cerebrospinal fluid in patients with brain malignancies

Recent technological advances in molecular diagnostics through liquid biopsies hold the promise to repetitively monitor tumor evolution and treatment response of brain malignancies without the need of invasive surgical tissue accrual. Here, we implemented a mass spectrometry-based protein analysis pipeline which identified hundreds of proteins in 251 cerebrospinal fluid (CSF) samples from patients with four types of brain malignancies (glioblastoma, lymphoma, brain metastasis, and leptomeningeal disease [LMD]) and from healthy individuals with a focus on glioblastoma in a retrospective and confirmatory prospective observational study. CSF proteome deregulation via disruption of the blood brain barrier appeared to be largely conserved across brain tumor entities. CSF analysis of glioblastoma patients identified two proteomic clusters that correlated with tumor size and patient survival. By integrating CSF data with proteomic analyses of matching glioblastoma tumor tissue and primary glioblastoma cells, we identified potential CSF biomarkers for glioblastoma, in particular chitinase-3-like protein 1 (CHI3L1) and glial fibrillary acidic protein (GFAP). Key findings were validated in a prospective cohort consisting of 35 glioma patients. Finally, in LMD patients who frequently undergo repeated CSF work-up, we explored our proteomic pipeline as a mean to profile consecutive CSF samples. Therefore, proteomic analysis of CSF in brain malignancies has the potential to reveal biomarkers for diagnosis and therapy monitoring.

Neuronal and glial CSF biomarkers in multiple sclerosis: a systematic review and meta-analysis

Multiple sclerosis (MS) is a neurodegenerative disease associated with inflammatory demyelination and astroglial activation, with neuronal and axonal damage as the leading factors of disability. We aimed to perform a meta-analysis to determine changes in CSF levels of neuronal and glial biomarkers, including neurofilament light chain (NFL), total tau (t-tau), chitinase-3-like protein 1 (CHI3L1), glial fibrillary acidic protein (GFAP), and S100B in various groups of MS (MS versus controls, clinically isolated syndrome (CIS) versus controls, CIS versus MS, relapsing-remitting MS (RRMS) versus progressive MS (PMS), and MS in relapse versus remission. According to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses, we included 64 articles in the meta-analysis, including 4071 subjects. For investigation of sources of heterogeneity, subgroup analysis, meta-regression, and sensitivity analysis were conducted. Meta-analyses were performed for comparisons including at least three individual datasets. NFL, GFAP, t-tau, CHI3L1, and S100B were higher in MS and NFL, t-tau, and CHI3L1 were also elevated in CIS patients than controls. CHI3L1 was the only marker with higher levels in MS than CIS. GFAP levels were higher in PMS versus RRMS, and NFL, t-tau, and CHI3L1 did not differ between different subtypes. Only levels of NFL were higher in patients in relapse than remission. Meta-regression showed influence of sex and disease severity on NFL and t-tau levels, respectively and disease duration on both. Added to the role of these biomarkers in determining prognosis and treatment response, to conclude, they may serve in diagnosis of MS and distinguishing different subtypes.

CSF levels of HoxB3 and YKL-40 may predict conversion from clinically isolated syndrome to relapsing remitting multiple sclerosis

INTRODUCTION

Multiple sclerosis (MS) often initiates with an acute episode of neurological disturbance, known as clinically isolated syndrome (CIS). There is an unmet need for biomarkers that differentiate patients who will convert to MS and who will remain as CIS after the first attack.

METHODS

First attack serum and cerebrospinal fluid (CSF) samples of 33 CIS patients were collected and these patients were divided as those who converted to MS (CIS-MS, n=17) and those who continued as CIS (CIS-CIS, n=16) in a 3-year follow-up period. Levels of homeobox protein Hox-B3 (HoxB3) and YKL-40 were measured by ELISA in samples of CIS-CIS, CIS-MS, relapsing remitting MS (RRMS) patients (n=15) and healthy controls (n=20).

RESULTS

CIS-CIS patients showed significantly reduced CSF levels of YKL-40 and increased serum/CSF levels of HoxB3 compared with CIS-MS and RRMS patients. CIS-MS and RRMS patients had comparable YKL-40 and HoxB3 level profiles. Receiver operating characteristic (ROC) curve analysis showed the highest sensitivity for CSF HoxB3 measurements in prediction of CIS-MS conversion. Kaplan-Meier analysis demonstrated that CIS patients with lower CSF HoxB3 (<3.678 ng/ml) and higher CSF YKL-40 (>654.9 ng/ml) displayed a significantly shorter time to clinically definite MS.

CONCLUSION

CSF levels of HoxB3 and YKL-40 appear to predict CIS to MS conversion, especially when applied in combination. HoxB3, which is a transcription factor involved in immune cell activity, stands out as a potential candidate molecule with biomarker capacity for MS.

Chitinase 3-like 1 and neurofilament light chain in CSF and CNS atrophy in MS

Objective

To investigate cross-sectional associations of CSF levels of neurofilament light chain (NfL) and of the newly emerging marker chitinase 3–like protein 1 (CHI3L1) with brain and spinal cord atrophy, which are established MRI markers of disease activity in MS, to study CHI3L1 and NfL in relapsing (RMS) and progressive MS (PMS), and to assess the expression of CHI3L1 in different cell types.

Methods

In a single-center study, 131 patients with MS (42 RMS and 89 PMS) were assessed for NfL and CHI3L1 concentrations in CSF, MRI-based spinal cord and brain volumetry, MS subtype, age, disease duration, and disability. We included 42 matched healthy controls receiving MRI. CHI3L1 expression of human brain cell types was examined in 2 published single-cell RNA sequencing data sets.

Results

CHI3L1 was associated with spinal cord volume (B = −1.07, 95% CI −2.04 to −0.11, p = 0.029) but not with brain volumes. NfL was associated with brain gray matter (B = −7.3, 95% CI −12.0 to −2.7, p = 0.003) but not with spinal cord volume. CHI3L1 was suitable to differentiate between progressive or relapsing MS (p = 0.015, OR 1.0103, CI for OR 1.002–1.0187), and its gene expression was found in MS-associated microglia and macrophages and in astrocytes of MS brains.

Conclusions

NfL and CHI3L1 in CSF were differentially related to brain and spinal cord atrophy. CSF CHI3L1 was associated with spinal cord volume loss and was less affected than NfL by disease duration and age, whereas CSF NfL was associated with brain gray matter atrophy. CSF NfL and CHI3L1 measurement provides complementary information regarding brain and spinal cord volumes.

Classification of evidence

This study provides Class II evidence that CSF CHI3L1 is associated with spinal cord volume loss and that CSF NfL is associated with gray matter atrophy.