Genetic, Environmental and Lifestyle Determinants of Accelerated Telomere Attrition as Contributors to Risk and Severity of Multiple Sclerosis

Telomeres are protective structures at the ends of linear chromosomes. Shortened telomere lengths (TL) are an indicator of premature biological aging and have been associated with a wide spectrum of disorders, including multiple sclerosis (MS). MS is a chronic inflammatory, demyelinating and neurodegenerative disease of the central nervous system. The exact cause of MS is still unclear. Here, we provide an overview of genetic, environmental and lifestyle factors that have been described to influence TL and to contribute to susceptibility to MS and possibly disease severity. We show that several early-life factors are linked to both reduced TL and higher risk of MS, e.g., adolescent obesity, lack of physical activity, smoking and vitamin D deficiency. This suggests that the mechanisms underlying the disease are connected to cellular aging and senescence promoted by increased inflammation and oxidative stress. Additional prospective research is needed to clearly define the extent to which lifestyle changes can slow down disease progression and prevent accelerated telomere loss in individual patients. It is also important to further elucidate the interactions between shared determinants of TL and MS. In future, cell type-specific studies and advanced TL measurement methods could help to better understand how telomeres may be causally involved in disease processes and to uncover novel opportunities for improved biomarkers and therapeutic interventions in MS.

Signs of neuroinflammation outweigh neurodegeneration as predictors for early conversion to MS

Background

The pathophysiological mechanisms underlying multiple sclerosis include both inflammatory and degenerative processes. We aimed to study and compare markers of neuroinflammation and neurodegeneration in patients with first presentation of demyelinating disorder and to prospectively identify which of the studied markers serve as predictors for early conversion to multiple sclerosis. Thus, 42 patients with first clinical manifestations suggestive of demyelinating disease were included in a prospective study. Subjects underwent thorough history taking and clinical evaluation. Laboratory studies involved analysis of cerebrospinal fluid (CSF) and serum chitinase 3-like 1 levels. Brain imaging included MRI and ultrasonographic assessment.

Results

T1 black holes, elevated oligoclonal bands (OCB), high baseline T2 lesion load, and enhanced MRI lesions were significantly higher in patients with 1st attack multiple sclerosis. Significantly higher CSF-OCB and serum chitinase 3-like 1 protein was detected in patients with multiple sclerosis (MS) compared to clinically isolated syndrome, and higher levels in MS convertors than non-convertors. Cognitive dysfunction evaluated by MoCA test and brain atrophy assessed using transcranial sonography did not show significant difference among the studied groups. Logistic regression analysis showed that heavy T2 lesion load served as the only predictor of conversion to MS.

Conclusion

Early conversion to MS after first attack of demyelination is related to detection of signs of neuroinflammation rather than neurodegeneration.

Potential Biomarkers Associated with Multiple Sclerosis Pathology

Multiple sclerosis (MS) is a complex disease of the central nervous system (CNS) that involves an intricate and aberrant interaction of immune cells leading to inflammation, demyelination, and neurodegeneration. Due to the heterogeneity of clinical subtypes, their diagnosis becomes challenging and the best treatment cannot be easily provided to patients. Biomarkers have been used to simplify the diagnosis and prognosis of MS, as well as to evaluate the results of clinical treatments. In recent years, research on biomarkers has advanced rapidly due to their ability to be easily and promptly measured, their specificity, and their reproducibility. Biomarkers are classified into several categories depending on whether they address personal or predictive susceptibility, diagnosis, prognosis, disease activity, or response to treatment in different clinical courses of MS. The identified members indicate a variety of pathological processes of MS, such as neuroaxonal damage, gliosis, demyelination, progression of disability, and remyelination, among others. The present review analyzes biomarkers in cerebrospinal fluid (CSF) and blood serum, the most promising imaging biomarkers used in clinical practice. Furthermore, it aims to shed light on the criteria and challenges that a biomarker must face to be considered as a standard in daily clinical practice.

YKL-40 and neuron-specific enolase in neurodegeneration and neuroinflammation

Neurodegenerative diseases comprise a large number of disorders with high impact on human health. Neurodegenerative processes are caused by various etiological factors and differ in their clinical presentation. Neuroinflammation is widely discussed as both a cause and a consequence in the manifestation of these disorders. The interplay between the two entities is considered as a major contributor to the ongoing disease progression. An attentive search and implementation of new and reliable markers specific for the processes of inflammation and degeneration is still needed. YKL-40 is a secreted glycoprotein produced by activated glial cells during neuroinflammation. Neuron-specific enolase (NSE), expressed mainly by neuronal cells, is a long-standing marker for neuronal damage. The aim of this review is to summarize, clarify, and evaluate the potential significance and relationship between YKL-40 and NSE as biomarkers in the monitoring and prognosis of a set of neurological diseases, such as Alzheimer's disease, Parkinson's disease, Huntington's disease, and multiple sclerosis. YKL-40 appears to be a more reliable biomarker in neurological diseases than NSE. The more prominent expression pattern of YKL-40 could be explained with the more obvious involvement of glial cells in pathological processes accompanying each neurodegenerative disease, whereas reduced NSE levels are likely related to low metabolic activity and increased death of neurons.

Clinical and Paraclinical Biomarkers and the Hitches to Assess Conversion to Secondary Progressive Multiple Sclerosis: A Systematic Review

Conversion to secondary progressive (SP) course is the decisive factor for long-term prognosis in relapsing multiple sclerosis (MS), generally considered the clinical equivalent of progressive MS-associated neuroaxonal degeneration. Evidence is accumulating that both inflammation and neurodegeneration are present along a continuum of pathologic processes in all phases of MS. While inflammation is the prominent feature in early stages, its quality changes and relative importance to disease course decreases while neurodegenerative processes prevail with ongoing disease. Consequently, anti-inflammatory disease-modifying therapies successfully used in relapsing MS are ineffective in SPMS, whereas specific treatment for the latter is increasingly a focus of MS research. Therefore, the prevention, but also the (anticipatory) diagnosis of SPMS, is of crucial importance. The problem is that currently SPMS diagnosis is exclusively based on retrospectively assessing the increase of overt physical disability usually over the past 6–12 months. This inevitably results in a delay of diagnosis of up to 3 years resulting in periods of uncertainty and, thus, making early therapy adaptation to prevent SPMS conversion impossible. Hence, there is an urgent need for reliable and objective biomarkers to prospectively predict and define SPMS conversion. Here, we review current evidence on clinical parameters, magnetic resonance imaging and optical coherence tomography measures, and serum and cerebrospinal fluid biomarkers in the context of MS-associated neurodegeneration and SPMS conversion. Ultimately, we discuss the necessity of multimodal approaches in order to approach objective definition and prediction of conversion to SPMS.

CSF Chitinase 3-Like 2 Is Associated With Long-term Disability Progression in Patients With Progressive Multiple Sclerosis

Objective

This study aimed to identify long-term prognostic protein biomarkers associated with disease progression in patients with progressive multiple sclerosis (MS).

Methods

CSF samples were collected from a discovery cohort of 28 patients with progressive MS who participated in a clinical trial with interferon beta. Patients were classified into high and low disability progression phenotypes according to numeric progression rates (NPR) and step-based progression rates (SPR) after a mean follow-up time of 12 years. Protein abundance was measured by shotgun proteomics. Selected proteins from the discovery cohort were quantified by parallel reaction monitoring in CSF samples from an independent validation cohort of 41 patients with progressive MS classified also into high and low disability progression phenotypes after a mean follow-up time of 7 years.

Results

Of 2,548 CSF proteins identified in the discovery cohort, 10 were selected for validation based on their association with long-term disability progression: SPATS2-like protein, chitinase 3–like 2 (CHI3L2), plasma serine protease inhibitor, metallothionein-3, phospholipase D4, beta-hexosaminidase, neurexophilin-1, adipocyte enhancer-binding protein 1, cathepsin L1, and lipopolysaccharide-binding protein. Only CHI3L2 was validated, and patients with high disability progression exhibited significantly higher CSF protein levels compared with patients with low disability progression (p = 0.03 for NPR and p = 0.02 for SPR). CHI3L2 levels showed good performance to discriminate between high and low disability progression in patients with progressive MS (area under the curve 0.73; sensitivity 90% and specificity 63%).

Conclusions

Although further confirmatory studies are needed, we propose CSF CHI3L2 as a prognostic protein biomarker associated with long-term disability progression in patients with progressive MS.

Classification of Evidence

This study provides Class II evidence that high CSF CHI3L2 levels identified higher disability progression in patients with progressive MS.

The blood biomarkers puzzle - A review of protein biomarkers in neurodegenerative diseases

Neurodegenerative diseases are heterogeneous in their cause and clinical presentation making clinical assessment and disease monitoring challenging. Because of this, there is an urgent need for objective tools such as fluid biomarkers able to quantitate different aspects of the disease. In the last decade, technological improvements and awareness of the importance of biorepositories led to the discovery of an evolving number of fluid biomarkers covering the main characteristics of neurodegenerative diseases such as neurodegeneration, protein aggregates and inflammation. The ability to quantitate each aspect of the disease at a high definition enables a more precise stratification of the patients at inclusion in clinical trials, hence reducing the noise that may hamper the detection of therapeutical efficacy and allowing for smaller but likewise powered studies, which particularly improves the ability to start clinical trials for rare neurological diseases. Moreover, the use of fluid biomarkers has the potential to support a targeted therapeutical intervention, as it is now emerging for the treatment of amyloid-beta deposition in patients suffering from Alzheimer's disease. Here we review the knowledge that evolved from the measurement of fluid biomarker proteins in neurodegenerative conditions.

Oxysterols and multiple sclerosis: Physiopathology, evolutive biomarkers and therapeutic strategy

Multiple sclerosis is an autoimmune disease that affects the central nervous system. Dysfunction of the immune system leads to lesions that cause motor, sensory, cognitive, visual and/or sphincter disturbances. In the long term, these disorders can progress towards an irreversible handicap. The diagnosis takes time because there are no specific criteria to diagnose multiple sclerosis. To realize the diagnosis, a combination of clinical, biological, and radiological arguments is therefore required. Hence, there is a need to identify multiple sclerosis biomarkers. Some biomarkers target immunity through the detection of oligoclonal bands, the measurement of the IgG index and cytokines. During the physiopathological process, the blood-brain barrier can be broken, and this event can be identified by measuring metalloproteinase activity and diffusion of gadolinium in the brain by magnetic resonance imaging. Markers of demyelination and of astrocyte and microglial activity may also be of interest as well as markers of neuronal damage and mitochondrial status. The measurement of different lipids in the plasma and cerebrospinal fluid can also provide suitable information. These different lipids include fatty acids, fatty acid peroxidation products, phospholipids as well as oxidized derivatives of cholesterol (oxysterols). Oxysterols could constitute new biomarkers providing information on the form of multiple sclerosis, the outcome of the disease and the answer to treatment.

Multiple Sclerosis Biomarker Discoveries by Proteomics and Metabolomics Approaches

Multiple sclerosis (MS) is an autoimmune inflammatory disorder of the central nervous system (CNS) resulting in demyelination and axonal loss in the brain and spinal cord. The precise pathogenesis and etiology of this complex disease are still a mystery. Despite many studies that have been aimed to identify biomarkers, no protein marker has yet been approved for MS. There is urgently needed for biomarkers, which could clarify pathology, monitor disease progression, response to treatment, and prognosis in MS. Proteomics and metabolomics analysis are powerful tools to identify putative and novel candidate biomarkers. Different human compartments analysis using proteomics, metabolomics, and bioinformatics approaches has generated new information for further clarification of MS pathology, elucidating the mechanisms of the disease, finding new targets, and monitoring treatment response. Overall, omics approaches can develop different therapeutic and diagnostic aspects of complex disorders such as multiple sclerosis, from biomarker discovery to personalized medicine.

CHI3L2 Is a Novel Prognostic Biomarker and Correlated With Immune Infiltrates in Gliomas

CHI3L2 (Chitinase-3-Like Protein 2) is a member of chitinase-like proteins (CLPs), which belong to the glycoside hydrolase 18 family. Its homologous gene, CHI3L1, has been extensively studied in various tumors and has been shown to be related to immune infiltration in breast cancer and glioblastoma. High CHI3L2 expression was reported to be associated with poor prognosis in breast cancer and renal cell carcinoma. However, the prognostic significance of CHI3L2 in glioma and its correlation between immune infiltration remains unclear. In this study, we examined 288 glioma samples by immunohistochemistry to find that CHI3L2 is expressed in tumor cells and macrophages in glioma tissues and highly expressed in glioblastoma and IDH wild-type gliomas. Relationships between CHI3L2 expression and clinical features (grade, age, Ki67 index, P53, PHH3 (mitotic figures), ATRX, TERTp, MGMTp, IDH, and 1p/19q co-deleted status) were evaluated. Kaplan-Meier survival was conducted to show high CHI3L2 expression in tumor cells (TC) and macrophage cells (MC) indicated poor prognosis in diffusely infiltrating glioma (DIG), lower-grade glioma (LGG), and IDH wild-type gliomas (IDH-wt). The overall survival time was higher in patients with dual-low CHI3L2 expression in TC and MC compared to those in patients with non-dual CHI3L2 expression and dual high expression in DIG and IDH wild-type gliomas. By univariate and multivariate analysis, we found that high CHI3L2 expression in tumor cells was an independent unfavorable prognostic factor in glioma patients. Moreover, we used two datasets (TCGA and CGGA) to verify the results of our study and explore the potential functional role of CHI3L2 by GO and KEGG analyses in gliomas. TIMER platform analysis indicated CHI3L2 expression was closely related to diverse marker genes of tumor immune infiltrating cells, including monocytes, TAMs, M1 macrophages, M2 macrophages, TGFβ1+ Treg and T cell exhaustion in GBM and LGG. Western Blot validated CHI3L2 is expressed in glioma cells and microglia cells. The results of flow cytometry showed that CHI3L2 induces the apoptosis of CD8+ T cells. In conclusion, these results demonstrate CHI3L2 is related to poor prognosis and immune infiltrates in gliomas, suggesting it may serve as a promising prognostic biomarker and represent a new target for glioma patients.

The Evolution of Neurofilament Light Chain in Multiple Sclerosis

Multiple sclerosis (MS) is an autoimmune, inflammatory neurodegenerative disease of the central nervous system characterized by demyelination and axonal damage. Diagnosis and prognosis are mainly assessed through clinical examination and neuroimaging. However, more sensitive biomarkers are needed to measure disease activity and guide treatment decisions in MS. Prompt and individualized management can reduce inflammatory activity and delay disease progression. Neurofilament Light chain (NfL), a neuron-specific cytoskeletal protein that is released into the extracellular fluid following axonal injury, has been identified as a biomarker of disease activity in MS. Measurement of NfL levels can capture the extent of neuroaxonal damage, especially in early stages of the disease. A growing body of evidence has shown that NfL in cerebrospinal fluid (CSF) and serum can be used as reliable indicators of prognosis and treatment response. More recently, NfL has been shown to facilitate individualized treatment decisions for individuals with MS. In this review, we discuss the characteristics that make NfL a highly informative biomarker and depict the available technologies used for its measurement. We further discuss the growing role of serum and CSF NfL in MS research and clinical settings. Finally, we address some of the current topics of debate regarding the use of NfL in clinical practice and examine the possible directions that this biomarker may take in the future.

Identifying cellular signalling molecules in developmental disorders of the brain: Evidence from focal cortical dysplasia and tuberous sclerosis

AIMS

We understand little of the pathogenesis of developmental cortical lesions, because we understand little of the diversity of the cell types that contribute to the diseases or how those cells interact. We tested the hypothesis that cellular diversity and cell-cell interactions play an important role in these disorders by investigating the signalling molecules in the commonest cortical malformations that lead to childhood epilepsy, focal cortical dysplasia (FCD) and tuberous sclerosis (TS).

METHODS

Transcriptional profiling clustered cases into molecularly distinct groups. Using gene expression data, we identified the secretory signalling molecules in FCD/TS and characterised the cell types expressing these molecules. We developed a functional model using organotypic cultures.

RESULTS

We identified 113 up-regulated secretory molecules in FCDIIB/TS. The top 12 differentially expressed genes (DEGs) were validated by immunohistochemistry. This highlighted two molecules, Chitinase 3-like protein 1 (CHI3L1) and C-C motif chemokine ligand 2 (CCL2) (MCP1) that were expressed in a unique population of small cells in close proximity to balloon cells (BC). We then characterised these cells and developed a functional model in organotypic slice cultures. We found that the number of CHI3L1 and CCL2 expressing cells decreased following inhibition of mTOR, the main aberrant signalling pathway in TS and FCD.

CONCLUSIONS

Our findings highlight previously uncharacterised small cell populations in FCD and TS which express specific signalling molecules. These findings indicate a new level of diversity and cellular interactions in cortical malformations and provide a generalisable approach to understanding cell-cell interactions and cellular heterogeneity in developmental neuropathology.

Clinically isolated syndrome: diagnosis and risk of developing clinically definite multiple sclerosis

INTRODUCTION

In most cases, multiple sclerosis (MS) initially presents as clinically isolated syndrome (CIS). Differentiating CIS from other acute or subacute neurological diseases and estimating the risk of progression to clinically definite MS is essential since presenting a second episode in a short time is associated with poorer long-term prognosis.

DEVELOPMENT

We conducted a literature review to evaluate the usefulness of different variables in improving diagnostic accuracy and predicting progression from CIS to MS, including magnetic resonance imaging (MRI) and such biofluid markers as oligoclonal IgG and IgM bands, lipid-specific oligoclonal IgM bands in the CSF, CSF kappa free light-chain (KFLC) index, neurofilament light chain (NfL) in the CSF and serum, and chitinase 3-like protein 1 (CHI3L1) in the CSF and serum.

CONCLUSIONS

Codetection of oligoclonal IgG bands and MRI lesions reduces diagnostic delays and suggests a high risk of CIS progression to MS. A KFLC index > 10.6 and CSF NfL concentrations > 1150 ng/L indicate that CIS is more likely to progress to MS within one year (40-50%); 90% of patients with CIS and serum CHI3L1 levels > 33 ng/mL and 100% of those with lipid-specific oligoclonal IgM bands present MS within one year of CIS onset.

Recent advances and remaining questions of autologous hematopoietic stem cell transplantation in multiple sclerosis

The judicious use of autologous hematopoietic stem cell transplantation (AHSCT) for MS requires understanding the potential benefits, identifying the most appropriate patient, and acknowledging the risks and differences between different protocols. Recently, AHSCT for MS is occurring more frequently, with a better safety profile than earlier studies. This review assesses recently published studies to determine the advances that have been made and remaining questions that future studies are poised to answer. We included studies from January 2016 to November 2020 with 20 or more patients. The benefits of AHSCT, including "no evidence of disease activity", functional and patient-reported outcomes, novel biomarkers such as brain atrophy or neurofilament light chain, and cost-effectiveness were assessed. The patient selection, treatment protocols, and safety outcomes differ between reports. The overall efficacy of AHSCT is better than standard treatments. Younger patients with highly active disease have greater chance for improvement, while patients who have comorbidities, failed more treatments, and are transitioning to a more progressive phase may not respond as well to AHSCT. The safety profiles for all AHSCT protocols is improving, however the durability of treatment response may not be the same for all protocols. The goal of AHSCT is to stop disease activity, avoid worsening disability, and obviate the need for further disease-modifying treatment, while improving patient quality of life and minimizing treatment-related risk. Results from currently enrolling randomized controlled trials, as well as ongoing registries, will provide more evidence for the safe and appropriate use of AHSCT.

Cognitive impairment in multiple sclerosis: lessons from cerebrospinal fluid biomarkers

Cognitive impairment is a common clinical manifestation of multiple sclerosis, but its pathophysiology is not completely understood. White and grey matter injury together with synaptic dysfunction do play a role. The measurement of biomarkers in the cerebrospinal fluid and the study of their association with cognitive impairment may provide interesting in vivo evidence of the biological mechanisms underlying multiple sclerosis-related cognitive impairment. So far, only a few studies on this topic have been published, giving interesting results that deserve further investigation. Cerebrospinal fluid biomarkers of different pathophysiological mechanisms seem to reflect different neuropsychological patterns of cognitive deficits in multiple sclerosis. The aim of this review is to discuss the studies that have correlated cerebrospinal fluid markers of immune, glial and neuronal pathology with cognitive impairment in multiple sclerosis. Although preliminary, these findings suggest that cerebrospinal fluid biomarkers show some correlation with cognitive performance in multiple sclerosis, thus providing interesting insights into the mechanisms underlying the involvement of specific cognitive domains.

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.

Development of robust targeted proteomics assays for cerebrospinal fluid biomarkers in multiple sclerosis

Background

Verification of cerebrospinal fluid (CSF) biomarkers for multiple sclerosis and other neurological diseases is a major challenge due to a large number of candidates, limited sample material availability, disease and biological heterogeneity, and the lack of standardized assays. Furthermore, verification studies are often based on a low number of proteins from a single discovery experiment in medium-sized cohorts, where antibodies and surrogate peptides may differ, thus only providing an indication of proteins affected by the disease and not revealing the bigger picture or concluding on the validity of the markers. We here present a standard approach for locating promising biomarker candidates based on existing knowledge, resulting in high-quality assays covering the main biological processes affected by multiple sclerosis for comparable measurements over time.

Methods

Biomarker candidates were located in CSF-PR (proteomics.uib.no/csf-pr), and further filtered based on estimated concentration in CSF and biological function. Peptide surrogates for internal standards were selected according to relevant criteria, parallel reaction monitoring (PRM) assays created, and extensive assay quality testing performed, i.e. intra- and inter-day variation, trypsin digestion status over time, and whether the peptides were able to separate multiple sclerosis patients and controls.

Results

Assays were developed for 25 proteins, represented by 72 peptides selected according to relevant guidelines and available literature and tested for assay peptide suitability. Stability testing revealed 64 peptides with low intra- and inter-day variations, with 44 also being stably digested after 16 h of trypsin digestion, and 37 furthermore showing a significant difference between multiple sclerosis and controls, thereby confirming literature findings. Calibration curves and the linear area of measurement have, so far, been determined for 17 of these peptides.

Conclusions

We present 37 high-quality PRM assays across 21 CSF-proteins found to be affected by multiple sclerosis, along with a recommended workflow for future development of new assays. The assays can directly be used by others, thus enabling better comparison between studies. Finally, the assays can robustly and stably monitor biological processes in multiple sclerosis patients over time, thus potentially aiding in diagnosis and prognosis, and ultimately in treatment decisions.

A Score Based on NfL and Glial Markers May Differentiate Between Relapsing-Remitting and Progressive MS Course

Background: The diagnostic use of biomarkers in body fluids of multiple sclerosis (MS) patients allows the monitoring of different pathophysiological aspects of the disease. We previously reported elevated cerebrospinal fluid (CSF) and serum levels of glial fibrillary acidic protein (GFAP) but not neurofilament light chain (NfL) in progressive (PMS) compared to relapsing–remitting MS (RRMS) patients.

Objectives: We analyzed the glial marker chitinase-3-like protein 1 (CHI3L1) in the CSF and serum of PMS and RRMS patients. To capture the extent of glial processes in relation to axonal damage in each individual patient, we established a score based on CHI3L1, GFAP, and NfL and compared this score between RRMS and PMS patients and its association with the extended disability status scale (EDSS).

Methods: For this retrospective study, we included 86 MS patients (47 RRMS and 39 PMS) and 20 patients with other non-inflammatory neurological diseases (OND) as controls. NfL and GFAP levels were determined by the single-molecule array (Simoa). CHI3L1 levels were measured with classical enzyme-linked immunosorbent assay. A score was calculated based on glial to axonal markers (CHI3L1^*GFAP/NfL, referred to as “Glia score”).

Results: CHI3L1 showed higher CSF levels in PMS vs. RRMS and controls (p < 0.001 and p < 0.0001, respectively), RMS vs. controls (p < 0.01), and higher serum levels for PMS vs. RRMS (p < 0.05). The Glia score was higher in the CSF of PMS compared to RRMS patients (p < 0.0001) and in the serum of PMS patients compared to RRMS (p < 0.01). Furthermore, the Glia score and CHI3L1 in serum but not in CSF correlated with the disability as determined by EDSS in the PMS group but not in the RRMS group (Spearman ρ = 0.46 and 0.45, p = 0.003 and 0.004, respectively).

Discussion: Our data indicate the involvement of glial mechanisms during the pathogenesis of PMS. Moreover, a calculated score may help to differentiate between PMS and RMS in the CSF and monitor disease progression in the serum of PMS patients.

Early Diagnosis of Multiple Sclerosis Based on Optical and Electrochemical Biosensors: Comprehensive Perspective

Background:

Multiple Sclerosis (MS) involves an immune-mediated response in which body’s immune system destructs the protective sheath (myelin). Part of the known MS biomarkers are discovered in cerebrospinal fluid like oligoclonal lgG (OCGB), and also in blood like myelin Oligodendrocyte Glycoprotein (MOG). The conventional MS diagnostic methods often fail to detect the disease in early stages such as Clinically Isolated Syndrome (CIS), which considered as a concerning issue since CIS highlighted as a prognostic factor of MS development in most cases.

Methods:

MS diagnostic techniques include Magnetic Resonance Imaging (MRI) of the brain and spinal cord, lumbar puncture (or spinal tap) that evaluate cerebrospinal fluid, evoked potential testing revealing abnormalities in the brain and spinal cord. These conventional diagnostic methods have some negative points such as extensive processing time as well as restriction in the quantity of samples that can be analyzed concurrently. Scientists have focused on developing the detection methods especially early detection which belongs to ultra-sensitive, non-invasive and needed for the Point of Care (POC) diagnosis because the situation was complicated by false positive or negative results.

Results:

As a result, biosensors are utilized and investigated since they could be ultra-sensitive to specific compounds, cost effective devices, body-friendly and easy to implement. In addition, it has been proved that the biosensors on physiological fluids (blood, serum, urine, saliva, milk etc.) have quick response in a non-invasive rout. In general form, a biosensor system for diagnosis and early detection process usually involves; biomarker (target molecule), bio receptor (recognition element) and compatible bio transducer.

Conclusion:

Studies underlined that early treatment of patients with high possibility of MS can be advantageous by postponing further abnormalities on MRI and subsequent attacks.

:

This Review highlights variable disease diagnosis approaches such as Surface Plasmon Resonance (SPR), electrochemical biosensors, Microarrays and microbeads based Microarrays, which are considered as promising methods for detection and early detection of MS.

CSF chitinase 3-like-1 association with disability of primary progressive MS

Objective

To assess the role of CSF chitinase 3-like-1 (CHI3L1), chitinase 3-like-2 (CHI3L2), and neurofilament light chain (NfL) in predicting the course of primary progressive MS (PPMS).

Methods

We analyzed CSF CHI3L1, CHI3L2, and NfL levels in 25 patients with PPMS with disease duration ≤10 years and no disease-modifying therapy for ≥6 months from the prospective Understanding Primary Progressive Multiple Sclerosis cohort study. CSF samples taken at disease diagnosis were analyzed using commercial ELISAs and following the manufacturer's instructions. Data on Expanded Disability Status Scale (EDSS) scores, disability progression, and cognitive function according to the Brief Repeatable Neuropsychological Battery were also assessed throughout the 1-year study follow-up.

Results

Increasing CHI3L1 levels correlated with higher EDSS scores at baseline (ρ = 0.490, 95% CI 0.118–0.742, p = 0.013) and month 12 (ρ = 0.455, 95% CI 0.063–0.725, p = 0.026) and tended to be associated with a higher risk of disability progression according to EDSS scores (OR = 1.008, 95% CI 0.999–1.017, p = 0.089). Increasing CHI3L2 levels also tended to correlate with lower baseline EDSS scores (ρ = −0.366, 95% CI -0.676–0.054, p = 0.086). There was no correlation with regard to NfL levels.

Conclusions

This analysis supports the association between CSF CHI3L1 levels and neurologic disability according to EDSS scores in patients with PPMS. Other chitinase-like proteins such as CHI3L2 may also be involved.

Classification of evidence

This study provides Class II evidence that CSF CHI3L1 is associated with neurologic disability in patients with PPMS.

What do we currently know about the clinically isolated syndrome suggestive of multiple sclerosis? An update

Multiple sclerosis (MS) is a chronic, demyelinating, not fully understood disease of the central nervous system. The first demyelinating clinical episode is called clinically isolated syndrome (CIS) suggestive of MS. Although the most common manifestations of CIS are long tracts dysfunction and unilateral optic neuritis, it can also include isolated brainstem syndromes, cerebellar involvement, and polysymptomatic clinical image. Recently, the frequency of CIS diagnosis has decreased due to the more sensitive and less specific 2017 McDonald criteria compared with the revisions from 2010. Not all patients with CIS develop MS. The risk of conversion can be estimated based on many predictive factors including epidemiological, ethnical, clinical, biochemical, radiological, immunogenetic, and other markers. The management of CIS is nowadays widely discussed among clinicians and neuroscientists. To date, interferons, glatiramer acetate, teriflunomide, cladribine, and some other agents have been evaluated in randomized, placebo-controlled, double-blind studies relying on large groups of patients with the first demyelinating event. All of these drugs were shown to have beneficial effects in patients with CIS and might be used routinely in the future. The goal of this article is to explore the most relevant topics regarding CIS as well as to provide the most recent information in the field. The review presents CIS definition, classification, clinical image, predictive factors, and management. What is more, this is one of very few reviews summarizing the topic in the light of the 2017 McDonald criteria.

Immune and central nervous system-related miRNAs expression profiling in monocytes of multiple sclerosis patients

It is widely recognized that monocytes-macrophages adopt a wide variety of phenotypes, influencing the inflammatory activity and demyelination in Multiple Sclerosis (MS). However, how the phenotype of human monocytes evolves in the course of MS is largely unknown. The aim of our preliminary study was to analyse in monocytes of relapsing-remitting and progressive forms of MS patients the expression of a set of miRNAs which impact monocyte-macrophage immune function and their communication with brain cells. Quantitative PCR showed that miRNAs with anti-inflammatory functions, which promote pro-regenerative polarization, are increased in MS patients, while pro-inflammatory miR-155 is downregulated in the same patients. These changes may indicate the attempt of monocytes to counteract neuroinflammation. miR-124, an anti-inflammatory marker but also of myeloid cell quiescence was strongly downregulated, especially in progressive MS patients, suggesting complete loss of homeostatic monocyte function in the progressive disease phase. Profiling of miRNAs that control monocyte polarization may help to define not only the activation state of monocytes in the course of the disease but also novel pathogenic mechanisms.

Cross-sectional and longitudinal measures of chitinase proteins in amyotrophic lateral sclerosis and expression of CHI3L1 in activated astrocytes

OBJECTIVE

Amyotrophic lateral sclerosis (ALS) is a complex disease with numerous pathological mechanisms resulting in a heterogeneous patient population. Using biomarkers for particular disease mechanisms may enrich a homogeneous subset of patients. In this study, we quantified chitotriosidase (Chit-1) and chitinase-3-like protein 1 (CHI3L1), markers of glial activation, in cerebrospinal fluid (CSF) and plasma and determined the cell types that express CHI3L1 in ALS.

METHODS

Immunoassays were used to quantify Chit-1, CHI3L1 and phosphorylated neurofilament heavy chain levels in longitudinal CSF and matching plasma samples from 118 patients with ALS, 17 disease controls (DCs), and 24 healthy controls (HCs). Immunostaining was performed to identify and quantify CHI3L1-positive cells in tissue sections from ALS, DCs and non-neurological DCs.

RESULTS

CSF Chit-1 exhibited increased levels in ALS as compared with DCs and HCs. CSF CHI3L1 levels were increased in ALS and DCs compared with HCs. No quantitative differences were noted in plasma for either chitinase. Patients with ALS with fast-progressing disease exhibited higher levels of CSF Chit-1 and CHI3L1 than patients with slow-progressing disease. Increased numbers of CHI3L1-positive cells were observed in postmortem ALS motor cortex as compared with controls, and these cells were identified as a subset of activated astrocytes located predominately in the white matter of the motor cortex and the spinal cord.

CONCLUSIONS

CSF Chit-1 and CHI3L1 are significantly increased in ALS, and CSF Chit-1 and CHI3L1 levels correlate to the rate of disease progression. CHI3L1 is expressed by a subset of activated astrocytes predominately located in white matter.

YKL-39 as a Potential New Target for Anti-Angiogenic Therapy in Cancer

YKL-39 belongs to the evolutionarily conserved family of Glyco_18-containing proteins composed of chitinases and chitinase-like proteins. Chitinase-like proteins (CLPs) are secreted lectins that lack hydrolytic activity due to the amino acid substitutions in their catalytic domain and combine the functions of cytokines and growth factors. One of the major cellular sources that produce CLPs in various pathologies, including cancer, are macrophages. Monocytes recruited to the tumor site and programmed by tumor cells differentiate into tumor-associated macrophages (TAMs), which are the primary source of pro-angiogenic factors. Tumor angiogenesis is a crucial process for supplying rapidly growing tumors with essential nutrients and oxygen. We recently determined that YKL-39 is produced by tumor-associated macrophages in breast cancer. YKL-39 acts as a strong chemotactic factor for monocytes and stimulates angiogenesis. Chemotherapy is a common strategy to reduce tumor size and aggressiveness before surgical intervention, but chemoresistance, resulting in the relapse of tumors, is a common clinical problem that is critical for survival in cancer patients. Accumulating evidence indicates that TAMs are essential regulators of chemoresistance. We have recently found that elevated levels of YKL-39 expression are indicative of the efficiency of the metastatic process in patients who undergo neoadjuvant chemotherapy. We suggest YKL-39 as a new target for anti-angiogenic therapy that can be combined with neoadjuvant chemotherapy to reduce chemoresistance and inhibit metastasis in breast cancer patients.

Molecular biomarkers in multiple sclerosis

Multiple sclerosis (MS) is an inflammatory-neurodegenerative disease of the central nervous system presenting with significant inter- and intraindividual heterogeneity. However, the application of clinical and imaging biomarkers is currently not able to allow individual characterization and prediction. Complementary, molecular biomarkers which are easily quantifiable come from the areas of immunology and neurobiology due to the causal pathomechanisms and can excellently complement other disease characteristics. Only a few molecular biomarkers have so far been routinely used in clinical practice as their validation and transfer take a long time. This review describes the characteristics that an ideal MS biomarker should have and the challenges of establishing new biomarkers. In addition, clinically relevant and promising biomarkers from the blood and cerebrospinal fluid are presented which are useful for MS diagnosis and prognosis as well as for the assessment of therapy response and side effects.

Diagnosis and management of secondary-progressive multiple sclerosis: time for change

Identifying the transition of relapsing-remitting multiple sclerosis (MS) to the secondary-progressive MS form remains a clinical challenge due to the gradual nature of the transition, superimposed relapses, the heterogeneous course of disease among patients and the absence of validated biomarkers and diagnostic tools. The uncertainty associated with the transition makes clinical care challenging for both patients and physicians. The emergence of new disease-modifying treatments for progressive MS and the increasing emphasis of nonpharmacological strategies mark a new era in the treatment of progressive MS. This article summarizes challenges in diagnosis and management, discusses novel treatment strategies and highlights the importance of establishing a clear diagnosis and instituting an interdisciplinary management plan in the care of patients with progressive MS.

CSF chitinase proteins in amyotrophic lateral sclerosis

OBJECTIVE

To evaluate the classifier performance, clinical and biochemical correlations of cerebrospinal fluid (CSF) levels of the chitinase proteins Chitotriosidase-1 (CHIT1), Chitinase-3-like protein 1 (CHI3L1) and Chitinase-3-like protein 2 (CHI3L2) in amyotrophic lateral sclerosis (ALS).

METHODS

CSF levels of CHIT1, CHI3L1, CHI3L2, phosphorylated neurofilament heavy chain (pNFH) and C-reactive protein were measured by ELISA in a longitudinal cohort of patients with ALS (n=82), primary lateral sclerosis (PLS, n=10), ALS-mimic conditions (n=12), healthy controls (n=25) and asymptomatic carriers of ALS-causing genetic mutations (AGC; n=5).

RESULTS

CSF CHIT1, CHI3L1 and CHI3L2 were elevated in patients with ALS compared with healthy controls (p<0.001) and ALS-mimics (CHIT1, p<0.001; CHI3L1, p=0.017; CHI3L2, p<0.001). CHIT1 and CHI3L2 were elevated in ALS compared with PLS (CHIT1, p=0.021; CHI3L1, p=0.417; CHI3L2, p<0.001). Chitinase levels were similar in AGCs and healthy controls. Chitinase proteins distinguished ALS from healthy controls (area under the curve (AUC): CHIT1 0.92; CHI3L1 0.80; CHI3L2 0.90), mimics (AUC: CHIT1 0.84; CHI3L1 0.73; CHI3L2 0.88) and, to a lesser extent, PLS (AUC: CHIT 0.73; CHI3L1 0.51; CHI3L2 0.82) but did not outperform pNFH. CHIT1 and CHI3L2 correlated with disease progression rate (Pearson's r=0.49, p<0.001; r=0.42, p<0.001, respectively). CHI3L1 correlated with degree of cognitive dysfunction (r=-0.25, p=0.038). All chitinases correlated with pNFH. CHIT1 levels were associated with survival in multivariate models. Chitinase levels were longitudinally stable.

CONCLUSIONS

CSF chitinase proteins may have limited value as independent diagnostic and stratification biomarkers in ALS, but offer a window into non-autonomous mechanisms of motor neuronal loss in ALS, specifically in assessing response to therapies targeting neuroinflammatory pathways.

Multiple sclerosis has a distinct lipid signature in plasma and cerebrospinal fluid

ABSTRACT The diagnosis of multiple sclerosis (MS) has changed over the last decade, but remains a composite of clinical assessment and magnetic resonance imaging to prove dissemination of lesions in time and space. The intrathecal synthesis of immunoglobulin may be a nonspecific marker and there are no plasma biomarkers that are useful in the diagnosis of MS, presenting additional challenges to their early detection. Methods We performed a preliminary untargeted qualitative lipidomics mass spectrometry analysis, comparing cerebrospinal fluid (CSF) and plasma samples from patients with MS, other inflammatory neurological diseases and idiopathic intracranial hypertension. Results Lipid identification revealed that fatty acids and sphingolipids were the most abundant classes of lipids in the CSF and that glycerolipids and fatty acids were the main class of lipids in the plasma of patients with MS. The area under the curve was 0.995 (0.912–1) and 0.78 (0.583–0.917), respectively. The permutation test indicated that this ion combination was useful for distinguishing MS from other inflammatory diseases (p < 0.001 and 0.055, respectively). Conclusion This study concluded that the CSF and plasma from patients with MS bear a unique lipid signature that can be useful as a diagnostic biomarker.

GFAP Mutations in Astrocytes Impair Oligodendrocyte Progenitor Proliferation and Myelination in an hiPSC Model of Alexander Disease

Alexander disease (AxD) is a leukodystrophy that primarily affects astrocytes and is caused by mutations in the astrocytic filament gene GFAP. While astrocytes are thought to have important roles in controlling myelination, AxD animal models do not recapitulate critical myelination phenotypes and it is therefore not clear how AxD astrocytes contribute to leukodystrophy. Here, we show that AxD patient iPSC-derived astrocytes recapitulate key features of AxD pathology such as GFAP aggregation. Moreover, AxD astrocytes inhibit proliferation of human iPSC-derived oligodendrocyte progenitor cells (OPCs) in co-culture and reduce their myelination potential. CRISPR/Cas9-based correction of GFAP mutations reversed these phenotypes. Transcriptomic analyses of AxD astrocytes and postmortem brains identified CHI3L1 as a key mediator of AxD astrocyte-induced inhibition of OPC activity. Thus, this iPSC-based model of AxD not only recapitulates patient phenotypes not observed in animal models, but also reveals mechanisms underlying disease pathology and provides a platform for assessing therapeutic interventions.

Combined Cerebrospinal Fluid Neurofilament Light Chain Protein and Chitinase-3 Like-1 Levels in Defining Disease Course and Prognosis in Multiple Sclerosis

Background: Neurofilament light chain protein (NFL) and chitinase3-like1 (CHI3L1) have gained importance recently as prognostic biomarkers in multiple sclerosis (MS). Objectives: We aimed to investigate NFL and CHI3L1 cerebrospinal fluid (CSF) profiles in multiple sclerosis and the informative and prognostic potential of the individual and combined measures. Methods: CSF NFL and CHI3L1 levels were measured in a cross-sectional cohort of 157 MS patients [99 relapsing-remitting (RRMS), 35 secondary progressive (SPMS), and 23 primary progressive (PPMS)]. Clinical relapse and/or gadolinium-enhanced lesions (GEL) in MRI within 90 days from CSF collection by lumbar puncture (LP) were registered and considered as indicators of disease activity. Longitudinal treatment and disability data were evaluated during medical visits with a median follow-up of 50 months. Results: CSF levels of NFL and CHI3L1 were higher in MS patients compared to non-MS controls. In RRMS and SPMS patients, increased NFL levels were associated with clinical relapse, and gadolinium-enhanced lesions in MRI (p < 0.001), while high CHI3L1 levels were characteristic of progressive disease (p = 0.01). In RRMS patients, CSF NFL, and CHI3L1 levels correlated with each other (r = 0.58), and with IgM-oligoclonal bands (p = 0.02 and p = 0.004, respectively). In addition, CSF CHI3L1 concentration was a predictor for 1-point EDSS worsening {HR = 2.99 [95% CI (1.27, 7.07)]} and progression during follow-up {HR = 18 [95% CI (2.31, 141.3)]}. The pattern of combined measure of biomarkers was useful to discriminate MS phenotypes and to anticipate clinical progression: RRMS more frequently presented high NFL combined with low CHI3L1 levels, compared to SPMS (HR 0.41 [0.18-0.82]), and PPMS (HR 0.46 [0.19-0.87]), while elevation of both biomarkers preceded diagnosis of clinical progression in RRMS patients (log rank = 0.02). Conclusions: Individual measures of CSF NFL and CHI3L1 are biomarkers of disease activity and progression, respectively. The pattern of combined measure discriminates MS phenotypes. It also predicts the subset of RRMS patients that will progress clinically allowing early intervention.

MRI features associated with high likelihood of conversion of radiologically isolated syndrome to multiple sclerosis

Radiologically isolated syndrome (RIS) is the asymptomatic precursor to clinically isolated syndrome, relapsing-remitting multiple sclerosis (MS) or primary progressive MS. RIS is frequently diagnosed when an individual gets an MRI for an unrelated medical issue, such as headache or trauma. Treating RIS patients is controversial, but physicians may be inclined to offer prophylactic treatment for high-risk RIS patients. Identifying imaging and clinical features associated with high likelihood of early clinical conversion may prove helpful to identify a high-risk subset for potential MS therapy. The goal of this paper is to review current literatures to identify imaging and clinical features that predict early (within 5 years) conversion from RIS to MS.

Proteomic Approaches to Decipher Mechanisms Underlying Pathogenesis in Multiple Sclerosis Patients

Multiple sclerosis (MS) is a chronic inflammatory demyelinating and neurodegenerative disease of the central nervous system (CNS). The cause of MS is unknown, with no effective therapies available to halt the progressive neurological disability. Development of new and improvement of existing therapeutic strategies therefore require a better understanding of MS pathogenesis, especially during the progressive phase of the disease. This can be achieved through development of biomarkers that can help to identify disease pathophysiology and monitor disease progression. Proteomics is a powerful and promising tool to accelerate biomarker detection and contribute to novel therapeutics. In this review, an overview of how proteomic technology using CNS tissues and biofluids from MS patients has provided important clues to the pathogenesis of MS is provided. Current publications, pitfalls, as well as directions of future research involving proteomic approaches to understand the pathogenesis of MS are discussed.

Roles of chitinase 3-like 1 in the development of cancer, neurodegenerative diseases, and inflammatory diseases

Chitinase 3-like 1 (CHI3L1) is a secreted glycoprotein that mediates inflammation, macrophage polarization, apoptosis, and carcinogenesis. The expression of CHI3L1 is strongly increased by various inflammatory and immunological conditions, including rheumatoid arthritis, multiple sclerosis, Alzheimer's disease, and several cancers. However, its physiological and pathophysiological roles in the development of cancer and neurodegenerative and inflammatory diseases remain unclear. Several studies have reported that CHI3L1 promotes cancer proliferation, inflammatory cytokine production, and microglial activation, and that multiple receptors, such as advanced glycation end product, syndecan-1/αVβ3, and IL-13Rα2, are involved. In addition, the pro-inflammatory action of CHI3L1 may be mediated via the protein kinase B and phosphoinositide-3 signaling pathways and responses to various pro-inflammatory cytokines, including tumor necrosis factor-α, interleukin-1β, interleukin-6, and interferon-γ. Therefore, CHI3L1 could contribute to a vast array of inflammatory diseases. In this article, we review recent findings regarding the roles of CHI3L1 and suggest therapeutic approaches targeting CHI3L1 in the development of cancers, neurodegenerative diseases, and inflammatory diseases.

Intrathecal B-cell accumulation and axonal damage distinguish MRI-based benign from aggressive onset in MS

Objective

We explored the incremental value of adding multiple disease activity biomarkers in CSF and serum for distinguishing MRI-based benign from aggressive MS in early disease course.

Methods

Ninety-three patients diagnosed with clinically isolated syndrome (CIS) or early MS were divided into 3 nonoverlapping severity groups defined by objective MRI criteria. Ninety-seven patients with noninflammatory neurologic disorders and 48 patients with other inflammatory neurologic diseases served as controls. Leukocyte subsets in the CSF were analyzed by flow cytometry. CSF neurofilament light chain (NfL) and chitinase-3-like protein 1 (CHI3L1) levels were measured by ELISA. Serum NfL levels were examined using single molecule array technology.

Results

CSF CD20+/CD14+ ratios and NfL levels in CSF and serum were significantly different between high and low MRI severity groups, whereas no difference was found for CSF CHI3L1 levels. NfL levels in CSF and serum highly correlated. Receiver operating characteristic analysis demonstrated that the cumulative sums combining CSF CD20+/CD14+ ratios and NfL levels in serum or CSF considerably improved diagnostic accuracy. A composite score built from these 2 cumulative sums best distinguished MRI severity. These findings were validated by support vector machine analysis, which confirmed that the accuracy of the cumulative sums and composite score outperforms single biomarkers.

Conclusion

Patients with extreme manifestations of CIS or early MS defined by strict MRI parameters can be best distinguished by combining markers of intrathecal B-cell accumulation and axonal damage. This could stratify individual treatment decisions toward a more personalized immunotherapy.

Neurofilament light chain and oligoclonal bands are prognostic biomarkers in radiologically isolated syndrome

The prognostic role of cerebrospinal fluid molecular biomarkers determined in early pathogenic stages of multiple sclerosis has yet to be defined. In the present study, we aimed to investigate the prognostic value of chitinase 3 like 1 (CHI3L1), neurofilament light chain, and oligoclonal bands for conversion to clinically isolated syndrome and to multiple sclerosis in 75 patients with radiologically isolated syndrome. Cerebrospinal fluid levels of CHI3L1 and neurofilament light chain were measured by enzyme-linked immunosorbent assay. Uni- and multivariable Cox regression models including as covariates age at diagnosis of radiologically isolated syndrome, number of brain lesions, sex and treatment were used to investigate associations between cerebrospinal fluid CHI3L1 and neurofilament light chain levels and time to conversion to clinically isolated syndrome and multiple sclerosis. Neurofilament light chain levels and oligoclonal bands were independent risk factors for the development of clinically isolated syndrome (hazard ratio = 1.02, P = 0.019, and hazard ratio = 14.7, P = 0.012, respectively) and multiple sclerosis (hazard ratio = 1.03, P = 0.003, and hazard ratio = 8.9, P = 0.046, respectively). The best cut-off to classify cerebrospinal fluid neurofilament light chain levels into high and low was 619 ng/l, and high neurofilament light chain levels were associated with a trend to shorter time to clinically isolated syndrome (P = 0.079) and significant shorter time to multiple sclerosis (P = 0.017). Similarly, patients with radiologically isolated syndrome presenting positive oligoclonal bands converted faster to clinically isolated syndrome and multiple sclerosis (P = 0.005 and P = 0.008, respectively). The effects of high neurofilament light chain levels shortening time to clinically isolated syndrome and multiple sclerosis were more pronounced in radiologically isolated syndrome patients with ≥37 years compared to younger patients. Cerebrospinal fluid CHI3L1 levels did not influence conversion to clinically isolated syndrome and multiple sclerosis in radiologically isolated syndrome patients. Overall, these findings suggest that cerebrospinal neurofilament light chain levels and oligoclonal bands are independent predictors of clinical conversion in patients with radiologically isolated syndrome. The association with a faster development of multiple sclerosis reinforces the importance of cerebrospinal fluid analysis in patients with radiologically isolated syndrome.

Cell-free mitochondrial DNA in progressive multiple sclerosis

Recent studies have linked cell-free mitochondrial DNA (ccf-mtDNA) to neurodegeneration in both Alzheimer's and Parkinson's disease, raising the possibility that the same phenomenon could be seen in other diseases which manifest a neurodegenerative component. Here, we assessed the role of circulating cell-free mitochondrial DNA (ccf-mtDNA) in end-stage progressive multiple sclerosis (PMS), where neurodegeneration is evident, contrasting both ventricular cerebral spinal fluid ccf-mtDNA abundance and integrity between PMS cases and controls, and correlating ccf-mtDNA levels to known protein markers of neurodegeneration and PMS. Our data indicate that reduced ccf-mtDNA is a component of PMS, concluding that it may indeed be a hallmark of broader neurodegeneration.

Unique RNA signature of different lesion types in the brain white matter in progressive multiple sclerosis

The heterogeneity of multiple sclerosis is reflected by dynamic changes of different lesion types in the brain white matter (WM). To identify potential drivers of this process, we RNA-sequenced 73 WM areas from patients with progressive MS (PMS) and 25 control WM. Lesion endophenotypes were described by a computational systems medicine analysis combined with RNAscope, immunohistochemistry, and immunofluorescence. The signature of the normal-appearing WM (NAWM) was more similar to control WM than to lesions: one of the six upregulated genes in NAWM was CD26/DPP4 expressed by microglia. Chronic active lesions that become prominent in PMS had a signature that were different from all other lesion types, and were differentiated from them by two clusters of 62 differentially expressed genes (DEGs). An upcoming MS biomarker, CHI3L1 was among the top ten upregulated genes in chronic active lesions expressed by astrocytes in the rim. TGFβ-R2 was the central hub in a remyelination-related protein interaction network, and was expressed there by astrocytes. We used de novo networks enriched by unique DEGs to determine lesion-specific pathway regulation, i.e. cellular trafficking and activation in active lesions; healing and immune responses in remyelinating lesions characterized by the most heterogeneous immunoglobulin gene expression; coagulation and ion balance in inactive lesions; and metabolic changes in chronic active lesions. Because we found inverse differential regulation of particular genes among different lesion types, our data emphasize that omics related to MS lesions should be interpreted in the context of lesion pathology. Our data indicate that the impact of molecular pathways is substantially changing as different lesions develop. This was also reflected by the high number of unique DEGs that were more common than shared signatures. A special microglia subset characterized by CD26 may play a role in early lesion development, while astrocyte-derived TGFβ-R2 and TGFβ pathways may be drivers of repair in contrast to chronic tissue damage. The highly specific mechanistic signature of chronic active lesions indicates that as these lesions develop in PMS, the molecular changes are substantially skewed: the unique mitochondrial/metabolic changes and specific downregulation of molecules involved in tissue repair may reflect a stage of exhaustion.

Glial Activation Markers in CSF and Serum From Patients With Primary Progressive Multiple Sclerosis: Potential of Serum GFAP as Disease Severity Marker?

Background: In progressive multiple sclerosis (MS), glial activation is thought to be a relevant mechanism of disability progression. Therefore, in vivo assessment of the glial cell activity is, in the emerging treatment era of primary progressive MS (PPMS), more important than ever. Objectives: To test the association of cerebrospinal fluid (CSF) and serum markers of glial activation in PPMS patients; including glial fibrillary acidic protein (GFAP), chitinase-3-like protein 1 (CHI3L1), soluble variant of triggering receptor expressed on myeloid cells 2 (sTREM2), and marker of neuroaxonal damage (Neurofilament light chain, NfL) as well as clinical severity. Methods: CSF and serum samples from PPMS patients were collected in the MS-centers at Universities of Freiburg (n = 49), Ulm (n = 27), Muenster (n = 11), and Rostock (n = 6). sTREM2 and CHI3L1 levels were measured using the previously reported ELISA assays, while NfL and GFAP were measured using SIMOA assays. Clinical data included age, gender, disease duration, treatment status, and Expanded Disability Status Scale (EDSS). Results: 93 CSF samples and 71 matching serum samples were analyzed. The median age of patients was 49 years and disease duration 4.5 years. GFAP_serum correlated with EDSS after correction for age (β = 0.3, p = 0.001). Furthermore, EDSS was higher in patients with a GFAP_serum level ≥ 151.7 pg/ml compared to patients with GFAP_serum below this cut-off (5.5 vs. 4.0, p = 0.009). Other markers did not correlate with the clinical severity. Moreover, we found a correlation between NfL_CSF and GFAP_CSF, sTREM2 and CHI3L1 (ρ = 0.4 for GFAP_CSF and sTREM2, ρ = 0.3 for CHI3L1, p < 0.01 for sTREM2 and CHI3L1 and <0.001 for GFAP_CSF). CHI3L1 did not correlate with GFAP_CSF but with sTREM2 (ρ = 0.4, p < 0.01). Discussion: The correlation between the glial activation markers in CSF with the markers of neuroaxonal demise supports the notion of the glial involvement in PPMS. The positive correlation between GFAP_CSF with disease duration and GFAP_serum with the clinical severity of the disease may highlight a particular role of the astrocytes in PPMS and mark the potential of GFAP_serum as a disease severity marker.

Identification of candidate biomarkers in converting and non-converting clinically isolated syndrome by proteomics analysis of cerebrospinal fluid

Multiple sclerosis (MS) often starts in the form of clinically isolated syndrome (CIS) and only some of the CIS patients progress to relapsing-remitting MS (RRMS). Biomarkers to predict conversion from CIS to MS are thus greatly needed for making correct treatment decisions. To identify a predictive cerebrospinal fluid (CSF) protein, we analyzed the first-attack CSF samples of CIS patients who converted (CIS-MS) (n = 23) and did not convert (CIS-CIS) (n = 19) to RRMS in a follow-up period of 5 years using proteomics analysis by liquid chromatography tandem-mass spectrometry (LC-MS/MS) and verified by ELISA. Label-free differential proteomics analysis of CSF ensured that 637 proteins were identified and 132 of these proteins were found to be statistically significant. Further investigation with the ingenuity pathway analysis (IPA) software led to identification of three pathway networks mostly comprised proteins involved in inflammatory response, cellular growth and tissue proliferation. CSF levels of four of the most differentially expressed proteins belonging to the cellular proliferation network function, chitinase-3-like protein 1 (CHI3L1), tumor necrosis factor receptor superfamily member 21 (TNFRSF21), homeobox protein Hox-B3 (HOXB3) and iduronate 2-sulfatase (IDS), were measured by ELISA. CSF levels of HOXB3 were significantly increased in CIS-MS patients. Our results indicate that cell and tissue proliferation functions are dysregulated in MS as early as the first clinical episode. HOXB3 has emerged as a potential novel biomarker which might be used for prediction of CIS-MS conversion.

Elevation of YKL-40 in the CSF of Anti-NMDAR Encephalitis Patients Is Associated With Poor Prognosis

Objective: Anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis predominantly affects children and young women; the disease can have a multistage presentation and exhibit a wide variety of neuropsychiatric features. This study aimed to investigate the profile of YKL-40 (Chitinase 3-like 1) in anti-NMDAR encephalitis patients and evaluate its association with modified Rankin Scale (mRS) scores and expression of inflammatory cytokines.

Methods: A total of 66 patients were enrolled in this study, 33 with anti-NMDAR encephalitis, 13 with viral meningitis and 20 with non-inflammatory neurological disease. Patients were evaluated to determine mRS scores at disease onset and at the 3 month follow-up; cerebrospinal fluid (CSF) samples were collected in the meantime. CSF levels of YKL-40 and cytokines (TNF-α, IL-6, IL-10) were measured by enzyme-linked immunosorbent assay.

Results: CSF levels of YKL-40 and inflammatory cytokines (TNF-α, IL-6, IL-10) were all more highly elevated in patients with anti-NMDAR encephalitis at the acute stage of disease compared with the controls. Levels of CSF YKL-40 were correlated with levels of IL-6 both at disease onset and at the 3 month follow-up. Changes in YKL-40 levels were significantly correlated with improved mRS scores in patients with anti-NMDAR encephalitis.

Conclusion: Our study suggests that CSF levels of YKL-40 in patients with anti-NMDAR encephalitis were increased and correlated with clinical mRS scores. This may be reflective of the underlying neuroinflammatory process. YKL-40 demonstrates potential as a possible biomarker for the prognosis of anti-NMDAR encephalitis.

K284-6111 prevents the amyloid beta-induced neuroinflammation and impairment of recognition memory through inhibition of NF-κB-mediated CHI3L1 expression

BACKGROUND

Alzheimer's disease, which is pathologically characterized by an excessive accumulation of amyloid beta (Aβ) fibrils, is a degenerative brain disease and the most common cause of dementia. In a previous study, it was reported that an increased level of CHI3L1 in plasma was found in AD patients. We investigated the inhibitory effect of 2-({3-[2-(1-cyclohexen-1-yl)ethyl]-6,7-dimethoxy-4-oxo-3,4-dihydro-2-quinazolinyl}sulfanyl)-N-(4-ethylphenyl)butanamide (K284-6111), an inhibitor of chitinase 3 like 1 (CHI3L1), on memory impairment in Aβ1-42-infused mice, and microglial BV-2 cells and astrocytes.

METHODS

We examined whether K284-6111 (3 mg/kg given orally for 4 weeks) prevents amyloidogenesis and memory loss in Aβ1-42-induced AD mice model. After intracerebroventrical (ICV) infusion of Aβ1-42 for 14 days, the cognitive function was assessed by the Morris water maze test and passive avoidance test. K284-6111 treatment was found to reduce Aβ1-42-induced memory loss.

RESULTS

A memory recovery effect was found to be associated with the reduction of Aβ1-42-induced expression of inflammatory proteins (iNOS, COX-2, GFAP, and Iba-1) and the suppression of CHI3L1 expression in the brain. Additionally, K284-6111 reduced Aβ1-42-induced β-secretase activity and Aβ generation. Lipopolysaccharide (LPS)-induced (1 μg/mL) expression of inflammatory (COX-2, iNOS, GFAP, Iba-1) and amyloidogenic proteins (APP, BACE1) were decreased in microglial BV-2 cells and cultured astrocytes by the K284-6111 treatment (0.5, 1, and 2 μM). Moreover, K284-6111 treatment suppressed p50 and p65 translocation into the nucleus, and phosphorylation of IκB in vivo and in vitro.

CONCLUSION

These results suggest that CHI3L1 inhibitor could be an applicable intervention drug in amyloidogenesis and neuroinflammation, thereby preventing memory dysfunction via inhibition of NF-κB.

Neurofilament levels, disease activity and brain volume during follow-up in multiple sclerosis

Background

There is a need for clinically useful biomarkers of disease activity in clinically isolated syndrome (CIS) and relapsing remitting MS (RRMS). The aim of this study was to assess the correlation between neurofilament light chain (NFL) in cerebrospinal fluid (CSF) and serum and the relationship between NFL and other biomarkers, subsequent disease activity, and brain volume loss in CIS and RRMS.

Methods

A panel of neurodegenerative and neuroinflammatory markers were analyzed in repeated CSF samples from 41 patients with CIS or RRMS in a prospective longitudinal cohort study and from 22 healthy controls. NFL in serum was analyzed using a single-molecule array (Simoa) method. “No evidence of disease activity-3” (NEDA-3) status and brain volume (brain parenchymal fraction calculated using SyMRI®) were recorded during 4 years of follow-up.

Results

NFL levels in CSF and serum correlated significantly (all samples, n = 63, r 0.74, p < 0.001), but CSF-NFL showed an overall stronger association profile with NEDA-3 status, new T2 lesions, and brain volume loss. CSF-NFL was associated with both new T2 lesions and brain volume loss during follow-up, whereas CSF-CHI3L1 was associated mainly with brain volume loss and CXCL1, CXCL10, CXCL13, CCL22, and MMP-9 were associated mainly with new T2 lesions.

Conclusions

Serum and CSF levels of NFL correlate, but CSF-NFL predicts and reflects disease activity better than S-NFL. CSF-NFL levels are associated with both new T2 lesions and brain volume loss. Our findings further add to the accumulating evidence that CSF-NFL is a clinically useful biomarker in CIS and RRMS and should be considered in the expanding NEDA concept. CSF-CXCL10 and CSF-CSF-CHI3L1 are potential markers of disease activity and brain volume loss, respectively.

Electronic supplementary material

The online version of this article (10.1186/s12974-018-1249-7) contains supplementary material, which is available to authorized users.

Increased cerebrospinal fluid chitinase 3-like 1 and neurofilament light chain in pediatric acquired demyelinating syndromes

BACKGROUND

Chitinase 3-like 1 (CHI3L1), neurofilament light chain (NFL) and oligoclonal bands (OCB) in cerebrospinal fluid are associated with central nervous system demyelination in adults. CHI3L1 and OCB are markers of central nervous system inflammation, whereas NFL is a marker of white-matter axonal injury. The aim was to examine whether CHI3L1 and NFL in cerebrospinal fluid are associated with acquired demyelinating syndromes at disease onset in a pediatric population.

METHODS

Children (<18 years) referred to hospital for possible neuroinflammatory disease were retrospectively included from 2010 to 2016. Case ascertainment was by review of medical records. NFL and CHI3L1 were measured by enzyme-linked immunosorbent assays. Endpoints were differences in concentrations of cerebrospinal fluid NFL and CHI3L1.

RESULTS

We included 193 children who all underwent cerebrospinal fluid OCB examination as part of their diagnostic work-up and classified these children into 5 groups: acquired demyelinating syndromes (n = 33), normal diagnostic work-up (n = 36), inflammatory neurological disease (n = 50), other neurological disease (n = 55), and systemic inflammatory diseases (n = 19). NFL and CHI3L1 in cerebrospinal fluid differed significantly between the five groups (p = 0.0001). CHI3L1 was significantly higher in acquired demyelinating syndromes than in all other groups, and NFL was significantly higher in acquired demyelinating syndromes than in the other groups except systemic inflammatory disease. Children with acute disseminated encephalomyelitis had significantly higher concentrations of CHI3L1 than did children with multiple sclerosis.

CONCLUSION

We provide class II evidence that CHI3L1 and NFL are associated with pediatric acquired demyelinating syndromes. CHI3L1 may help distinguishing between acute disseminated encephalomyelitis and multiple sclerosis, but this needs further confirmation.

Multiple sclerosis biomarkers: Helping the diagnosis?

Multiple sclerosis (MS) is a complex heterogeneous disease. Diagnostic criteria are based on symptoms, biomarkers, MRI data and exclusion of differential diagnoses. Over the past few years, the usefulness of biomarkers has progressively decreased with the development of new MRI criteria, yet dozens of new biomarkers, especially in cerebrospinal fluid, for MS diagnosis and prognosis have been described. Large-scale studies validating some of these new biomarkers have also provided confirmation of a restricted set of biomarkers (presented here in this review) as having potential value for different stages of the disease, including as early as clinically isolated syndrome and radiologically isolated syndrome. However, differentiating progressive forms of MS from relapsing-remitting MS remains a genuine challenge, and could help to predict future conversion to secondary-progressive MS. In addition, new approaches combining multiple biomarkers might allow us to unravel the complexity of the disease and determine disease stages more precisely. Moreover, recent technological developments allowing analysis of biomarkers in plasma have also provided less invasive analysis of MS, and should serve to predict MS evolution and therapeutic responses during follow-up.

Cerebrospinal fluid chitinase-3-like protein 1 level is not an independent predictive factor for the risk of clinical conversion in radiologically isolated syndrome

Background:

Younger age, male sex and presence of spinal cord lesion(s) increase the risk of conversion from radiologically isolated syndrome (RIS) to relapsing-remitting multiple sclerosis (RRMS). Elevated cerebrospinal fluid (CSF) chitinase-3-like protein 1 (CHI3L1) levels predict conversion from clinically isolated syndrome (CIS) to RRMS.

Objective:

To evaluate the prognostic value of CSF CHI3L1 in RIS patients for conversion to RRMS.

Methods:

We compared CSF CHI3L1 concentrations in RIS, CIS, RRMS and symptomatic controls (SCs). We analysed the influence of epidemiological, radiological and CSF parameters on the risk of clinical event.

Results:

A total of 211 patients (71 RIS, 48 CIS, 50 RRMS and 42 SC) were included. CSF CHI3L1 levels were lower in RIS than in RRMS and higher in RIS with positive CSF versus negative CSF and SC. The presence of at least one spinal cord lesion was the only independent predictor of faster conversion to RRMS. Association of high CSF CHI3L1 levels, positive CSF (presence of oligoclonal bands and/or an elevated IgG index) or four Barkhof criteria with any spinal cord lesion showed a tendency for reduced mean conversion time.

Conclusion:

CSF CHI3L1 correlates with positive CSF but is not an independent predictor of the risk of conversion from RIS to RRMS.