Biomarkers of inflammation and axonal degeneration/damage in patients with newly diagnosed multiple sclerosis: contributions of the soluble CD163 CSF/serum ratio to a biomarker panel

From progression to progress: The future of multiple sclerosis

Significant advances have been made in the diagnosis and treatment of multiple sclerosis in recent years yet challenges remain. The current classification of MS phenotypes according to disease activity and progression, for example, does not adequately reflect the underlying pathophysiological mechanisms that may be acting in an individual with MS at different time points. Thus, there is a need for clinicians to transition to a management approach based on the underlying pathophysiological mechanisms that drive disability in MS. A Canadian expert panel convened in January 2023 to discuss priorities for clinical discovery and scientific exploration that would help advance the field. Five key areas of focus included: identifying a mechanism-based disease classification system; developing biomarkers (imaging, fluid, digital) to identify pathologic processes; implementing a data-driven approach to integrate genetic/environmental risk factors, clinical findings, imaging and biomarker data, and patient-reported outcomes to better characterize the many factors associated with disability progression; utilizing precision-based treatment strategies to target different disease processes; and potentially preventing disease through Epstein-Barr virus (EBV) vaccination, counselling about environmental risk factors (e.g. obesity, exercise, vitamin D/sun exposure, smoking) and other measures. Many of the tools needed to meet these needs are currently available. Further work is required to validate emerging biomarkers and tailor treatment strategies to the needs of individual patients. The hope is that a more complete view of the individual's pathobiology will enable clinicians to usher in an era of truly personalized medicine, in which more informed treatment decisions throughout the disease course achieve better long-term outcomes.

Blood-brain barrier biomarkers

The blood-brain barrier (BBB) is a dynamic interface that regulates the exchange of molecules and cells between the brain parenchyma and the peripheral blood. The BBB is mainly composed of endothelial cells, astrocytes and pericytes. The integrity of this structure is essential for maintaining brain and spinal cord homeostasis and protection from injury or disease. However, in various neurological disorders, such as traumatic brain injury, Alzheimer's disease, and multiple sclerosis, the BBB can become compromised thus allowing passage of molecules and cells in and out of the central nervous system parenchyma. These agents, however, can serve as biomarkers of BBB permeability and neuronal damage, and provide valuable information for diagnosis, prognosis and treatment. Herein, we provide an overview of the BBB and changes due to aging, and summarize current knowledge on biomarkers of BBB disruption and neurodegeneration, including permeability, cellular, molecular and imaging biomarkers. We also discuss the challenges and opportunities for developing a biomarker toolkit that can reliably assess the BBB in physiologic and pathophysiologic states.

Plasma IgG aggregates as biomarkers for multiple sclerosis

We recently reported that multiple sclerosis (MS) plasma contains IgG aggregates and induces complement-dependent neuronal cytotoxicity (Zhou et al., 2023). Using ELISA, we report herein that plasma IgG levels in the aggregates can be used as biomarkers for MS. We enriched the IgG aggregates from samples of two cohorts (190 MS and 160 controls) by collecting flow-through after plasma binding to Protein A followed by detection of IgG subclass. We show that there are significantly higher levels of IgG1, IgG3, and total IgG antibodies in MS IgG aggregates, with an AUC >90%; higher levels of IgG1 distinguish secondary progressive MS from relapsing-remitting MS (AUC = 91%). Significantly, we provided the biological rationale for MS plasma IgG biomarkers by demonstrating the strong correlation between IgG antibodies and IgG aggregate-induced neuronal cytotoxicity. These non-invasive, simple IgG-based blood ELISA assays can be adapted into clinical practice for diagnosing MS and SPMS and monitoring treatment responses.

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.

Clinical validation of a multi-protein, serum-based assay for disease activity assessments in multiple sclerosis

An 18-protein multiple sclerosis (MS) disease activity (DA) test was validated based on associations between algorithm scores and clinical/radiographic assessments (N = 614 serum samples; Train [n = 426; algorithm development] and Test [n = 188; evaluation] subsets). The multi-protein model was trained based on presence/absence of gadolinium-positive (Gd+) lesions and was also strongly associated with new/enlarging T2 lesions, and active versus stable disease (composite of radiographic and clinical evidence of DA) with improved performance (p < 0.05) compared to the neurofilament light single protein model. The odds of having ≥1 Gd + lesions with a moderate/high DA score were 4.49 times that of a low DA score, and the odds of having ≥2 Gd + lesions with a high DA score were 20.99 times that of a low/moderate DA score. The MSDA Test was clinically validated with improved performance compared to the top-performing single-protein model and can serve as a quantitative tool to enhance the care of MS patients.

Regulation of CD163 Receptor in Patients with Abdominal Aortic Aneurysm and Associations with Antioxidant Enzymes HO-1 and NQO1

Red blood cells are found within the abdominal aortic aneurysm (AAA), in the intraluminal thrombus (ILT), and in neovessels. Hemolysis promotes aortic degeneration, e.g., by heme-induced reactive oxygen species formation. To reduce its toxicity, hemoglobin is endocytosed by the CD163 receptor and heme is degraded by heme oxygenase-1 (HO-1). A soluble form (sCD163) is discussed as an inflammatory biomarker representing the activation of monocytes and macrophages. HO-1 and NAD(P)H quinone dehydrogenase 1 (NQO1) are antioxidant genes that are induced by the Nrf2 transcription factor, but their regulation in AAA is only poorly understood. The aim of the present study was to analyze linkages between CD163, Nrf2, HO-1, and NQO1 and to clarify if plasma sCD163 has diagnostic and risk stratification potential. Soluble CD163 was 1.3-fold (p = 0.015) higher in AAA compared to patients without arterial disease. The difference remained significant after adjusting for age and sex. sCD163 correlated with the thickness of the ILT (r_s = 0.26; p = 0.02) but not with the AAA diameter or volume. A high aneurysmal CD163 mRNA was connected to increases in NQO1, HMOX1, and Nrf2 mRNA. Further studies are needed to analyze the modulation of the CD163/HO-1/NQO1 pathway with the overall goal of minimizing the detrimental effects of hemolysis.

A Novel Fatty Acid Metabolism-Associated Risk Model for Prognosis Prediction in Acute Myeloid Leukaemia

Acute myeloid leukaemia (AML) is the most common acute leukaemia in adults, with an unfavourable outcome and a high rate of recurrence due to its heterogeneity. Dysregulation of fatty acid metabolism plays a crucial role in the development of several tumours. However, the value of fatty acid metabolism (FAM) in the progression of AML remains unclear. In this study, we obtained RNA sequencing and corresponding clinicopathological information from the TCGA and GEO databases. Univariate Cox regression analysis and subsequent LASSO Cox regression analysis were utilized to identify prognostic FAM-related genes and develop a potential prognostic risk model. Kaplan-Meier analysis was used for prognostic significances. We also performed ROC curve to illustrate that the risk model in prognostic prediction has good performance. Moreover, significant differences in immune infiltration landscape were found between high-risk and low-risk groups using ESTIMATE and CIBERSOT algorithms. In the end, differential expressed genes (DEGs) were analyzed by gene set enrichment analysis (GSEA) to preliminarily explore the possible signaling pathways related to the prognosis of FAM and AML. The results of our study may provide potential prognostic biomarkers and therapeutic targets for AML patients, which is conducive to individualized precision therapy.

The conundrum of neuropsychiatric systemic lupus erythematosus: Current and novel approaches to diagnosis

Recognising neuropsychiatric involvement by systemic lupus erythematosus (SLE) is of growing importance, however many barriers to this exist at multiple levels of our currently available diagnostic algorithms that may ultimately delay its diagnosis and subsequent treatment. The heterogeneous and non-specific clinical syndromes, serological and cerebrospinal fluid (CSF) markers and neuroimaging findings that often do not mirror disease activity, highlight important research gaps in the diagnosis of neuropsychiatric SLE (NPSLE). Formal neuropsychological assessments or the more accessible screening metrics may also help improve objective recognition of cognitive or mood disorders. Novel serum and CSF markers, including autoantibodies, cytokines and chemokines have also shown increasing utility as part of diagnosis and monitoring, as well as in distinguishing NPSLE from SLE patients without SLE-related neuropsychiatric manifestations. Novel neuroimaging studies also expand upon our existing strategy by quantifying parameters that indicate microarchitectural integrity or provide an assessment of neuronal function. Some of these novel markers have shown associations with specific neuropsychiatric syndromes, suggesting that future research move away from considering NPSLE as a single entity but rather into its individually recognized neuropsychiatric manifestations. Nevertheless, it is likely that a composite panel of these investigations will be needed to better address the gaps impeding recognition of neuropsychiatric involvement by SLE.

Neurofilament light oligomers in neurodegenerative diseases: quantification by homogeneous immunoassay in cerebrospinal fluid

Background

Neurofilament light (NfL) is a widely used biomarker for neurodegeneration. NfL is prone to oligomerisation, but available assays do not reveal the exact molecular nature of the protein variant measured. The objective of this study was to develop a homogeneous ELISA capable of quantifying oligomeric NfL (oNfL) in cerebrospinal fluid (CSF).

Methods

A homogeneous ELISA, based on the same capture and detection antibody (NfL21), was developed and used to quantify oNfL in samples from patients with behavioural variant frontotemporal dementia (bvFTD, n=28), non-fluent variant primary progressive aphasia (nfvPPA, n=23), semantic variant PPA (svPPA, n=10), Alzheimer's disease (AD, n=20) and healthy controls (n=20). The nature of NfL in CSF, and the recombinant protein calibrator, was also characterised by size exclusion chromatography (SEC).

Results

CSF concentration of oNfL was significantly higher in nfvPPA (p<0.0001) and svPPA patients (p<0.05) compared with controls. CSF oNfL concentration was also significantly higher in nfvPPA compared with bvFTD (p<0.001) and AD (p<0.01) patients. SEC data showed a peak fraction compatible with a full-length dimer (~135 kDa) in the in-house calibrator. For CSF, the peak was found in a fraction of lower molecular weight (~53 kDa), suggesting dimerisation of NfL fragments.

Conclusions

The homogeneous ELISA and SEC data suggest that most of the NfL in both the calibrator and human CSF is present as a dimer. In CSF, the dimer appears to be truncated. Further studies are needed to determine its precise molecular composition.

Intrathecal B cell-related markers for an optimized biological investigation of multiple sclerosis patients

In multiple sclerosis (MS) disease, the importance of the intrathecal B cell response classically revealed as IgG oligoclonal bands (OCB) in cerebrospinal fluid (CSF) was reaffirmed again in the recently revised diagnostic criteria. We aimed to optimize Laboratory investigation by testing the performance of new B cell-related molecules in CSF (Ig free light chains (FLCκ and λ) and CXCL13 (B-Cell Attracting chemokine1)) for MS diagnosis. 320 paired (CSF-serum) samples were collected from 160 patients with MS (n = 82) and non-MS diseases (n = 78). All patients benefited from IgG index determination, OCB detection, CSF CXCL13 and FLC (κ and λ) measurement in CSF and serum for metrics calculation (κ/λ ratio, FLC-related indexes, and κFLC-intrathecal fraction (IF)). CXCL13 and FLC metrics in CSF were higher in patients with MS and positive OCB. As expected, κFLC metrics—in particular, κFLC index and κFLC IF—had the highest accuracy for MS diagnosis. κ index showed the best performance (sensitivity 83% and specificity 91.7%) at a cut-off of 14.9. Most of the FLC-related parameters were positively correlated with IgG index and the level of CXCL13. In conclusion, the quantitative, standardizable, and technically simple CSF FLCκ metrics seem to be reliable for MS diagnosis, but could not replace OCB detection. CXCL13 appears to be an effective parameter reflecting the intrathecal B cell response. An optimized way for CSF testing combining the conventional and the new B cell-related parameters is proposed in this study.

Investigation of differentially expressed genes and dysregulated pathways involved in multiple sclerosis

Multiple Sclerosis (MS) is a neurodegenerative autoimmune and organ-specific demyelinating disorder, known to affect the central nervous system (CNS). While genetic studies have revealed several critical genes and diagnostic biomarkers associated with MS, the etiology of the disease remains poorly understood. This study is aimed at screening and identifying the key genes and canonical pathways associated with MS. Gene expression profiling of the microarray dataset GSE38010 was used to analyze two control brain samples (control 1; GSM931812, control 2; GSM931813), active inflammation stage samples (CAP1; GSM931815, CAP2; GSM931816) and late subsided stage samples (CP1; GSM931817, CP2; GSM931818) collected from patients ranging between 23 and 54years and both genders. This analysis yielded a list of 58,866 DEGs (29,433 for active-inflammation stage and 29,433 for late-subsided Stage). The interactions between the DEGs were then studied using STRING, Cytoscape software, and MCODE was employed to find the genes that form clusters. Functional enrichment and integrative analysis were performed using ClueGO/CluePedia and MetaCore™. Our data revealed dysregulated key canonical pathways in MS patients. In addition, we identified three hub genes (SCN2A, HTR2A, and HCN1) that may serve as potential biomarkers for the prognosis of MS. Furthermore, the expression patterns of HPCA and PLCB1 provide insights into the progressive stages of MS, indicating that these genes could be used in predicting MS progression. We were able to map potential biomarkers that could be used for the prognosis and diagnosis of MS.

Experimental laboratory biomarkers in multiple sclerosis

BACKGROUND

Multiple sclerosis (MS) is a chronic autoimmune disorder of the central nervous system; the cause of this condition remains unknown. Researchers have analyzed different biomarkers related to MS. Here, experimental laboratory biomarkers for MS are identified and analyzed.

METHODS

The current study examined articles investigating biomarkers for MS. Records were obtained from the PubMed, LILACS, and EBSCO databases using an identical search strategy and terms that included "multiple sclerosis," "MS," and "biomarkers." In the current review, we also focus on lesser known biomarkers that have not yet been established for use in clinical practice.

RESULTS

Previous studies have explored molecular substances that may help diagnose MS and manage its adverse effects. Commonly studied factors include neurofilaments, sCD163, CXCL13, NEO, NF‑L, OPN, B cells, T cells, and integrin-binding proteins.

CONCLUSIONS

Interactions between environmental and genetic factors have been implicated in the development of MS. Previous investigations have identified a wide range of biomarkers that can be used for diagnosis and disease management. These molecules and their associated studies provide vital insight and data to help primary physicians improve clinical and health outcomes for MS patients.

Analysis of Early Biomarkers Associated with the Development of Critical Respiratory Failure in Coronavirus Disease 2019 (COVID-19)

Certain biomarkers predict death due to acute respiratory distress syndrome in COVID-19 patients. We retrospectively analyzed biomarkers associated with time to mechanical ventilation for respiratory failure due to COVID-19 (time-to-mechanical ventilation) in 135 consecutive patients in our hospital. We analyzed biomarkers that were elevated immediately (at admission) and later (3 days after admission) using Cox proportional hazards regression analysis. Independent biomarkers of time-to-mechanical ventilation were high C-reactive protein (CRP), interleukin (IL)-6, and Krebs von den Lungen-6 (KL-6) concentrations at admission and elevated CRP, high-mobility group box-1 protein (HMGB-1), and d-dimer levels and low platelets 3 days after admission. Receiver operating characteristic analysis for detecting the association between independent biomarkers associated with time-to-event in multivariate analyses and the start of mechanical ventilation revealed that these biomarkers had area under the curve values higher than 0.700. The present study suggests that CRP was the only biomarker associated with time-to-mechanical ventilation both at admission and 3 days after admission. Moreover, IL-6 (an inflammatory cytokine), HMGB-1 (a late inflammatory mediator), and KL-6 (reflecting injury and/or remodeling of type II pneumocytes) were associated with outcomes in COVID-19 as reported previously. In conclusion, increased CRP, IL-6, KL-6, HMGB-1, and d-dimer levels and decreased platelet counts were associated with the start of mechanical ventilation due to COVID-19.

Neurodegenerative Disorders of Alzheimer, Parkinsonism, Amyotrophic Lateral Sclerosis and Multiple Sclerosis: An Early Diagnostic Approach for Precision Treatment

Neurodegenerative diseases (NDs) are characterised by progressive dysfunction of synapses, neurons, glial cells and their networks. Neurodegenerative diseases can be classified according to primary clinical features (e.g., dementia, parkinsonism, or motor neuron disease), anatomic distribution of neurodegeneration (e.g., frontotemporal degenerations, extrapyramidal disorders, or spinocerebellar degenerations), or principal molecular abnormalities. The most common neurodegenerative disorders are amyloidosis, tauopathies, a-synucleinopathy, and TAR DNA-binding protein 43 (TDP-43) proteopathy. The protein abnormalities in these disorders have abnormal conformational properties along with altered cellular mechanisms, and they exhibit motor deficit, mitochondrial malfunction, dysfunctions in autophagic-lysosomal pathways, synaptic toxicity, and more emerging mechanisms such as the roles of stress granule pathways and liquid-phase transitions. Finally, for each ND, microglial cells have been reported to be implicated in neurodegeneration, in particular, because the microglial responses can shift from neuroprotective to a deleterious role. Growing experimental evidence suggests that abnormal protein conformers act as seed material for oligomerization, spreading from cell to cell through anatomically connected neuronal pathways, which may in part explain the specific anatomical patterns observed in brain autopsy sample. In this review, we mention the human pathology of select neurodegenerative disorders, focusing on how neurodegenerative disorders (i.e., Alzheimer's disease, Parkinson's disease, amyotrophic lateral sclerosis, and multiple sclerosis) represent a great healthcare problem worldwide and are becoming prevalent because of the increasing aged population. Despite many studies have focused on their etiopathology, the exact cause of these diseases is still largely unknown and until now with the only available option of symptomatic treatments. In this review, we aim to report the systematic and clinically correlated potential biomarker candidates. Although future studies are necessary for their use in early detection and progression in humans affected by NDs, the promising results obtained by several groups leads us to this idea that biomarkers could be used to design a potential therapeutic approach and preclinical clinical trials for the treatments of NDs.

CSF neurofilament light chain predicts 10-year clinical and radiologic worsening in multiple sclerosis

Background

Neurofilament light chain (NfL) is an attractive biomarker of disease activity and progression in MS, but there is a lack in long-term prognostic data.

Objective

To test the long-term clinical and radiological prognostic value of cerebrospinal fluid (CSF)-NfL among newly diagnosed patients with MS.

Methods

Newly diagnosed MS patients where followed prospectively with baseline CSF-NfL and repeated MRI and clinical assessments for up to 10 years. Associations between baseline CSF-NfL and longitudinal MRI and clinical assessments were found by Generalized Estimating Equations analysis.

Results

Forty-two participants were included. CSF-NfL at baseline was significantly associated with the rate of atrophy in globus pallidus (p = 0.009) and hippocampus (p = 0.001) as evaluated by MRI. Baseline volumes of thalamus (β −0.33; 95% CI −0.57 to −0.10, p = 0.006), T1 (β 0.28; 95% CI 0.11 to 0.44, p = 0.001) and T2 (β 0.16; 95% CI 0.04 to 0.27, p = 0.008) lesions and baseline levels of CSF-NfL (β 0.9; 95% CI 0.3 to 1.5, p = 0.002) significantly predicted EDSS worsening over 10 years. Baseline CSF-NfL gave a comparable prediction to the best MRI volumetric predictors.

Conclusion

CSF-NfL predicted the clinical and radiological course of newly diagnosed patients with MS over a 10-year period, underlining its prognostic role.

Neurofilaments in progressive multiple sclerosis: a systematic review

BACKGROUND

Neurofilament proteins have been extensively studied in relapsing-remitting multiple sclerosis, where they are promising biomarkers of disease activity and treatment response. Their role in progressive multiple sclerosis, where there is a particularly urgent need for improved biomarkers, is less clear. The objectives of this systematic review are to summarise the literature on neurofilament light and heavy in progressive multiple sclerosis, addressing key questions.

METHODS

A systematic search of PubMed, Embase, Web of Science and Scopus identified 355 potential sources. 76 relevant sources were qualitatively reviewed using QUADAS-2 criteria, and 17 were identified as at low risk of bias. We summarise the findings from all relevant sources, and separately from the 17 high-quality studies.

RESULTS

Differences in neurofilament light between relapsing-remitting and progressive multiple sclerosis appear to be explained by differences in covariates. Neurofilament light is consistently associated with current inflammatory activity and future brain atrophy in progressive multiple sclerosis, and is consistently shown to be a marker of treatment response with immunosuppressive disease-modifying therapies. Associations with current or future disability are inconsistent, and there is no evidence of NFL being a responsive marker of purportedly neuroprotective treatments. Evidence on neurofilament heavy is more limited and inconsistent.

CONCLUSIONS

Neurofilament light has shown consistent utility as a biomarker of neuroinflammation, future brain atrophy and immunosuppressive treatment response at a group level. Neither neurofilament light or heavy has shown a consistent treatment response to neuroprotective disease-modifying therapies, which will require further data from successful randomised controlled trials.

Cerebrospinal fluid metabolomics: detection of neuroinflammation in human central nervous system disease

The high morbidity and mortality of neuroinflammatory diseases drives significant interest in understanding the underlying mechanisms involved in the innate and adaptive immune response of the central nervous system (CNS). Diagnostic biomarkers are important to define treatable neuroinflammation. Metabolomics is a rapidly evolving research area offering novel insights into metabolic pathways, and elucidation of reliable metabolites as biomarkers for diseases. This review focuses on the emerging literature regarding the detection of neuroinflammation using cerebrospinal fluid (CSF) metabolomics in human cohort studies. Studies of classic neuroinflammatory disorders such as encephalitis, CNS infection and multiple sclerosis confirm the utility of CSF metabolomics. Additionally, studies in neurodegeneration and neuropsychiatry support the emerging potential of CSF metabolomics to detect neuroinflammation in common CNS diseases such as Alzheimer's disease and depression. We demonstrate metabolites in the tryptophan-kynurenine pathway, nitric oxide pathway, neopterin and major lipid species show moderately consistent ability to differentiate patients with neuroinflammation from controls. Integration of CSF metabolomics into clinical practice is warranted to improve recognition and treatment of neuroinflammation.

Regulation of the expression of human endogenous retroviruses: elements in fetal development and a possible role in the development of cancer and neurological diseases

Human endogenous retroviruses (HERVs) are remnants of ancient retroviral germline infections. Most HERV sequences are silenced in somatic cells, but interest is emerging on the involvement of HERV derived transcripts and proteins in human physiology and disease. A HERV-W encoded protein, syncytin-1, has been co-opted into fetal physiology, where it plays a role in trophoblast formation. Altered HERV transcription and expression of HERV derived proteins are associated with various cancer types and neurological diseases such as multiple sclerosis (MS). The implication of HERVs as potential mediators of both health and disease suggests important roles of regulatory mechanisms and alterations of these in physiological and pathological processes. The regulation of HERV sequences is mediated by a wide variety of mechanisms, and the focus of this review is on selected aspects of these, including epigenetic mechanisms such as CpG methylation and histone modifications of the HP1-H3K9me axis, viral transactivation events, and regulatory perspectives of transient stimuli in the microenvironment. Increasing knowledge of the regulation of HERV sequences will not only contribute to the understanding of complex pathogeneses, but also may pinpoint potential targets for better diagnosis and treatment in complex diseases as MS.

A comprehensive review on the role of chemokines in the pathogenesis of multiple sclerosis

Multiple sclerosis (MS) as a chronic inflammatory disorder of the central nervous system (CNS) is thought to be caused by the abnormal induction of immune responses. Chemokines as molecules that can engage leukocytes into the location of inflammation, actively participate in the pathogenesis of MS. Several members of this family of chemo attractants have been shown to be dysregulated in the peripheral blood, cerebrospinal fluid or CNS lesions of MS patients. Studies in animal models of MS particularly experimental autoimmune encephalomyelitis have indicated the critical roles of chemokines in the pathophysiology of MS. In the current review, we summarize the data regarding the role of CCL2, CCL3, CCL4, CCL11, CCL20, CXCL1, CXCL2, CXCL8, CXCL10, CXCL12 and CXCL13 in the pathogenesis of MS.

Glycoproteins as diagnostic and prognostic biomarkers for neurodegenerative diseases: A glycoproteomic approach

Neurodegenerative diseases (NDs) are incurable and can develop progressively debilitating disorders, including dementia and ataxias. Alzheimer's disease and Parkinson's disease are the most common NDs that mainly affect the elderly people. There is an urgent need to develop new diagnostic tools so that patients can be accurately stratified at an early stage. As a common post-translational modification, protein glycosylation plays a key role in physiological and pathological processes. The abnormal changes in glycosylation are associated with the altered biological pathways in NDs. The pathogenesis-related proteins, like amyloid-β and microtubule-associated protein tau, have altered glycosylation. Importantly, specific glycosylation changes in cerebrospinal fluid, blood and urine are valuable for revealing neurodegeneration in the early stages. This review describes the emerging biomarkers based on glycoproteomics in NDs, highlighting the potential applications of glycoprotein biomarkers in the early detection of diseases, monitoring of the disease progression, and measurement of the therapeutic responses. The mass spectrometry-based strategies for characterizing glycoprotein biomarkers are also introduced.

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.

The Impact of SARS-CoV-2 Infection on the Development of Neurodegeneration in Multiple Sclerosis

The novel coronavirus disease 2019 (COVID-19) pandemic, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), remains a global challenge. Currently, there is some information on the consequences of COVID-19 infection in multiple sclerosis (MS) patients, as it is a newly discovered coronavirus, but its far-reaching effects on participation in neurodegenerative diseases seem to be significant. Recent cases reports showed that SARS-CoV-2 may be responsible for initiating the demyelination process in people who previously had no symptoms associated with any nervous system disorders. It is presently known that infection of SARS-CoV-2 evokes cytokine storm syndrome, which may be one of the factors leading to the acute cerebrovascular disease. One of the substantial problems is the coexistence of cerebrovascular disease and MS in an individual's life span. Epidemiological studies showed an enhanced risk of death rate from vascular disabilities in MS patients of approximately 30%. It has been demonstrated that patients with severe SARS-CoV-2 infection usually show increased levels of D-dimer, fibrinogen, C-reactive protein (CRP), and overactivation of blood platelets, which are essential elements of prothrombotic events. In this review, the latest knowledge gathered during an ongoing pandemic of SARS-CoV-2 infection on the neurodegeneration processes in MS is discussed.

COVID-19 and Multiple Sclerosis: Predisposition and Precautions in Treatment

Infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), leading to Coronavirus disease 2019 (COVID-19), is not always confined to the respiratory tract, while patients with can develop neurological manifestations. The patients with multiple sclerosis (MS) pose challenges in this pandemic situation, because of the immunosuppressive medications they get and the fact that viral infections may contribute to MS exacerbation and relapses as an environmental factor in genetically predisposed individuals. Herein, possible consequences of COVID-19 which may carry for the MS patients and the underlying mechanisms of its impact are discussed.

The CSF Profile Linked to Cortical Damage Predicts Multiple Sclerosis Activity

OBJECTIVE

Intrathecal inflammation correlates with the grey matter damage since the early stages of multiple sclerosis (MS), but whether the cerebrospinal fluid (CSF) profile can help to identify patients at risk of disease activity is still unclear.

METHODS

We evaluated the association between CSF levels of 18 cytokines, previously found to be associated to grey matter damage, and the disease activity, among 99 patients with relapsing-remitting MS, who underwent blinded clinical and 3 T magnetic resonance imaging (MRI) evaluations for 4 years. Groups with evidence of disease activity (EDA) or no evidence of disease activity (NEDA; occurrence of relapses, new white matter lesions, and Expanded Disability Status Scale [EDSS] change) were identified. Cortical lesions and the annualized cortical thinning were also evaluated.

RESULTS

Forty-one patients experienced EDA and, compared to the NEDA group, had at diagnosis higher CSF levels of CXCL13, CXCL12, IFNγ, TNF, sCD163, LIGHT, and APRIL (p < 0.001). In the multivariate analysis, CXCL13 (hazard ratio [HR] = 1.35; p = 0.0002), LIGHT (HR = 1.22; p = 0.005) and APRIL (HR = 1.78; p = 0.0001) were the CSF molecules more strongly associated with the risk of EDA. The model, including CSF variables, predicted more accurately the occurrence of disease activity than the model with only clinical/MRI parameters (C-index at 4 years = 71% vs 44%). Finally, higher CSF levels of CXCL13 (β = 4.7*10^-4 ; p < 0.001), TNF (β = 3.1*10^-3 ; p = 0.004), LIGHT (β = 2.6*10^-4 ; p = 0.003), sCD163 (β = 4.3*10^-3 ; p = 0.009), and TWEAK (β = 3.4*10^-3 ; p = 0.024) were associated with more severe cortical thinning.

INTERPRETATION

A specific CSF profile, mainly characterized by elevated levels of B-cell related cytokines, distinguishes patients at high risk of disease activity and severe cortical damage. The CSF analysis may allow stratifications of patients at diagnosis for optimizing therapeutic approaches. ANN NEUROL 2020;88:562-573.

Relationship Between sCD163 and mCD163 and Their Implication in the Detection and Typing of Leprosy

Background

Leprosy is a chronic contagious disease caused by Mycobacterium lepraea. CD163 is a monocyte trans-membrane glycoprotein receptor (mCD163) that sheds from the cell surface and circulates as a soluble (serum) form (sCD163). Changes in the mCD163 and sCD163 levels could mirror the categorization of inflammatory procedure, demonstrating a possible use of CD163 as a diagnostic indicator of inflammation.

Objective

To investigate the possible role of CD163 (sCD163 and mCD163) in leprosy pathogenesis and to assess whether CD163 is a helpful inflammatory marker of leprosy development and typing.

Patients and Methods

This case control study included 70 leprosy patients and 30 healthy controls. Leprosy patients were classified according to the Madrid criteria (1953) into: tuberculoid leprosy (TT), border-line leprosy (BL), and lepromatous leprosy (LL). For all participants, complete blood count (CBC), serum CD163 using ELISA and monocytes positive for CD163 using flow cytometry were done.

Results

Leprosy patients had significantly low WBCs and platelet counts (p<0.001) and had significantly higher sCD163 (p=0.025) and mCD163 (p=0.042) that were highest in LL followed by BL, then TT patients (p<0.001). There was a significant positive correlation between mCD163 and sCD163 levels in leprosy patients (r=0.896, p<0.001). ROC analysis revealed a significant role of serum sCD163 and of mCD163 positive monocytes in the detection (p<0.001) and typing of leprosy (p=0.002 and p<0.001, respectively).

Conclusion

Both sCD163 and mCD163 positive monocytes may have an active role in leprosy pathogenesis. They could be potential biomarkers for leprosy detection and typing.

Activated monocytes and markers of inflammation in newly diagnosed multiple sclerosis

In multiple sclerosis (MS), the inflammation and demyelination of the central nervous system (CNS) develop in distinct ways. This makes diagnosing patients difficult, imperative to initiating early and proper treatment. Several common features exist, among them a profound infiltration of monocytes into the CNS mediating demyelination and tissue destruction. In the periphery, monocytes are divided into three subsets depending on expression of CD14 and CD16, representing different stages of activation and differentiation. To investigate their involvement in MS, peripheral blood mononuclear cells (PBMCs) from 61 patients with incipient, untreated MS and 22 symptomatic control (SC) patients as well as 6 patients with radiologically isolated syndrome (RIS) were characterized ex vivo. In addition, paired serum and cerebrospinal fluid (CSF) samples were analyzed with a panel of biomarkers. In PBMC samples, we demonstrate decreased levels of nonclassical monocytes with a concomitant significant decrease of human endogenous retrovirus (HERV) H3 envelope epitopes on this monocyte subset compared with SC and RIS. The observed HERV expression is present on nonclassical monocytes irrespective of MS and thus presumably a result of the inflammatory activation. For the other surface markers analyzed, we found significantly decreased expression between classical and nonclassical monocytes. In matched samples of CSF a highly significant increase in levels of soluble markers of activation and inflammation is shown, and notably this is not the case for the serum samples. Of the soluble markers investigated, interleukin (IL)‐12/IL‐23p40 had the highest discriminatory power in differentiating patients with MS from SC and RIS, almost comparable to the immunoglobulin G index.

Microglia in Multiple Sclerosis: Friend or Foe?

Microglia originate from myeloid progenitors in the embryonic yolk sac and play an integral role in central nervous system (CNS) development, immune surveillance and repair. The role of microglia in multiple sclerosis (MS) has been complex and controversial, with evidence suggesting that these cells play key roles in both active inflammation and remyelination. Here we will review the most recent histological classification of MS lesions as well as the evidence supporting both inflammatory and reparative functions of these cells. We will also review how microglia may yield new biomarkers for MS activity and serve as a potential target for therapy.

The GPR17 Receptor-A Promising Goal for Therapy and a Potential Marker of the Neurodegenerative Process in Multiple Sclerosis

One of the most important goals in the treatment of demyelinating diseases such as multiple sclerosis (MS) is, in addition to immunomodulation, reconstruction of the lost myelin sheath. The modulator of the central nervous system myelination is the metabotropic receptor coupled to the G-protein: GPR17. GPR17 receptors are considered to be sensors of local damage to the myelin sheath, and play a role in the reconstruction and repair of demyelinating plaques caused by ongoing inflammatory processes. GPR17 receptors are present on nerve cells and precursor oligodendrocyte cells. Under physiological conditions, they are responsible for the differentiation and subsequent maturation of oligodendrocytes, while under pathological conditions (during damage to nerve cells), their expression increases to become mediators in the demyelinating processes. Moreover, they are essential not only in both the processes of inducing damage and the death of neurons, but also in the local repair of the damaged myelin sheath. Therefore, GPR17 receptors may be recognized as the potential goal in creating innovative therapies for the treatment of the neurodegenerative process in MS, based on the acceleration of the remyelination processes. This review examines the role of GRP17 in pathomechanisms of MS development.

Iron homeostasis, complement, and coagulation cascade as CSF signature of cortical lesions in early multiple sclerosis

Objective

Intrathecal inflammation, compartmentalized in cerebrospinal fluid (CSF) and in meningeal infiltrates, has fundamental role in inflammation, demyelination, and neuronal injury in cerebral cortex in multiple sclerosis (MS). Since the exact link between intrathecal inflammation and mechanisms of cortical pathology remains unknown, we aimed to investigate a detailed proteomic CSF profiling which is able to reflect cortical damage in early MS.

Methods

We combined new proteomic method, TRIDENT, CSF analysis, and advanced 3T magnetic resonance imaging (MRI), in 64 MS patients at the time of diagnosis and 26 controls with other neurological disorders. MS patients were stratified according to cortical lesion (CL) load.

Results

We identified 227 proteins differently expressed between the patients with high and low CL load. These were mainly related to complement and coagulation cascade as well as to iron homeostasis pathway (30 and 6% of all identified proteins, respectively). Accordingly, in the CSF of MS patients with high CL load at diagnosis, significantly higher levels of sCD163 (P < 0.0001), free hemoglobin (Hb) (P < 0.05), haptoglobin (P < 0.0001), and fibrinogen (P < 0.01) were detected. By contrast, CSF levels of sCD14 were significantly (P < 0.05) higher in MS patients with low CL load. Furthermore, CSF levels of sCD163 positively correlated (P < 0.01) with CSF levels of neurofilament, fibrinogen, and B cell‐related molecules, such as CXCL13, CXCL12, IL10, and BAFF.

Interpretation

Intrathecal dysregulation of iron homeostasis and coagulation pathway as well as B‐cell and monocyte activity are strictly correlated with cortical damage at early disease stages.

Cerebrospinal fluid neurofilament light chain in multiple sclerosis and its subtypes: a meta-analysis of case-control studies

OBJECTIVE

Neurofilament is a biomarker of axonal injury proposed as a useful adjunct in the monitoring of patients with multiple sclerosis (MS). We conducted a systematic review and meta-analysis of case-control studies that have measured neurofilament light chain (NfL) levels in cerebrospinal fluid (CSF) of people with MS (pwMS), in order to determine whether, and to what degree, CSF NfL levels differentiate MS from controls, or the subtypes or stages of MS from each other.

METHODS

Guidelines on Preferred Reporting Items for Systematic Reviews and Meta-Analyses were followed. Electronic databases were searched for published and 'grey' literature, with 151 hits. Of 51 full articles screened, 20 were included in qualitative analysis, and 14 in meta-analysis.

RESULTS

CSF NfL was higher in 746 pwMS than 435 (healthy and disease) controls, with a moderate effect size of 0.61 (p < 0.00001). Mean CSF NfL levels were significantly higher in 176 pwMS with relapsing disease than 92 with progressive disease (2124.8 ng/L, SD 3348.9 vs 1121.4 ng/L, SD 947.7, p = 0.0108). CSF NfL in 138 pwMS in relapse (irrespective of MS subtype) was double that seen in 268 pwMS in remission (3080.6 ng/L, SD 4715.9 vs 1541.7 ng/L, SD 2406.5, p < 0.0001).

CONCLUSIONS

CSF NfL correlates with MS activity throughout the course of MS, reflecting the axonal damage in pwMS. Relapse is more strongly associated with elevated CSF NfL levels than the development of progression, and NfL may be most useful as a marker of disease 'activity' rather than as a marker of disability or disease stage.

Diagnostic Value of Cerebrospinal Fluid Neurofilament Light Protein in Neurology: A Systematic Review and Meta-analysis

IMPORTANCE

Neurofilament light protein (NfL) is elevated in cerebrospinal fluid (CSF) of a number of neurological conditions compared with healthy controls (HC) and is a candidate biomarker for neuroaxonal damage. The influence of age and sex is largely unknown, and levels across neurological disorders have not been compared systematically to date.

OBJECTIVES

To assess the associations of age, sex, and diagnosis with NfL in CSF (cNfL) and to evaluate its potential in discriminating clinically similar conditions.

DATA SOURCES

PubMed was searched for studies published between January 1, 2006, and January 1, 2016, reporting cNfL levels (using the search terms neurofilament light and cerebrospinal fluid) in neurological or psychiatric conditions and/or in HC.

STUDY SELECTION

Studies reporting NfL levels measured in lumbar CSF using a commercially available immunoassay, as well as age and sex.

DATA EXTRACTION AND SYNTHESIS

Individual-level data were requested from study authors. Generalized linear mixed-effects models were used to estimate the fixed effects of age, sex, and diagnosis on log-transformed NfL levels, with cohort of origin modeled as a random intercept.

MAIN OUTCOME AND MEASURE

The cNfL levels adjusted for age and sex across diagnoses.

RESULTS

Data were collected for 10 059 individuals (mean [SD] age, 59.7 [18.8] years; 54.1% female). Thirty-five diagnoses were identified, including inflammatory diseases of the central nervous system (n = 2795), dementias and predementia stages (n = 4284), parkinsonian disorders (n = 984), and HC (n = 1332). The cNfL was elevated compared with HC in a majority of neurological conditions studied. Highest levels were observed in cognitively impaired HIV-positive individuals (iHIV), amyotrophic lateral sclerosis, frontotemporal dementia (FTD), and Huntington disease. In 33.3% of diagnoses, including HC, multiple sclerosis, Alzheimer disease (AD), and Parkinson disease (PD), cNfL was higher in men than women. The cNfL increased with age in HC and a majority of neurological conditions, although the association was strongest in HC. The cNfL overlapped in most clinically similar diagnoses except for FTD and iHIV, which segregated from other dementias, and PD, which segregated from atypical parkinsonian syndromes.

CONCLUSIONS AND RELEVANCE

These data support the use of cNfL as a biomarker of neuroaxonal damage and indicate that age-specific and sex-specific (and in some cases disease-specific) reference values may be needed. The cNfL has potential to assist the differentiation of FTD from AD and PD from atypical parkinsonian syndromes.

Biomarkers in Multiple Sclerosis

Multiple sclerosis (MS) is a chronic neurodegenerative autoimmune disease with a complex clinical course characterized by inflammation, demyelination, and axonal degeneration. Diagnosis of MS most commonly includes finding lesions in at least two separate areas of the central nervous system (CNS), including the brain, spinal cord, and optic nerves. In recent years, there has been a remarkable increase in the number of available treatments for MS. An optimal treatment is usually based on a personalized approach determined by an individual patient's prognosis and treatment risks. Biomarkers that can predict disability progression, monitor ongoing disease activity, and assess treatment response are integral in making important decisions regarding MS treatment. This review describes MS biomarkers that are currently being used in clinical practice; it also reviews and consolidates published findings from clinically relevant potential MS biomarkers in recent years. The work also discusses the challenges of validating and application of biomarkers in MS clinical practice.

Increased cerebrospinal fluid neurofilament light chain in central nervous system inflammatory demyelinating disease

BACKGROUND

Central nervous system (CNS) inflammatory demyelinating disease (IDD) is an immune-mediated disease that is pathologically characterized by demyelination and inflammatory infiltration in the CNS and includes clinically isolated syndrome (CIS), multiple sclerosis (MS), and neuromyelitis optica spectrum disorders (NMOSD). IDD is usually characterized by variable symptoms, multivariate imaging, uncertain reactions to treatment, and a variable prognosis, which makes it difficult to diagnose early. In recent years, the role of the neurofilament light chain (NFL), an axonal injury biomarker, in IDD has become increasingly important. We will detect and analyse cerebrospinal fluid (CSF) NFL levels in IDD and normal control patients to determine the significance of NFL in the diagnosis and prognostic prediction of IDD.

METHODS

A total of 41 CIS, 34 MS and 73 NMOSD patients and 40 other patients with conditions such as neurosis and migraine with lumbar puncture were enrolled as the patient groups and the normal control (NC) group from the population of in- and outpatients of the Department of Neurology of the Sixth Medical Centre of Chinese People's Liberation Army General Hospital from January 2014 to October 2016. Clinical and neuroimaging features of the patient groups as well as CSF samples from both types of groups were collected, and the NFL levels of CSF were measured by enzyme linked immunosorbent assay.

RESULTS

CSF NFL levels in the CIS, MS and NMOSD groups were significantly higher than those in the NC group (P < 0.05, analysis of variance of NFL levels was performed after logarithmic transformation based on 10). There were no statistically significant differences in the CSF NFL levels among the CIS, MS and NMOSD groups (P > 0.05). The NFL levels of CSF in the CIS, MS and NMOSD groups were correlated with the expanded disability status scale score and enhancement in gadolinium-magnetic resonance imaging (all P < 0.05). Gender, oligoclonal band in CSF, aquaporin 4 antibody and 25‑hydroxy vitamin D₃ [25(OH)D₃] in serum were not related to the NFL levels (P > 0.05).

CONCLUSION

The NFL level of CSF is conducive to assessing the severity and probable progress of IDD but is not helpful in distinguishing IDD among Chinese.

Cerebrospinal fluid free kappa light chains and kappa index perform equal to oligoclonal bands in the diagnosis of multiple sclerosis

Background

Detection of intrathecal immunoglobulin G (IgG) synthesis by gold standard oligoclonal bands (OCB) or IgG index remains an integral part of multiple sclerosis (MS) diagnostics, although both methods have weaknesses. Emerging evidence suggests that automated detection of free light chains (FLC) in the cerebrospinal fluid (CSF) has diagnostic performance equal to OCB. The objective of this study was to compare the diagnostic performance of CSF FLC with OCB and IgG index in a large cohort of Scandinavian patients referred for MS evaluation.

Methods

We prospectively included 230 patients suspected for MS. They are composed of patients with MS (n=96), clinically isolated syndrome (n=37), other neurological diseases (OND, n=31) and symptomatic controls (SC, n=66). CSF and serum samples were analyzed for kappa and lambda FLC, OCB and IgG index. Diagnostic performance was evaluated by receiver operating characteristic (ROC) analysis.

Results

Both the absolute concentration of CSF-kappa and the kappa index had excellent MS diagnostic performances with ROC area under the curve of 0.93 and 0.94 (MS vs. SC+OND). At the 0.42 mg/L cutoff, CSF-kappa had sensitivity and specificity of 93.8% and 85.6%, whereas sensitivity and specificity for OCB was 82.3% and 93.8% (72.9% and 95.9% for IgG index at cutoff 0.64). CSF-lambda and lambda index performed inferior to CSF-kappa and kappa index.

Conclusions

CSF-kappa and kappa index represent automated, rapid and low-cost alternatives to OCB. Using merely the absolute concentration of CSF-kappa is a logistic advantage in the clinical laboratories.

Emerging Biosensing Technologies for Neuroinflammatory and Neurodegenerative Disease Diagnostics

Neuroinflammation plays a critical role in the onset and progression of many neurological disorders, including Multiple Sclerosis, Alzheimer's and Parkinson's diseases. In these clinical conditions the underlying neuroinflammatory processes are significantly heterogeneous. Nevertheless, a common link is the chronic activation of innate immune responses and imbalanced secretion of pro and anti-inflammatory mediators. In light of this, the discovery of robust biomarkers is crucial for screening, early diagnosis, and monitoring of neurological diseases. However, the difficulty to investigate biochemical processes directly in the central nervous system (CNS) is challenging. In recent years, biomarkers of CNS inflammatory responses have been identified in different body fluids, such as blood, cerebrospinal fluid, and tears. In addition, progress in micro and nanotechnology has enabled the development of biosensing platforms capable of detecting in real-time, multiple biomarkers in clinically relevant samples. Biosensing technologies are approaching maturity where they will become deployed in community settings, at which point screening programs and personalized medicine will become a reality. In this multidisciplinary review, our goal is to highlight both clinical and recent technological advances toward the development of multiplex-based solutions for effective neuroinflammatory and neurodegenerative disease diagnostics and monitoring.

Osteopontin (OPN) as a CSF and blood biomarker for multiple sclerosis: A systematic review and meta-analysis

Identifying a reliable biomarker may accelerate diagnosis of multiple sclerosis (MS) and lead to early management of the disease. Accumulating evidence suggest that cerebrospinal fluid (CSF) and peripheral blood concentration of osteopontin (OPN) may have diagnostic and prognostic value in MS. We conducted a systematic review and meta-analysis of studies that measured peripheral blood and CSF levels of OPN in MS patients and controls to evaluate the diagnostic potential of this biomarker better. We searched PubMed, Web of Science and Scopus databases to find articles that measured OPN concentration in peripheral blood and CSF samples from MS patients up to October 19, 2016. Q statistic tests and the I2 index were applied for heterogeneity assessment. If the I2 index was less than 40%, the fixed-effects model was used for meta-analysis. Random-effects meta-analysis was chosen if the I2 value was greater than 40%. After removal of duplicates, 918 articles were identified, and 27 of them fulfilled the inclusion criteria. We included 22 eligible studies in the final meta-analysis. MS patients, in general, had considerably higher levels of OPN in their CSF and blood when compared to all types of controls (p<0.05). When the comparisons were made between different subtypes of MS patients and controls, the results pointed to significantly higher levels of OPN in CSF of MS subgroups (p<0.05). All subtypes of MS patients, except CIS patients, had increased blood levels of OPN compared to controls (p<0.05). In the second set of meta-analyses, we compared the peripheral blood and CSF concentrations of OPN between MS patient subtypes. CIS patients had significantly lower levels of OPN both in their peripheral blood and CSF compared to patients with progressive subtypes of MS (p<0.05). CSF concentration of OPN was significantly higher among RRMS patients compared to the CIS patients and SPMS patients (P<0.05). Finally, patients with active MS had significantly higher OPN levels in their CSF compared to patients with stable disease (P = 0.007). The result of this study confirms that increased levels of OPN exist in CSF and peripheral blood of MS patients and strengthens the evidence regarding the clinical utility of OPN as a promising and validated biomarker for MS.

Multiple sclerosis: genetics, biomarkers, treatments

PURPOSE OF REVIEW

We discuss new paradigms for understanding the immunopathology of multiple sclerosis through the recent development of high throughput genetic analysis, emergence of numerous candidate biomarkers, and the broadening of the treatment arsenal.

RECENT FINDINGS

The recent use of genome wide association studies provide new tools for a better understanding of multiple sclerosis etiology. Genome-wide association studies have identified many genes implicated in immune regulation and the next step will be to elucidate how those genetic variations influence immune cell function to drive disease development and progression. Furthermore, patient care has seen the emergence of new biomarkers for monitoring disease progression and response to treatment. Finally, the introduction of numerous immunomodulatory treatments will likely improve clinical outcome of multiple sclerosis patients in the future.

SUMMARY

Breakthroughs in the field of multiple sclerosis have led to a better understanding of the physiopathology of the disease, follow up, and treatment of the patients that develop relapsing remitting multiple sclerosis. The next challenge for multiple sclerosis will be to press forward to model and decipher multiple sclerosis progression, which will help both to develop therapeutics and generate knowledge about mechanisms of neurodegeneration.

Shifting paradigms in multiple sclerosis: from disease-specific, through population-specific toward patient-specific

PURPOSE OF REVIEW

In recent years we notice paradigm shifts in the understanding of multiple sclerosis (MS), leading to important transition in the patients' management. This review discusses some of the recent findings and developments underlying the conceptual changes being translated from 'treating the disease' to 'treating the patient' with MS (PwMS).

RECENT FINDINGS

Applying advanced technologies combined with cross-disciplinary efforts in the fields of neuropathology, neuroimmunology, neurobiology, and neuroimaging, together with clinical neurology provided support for the notion that MS is not a single disease but rather a spectrum. Predictive markers of disease subtypes, disease activity and response to therapy are being developed; some already applied to practice, allowing informed management. In parallel, population-specific issues, some genetic-driven, others caused by environmental (sun-exposure, life-style, etc.), gender-related (hormones) and epigenetic factors, are being elucidated. Additionally, patient empowerment-based approaches, including integration of patient-reported outcome measures (PRO) as well as tools to enhance patients' adherence to medications, are being developed, some already provided as part of emerging mobile-health technologies.

SUMMARY

Developments in the MS field, elucidating disease subtypes and interpopulation diversities, together with integration of patient-centered approaches, allow transition toward precision medicine in MS clinical trials and patient care.

Subsets of activated monocytes and markers of inflammation in incipient and progressed multiple sclerosis

Multiple sclerosis (MS) is an immune mediated, inflammatory and demyelinating disease of the central nervous system (CNS). Substantial evidence points toward monocytes and macrophages playing prominent roles early in disease, mediating both pro- and anti-inflammatory responses. Monocytes are subdivided into three subsets depending on the expression of CD14 and CD16, representing different stages of inflammatory activation. To investigate their involvement in MS, peripheral blood mononuclear cells from 40 patients with incipient or progressed MS and 20 healthy controls were characterized ex vivo. In MS samples, we demonstrate a highly significant increase in nonclassical monocytes (CD14+CD16++), with a concomitant significant reduction in classical monocytes (CD14++CD16-) compared with healthy controls. Also, a significant reduction in the surface expression of CD40, CD163, and CD192 was found, attributable to the upregulation of the nonclassical monocytes. In addition, significantly increased levels of human endogenous retrovirus (HERV) envelope (Env) epitopes, encoded by both HERV-H/F and HERV-W, were specifically found on nonclassical monocytes from patients with MS; emphasizing their involvement in MS disease. In parallel, serum and cerebrospinal fluid (CSF) samples were analyzed for soluble biomarkers of inflammation and neurodegeneration. For sCD163 versus CD163, no significant correlations were found, whereas highly significant correlations between levels of soluble neopterine and the intermediate monocyte (CD14++CD16+) population was found, as were correlations between levels of soluble osteopontin and the HERV Env expression on nonclassical monocytes. The results from this study emphasize the relevance of further focus on monocyte subsets, particularly the nonclassical monocytes in monitoring of inflammatory diseases.

Molecular Mechanisms Modulating the Phenotype of Macrophages and Microglia

Macrophages and microglia play crucial roles during central nervous system development, homeostasis and acute events such as infection or injury. The diverse functions of tissue macrophages and microglia are mirrored by equally diverse phenotypes. A model of inflammatory/M1 versus a resolution phase/M2 macrophages has been widely used. However, the complexity of macrophage function can only be achieved by the existence of varied, plastic and tridimensional macrophage phenotypes. Understanding how tissue macrophages integrate environmental signals via molecular programs to define pathogen/injury inflammatory responses provides an opportunity to better understand the multilayered nature of macrophages, as well as target and modulate cellular programs to control excessive inflammation. This is particularly important in MS and other neuroinflammatory diseases, where chronic inflammatory macrophage and microglial responses may contribute to pathology. Here, we perform a comprehensive review of our current understanding of how molecular pathways modulate tissue macrophage phenotype, covering both classic pathways and the emerging role of microRNAs, receptor-tyrosine kinases and metabolism in macrophage phenotype. In addition, we discuss pathway parallels in microglia, novel markers helpful in the identification of peripheral macrophages versus microglia and markers linked to their phenotype.

Clinical significance of the serum biomarker index detection in children with Henoch-Schonlein purpura

OBJECTIVE

To explore a panel of serum biomarkers for laboratory diagnosis of pediatric Henoch-Schönlein purpura (HSP).

METHODS

The blood white blood cells (WBC) and serum levels of serum amyloid A (SAA), interleukin 6 (IL-6), immunoglobulin A (IgA), immunoglobulin G (IgG), immunoglobulin M (IgM), immunoglobulin E (IgE), C-reactive protein (CRP), complement component 3 (C3), complement component 4 (C4), and ASO (anti-streptolysin O) were detected in 127 patients with Henoch-Schonlein purpura (HSP), 110 cases of septicemia patients, and 121 healthy volunteers. The diagnostic ability of biomarkers selected from HSP and septicemia patients was analyzed by ROC curve. By designing the calculation model, the biomarker index was calculated for laboratory diagnosis of HSP and differential diagnosis between HSP and septicemia.

RESULTS

The levels of serum WBC, CRP, IL-6 and SAA in the septicemia patients were significantly higher than those in the control group (p<0.05). Compared with the healthy individuals, serum levels of WBC, CRP, IL-6, SAA, IgA and IgM were significantly increased in patients with HSP (p<0.05). The area under the curve (AUC) of SAA, IgA, IgM, WBC, IL-6, and CRP in the patients with HSP was 0.964, 0.855, 0.849, 0.787, 0.765, and 0.622, respectively. The values of SAA, IgA, IgM, WBC, IL-6, and CRP in septicemia patients were 0.700, 0.428, 0.689, 0.682, 0.891, and 0.853, respectively. Biomarker index=SAA+IgA/4000+IgM/4000×0.4CRPmean valueCRPi_. The biomarker index in HSP patients was significantly higher than that of the healthy controls. However, the biomarker index in septicemia patients was significantly lower than the control.

CONCLUSION

The biomarker index of HSP patients is higher than that of the control group. While in the infectious disease represented by septicemia, it is decreased. The detection of biomarker index could exclude the interference of infection as the auxiliary examination to HSP patients.

sCD163 levels as a biomarker of disease severity in leprosy and visceral leishmaniasis

Background

CD163, receptor for the haptoglobin–hemoglobin complex, is expressed on monocytes/macrophages and neutrophils. A soluble form of CD163 (sCD163) has been associated with the M2 macrophage phenotype, and M2 macrophages have been shown to down-modulate inflammatory responses. In particular, previous studies have shown that M2 is closely associated with the most severe clinical presentation of leprosy (i.e. lepromatous leprosy (LL)), as well as tuberculosis. We hypothesized that sCD163 correlates with severity of diseases caused by intracellular pathogens.

Methodology/Principal findings

To assess this hypothesis, sCD163 levels were measured in the serum of leprosy and visceral leishmaniasis (VL) patients stratified by severity of the clinical presentation. sCD163 levels were significantly higher in patients with these diseases than those observed in healthy control individuals. Further analyses on infection and disease status of leprosy and VL patients revealed a clear association of sCD163 levels with clinical parameters of disease severity. In vitro culture assays revealed that Leishmania infection induced CD163 expression on the surface of both monocyte/macrophages and neutrophils, suggesting these cells as possible sources of sCD163. FACS analyses shows that the cells expressing CD163 produces both TNF-α and IL-4.

Conclusions/Significance

Taken together, our results reveal sCD163 as a potential biomarker of severity of diseases caused by intracellular pathogens M. leprae and Leishmania spp. and have a modulatory role, with a mix of an inflammatory property induced by TNF-α release, but that potentially induces an anti-inflammatory T cell response, related to IL-4 release.

Visceral leishmaniasis (VL) is a systemic, and most severe form of leishmaniasis. Soluble CD163 (sCD163) levels can serve as biomarker for disease severity in several inflammatory disorders. However, no linkage has been reported for its relationship with Leishmania infections. We now demonstrate, for the first time, that sCD163 is increased in VL patients, and its presence is directly correlated to clinical parameters of disease severity. In vitro infection of monocyte-derived macrophages and neutrophils with L. infantum and L. amazonensis induces, while BCG reduce the expression of CD163 on macrophage surface Furthermore, presence of sCD163 is reduced during clinical improvements. Taken together, results reveal an important role for sCD163 in immune modulation during disease progression, and suggest a potential role as biomarker for determining disease severity and clearance.

Increased cortical lesion load and intrathecal inflammation is associated with oligoclonal bands in multiple sclerosis patients: a combined CSF and MRI study

BACKGROUND

Although IgG oligoclonal bands (OCBs) in the cerebrospinal fluid (CSF) are a frequent phenomenon in multiple sclerosis (MS) patients, their relationship with grey matter lesions, intrathecal/meningeal inflammation and clinical evolution has not been clarified yet. The aim of our study was to assess the relationship between the OCBs, the inflammatory/neurodegenerative CSF profile at diagnosis, the cortical lesion load and the clinical evolution after 10 years.

METHODS

This is a 10-year observational, cross-sectional study based on a combined MRI, cognitive and CSF profiling of the examined patients. Forty consecutive OCB-negative (OCB-) and 50 OCB-positive (OCB+) MS patients were included in this study. Both groups had mean disease duration of 10 years and were age and gender matched. Each patient underwent neurological and neuropsychological evaluation and 3-T MRI. Analysis of the presence and levels of 28 inflammatory mediators was performed in the CSF obtained from 10 OCB- MS, 11 OCB+ MS and 10 patients with other neurological conditions.

RESULTS

Increased number of CLs was found in OCB+ compared to OCB- patients (p < 0.0001), whereas no difference was found in white matter lesion (WML) load (p = 0.36). The occurrence of OCB was also associated with increased levels of neurofilament light chains and of several inflammatory mediators linked to B lymphocyte activity and lymphoid-neogenesis (CXCL13, CXCL12, CXCL10, TNFSF13, TNFSF13B, IL6, IL10) and other pro-inflammatory molecules, such as IFN-γ, TNF, MMP2, GM-CSF, osteopontin and sCD163. Finally, the occurrence of OCB was found associated with poor prognosis, from both physical and cognitive points of view.

CONCLUSIONS

OCB at MS onset are associated with more severe GM pathology and with a more severe physical disability and cognitive impairment after 10 years. Increased levels of cytokines linked to B cell activation, lymphoid-neogenesis, and pro-inflammatory immune response in the CSF of OCB+ patients support the hypothesis of crucial role played by compartmentalized, intrathecal B cell response in the pathogenesis of CLs and OCB production.

The role of exosomes in CNS inflammation and their involvement in multiple sclerosis

Multiple sclerosis (MS) is a putative autoimmune disease of the central nervous system (CNS) in which autoreactive immune cells recognizing myelin antigens lead to demyelination and axonal injury. Mechanisms relevant to the pathogenesis of MS have not been fully elucidated, particularly those underlying initiation of immune system dysfunction. For example, it is not known how reactivity against CNS components is generated within the peripheral immune system. In this review, we propose that a significant contribution to the immunoregulatory events may derive from a cell-to-cell communication system involving the production, secretion and transfer of extracellular vesicles known as exosomes. Herein, we discuss in detail the biogenesis and roles of these cell surface-generated vesicles from the standpoint of receptors and their cargo, microRNA. It is well known that exosomes can cross the blood-brain barrier and thus may contribute to the spread of brain antigens to the periphery. Further understanding of exosome-dependent mechanisms in MS should provide a novel angle to the analysis of the pathogenesis of this disease. Finally, we launch the idea that exosomes and their contents may serve as biomarkers in MS.

Biomarkers of multiple sclerosis: current findings

Multiple sclerosis (MS) is an autoimmune disease affecting the brain and spinal cord that is associated with chronic inflammation leading to demyelination and neurodegeneration. With the recent increase in the number of available therapies for MS, optimal treatment will be based on a personalized approach determined by an individual patient's prognosis and treatment risks. An integral part of such therapeutic decisions will be the use of molecular biomarkers to predict disability progression, monitor ongoing disease activity, and assess treatment response. This review describes current published findings within the past 3 years in biomarker research in MS, specifically highlighting recent advances in the validation of cerebrospinal fluid biomarkers such as neurofilaments (light and heavy chains), chitinases and chitinase 3-like proteins, soluble surface markers of innate immunity, and oligoclonal immunoglobulin M antibodies. Current research in circulating miRNAs as biomarkers of MS is also discussed. Continued validation and testing will be required before MS biomarkers are routinely applied in a clinical setting.