Importance:Capturing individual multiple sclerosis (MS) progression is difficult; few studies have evaluated glial fibrillary acidic protein (GFAP) in large longitudinal cohorts with independent validation. Objective:To investigate whether serum GFAP levels and treatment-related changes are associated with future progression independent of relapse activity (PIRA). Design, Setting, and Participants:This was a prospective observational study using 2 large MS cohorts: the Swiss MS Cohort (SMSC; initiated in June 2012; data extraction September 22, 2025) and the Expression, Proteomics, Imaging, Clinical study (EPIC; initiated in July 2004; data extraction February 21, 2024). The study took place at tertiary MS centers (8 for SMSC and 1 for EPIC). A total of 2329 persons with MS from both cohorts with at least 1 available time point with neurofilament light chain (NfL) and GFAP measurements were included (overall 18 629 measurements). Exposures:Clinical data and NfL and GFAP z scores, collected and calculated every 6 or 12 months. Main Outcomes and Measures:Risk of future PIRA, defined as Expanded Disability Status Scale score worsening confirmed after 6 or more months without relapses (in SMSC), or a composite additionally including greater than 20% worsening in the 9-hole peg test or timed 25-ft walk test (in EPIC). Results:The SMSC and EPIC cohorts consisted of 1709 (13 375 samples; median [IQR] follow-up, 6.9 [2.5-10.7] years and age, 40.6 [32.1-50.1] years; 1128 [66.0%] female) and 620 (5254 samples; median [IQR] follow-up, 13.1 [9.4-14.0] years and age, 42.0 [35.0-50.0] years; 432 [69.7%] female) persons with MS, respectively. Consistent with prior work, high NfL was associated with relapse risk within the next year, whereas high GFAP was associated with long-term PIRA risk. In addition, elevated GFAP (z score >1.0 [84th percentile]) was associated with an average 40% higher hazard of short-term PIRA in the subsequent visit interval (SMSC: median [IQR] 346 [190-375] days; hazard ratio [HR], 1.45, 95% CI, 1.21-1.75; P < .001; EPIC: 385 [355-518] days; HR, 1.36; 95% CI, 1.07-1.71; P = .01). GFAP-based cohort enrichment in clinical trials targeting PIRA as an end point could reduce sample size by approximately 20%. Further, in SMSC, every yearly GFAP z score unit reduction during the first 2 years receiving fingolimod or B-cell-depleting therapy was associated with a lower risk of subsequent PIRA (54% risk reduction; HR, 0.46; 95% CI, 0.26-0.84; P = .01 and 67% risk reduction; HR, 0.33; 95% CI, 0.18-0.61; P < .001), respectively. Conclusions and Relevance:In this cohort study, elevated GFAP was associated with a higher risk of PIRA, while treatment-associated reductions were associated with a lower PIRA risk. Together, these results suggest that serum GFAP may serve as a biomarker for personalized risk stratification and treatment monitoring and as a screening tool to reduce cohort size in clinical trials targeting MS progression.

In multiple sclerosis (MS) patients under therapy, the increase of serum glial fibrillary acidic protein (sGFAP) concentrations is associated with the course of 'progression in absence of relapse' (PIRA). While serum neurofilament light chain (sNfL) reflects both response as well as insufficient or lack of efficiency of disease-modifying therapies (DMT), the longitudinal course of sGFAP levels as a drug response marker for future PIRA in relation to specific types of DMT is less clear. We aimed to compare the predictive capacity of sGFAP and sNfL for PIRA and relapse activity and the longitudinal course in people with MS (PwMS) treated with fingolimod, based on Z scores derived from normative values. Overall, 420 PwMS under fingolimod treatment with follow-up of 9.1 years (interquartile range: 7.0-11.0) from the Swiss MS Cohort, contributing 2935 longitudinal serum samples, were included. A reference data set for sGFAP established from 4297 healthy controls across three European and North American cohorts was used to calculate Z scores. The longitudinal course and the predictive capacity of biomarkers for time to PIRA and relapse were assessed by Cox proportional hazards and linear mixed-effects models. In controls, sGFAP concentrations were 13.6% higher in females than males and increased exponentially with age. Altogether, 31.0% of PwMS experienced ≥1 PIRA event. Elevated sGFAP Z scores (>0.75) were associated with increased risk of PIRA [hazard ratio (HR): 1.64; 95% confidence interval (CI): 1.16-2.32; P = 0.006], while this was not the case for sNfL. Conversely, elevated sNfL predicted relapses (HR: 1.58; 95% CI: 1.13-2.23; P = 0.008), while sGFAP did not. Both biomarkers decreased under treatment: sGFAP by 0.19 Z score units (ZSU)/10 years (95% CI: -0.27 to -0.11; P < 0.001) and sNfL by 0.16 ZSU/10 years (95% CI: -0.27 to -0.06; P = 0.002). Serum GFAP remained elevated in PwMS with future PIRA events (estimate: 0.29; 95% CI: 0.07-0.50; P = 0.009); no such association was found for sNfL. Serum GFAP and sNfL Z scores provide complementary predictive capacity for PIRA and relapse risk. The decrease of sGFAP under fingolimod is a feature not observed with other types of DMT and may hint to a specific anti-neurodegenerative effect of Sphingosine-1-phosphate-receptor modulators on astrocytes.

Multiple sclerosis (MS) is a complex, genetically mediated autoimmune disease of the CNS, in which anti-CD20-mediated B cell depletion is remarkably effective in the treatment of early disease. Although previous studies investigated the effect of B cell depletion on select immune cell subsets using flow cytometry-based methods, the therapeutic effect on the patient's immune landscape is unknown. In this study, we explored how B cell-depleting therapies modulate the immune landscape using single-cell RNA-Seq. We demonstrate that B cell depletion led to cell-type-specific changes in the abundance and function of cerebrospinal fluid (CSF) macrophages and peripheral blood monocytes. Specifically, a CSF-specific macrophage population with an antiinflammatory transcriptomic signature and peripheral CD16+ monocytes increased in frequency after B cell depletion. This was accompanied by increases in TNF-α mRNA and protein levels in monocytes following B cell depletion, consistent with the finding that anti-TNF-α treatment exacerbated autoimmune activity in MS. In parallel, B cell depletion induced changes in peripheral CD4+ T cell populations, including increases in the frequency of TIGIT+ Tregs and marked decreases in the frequency of myelin peptide-loaded, tetramer-binding CD4+ T cells. Collectively, this study provides an exhaustive transcriptomic map of immunological changes, revealing different cell-type-specific reprogramming as a result of B cell depletion treatment of MS.

Utility of repeated boosts of anti-SARS-CoV-2 vaccination in persons with MS (pwMS) treated with ocrelizumab is questioned. Investigate antiviral antibody and T-cell responses after mRNA vaccination for SARS-CoV-2 in ocrelizumab-treated pwMS. Peripheral blood mononuclear cells were stimulated with SARS-CoV-2 peptide pools and T-cell reactivity was assessed by ELISPOT for IFN-γ detection, and by multiparametric flow cytometry analyses for assessment and characterization of T-cell activation. Anti-SARS-CoV-2 spike and nucleocapsid antibodies were analyzed in plasma of pwMS using two commercial platforms. ELISPOT assay against the spike protein of SARS-CoV-2 showed that COVID vaccination with mRNA results in the development of a robust specific T-cell reactivity that is sustained over repeated cycles of vaccination and tends to decline 2 years after last boost. Flow cytometry analysis following stimulation with SARS-CoV-2 peptide pools confirmed the presence of CD8+ T memory stem cells. CD8+ T memory stem cells, in particular, increased after repeated boosts of vaccination, as occurred for anti-SARS-CoV-2 antibodies. Repeated cycles of vaccination increase T and B-cell reactivity against SARS-CoV-2.

Multiple sclerosis (MS) is a complex inflammatory and neurodegenerative disease of the central nervous system (CNS) with a multifaceted pathophysiology, likely involving a variety of mechanisms and effectors. To characterize the spectrum of cellular and molecular factors involved in MS at an unprecedented level, we here performed a comprehensive analysis of cerebrospinal fluid (CSF) and peripheral blood using multiple high-dimensional technologies, including mass cytometry, metabolomics and proteomics (NULISA and Olink Explore 3072). Enriched B cells and proteins involved in B cell functions in the CSF separated MS patients from other neurological disease entities. Specific B cell subpopulations and molecular markers including gut-microbiota-derived metabolites and neurofilament light protein, a marker of neuroaxonal damage, in CSF correlated with clinical (acute vs. stable disease) and/or radiological (gadolinium enhancement) disease activity. Altogether, unbiased broad phenotyping suggests key roles of diverse B subpopulations and B cell related molecular markers in MS, which are associated with both, inflammatory and degenerative aspects of the disease and may serve as disease activity and treatment response biomarkers. ### Competing Interest Statement F.P. received research support from F. Hoffmann-La Roche Ltd., Alexion Pharma Germany GmbH and Horizon Therapeutics Ireland DAC. ### Funding Statement This study was in part funded by F. Hoffmann-La Roche Ltd as part of Integrative Neuroscience Collaborations Network (INTONATE, MOGAD Precision). M. W. received the PhD scholarship from the Chinese Scholarship Council (CSC). C.B. was funded by the Deutsche Forschungsgemeinschaft (DFG, the German Research Foundation Project ID 259373024 CRC/TRR 167 (B05) and the BMBF (German Ministry of Education and Research), Foerderkennzeichen 01EJ2202A (TAhRget consortium). ### Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes The details of the IRB/oversight body that provided approval or exemption for the research described are given below: The study was approved by the ethics committee of the Charite Universitaetsmedizin Berlin (Ethikkommission der Charite Universitaetsmedizin Berlin; registration number EA1/386/20) in accordance with the Declaration of Helsinki of 1964 and its later amendments. All study participants provided informed consent before any study related procedures were undertaken and did not receive a compensation. I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable. Yes Source data are provided with this paper as Source Data file.

OBJECTIVE:To investigate the longitudinal dynamics of serum glial fibrillary acidic protein (sGFAP) and serum neurofilament light chain (sNfL) levels in people with multiple sclerosis (pwMS) under B-cell depleting therapy (BCDT) and their capacity to prognosticate future progression independent of relapse activity (PIRA) events. METHODS:A total of 362 pwMS (1,480 samples) starting BCDT in the Swiss Multiple Sclerosis (MS) Cohort were included. sGFAP levels in 2,861 control persons (4,943 samples) provided normative data to calculate adjusted Z scores. RESULTS:Elevated sGFAP levels (Z score >1) at 1 year were associated with a higher hazard for PIRA (hazard ratio [HR]: 1.80 [95% CI: 1.17-2.78]; p = 0.0079) than elevated sNfL levels (HR, 1.45 [0.95-2.24], p = 0.0886) in a combined model. Independent of PIRA events, sGFAP levels longitudinally increased by 0.49 Z score units per 10 years follow-up (estimate, 0.49 [0.29, 0.69], p < 0.0001). In patients experiencing PIRA, sGFAP Z scores were 0.52 Z score units higher versus stable patients (0.52 [0.22, 0.83], p = 0.0009). Different sNfL Z score trajectories were found in pwMS with versus without PIRA (interaction p = 0.0028), with an average decrease of 0.92 Z score units per 10 years observed without PIRA (-0.92 [-1.23, -0.60], p < 0.0001), whereas levels in patients with PIRA remained high. INTERPRETATION:Elevated sGFAP and lack of drop in sNfL after BCDT start are associated with increased risk of future PIRA. These findings provide a rationale for combined monitoring of sNfL and sGFAP in pwMS starting BCDT to predict the risk of PIRA, and to use sGFAP as an outcome in clinical trials aiming to impact on MS progressive disease biology. ANN NEUROL 2024.

Our objective was to analyze longitudinal cellular and humoral immune responses to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccination in people with multiple sclerosis (pwMS) on B-cell depleting treatment (BCDT) compared to pwMS without immunotherapy. We further evaluated the impact of COVID-19 infection and vaccination timing. PwMS (n = 439) on BCDT (ocrelizumab, rituximab, ofatumumab) or without immunotherapy were recruited for this prospective cohort study between June 2021 and June 2022. SARS-CoV-2 spike-specific antibodies and interferon-γ release of CD4 and CD8 T-cells upon stimulation with spike protein peptide pools were analyzed at different timepoints (after primary vaccination, 3 and 6 months after primary vaccination, after booster vaccination, 3 months after booster). Humoral response to SARS-CoV-2 was consistently lower whereas T-cell response was higher in patients with BCDT compared to controls. Cellular and humoral responses decreased over time after primary vaccination and increased again upon booster vaccination, with significantly higher antibody titers after booster than after primary vaccination in both untreated and B-cell-depleted pwMS. COVID-19 infection further led to a significant increase in SARS-CoV-2-specific responses. Despite attenuated B-cell responses, a third vaccination for patients with BCDT seems recommendable, since at least partial protection can be expected from the strong T-cell response. Moreover, our data show that an assessment of T-cell responses may be helpful in B-cell-depleted patients to evaluate the efficacy of SARS-CoV-2 vaccination.

BACKGROUND:The use and potential benefit of anti-severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) monoclonal antibodies (mAbs) for the treatment of mild-to-moderate coronavirus disease 2019 (COVID-19) in people living with multiple sclerosis (pwMS) remains poorly studied. The objective of this study is to describe the therapeutic use of anti-SARS-CoV-2 mAbs among pwMS.METHODS:This retrospective cohort study used electronic medical records data from the TriNetX Dataworks USA Network and included adult pwMS, diagnosed with COVID-19, who received anti-SARS-CoV-2 mAbs in the outpatient setting between November 2020 and April 2022. We analyzed COVID-19 severity at anti-SARS-CoV-2 mAb initiation and up to 30 days, stratified by before/after emergence of Omicron variant and by disease-modifying therapy (DMT).RESULTS:The study included 434 pwMS treated with anti-SARS-CoV-2 mAbs for mild-to-moderate COVID-19, including 270 patients before and 174 after Omicron emergence. Most pwMS were female (80.2%), mean age (SD) was 51.5 (12.5) years. Two-hundred-and-five patients were on DMTs, 51% of whom received anti-CD20s. One patient with moderate COVID-19 was hospitalized whilst receiving glatiramer acetate. No patients required intensive care and there were no deaths. COVID-19 outcomes were comparable following anti-SARS-CoV-2 mAb therapy in patients receiving different DMTs.CONCLUSION:Anti-SARS-CoV-2 mAb treatment for pwMS with mild-to-moderate COVID-19 may reduce the risk of COVID-19-related hospitalization and death.

The coronavirus disease 2019 (COVID-19) pandemic caused challenges in the management of patients living with multiple sclerosis (PLwMS). We investigated the occurrence and severity of COVID-19 infection post-vaccination among PLwMS treated with ocrelizumab and enrolled in the Maccabi Health Services (MHS) (n = 289) or followed at the Hadassah Medical Center (HMC) (n = 80) in Israel. Most patients were fully vaccinated (MHS n = 218; HMC n = 76) and confirmed infection post-vaccination was low (3.7% and 2.6%, respectively). MHS: infection was more severe (hospitalization/intensive care unit/death) in non-vaccinated (33.3%) vs vaccinated patients (25%). HMC: one vaccinated patient required hospitalization with COVID-19 vs two unvaccinated patients. These data from two Israel cohorts suggest that occurrence of COVID-19 after mRNA vaccination is low and limited in severity.

Background and Objectives Our objective was to investigate cellular and humoral immune responses to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccination in a cohort of people with multiple sclerosis (pwMS) on pulsed B-cell–depleting treatment (BCDT). In particular, we intended to evaluate a possible association between immune responses and the timing of vaccination under BCDT. Methods We conducted a cross-sectional study among pwMS on pulsed BCDT or without disease-modifying treatment after completed SARS-CoV-2 vaccination. Samples were collected during routine clinical visits at the Multiple Sclerosis Center Dresden, Germany, between June 2021 and September 2021. Blood was analyzed for SARS-CoV-2 spike protein–specific antibodies and interferon-γ release of CD4 and CD8 T cells on stimulation with spike protein peptide pools. Lymphocyte subpopulations and total immunoglobulin levels in the blood were measured as part of clinical routine. Results We included 160 pwMS in our analysis, comprising 133 pwMS on BCDT (n = 132 on ocrelizumab and n = 1 on rituximab) and 27 without disease-modifying treatment. Humoral and cellular anti–SARS-CoV-2 responses were reciprocally regulated by the time between the last BCDT cycle and vaccination. Although antibody responses increased with prolonged intervals between the last BCDT cycle and vaccination, CD4 and CD8 T-cell responses were higher in pwMS vaccinated at early time points after the last BCDT cycle compared with untreated pwMS. T-cellular vaccination responses correlated with total, CD3 CD4, and partly with CD3 CD8 lymphocyte counts. Humoral responses correlated with CD19 lymphocyte counts. Status post coronavirus disease 2019 infection led to significantly increased SARS-CoV-2–specific T-cell and antibody responses. Discussion Delaying BCDT is currently discussed as a strategy to optimize humoral responses to SARS-CoV-2 vaccination. However, T cells represent an important line of defense against SARS-CoV-2 infection as well, especially in light of emerging variants of concern. We observed enhanced CD4 and CD8 T-cellular responses in pwMS receiving vaccination at early time points after their last BCDT cycle. These data may influence clinical decision making with respect to vaccination strategies in patients receiving BCDT.

Objective To determine the impact of MS disease-modifying therapies (DMTs) on the development of cellular and humoral immunity to SARS-CoV-2 infection. Methods MS patients aged 18-60 were evaluated for anti-nucleocapsid and anti-Spike RBD antibody with electro-chemiluminescence immunoassay; antibody responses to Spike protein, RBD, N-terminal domain with multiepitope bead-based immunoassays (MBI); live virus immunofluorescence-based microneutralization assay; T-cell responses to SARS-CoV-2 Spike using TruCulture ELISA; and IL-2 and IFNγ ELISpot assays. Assay results were compared by DMT class. Spearman correlation and multivariate analyses were performed to examine associations between immunologic responses and infection severity. Results Between 1/6/2021 and 7/21/2021, 389 MS patients were recruited (mean age 40.3 years; 74% female; 62% non-White). Most common DMTs were ocrelizumab (OCR) - 40%; natalizumab - 17%, Sphingosine 1-phosphate receptor (S1P) modulators −12%; and 15% untreated. 177 patients (46%) had laboratory evidence of SARS-CoV-2 infection; 130 had symptomatic infection, 47 - asymptomatic. Antibody responses were markedly attenuated in OCR compared to other groups (p≤ 0001). T-cell responses (IFNγ were decreased in S1P (p=0.03), increased in natalizumab (p<0.001), and similar in other DMTs, including OCR. Cellular and humoral responses were moderately correlated in both OCR (r=0.45, p=0.0002) and non-OCR (r=0.64, p<0.0001). Immune responses did not differ by race/ethnicity. COVID-19 clinical course was mostly non-severe and similar across DMTs; 7% (9/130) were hospitalized. Interpretation DMTs had differential effects on humoral and cellular immune responses to SARS-CoV-2 infection. Immune responses did not correlate with COVID-19 clinical severity in this relatively young and non-disabled group of MS patients.