{"product_id":"epstein-barr-virus-reactivation-and-the-immune-events-that-precede-multiple-sclerosis-relapse","title":"Epstein-Barr Virus Reactivation and the Immune Events That Precede Multiple Sclerosis Relapse","description":"\u003cp\u003eIn a longitudinal study of blood samples from people with relapsing-remitting multiple sclerosis, researchers identified a reproducible immune signature in monocytes and B cells. This immune signature appears up to three months before a clinical relapse. This pre-relapse signature was enriched for genes responsive to Epstein-Barr virus (EBV) reactivation. The team confirmed elevated EBV LMP-1 transcripts and expansion of CD11c+ atypical B cells carrying the EBV surface protein gp350 before relapse. The findings suggest that EBV reactivation, occurring in a genetically predisposed immune environment, may be a proximal precursor of MS relapse, though the study could not prove causation.\u003c\/p\u003e\n\n\u003ch1\u003eEpstein-Barr Virus Reactivation and the Immune Events That Precede Multiple Sclerosis Relapse\u003c\/h1\u003e\n\n\u003ch2\u003eTable of Contents\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003e\u003ca href=\"#ddn-key-points\"\u003eKey Points\u003c\/a\u003e\u003c\/li\u003e\n\n\u003cli\u003e\u003ca href=\"#background\"\u003eBackground: Why This Research Matters\u003c\/a\u003e\u003c\/li\u003e\n\u003cli\u003e\u003ca href=\"#study-design\"\u003eStudy Design: How the Research Was Conducted\u003c\/a\u003e\u003c\/li\u003e\n\u003cli\u003e\u003ca href=\"#single-cell-atlas\"\u003eA Time-Resolved Single-Cell Atlas of Immune States\u003c\/a\u003e\u003c\/li\u003e\n\u003cli\u003e\u003ca href=\"#atypical-b-cells\"\u003eAtypical B Cells Define the Pre-Relapse Immune State\u003c\/a\u003e\u003c\/li\u003e\n\u003cli\u003e\u003ca href=\"#ebv-transcripts\"\u003eEBV Viral and Host Transcriptional Programs Before Relapse\u003c\/a\u003e\u003c\/li\u003e\n\u003cli\u003e\u003ca href=\"#clinical-implications\"\u003eClinical Implications: What This Means for Patients\u003c\/a\u003e\u003c\/li\u003e\n\u003cli\u003e\u003ca href=\"#limitations\"\u003eLimitations: What the Study Could Not Prove\u003c\/a\u003e\u003c\/li\u003e\n\u003cli\u003e\u003ca href=\"#recommendations\"\u003eRecommendations and Future Directions\u003c\/a\u003e\u003c\/li\u003e\n\u003cli\u003e\u003ca href=\"#ddn-faq\"\u003eFrequently Asked Questions\u003c\/a\u003e\u003c\/li\u003e\n\u003cli\u003e\u003ca href=\"#source\"\u003eSource Information\u003c\/a\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003c!-- ddn:keypoints:start --\u003e\n\u003ch2 id=\"ddn-key-points\"\u003eKey Points\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003eIn a longitudinal study, a reproducible immune signature in monocytes and B cells appeared up to three months before MS relapse.\u003c\/li\u003e\n\u003cli\u003eThe pre-relapse signature was enriched for genes responsive to Epstein-Barr virus reactivation, with elevated EBV LMP-1 transcripts and gp350+ B cells.\u003c\/li\u003e\n\u003cli\u003eCD11c+ atypical B cells expanded before relapse in 21 of 23 patients, with a median 1.6-fold increase.\u003c\/li\u003e\n\u003cli\u003eThe study could not prove causation; it showed an association between EBV reactivation and immune changes preceding relapse.\u003c\/li\u003e\n\u003cli\u003eFindings do not change current MS treatment recommendations; larger studies are needed to confirm and extend them.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c!-- ddn:keypoints:end --\u003e\n\n\n\u003ch2 id=\"background\"\u003eBackground: Why This Research Matters\u003c\/h2\u003e\n\n\u003cp\u003eMultiple sclerosis (MS) is a chronic inflammatory disease of the central nervous system (CNS, the brain and spinal cord). It is a leading cause of neurologic disability in young adults and affects approximately 2.9 million people worldwide.\u003c\/p\u003e\n\n\u003cp\u003eThe disease course, particularly in its early stages, is characterized by symptomatic flare-ups called relapses. These relapses are separated by periods of remission. The timing of relapses is highly variable and difficult to predict.\u003c\/p\u003e\n\n\u003cp\u003eA central challenge in identifying what triggers MS relapses is uncertainty about when the molecular events that precede clinical symptoms actually begin. Many inflammatory processes participate in relapse pathophysiology, and many of these processes are transient.\u003c\/p\u003e\n\n\u003cp\u003eIn viral meningitis, for example, neutrophilic pleocytosis (an increase in a type of immune cell called neutrophils in the cerebrospinal fluid) may be detectable for only hours after infection. Lymphocytic dominance (an increase in lymphocytes) persists weeks later. In MS, the inability to sample immune activity during such short-lived presymptomatic windows has limited efforts to capture the molecular events that initiate relapses.\u003c\/p\u003e\n\n\u003cp\u003eA growing body of evidence supports serum neurofilament light chain (NfL) as a useful biomarker of disease activity in MS. Proteomic studies have also identified elevated cytokines (immune signaling proteins) that accompany relapse. However, these markers reflect tissue damage that has already occurred and an inflammatory process already underway. They do not reveal the upstream factors that instigate relapse.\u003c\/p\u003e\n\n\u003cp\u003eIn parallel, B cell dysregulation has emerged as a central feature of MS relapse biology. Since B cell depletion was shown to reduce relapse rates, experimental and human studies have demonstrated that B cells function not only as antibody producers. B cells also act as antigen-presenting cells and sources of inflammatory cytokines that activate pathogenic T cell programs.\u003c\/p\u003e\n\n\u003cp\u003eAmong B cell subsets, CD11c+T-bet+ atypical memory B cells (ABCs) expand in autoimmune diseases and chronic viral infections. These infections include Epstein-Barr virus (EBV), HIV and hepatitis C. In MS, ABCs accumulate in blood and in compartments adjacent to the central nervous system. These cells display elevated expression of interferon-stimulated genes and antigen presentation machinery. They are also less effectively depleted by anti-CD20 therapies.\u003c\/p\u003e\n\n\u003cp\u003eWhether ABCs expand before relapse and whether they contribute to the inflammatory cascade remained undetermined before this study.\u003c\/p\u003e\n\n\u003cp\u003eMS is further shaped by host genetics. Genome-wide association studies (GWASs) have identified more than 200 independent risk loci (regions of the genome associated with disease risk). Many of these loci map to regulators of immune activation, B cell differentiation and antigen presentation.\u003c\/p\u003e\n\n\u003cp\u003eThe HLA-DRB1*15:01 allele confers the largest individual risk effect. Additional non-HLA loci are concentrated in B cell and innate immunoregulatory pathways. Notably, the EBV nuclear antigen EBNA-2 binds preferentially to enhancers at MS risk loci and remodels host transcriptional landscapes. This provides a direct molecular link between viral biology and host genetic susceptibility.\u003c\/p\u003e\n\n\u003cp\u003eThese genetic studies, however, address lifetime disease risk. Whether the same alleles shape the timing and instigation of relapses was unknown.\u003c\/p\u003e\n\n\u003cp\u003eThis study presents a time-resolved, single-cell atlas of the peripheral immune system surrounding MS relapse. The researchers identified reproducible immune perturbations emerging weeks to months before clinical relapse. These perturbations centered on monocytes and CD11c+ atypical B cell populations. They were enriched for host genes regulated by early-lytic EBV factors and overlapped with MS GWAS risk loci and EBNA-2-bound regulatory elements.\u003c\/p\u003e\n\n\u003cp\u003eAlthough the observational design precludes definitive causal inference, the findings implicate viral reactivation and host genetic susceptibility in the immune cascade that precedes relapse.\u003c\/p\u003e\n\n\u003ch2 id=\"study-design\"\u003eStudy Design: How the Research Was Conducted\u003c\/h2\u003e\n\n\u003cp\u003eTo investigate immune mechanisms preceding MS relapse, researchers leveraged the Comprehensive Longitudinal Investigation in MS at Brigham and Women's Hospital (CLIMB) study. CLIMB is an ongoing prospective cohort that has followed thousands of patients with MS for more than 25 years. It uses annual magnetic resonance imaging (MRI), standardized neurological examinations and systematic biospecimen collection.\u003c\/p\u003e\n\n\u003cp\u003eAs part of routine CLIMB enrollment, participants donate blood samples at annual or scheduled clinic visits. Peripheral blood mononuclear cells (PBMCs) are cryopreserved alongside detailed clinical metadata.\u003c\/p\u003e\n\n\u003cp\u003ePre-relapse samples are exceedingly rare. They are identifiable only retrospectively, when a clinically stable patient happens to suffer a relapse after a routine blood draw. Decades of systematic biobanking were required to accumulate sufficient specimens for molecular investigation of the presymptomatic immune state.\u003c\/p\u003e\n\n\u003cp\u003eThe researchers screened 85 participants with available biospecimens. They identified 15 individuals for initial single-cell discovery profiling. Selection was based on the availability of remission, pre-relapse and\/or acute relapse samples captured within defined peri-attack windows.\u003c\/p\u003e\n\n\u003cp\u003eAn additional 99 patients were evaluated using one or more orthogonal methodologies:\u003c\/p\u003e\n\n\u003cul\u003e\n\u003cli\u003eBulk RNA sequencing (RNA-seq) of sorted CD19+ B cells (n = 70 patients, one of whom also contributed to the discovery cohort)\u003c\/li\u003e\n\u003cli\u003eTargeted viral transcript detection by reverse transcription quantitative polymerase chain reaction (RT-qPCR) (n = 30)\u003c\/li\u003e\n\u003cli\u003eMultiparameter flow cytometry (n = 23)\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eEBNA-1 IgG ELISA was performed on 59 participants with available serum. All 38 patients with MS were seropositive, as were 19 of 21 healthy controls. These 21 healthy controls served as a comparative reference population for single-cell sequencing.\u003c\/p\u003e\n\n\u003cp\u003eIn total, 135 participants (114 patients with MS and 21 healthy controls) contributed 240 PBMC samples profiled across five assays:\u003c\/p\u003e\n\n\u003cul\u003e\n\u003cli\u003eSingle-cell RNA sequencing (scRNA-seq): 52 vials across 42 samples\u003c\/li\u003e\n\u003cli\u003eWhole genome sequencing (WGS): 36 individuals (15 with MS and 21 healthy controls), used for genotype-based demultiplexing of pooled scRNA-seq libraries\u003c\/li\u003e\n\u003cli\u003eBulk RNA-seq of CD19+ B cells: 130 samples\u003c\/li\u003e\n\u003cli\u003eMultiparameter flow cytometry: 46 samples\u003c\/li\u003e\n\u003cli\u003eTargeted RT-qPCR: 60 samples\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eAll samples were collected at least 30 days after corticosteroid exposure. Disease-modifying therapy (DMT) was unchanged between paired timepoints in all but two patients.\u003c\/p\u003e\n\n\u003cp\u003eAge distributions were comparable between the MS and healthy cohorts. The MS cohort had a higher proportion of female participants, consistent with MS epidemiology.\u003c\/p\u003e\n\n\u003cp\u003eRelapses were confirmed independently by two neurologists and required a contrast-enhancing lesion on MRI. Remission required flanking clinical and radiographic stability.\u003c\/p\u003e\n\n\u003cp\u003eWhere possible, samples were paired within patients. This allowed individuals to contribute both a relapse-associated and a remission timepoint, enabling within-patient comparisons in downstream analyses.\u003c\/p\u003e\n\n\u003ch2 id=\"single-cell-atlas\"\u003eA Time-Resolved Single-Cell Atlas of Immune States\u003c\/h2\u003e\n\n\u003cp\u003ePBMCs from the discovery cohort were subjected to 10x Genomics 3' single-cell RNA sequencing. This yielded 281,799 high-quality cells after quality control filtering and doublet exclusion. This included 154,709 cells from patients with MS across remission, pre-relapse and relapse timepoints, and 127,090 cells from healthy donors.\u003c\/p\u003e\n\n\u003cp\u003eDatasets were integrated using Harmony batch correction while preserving disease-associated transcriptional structure. Reference-based annotation complemented by careful manual assignment resolved major circulating lineages. These lineages included classical and non-classical monocytes, naive and memory B cells, plasmablasts, T cell subsets, dendritic cells and natural killer cells.\u003c\/p\u003e\n\n\u003cp\u003eKey patient and technical metadata, including donor, DMT, sex, age and experimental batch, were inspected on the integrated uniform manifold approximation and projection (UMAP). Donor was modeled as a random effect in downstream analyses.\u003c\/p\u003e\n\n\u003cp\u003eTo quantify cell-state-specific transcriptional shifts while accounting for donor-level heterogeneity, the researchers applied the scDist mixed-effects model. Negative control contrasts (healthy versus healthy, remission versus remission) produced negligible perturbations, confirming robustness. A complementary sensitivity analysis restricted to donors with paired pre-relapse and remission samples recapitulated the primary perturbation pattern.\u003c\/p\u003e\n\n\u003cp\u003eIn striking contrast, the pre-relapse versus remission comparison revealed widespread transcriptional divergence across nearly all immune populations. The most pronounced perturbations occurred in FGFBP2+ cytotoxic gamma-delta T cells, monocytes and activated type 2 conventional dendritic cells (cDC2s).\u003c\/p\u003e\n\n\u003cp\u003eMultiple B cell subsets also ranked among the top third of perturbed populations in the pre-relapse contrast. Notably, perturbation magnitudes were generally larger in the pre-relapse state than during overt relapse. This may indicate that peripheral immune dysregulation peaks during the presymptomatic phase before attenuating once clinical symptoms emerge.\u003c\/p\u003e\n\n\u003cp\u003eTo integrate genetic risk information at single-cell resolution, the researchers performed patient-aware single-cell disease relevance scoring (scDRS) using MS GWAS summary statistics. Across PBMC states, pre-relapse perturbation magnitude was not correlated with the pre-relapse change in MS genetic risk enrichment (Spearman's rho = -0.14, P = 0.53).\u003c\/p\u003e\n\n\u003cp\u003eB cell subsets were the exception. Intermediate, switched memory and TCL1A+ naive B cells showed both substantial pre-relapse perturbation (scDist 5.79-6.47) and the three largest pre-relapse increases in scDRS score of any population (change of 0.44-0.54). This rendered B cells a population that the researchers dissected at high resolution.\u003c\/p\u003e\n\n\u003ch2 id=\"atypical-b-cells\"\u003eAtypical B Cells Define the Pre-Relapse Immune State\u003c\/h2\u003e\n\n\u003cp\u003eThe researchers reclustered approximately 30,000 high-confidence B cells to resolve within-lineage heterogeneity. This analysis delineated 14 discrete populations. These included naive, switched memory, activated memory, atypical\/ABC-like memory, ABC, CD11c++ activated memory, plasmablast and cycling plasmablast states, among others.\u003c\/p\u003e\n\n\u003cp\u003eImputed surface protein markers were consistent with subset organization. They distinguished naive, memory, activated and plasmablast compartments.\u003c\/p\u003e\n\n\u003cp\u003eSubset-level scDist analysis revealed that naive B cells exhibited the largest transcriptional perturbations in the pre-relapse condition. These were followed by atypical\/ABC-like memory, ABC, switched memory and CD11c++ activated memory B cells.\u003c\/p\u003e\n\n\u003cp\u003eDifferential expression revealed enrichment for type I interferon signaling, antigen processing and viral defense pathways. Canonical interferon-stimulated genes (IFITM2, IRF7) and major histocompatibility complex class II (MHC-II) components (HLA-DQA1, HLA-DQA2) were upregulated in pre-relapse naive B cells. HLA-DQA1 was additionally upregulated in atypical\/ABC-like memory, switched memory, anergic\/naive-leaning and ABC subsets.\u003c\/p\u003e\n\n\u003cp\u003eViral mRNA translation was the top Reactome pathway upregulated in pre-relapse B cells (Benjamini-Hochberg-adjusted P = 6.3 x 10^-90). These enriched pathways implicate early activation of innate antiviral programs as a defining feature of the pre-relapse immune state.\u003c\/p\u003e\n\n\u003cp\u003eNotably, these enrichments persisted after regression of cell-cycle-associated transcripts. This excluded generalized proliferation as the basis and supported a bona fide activation phenotype rather than non-specific clonal expansion.\u003c\/p\u003e\n\n\u003cp\u003ePatient-aware scDRS analysis showed that ABCs carried the strongest enrichment (estimated marginal mean = 1.16, 95% confidence interval: 1.06-1.25). This was matched by cycling plasmablasts (1.16, 0.81-1.50, although estimated from only 70 cells). These were followed by CD11c++ activated memory B, activated switched memory B, plasmablast and atypical\/ABC-like memory B cells.\u003c\/p\u003e\n\n\u003cp\u003eThe researchers labeled the CD11c+ metaclusters (13 and 15, analyzed together) \"ABC-like\" given the surface marker phenotype. They noted that without intracellular staining for T-bet and ZEB2, a canonical ABC identity is not confirmed.\u003c\/p\u003e\n\n\u003cp\u003eWithin-patient analysis of 23 paired pre-relapse and remission samples demonstrated a significant increase in ABC-like B cell abundance during the pre-relapse window. Twenty-one of 23 patients increased (median 1.6-fold; two-sided Wilcoxon signed-rank P = 8.8 x 10^-5).\u003c\/p\u003e\n\n\u003cp\u003eUsing fluorescence-minus-one (FMO) thresholding, the researchers assessed expression of the EBV late-lytic glycoprotein gp350 across metaclusters. gp350+ cells localized preferentially with activated memory and ABC-like metaclusters.\u003c\/p\u003e\n\n\u003cp\u003eCritically, the frequency of gp350+ B cells among CD19+ cells was significantly increased in pre-relapse relative to remission. This was measured with a binomial mixed model with donor random intercepts and experiment day as a fixed effect: odds ratio = 1.41, 95% CI: 1.11-1.79, P = 0.0043. The model-predicted frequency was 0.263% versus 0.186%.\u003c\/p\u003e\n\n\u003cp\u003eFrequencies peaked in the 0-90-day pre-relapse window (odds ratio = 1.47, 95% CI: 1.12-1.94, Benjamini-Hochberg-adjusted P = 0.011). These data provide orthogonal validation that ABC-like B cells expand before relapse, accompanied by an increased frequency of EBV gp350+ B cells.\u003c\/p\u003e\n\n\u003ch2 id=\"ebv-transcripts\"\u003eEBV Viral and Host Transcriptional Programs Before Relapse\u003c\/h2\u003e\n\n\u003cp\u003eTo directly assess EBV transcript expression during disease activity windows, the researchers performed RT-qPCR on FACS-sorted CD19+ B cells from 30 patients with MS. These patients had paired pre-relapse and remission samples, and 25 of the samples passed quality control. They targeted LMP-1, BZLF1, BLLF1 (gp350), EBER2 and additional EBV transcripts.\u003c\/p\u003e\n\n\u003cp\u003ePrincipal component analysis (PCA) of normalized delta-Ct values revealed separation along principal component 1 of pre-relapse from remission samples. This separation was based on the EBV transcript profile.\u003c\/p\u003e\n\n\u003cp\u003eThe study confirmed elevated EBV LMP-1 transcripts in pre-relapse B cells. Flow cytometry demonstrated expansion of CD11c+ atypical B cell populations displaying EBV surface protein gp350.\u003c\/p\u003e\n\n\u003cp\u003ePre-relapse transcriptional modules overlapped with MS GWAS risk loci and EBNA-2-bound enhancers. This suggests that inherited MS susceptibility and EBV-responsive programs operate through shared regulatory elements.\u003c\/p\u003e\n\n\u003cp\u003eThe researchers noted that how this peripheral activation relates to central nervous system lesion formation remains to be established.\u003c\/p\u003e\n\n\u003ch2 id=\"clinical-implications\"\u003eClinical Implications: What This Means for Patients\u003c\/h2\u003e\n\n\u003cp\u003eThese findings suggest that EBV reactivation, when occurring within a genetically predisposed peripheral immune environment, is a proximal precursor of MS relapse. This means that the immune events that trigger a relapse may begin weeks to months before a patient feels any symptoms.\u003c\/p\u003e\n\n\u003cp\u003eThe study identified a reproducible pre-relapse signature in monocytes and B cells that emerges up to 3 months before clinical onset. This signature is enriched for host genes responsive to EBV lytic reactivation factors.\u003c\/p\u003e\n\n\u003cp\u003eFor patients, this research offers several important insights:\u003c\/p\u003e\n\n\u003cul\u003e\n\u003cli\u003eThe immune system shows measurable changes well before a relapse occurs, potentially opening a window for earlier monitoring or intervention.\u003c\/li\u003e\n\u003cli\u003eEBV reactivation appears to play a role in triggering the immune cascade that leads to relapse, not just in increasing lifetime risk of developing MS.\u003c\/li\u003e\n\u003cli\u003eAtypical B cells (CD11c+ ABCs) expand significantly before relapse, with 21 of 23 patients showing an increase (median 1.6-fold).\u003c\/li\u003e\n\u003cli\u003eEBV gp350+ B cells increase in frequency before relapse, with the highest frequencies in the 0-90-day pre-relapse window.\u003c\/li\u003e\n\u003cli\u003eInherited genetic risk factors for MS and EBV-responsive programs appear to operate through shared regulatory elements in the genome.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eThe finding that peripheral immune dysregulation peaks during the presymptomatic phase, before attenuating once clinical symptoms emerge, is particularly notable. It suggests that the most intense immune activity may occur before a patient is even aware that a relapse is coming.\u003c\/p\u003e\n\n\u003cp\u003eThe overlap between pre-relapse transcriptional modules and MS GWAS risk loci provides a direct molecular link between viral biology and host genetic susceptibility. This means that a person's inherited genetic makeup may influence how their immune system responds to EBV reactivation.\u003c\/p\u003e\n\n\u003cp\u003eThe researchers emphasize that the observational design of the study precludes definitive causal inference. The study cannot prove that EBV reactivation directly causes MS relapse. It can only show that EBV reactivation is associated with the immune changes that precede relapse.\u003c\/p\u003e\n\n\u003ch2 id=\"limitations\"\u003eLimitations: What the Study Could Not Prove\u003c\/h2\u003e\n\n\u003cp\u003eThe study has several important limitations that patients and clinicians should understand.\u003c\/p\u003e\n\n\u003cp\u003eFirst, the observational design means the researchers cannot definitively conclude that EBV reactivation causes MS relapse. They can only demonstrate a strong association between EBV reactivation and the immune changes that precede relapse.\u003c\/p\u003e\n\n\u003cp\u003eSecond, the study could not establish how peripheral immune activation relates to central nervous system lesion formation. The researchers note that this relationship remains to be established.\u003c\/p\u003e\n\n\u003cp\u003eThird, pre-relapse samples are exceedingly rare. They are identifiable only retrospectively when a clinically stable patient happens to suffer a relapse after a routine blood draw. This limits the number of samples available for analysis.\u003c\/p\u003e\n\n\u003cp\u003eFourth, the ABC-like B cell identity was not confirmed with intracellular staining for T-bet and ZEB2. The researchers labeled these cells \"ABC-like\" based on surface marker phenotype. Without intracellular staining, a canonical ABC identity is not confirmed.\u003c\/p\u003e\n\n\u003cp\u003eFifth, some analyses were based on small numbers of cells. For example, the cycling plasmablast scDRS estimate was derived from only 70 cells.\u003c\/p\u003e\n\n\u003cp\u003eSixth, the study population was predominantly female, consistent with MS epidemiology, but this may limit generalizability to male patients.\u003c\/p\u003e\n\n\u003cp\u003eSeventh, all samples were collected at least 30 days after corticosteroid exposure, and DMT was unchanged between paired timepoints in all but two patients. This controlled for treatment effects but may not reflect the immune state in patients with recent steroid exposure or treatment changes.\u003c\/p\u003e\n\n\u003ch2 id=\"recommendations\"\u003eRecommendations and Future Directions\u003c\/h2\u003e\n\n\u003cp\u003eBased on these findings, the researchers suggest several directions for future research and clinical practice.\u003c\/p\u003e\n\n\u003col\u003e\n\u003cli\u003e\n\u003cstrong\u003eEarlier monitoring:\u003c\/strong\u003e The identification of a pre-relapse immune signature emerging up to 3 months before clinical onset suggests that monitoring immune changes could potentially predict relapse before symptoms appear.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eEBV-targeted therapies:\u003c\/strong\u003e The confirmation of EBV reactivation before relapse raises the possibility that therapies targeting EBV reactivation could help prevent relapses. This requires further study.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eGenetic profiling:\u003c\/strong\u003e The overlap between MS GWAS risk loci and EBV-responsive programs suggests that genetic profiling could help identify patients at higher risk of EBV-triggered relapse.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eB cell therapies:\u003c\/strong\u003e The expansion of ABC-like B cells before relapse, and their relative resistance to anti-CD20 therapies, suggests that new approaches targeting these specific B cell populations may be needed.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eLarger studies:\u003c\/strong\u003e The researchers call for larger studies to confirm these findings and to establish how peripheral immune activation relates to central nervous system lesion formation.\u003c\/li\u003e\n\u003c\/ol\u003e\n\n\u003cp\u003eFor patients currently managing MS, these findings do not change current treatment recommendations. However, they provide hope that a better understanding of relapse triggers could lead to more personalized and proactive approaches to MS management in the future.\u003c\/p\u003e\n\n\u003cp\u003ePatients who are interested in participating in MS research should discuss opportunities with their neurologist. The CLIMB study and similar longitudinal cohorts rely on patient participation to advance understanding of MS.\u003c\/p\u003e\n\n\u003c!-- ddn:faq:start --\u003e\n\u003ch2 id=\"ddn-faq\"\u003eFrequently Asked Questions\u003c\/h2\u003e\n\u003ch3\u003eCan a multiple sclerosis relapse be predicted before symptoms start?\u003c\/h3\u003e\n\u003cp\u003eIn a longitudinal study of blood samples from people with relapsing-remitting MS, researchers found a reproducible immune signature in monocytes and B cells that appeared up to three months before a clinical relapse. This suggests the immune events that trigger a relapse may begin weeks to months before symptoms are felt, though the study could not prove causation.\u003c\/p\u003e\n\u003ch3\u003eWhat role does Epstein-Barr virus (EBV) play in MS relapses?\u003c\/h3\u003e\n\u003cp\u003eThe pre-relapse immune signature was enriched for genes responsive to EBV reactivation. Researchers confirmed elevated EBV LMP-1 transcripts and expansion of CD11c+ atypical B cells carrying the EBV surface protein gp350 before relapse. The findings suggest EBV reactivation, in a genetically predisposed immune environment, may be a proximal precursor of MS relapse, though causation was not proven.\u003c\/p\u003e\n\u003ch3\u003eDoes this research change how my MS is treated now?\u003c\/h3\u003e\n\u003cp\u003eNo. The findings do not change current treatment recommendations for patients managing MS. The study was observational and could not prove that EBV reactivation causes relapse. However, it provides hope that a better understanding of relapse triggers could lead to more personalized and proactive approaches to MS management in the future. Discuss any treatment questions with your neurologist.\u003c\/p\u003e\n\u003ch3\u003eCould therapies targeting EBV help prevent MS relapses?\u003c\/h3\u003e\n\u003cp\u003eThe confirmation of EBV reactivation before relapse raises the possibility that therapies targeting EBV reactivation could help prevent relapses. However, this requires further study. The research is at an early stage, and no EBV-targeted therapy is currently recommended for MS relapse prevention based on these findings. Patients should not change their treatment without consulting their neurologist.\u003c\/p\u003e\n\u003ch3\u003eWhat were the limitations of the study on EBV and MS relapse?\u003c\/h3\u003e\n\u003cp\u003eThe observational design means researchers cannot definitively conclude that EBV reactivation causes MS relapse. The study could not establish how peripheral immune activation relates to central nervous system lesion formation. Pre-relapse samples are exceedingly rare, some analyses used small numbers of cells, and the population was predominantly female, which may limit generalizability to male patients.\u003c\/p\u003e\n\u003ch3\u003eHow might this research help predict or monitor MS relapses in the future?\u003c\/h3\u003e\n\u003cp\u003eThe identification of a pre-relapse immune signature emerging up to three months before clinical onset suggests that monitoring immune changes could potentially predict relapse before symptoms appear. The researchers call for larger studies to confirm these findings and to establish how peripheral immune activation relates to central nervous system lesion formation. This may lead to earlier monitoring or intervention.\u003c\/p\u003e\n\u003ch3\u003eI have relapsing-remitting MS and my neurologist wants to switch my B-cell therapy — when should I get a second opinion?\u003c\/h3\u003e\n\u003cp\u003eA second opinion can help when the treatment decision is unclear. This research identifies a pre-relapse immune signature in monocytes and B cells emerging up to three months before clinical relapse, with expansion of CD11c+ atypical B cells and EBV gp350+ B cells. These atypical B cells are less effectively depleted by anti-CD20 therapies. If your neurologist proposes a B-cell therapy change, an independent review of your records, MRI and prior treatments can clarify whether the plan fits your relapse pattern. Diagnostic Detectives Network provides independent expert second opinions.\u003c\/p\u003e\n\u003c!-- ddn:faq:end --\u003e\n\n\u003ch2 id=\"source\"\u003eSource Information\u003c\/h2\u003e\n\n\u003cp\u003e\u003cstrong\u003eOriginal article title:\u003c\/strong\u003e EBV reactivation priming of the peripheral immune system in multiple sclerosis relapse\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eAuthors:\u003c\/strong\u003e Devin A. King, Shrishti Saxena, Danielle Caefer, Kyle C. Downer, Laura E. Saucier, Ethan Goodman, Jonmichael Aracena, Alena Zhirova, Anthilia Alchanat, Saoirse Nolan, Hrishikesh Lokhande, Howard L. Weiner, Benjamin E. Gewurz \u0026amp; Tanuja Chitnis\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003ePublication:\u003c\/strong\u003e Nature Medicine\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eDOI:\u003c\/strong\u003e https:\/\/doi.org\/10.1038\/s41591-026-04665-3\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eReceived:\u003c\/strong\u003e 8 July 2025\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eAccepted:\u003c\/strong\u003e 18 August 2026\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eCorresponding author:\u003c\/strong\u003e Tanuja Chitnis (tchitnis@bwh.harvard.edu)\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eAffiliations:\u003c\/strong\u003e Translational Neuroimmunology Research Center, Brigham and Women's Hospital, Boston, MA, USA; Ann Romney Center, Brigham and Women's Hospital, Boston, MA, USA; Neurosciences Institute, Mass General Brigham, Boston, MA, USA; Harvard Medical School, Boston, MA, USA; Brigham Multiple Sclerosis Center, Division of Neuroimmunology, Department of Neurology, Mass General Brigham, Boston, MA, USA; Division of Infectious Diseases, Department of Medicine, Mass General Brigham, Boston, MA, USA; Center for Integrated Solutions to Infectious Diseases, Broad Institute, Cambridge, MA, USA\u003c\/p\u003e\n\n\u003cp\u003e\u003cem\u003eThis patient-friendly article is based on peer-reviewed research. It is intended for educational purposes and should not replace consultation with a qualified healthcare provider. Patients should discuss any questions about their MS treatment or care with their neurologist or MS specialist.\u003c\/em\u003e\u003c\/p\u003e","brand":"DiagnosticDetectives.Com","offers":[{"title":"Default Title","offer_id":47807286149276,"sku":null,"price":0.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0599\/5449\/5644\/files\/ddn-medical-article-epstein-barr-virus-reactivation-and-the-immune-events-that-precede-multiple-sclerosis-relapse-hero.png?v=1792041755","url":"https:\/\/diagnosticdetectives.com\/ar\/products\/epstein-barr-virus-reactivation-and-the-immune-events-that-precede-multiple-sclerosis-relapse","provider":"DiagnosticDetectives.Com","version":"1.0","type":"link"}