An EBV blood signature showed up months before MS relapse
Nature Medicine reports an observational CLIMB-cohort study: EBV-responsive programs and CD11c+ atypical B cells in blood up to three months before relapse. News Medical's Mass General Brigham note puts the cohort at 114 MS patients and 21 healthy participants. The paper does not prove EBV is the relapse driver.
Science··Midday
The paper is observational
A peer-reviewed Nature Medicine study in the Brigham and Women's Hospital CLIMB cohort reported host genes responsive to Epstein-Barr virus lytic reactivation, plus CD11c+ atypical B cells displaying gp350, in blood taken up to three months before relapse. The authors screened biospecimens from 85 participants and selected 15 people for the initial single-cell discovery profile. RT-qPCR confirmed elevated EBV LMP-1 transcripts in pre-relapse B cells. The authors write that how this peripheral activation relates to central-nervous-system lesion formation remains to be established.[1], [2]
News Medical counts 114 patients
News Medical carried a 16 September Mass General Brigham note saying researchers analyzed blood from 114 patients with multiple sclerosis and 21 healthy participants in CLIMB, with samples up to 90 days before relapse. It said B cells showed some of the strongest changes, activating genes associated with antiviral responses, inflammation and EBV activity, and that ABC-like B cells increased. It said EBV proteins raised MS risk genes to be expressed in immune cells before relapse, but not during remission or in healthy controls. That 114-and-21 census is the hospital note's; the Nature Medicine methods block the desk retained uses 85 screened and 15 for the first single-cell slice.[2], [1]
Lesions are still unmapped
The Nature Medicine authors state that the observational design stops short of a definitive inference even while they implicate viral reactivation and host genetic susceptibility. Pre-relapse samples were identified retrospectively among people who then relapsed within 90 days. News Medical's press note uses stronger phrasing about ahead of attacks; that wording is the hospital communication, not a substitute for the paper's limit. Both accounts agree the work is published in Nature Medicine on 16 September 2026. An alternative reading is that the signature is a correlate of upcoming inflammation rather than EBV sitting next to the attack; the authors leave that open.[1], [2]
