Seroreactivity against lytic, latent and possible cross-reactive EBV antigens appears on average 10 years before MS induced preclinical neuroaxonal damage

BackgroundMultiple sclerosis (MS) and presymptomatic axonal injury appear to develop only after an Epstein-Barr virus (EBV) infection. This association remains to be confirmed across a broad preclinical time range, for lytic and latent EBV seroreactivity, and for potential cross-reacting antigens.MethodsWe performed a case-control study with 669 individual serum samples obtained before clinical MS onset, identified through cross-linkage with the Swedish MS register. We assayed antibodies against EBV nuclear antigen 1 (EBNA1), viral capsid antigen p18, glycoprotein 350 (gp350), the potential cross-reacting protein anoctamin 2 (ANO2) and the level of sNfL, a marker of axonal injury.ResultsEBNA1 (latency) seroreactivity increased in the pre-MS group, at 15-20 years before clinical MS onset, followed by gp350 (lytic) seroreactivity (p=0.001-0.009), ANO2 seropositivity appeared shortly after EBNA1-seropositivity in 16.7% of pre-MS cases and 10.0% of controls (p=0.001).With an average lag of almost a decade after EBV, sNfL gradually increased, mainly in the increasing subgroup of seropositive pre-MS cases (p=8.10-5 compared with non-MS controls). Seropositive pre-MS cases reached higher sNfL levels than seronegative pre-MS (p=0.038). In the EBNA1-seropositive pre-MS group, ANO2 seropositive cases had 26% higher sNfL level (p=0.0026).ConclusionsSeroreactivity against latent and lytic EBV antigens, and in a subset ANO2, was detectable on average a decade before the appearance of a gradually increasing axonal injury occurring in the last decade before the onset of clinical MS. These findings strengthen the hypothesis of latent EBV involvement in the pathogenesis of MS.

Automated summary

The study found that seroreactivity against latent and lytic EBV antigens, as well as ANO2, could be detected around a decade before clinical MS onset, with a gradual increase in axonal injury levels. These findings support the hypothesis of latent EBV involvement in the pathogenesis of MS.