Multiple sclerosis is an autoimmune disease of the central nervous system (brain and spinal cord) which is characterized by the destruction of myelin sheaths, protective sheaths of nerve fibers which play a key role in the propagation of nerve impulses. Its origin remains unknown, although several hypotheses have been put forward.
One of them is infection with the Epstein-Barr virus (EBV), the mononucleosis virus, which survives latently in the body. In a new study, published on January 13, 2022 in the journal Science (Source 1), researchers support this link between EBV and the onset of multiple sclerosis (MS).
“The hypothesis that EBV causes MS has been studied by our group and others for several years, but this is the first study providing convincing evidence of causation”, commented Alberto Ascherio, professor of epidemiology and nutrition at Harvard Chan School and lead author of the study, in a press release (Source 2). “This is a big step as it suggests that most MS cases could be prevented by stopping EBV infection, and that targeting EBV could lead to the discovery of a cure for MS.“, he added.
The team here followed more than 10 million young adults serving in the US military, and identified 655 people who were diagnosed with multiple sclerosis during their years of service. Serum samples were collected every two years, and soldiers’ EBV infection status was annotated.
The data compared, it turned out that MS risk increased 32-fold after EBV infection, but remained unchanged after other viral infections. As for serum levels of a biomarker of nerve degeneration observed in MS, they only increased after infection with the Epstein-Barr virus. Results that “cannot be explained by any known risk factors for MS and suggest that EBV is the primary cause of MS”, believe the researchers.
The Epstein-Barr virus could cause multiple sclerosis through the immune stimulation it induces, which occurs each time the latent virus reactivates. This avenue would therefore deserve to be further explored, since a vaccine against EBV or an effective antiviral treatment could contribute to preventing or even curing multiple sclerosis.