A groundbreaking study solidifies the connection between the Epstein-Barr virus (EBV) and multiple sclerosis (MS), identifying EBV as a critical trigger for this debilitating neurological condition.
Multiple sclerosis is an autoimmune disorder that targets the central nervous system, damaging myelin—the protective sheath around nerve fibers in the brain and spinal cord. This disrupts electrical signals, leading to a range of symptoms. Globally, about 2.3 million people live with MS.
Prior research has hinted at ties between MS and EBV, the herpesvirus responsible for infectious mononucleosis (often called "mono" or the kissing disease), which infects over 90% of people worldwide by age 20. Yet, the precise mechanism—and why only a small subset develops MS—remained elusive. Now, compelling new evidence from a study in Science strengthens this association.
Led by Dr. Kjetil Bjornevik at Harvard University's T.H. Chan School of Public Health, researchers analyzed blood serum from over 10 million U.S. military personnel sampled between 1993 and 2013 during routine infection screenings, like those for HIV.
Among them, 801 developed MS and provided up to three pre-diagnosis samples. These were compared to 1,566 matched controls without MS.
At baseline, just 35 of the future MS patients were EBV-negative. By study's end, 34 of those 35 had seroconverted—developing anti-EBV antibodies—before MS onset.
Comparing those 35 cases to 107 EBV-negative controls, seroconversion occurred in 97% of future MS patients versus 57% of controls. This translated to a 32 times higher risk of MS following EBV infection.
One case without detectable EBV antibodies raises questions: possible sampling error, misdiagnosis, atypical infection, or a rare non-EBV MS variant.
Notably, the team screened for over 200 viruses, but only EBV infection elevated MS risk.
Mechanisms under investigation include molecular mimicry, where EBV proteins resemble myelin components, prompting the immune system to attack both the virus and healthy tissue.
EBV is a major factor, but not the sole one. Established risks like vitamin D deficiency, smoking, obesity, and low UVB exposure also contribute.
