Multiple sclerosis (MS) is a chronic inflammatory demyelinating disease of the central nervous system of unknown etiology. Is a potentially disabling disease of the brain and spinal cord in which the immune system attacks the protective sheath (myelin) that covers nerve fibers and causes communication problems between the brain and the rest of the body. Eventually, the disease can cause permanent damage or deterioration of the nerves.
New Study Results
In a recently published study in the journal Science, a group of researchers from Harvard Medical School tested the hypothesis that Ms is caused by the Epstein-Barr virus (EBV) in a cohort comprising more than 10 million young adults on active duty in the US military, 955 of whom were diagnosed with MS during their period of service.
The Epstein-Barr virus is a herpes virus that causes the childhood disease infectious mononucleosis, which is primarily transmitted through saliva, and it persists as a latent infection in human B-cells.
According to their study, the risk of MS increased 32-fold after infection with EBV but was not increased after infection with other viruses, including cytomegalovirus. Also, serum levels of neurofilament light chain, a biomarker of neuroaxonal degeneration, increased only after EBV seroconversion.
The researchers also conclude that the findings of their study cannot be explained by any other known risk factor for MS and suggest that EBV as the leading cause of MS.
“The key finding is that MS is a complication of infection with EBV,” says study senior author Alberto Ascherio, a professor of epidemiology and nutrition at Harvard’s T.H. Chan School of Public Health. MS has been considered for many years an autoimmune disease of unknown etiology. I think this study establishes that this immune process that leads to brain damage is driven by infection with EBV.
The link between MS and EBV has been suspected for many years, without any killer study able to establish a solid causal link. While the great majority of healthy adults show prior EBV infection, the number rises even further for MS patients – 99.5% of this group test positive. Ascherio says that this new study firmly establishes that connection. “It was quite striking how black and white the results are. I think the results are very solid and leave very little doubt [about the causal link],” he says.
All active US military personnel are required to submit a blood serum sample at the start and then after every 2 years of service. This database has over 62 million serum samples taken from over 10 million individuals. According to the researchers, there is not any other comparable population in the world.
Just 5.3% of the individuals examined were not infected with EBV, proving the ubiquitous nature of the infection. They looked for individuals that developed MS during their service period. 801 cases were reported, of which 800 tested positive for EBV.
Apart from 1 case, every single MS patient documented in the study became EBV-positive prior to their symptoms developing. The median time from seroconversion to MS diagnosis was 7.5 years, with a wide range seen from 2 to 15 years.
Could we eradicate MS?
There is currently no vaccine against EBV, but according to the researchers, its development is realistic.
Ruairi Mackenzie. (2022, Jan 13) Multiple Sclerosis Is Likely Caused by a Virus, Finds Study of 10 Million Military Personnel. Technology Networks, Immunology & Microbiology. Retrieved from: