WASHINGTON, May 2 (UPI) -- Researchers said Monday that some cases of MS may be caused by a strong reaction to the Epstein-Barr virus.
Although experts have long suspected a link between the virus and multiple sclerosis, researchers at the National Institutes of Health say they have uncovered a clear connection in data showing that patients with MS have a population of immune cells that overreact to the Epstein-Barr virus.
Specifically, MS patients have T cells that appear to help boost other components of the immune system in response to the virus.
"What we discovered in the peripheral blood of the MS patients were T cells that appeared to be primed for action against EBV," said Nancy Edwards, a researcher scholar at NIH and co-author of the study.
Study First Author Jan Lunemann added, "The susceptibility to acquire MS is inherited, but environmental insults such as viral infections are thought to trigger the disease, and Epstein-Barr virus is one of the leading candidate triggers. Epstein-Barr virus does not cause MS, but the immune response to this virus is different in MS patients, and our hypothesis is that the altered immune response contributes to the development and progression of the disease."
Although not all MS patients have the virus, Lunemann noted that those with MS who do have EBV "showed increased antibody responses to certain EBV proteins in previous studies (and) very recent investigations have shown that such enhanced responses occur years before onset of clinical symptoms of MS."
MS is a debilitating disease of the central nervous system caused when the body's immune system attacks the brain's myelin sheath, or the neurons' protective covering over which the brain's electrical signals are transmitted to other parts of the body.
The study findings appear in the June issue of the journal Brain.
