Epstein-Barr Virus May Be Leading Cause of Multiple Sclerosis

Harvard's School of Public Health has an announcement... "Multiple sclerosis (MS), a progressive disease that affects 2.8 million people worldwide and for which there is no definitive cure, is likely caused by infection with the Epstein-Barr virus (EBV), according to a study led by Harvard T.H. Chan School of Public Health researchers." Epstein-Barr virus has already been linked to some forms of cancer. But now, as the New York Times put it, "New research proves a virus — one that almost all of us have — 'causes' multiple sclerosis." (More than 90% of adults have the Epstein-Barr virus, and "The very ubiquity of Epstein-Barr has made it especially difficult to isolate as a causal factor...") Researchers from the Harvard T.H. Chan School of Public Health and elsewhere, however, devised a novel way to carry out that study, and they published their findings in January in Science. U.S. military recruits, a group of more than 10 million people, are screened for H.I.V. when their service starts and biennially thereafter. Their blood serum samples are then archived in the Department of Defense Serum Repository and can be retested for other pathogens. Between 1993 and 2013, the researchers identified cases of M.S. among active-duty U.S. military personnel. Then they tested their first serum sample; their last sample before M.S. onset; and one in between. They found that of 801 soldiers with M.S., 800 were positive for Epstein-Barr.... "In practical terms, if you're not infected with E.B.V., your risk of M.S. is virtually zero," says Alberto Ascherio, a professor of epidemiology and nutrition at Harvard and a senior author of the Science study. "After infection, your risk jumps by over 30-fold." The odds of that increase having occurred by chance are less than one in a million.... That was the strongest evidence yet that Epstein-Barr initiates M.S., but it didn't explain why. Just over a week after the Science paper came out, though, Robinson and colleagues published their own paper in Nature that demonstrated how the virus triggers the disease in some people. Epstein-Barr produces proteins that mimic a protein in the myelin sheath, they found; when the immune system makes antibodies to attack the virus, they also attack the myelin — "the insulation around your neurons," as Robinson puts it. "Like electrical wires, if the insulation gets stripped off, it short-âcircuits," he says. "That's what results in M.S." This protein mix-up, though, can only explain about a quarter of M.S. cases. And while the Science paper concludes that Epstein-Barr is the "leading cause" of M.S., Cohen says he wants to be careful with the word "cause." He thinks the study proves that the virus is a necessary precondition for M.S., but the fact that so many people have Epstein-Barr and so few of them get M.S. demonstrates that other factors, very likely including genetic susceptibility, must play a significant role in the development of the disease.... What is exciting about the discovery that Epstein-Barr is necessary for M.S. is that it raises the prospect that a vaccine could prevent that disease — as well as other serious conditions — even if we never understand precisely why the virus behaves as it does in a given individual. Thanks to long-time Slashdot reader Thelasko for sharing the news!

Read more of this story at Slashdot.

from Slashdot https://ift.tt/TIEa3Gd

Share on FacebookPlus on Google+

SUBSCRIBE TO OUR NEWSLETTER