Researchers at Stanford University have linked the mononucleosis virus, Epstein-Barr, as a cause of multiple sclerosis.
Multiple sclerosis is a potentially disabling disease of the brain and spinal cord, which make up the central nervous system. In MS, the immune system attacks the protective sheath, or myelin, that covers nerve fibers and causes communication problems between your brain and the rest of your body. Eventually, the disease can cause permanent damage or deterioration of the nerves.
Epstein-Barr virus, one of the most common human viruses, is found all over the world. Most people get infected with EBV at some point in their lives, according to the Centers for Disease Control and Prevention. It spreads most commonly through bodily fluids, and can cause infectious mononucleosis, also called mono.
EBV appears to trigger multiple sclerosis by tricking some people's immune systems into attacking their body's own nerve cells, the new study indicates.
"We demonstrated that a specific protein in EBV mimics a protein in people's brains, and that mimicry is what makes EBV cause multiple sclerosis," explained senior researcher Dr. William Robinson, chief of immunology and rheumatology at Stanford.
According to study co-author Lawrence Steinman: "This is the first time anyone has shown rather definitively that a virus is the trigger for multiple sclerosis. And these exciting findings open up some new directions for clinical trials in MS treatment."
Blood samples from nine MS patients revealed these people carried antibodies that bonded both to the Epstein-Barr virus and to a protein called GlialCAM, which is found in the nervous system.
GlialCAM is an "adhesion molecule" that serves as the glue for myelin, Robinson said.
"EBV tricks the immune system into responding not only to the virus, but also to this critical component of the cells that make up the white matter in our brains," Steinman said. "To use a military metaphor, it's like friendly fire: In fighting the virus, we damage our own army."
The scientists said their discovery could create new ways to treat multiple sclerosis. "If a virus is the target of the immune response that's going an unwanted way in the MS brain, why not get rid of the virus?" Steinman asked.
Their discovery could also benefit research into lupus, rheumatoid arthritis and other autoimmune diseases, the researchers said. The study was published in the journal Nature.
