Multiple sclerosis (MS) has long been considered an autoimmune disease. But new research suggests that it is not immune cells that strip the insulation off neurons and cause neurological symptoms. On the contrary, the insulation can be disturbed when cells that construct self-destruct.
In MS, the insulating layer of myelin around neurons degrades, which leads to loss of muscle control, numbness or cognitive problems. Most researchers thought that this happens when the own immune cells of the victim move on myelin and chew, leaving scars behind plaquelike.
Now, neurologists Michael Barnett and John Prineas the University of Sydney, Australia, have found evidence to the contrary. They autopsied 12 patients who died from MS shortly after suffering an episode of neurological symptoms. All patients had scars plaquelike typical of MS. But against all odds, seven of them were intact and little inflammation myelin, the researchers reported online this week in Annals of Neurology . Is also surprising that, in the plates until 30% of the cells which form the lining of myelin appeared to be suicidal. The researchers conclude that MS is triggered by an autoimmune insult, but rather by something - maybe a virus - which encourages cell suicide. In this scenario, the dead cells cause the immune response, and not the reverse.
"The MS field is so focused on autoimmunity as a cause that we rarely hear an alternative hypothesis," says cell biologist Bruce Trapp at the Cleveland Clinic Foundation in Ohio. The study is refreshing, he said, because "the pathology of MS can not be explained by what we know now." Experimental neuropathologist Moses Rodriguez of the Mayo Clinic in Rochester, New York, agrees that viruses are likely suspects. He said the result could explain why some anti-inflammatory drugs have not helped and why an antiviral drug, interferon, is one of the best treatments.
Related Sites
John Prineas website
National Multiple Sclerosis Society
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