Tuesday, January 16, 2007
Patients with multiple sclerosis who also happen to have an intestinal parasite appear to have significantly fewer relapses and better outcomes than other MS patients, a new study found.
The finding suggests that when the body's immune system is occupied with an external threat, it may be less likely to misfire, which happens in conditions known as autoimmune disorders. Multiple sclerosis is an autoimmune disorder that attacks the myelin sheath that protects nerve fibers.
The study tracked 12 multiple sclerosis patients who were found to have an intestinal parasite and compared them with 12 other patients. Over four years, there were stark differences. There were three relapses among the patients who had the intestinal infection and 56 relapses in the other group.
Patients with the parasitic infection also had minimal changes in disability scores compared with the other group, according to a study in this month's Annals of Neurology by Jorge Correale and Mauricio Farez of the Ra?l Carrea Institute for Neurological Research in Buenos Aires.
The study suggests that one reason for the apparent increase in autoimmune disorders in recent years could be the decline of infectious diseases in certain countries. Because parasites often cause long-lasting infections, the researchers hypothesized that such infections could make persistent demands on the body and thereby reduce the likelihood that the immune system will attack healthy tissue.
-- Shankar Vedantam