St. Louis An antibody frequently used as a diagnostic marker for multiple sclerosis (MS) is present at greater levels in the cerebrospinal fluid of blacks with MS than Caucasians with the disease. The findings suggest that genetic differences among ethnic groups contribute to changes in the immune system, affecting susceptibility to MS. And they add another piece to a tantalizing but stubborn puzzle: Why do blacks get MS less often than other ethnic groups but suffer more serious symptoms when they develop the disease"
"These antibodies are indicators of inflammation, but we don't yet understand how inflammation is linked to prognosis," says first author John R. Rinker II, M.D., who did the work as a fellow at Washington University School of Medicine in St. Louis and is now assistant professor of neurology at the University of Alabama at Birmingham. "No one really understands yet why inflammation levels differ from one MS patient to the next."
The new study measured cerebrospinal fluid levels of IgG, an immune system antibody. Rinker and others have previously linked greater IgG to more aggressive MS in the general patient population. But that same link could not be reestablished in the new study, which assessed disease severity by comparing the time from MS diagnosis to when the patient first needed assistance walking. Black patients needed help walking sooner an average of nine years after diagnosis versus 17 years for Caucasians but on a case-by-case basis, scientists couldn't use greater IgG to predict an earlier need for assistance in walking.
"It may be that we haven't yet focused on the right disease characteristic or milestone in our search for factors that correlate with spinal inflammation," says Rinker. "I'm hoping to expand the search for correlations in follow-up studies."
The results are published in the July 3 issue of Neurology.