NEW YORK (Reuters Health) – The antibody response in the cerebrospinal fluid (CSF) of African Americans with multiple sclerosis is greater than that seen in whites with the disease, which may partly explain why the former group often experiences greater disability, new research indicates.
While this finding might help explain some of the racial differences seen with multiple sclerosis, it remains unclear why African Americans typically require ambulatory assistance earlier in the course of the disease.
"The findings show that ethnic differences in multiple sclerosis extend to the immune response system, which plays a central role in multiple sclerosis," lead author Dr. John R. Rinker, from Washington University School of Medicine in St. Louis, said in a statement.
The results, which appear in the July 3rd issue of Neurology, stem from a comparison of the immune responses seen in 66 African Americans with multiple sclerosis and in 132 whites with the disease. In addition, the time to ambulatory assistance was recorded for all patients.
As noted, CSF humoral activity was greater in African Americans. Specifically, the IgG index in this group was significantly higher than that seen in whites (p = 0.001). Further analysis indicated heightened IgG synthesis in African Americans.
Consistent with previous reports, the African American patients required ambulatory assistance sooner than did their white counterparts. However, the IgG index was not found to be a predictor of earlier ambulatory assistance.
"It remains possible that genes are unevenly distributed between ethnic groups to account for different susceptibility to some diseases," Dr. Rinker noted. "In multiple sclerosis, recent genetic studies have begun to identify certain genes which may explain why African Americans experience more disability, but the products of these genes and the mechanism of their effects remain unknown."