July 6, 2007 -- Multiple sclerosis may affect the immune systems of African-Americans and whites differently, a new study shows.
The study, published in the latest edition of the journal Neurology, points out that multiple sclerosis (MS) is rarer but often more severe in African-Americans than in whites.
No one knows exactly why that is, but genetics might be a factor, according to the new study, which appears in the latest issue of the journal Neurology.
The study comes from John Rinker II, MD, and colleagues. They work in St. Louis at Washington University's medical school.
The researchers checked the medical records of 66 African-Americans with multiple sclerosis and 132 whites with multiple sclerosis.
All of those patients had had their spinal fluid tested. The researchers noted higher levels of antibodies in the African-Americans' spinal fluid.
Antibodies are part of the body's immune system. Normally, antibodies attack foreign matter, such as viruses, to protect the body.
But in autoimmune diseases including multiple sclerosis, the body's immune system fights the body's own tissue for reasons that aren't fully understood. In MS, the brain and nervous system bear the brunt of the immune system's misguided attacks.
Multiple Sclerosis Genetic Link?
Higher levels of antibodies might stem from racial genetic differences, but that's not certain, note Rinker and colleagues.
"The findings show that ethnic differences in MS extend to the immune response system, which plays a central role in MS," Rinker says in an American Academy of Neurology news release.
"It remains possible that genes are unevenly distributed between ethnic groups to account for different susceptibility to some diseases," says Rinker.
"In MS, 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," Rinker adds.
However, the study doesn't prove that high levels of antibodies make multiple sclerosis worse. The exact cause of multiple sclerosis isn't known.
Not all MS patients get their spinal fluid checked, and lab results may vary, so it's not clear if the study's findings apply to all African-Americans or whites with MS.
In Rinker's study, African-Americans with multiple sclerosis developed trouble walking sooner than whites. But that didn't appear to be due solely to African-Americans' higher levels of antibodies in their spinal fluid.
The researchers call for further studies to learn more about the differences in multiple sclerosis between African-Americans and whites.