Researchers have long known that lupus strikes African-Americans at a disproportionately high rate. Now, in the most comprehensive genetic study to date of this group, Oklahoma Medical Research Foundation scientists have found evidence linking the disease in African-Americans to five genes.
Previously, genetic studies of lupus have focused primarily on European-American and Asian populations, said the study’s senior author, Amr Sawalha, M.D., an assistant member in OMRF’s Arthritis and Clinical Immunology Research Program. This study, published in the journal Arthritis and Rheumatism, examined DNA from 1,724 African-American lupus patients and compared the results against 2,024 healthy volunteers.
“By looking exclusively at African-American lupus patients, we were able to establish these genetic links,” said Sawalha, who also holds appointments as an associate professor at the OU College of Medicine and a staff physician at the VA Medical Center. “We were also able to confirm two previously reported genetic links with a genome-wide level of significance.”
Lupus is a chronic autoimmune disease in which the body’s immune system confuses healthy cells with foreign substances, like viruses and bacteria, attacking the body’s tissues and organs. The disease affects as many as 2 million Americans and has no known cure.
Understanding the role genetics plays in lupus will help scientists and doctors find new diagnostic tools and new treatments for those suffering from the disease, said Sawalha.
“We’re finding that different genetic combinations are associated with different kinds of lupus,” he said. “Hopefully, we’ll reach a time when physicians are able to look at patients’ DNA and predict and prevent some of the symptoms they might encounter.”
Another new study from Sawalha, published in the Annals of Rheumatic Diseases, found information linking genetic variation in lupus patients with different manifestations of the disease.
“Genetic profiling might be useful to predict disease complications in the future,” he said. “As we learn more, there’s a chance it could become part of the standard of care for lupus patients.”
Blood samples for the study were obtained from a number of collaborative sites that received funding from more than 30 separate grants from the National Institutes for Health. OMRF scientists Jennifer Kelly, Joan Merrill, M.D., Judith James, M.D., Ph.D., Kathy Moser, Ph.D., Patrick Gaffney, M.D., and Marta Alarcon-Riquelme, M.D., Ph.D. also contributed to the research.