THURSDAY, May 5, 2005 (HealthDay News) -- Tests that spot heightened expression of a specific group of genes could improve the treatment of lupus patients, according to a new report.
The finding also provides important new insight into the role that interferon -- a protein key to the immune response -- plays in the progression of systemic lupus erythematosus (SLE).
SLE, which is characterized by the production of autoantibodies throughout the body, affects women more than men and can cause problems ranging from skin rash and joint pain to kidney failure and stroke, the researchers said.
Scientists, including those at the Mary Kirkland Center for Lupus Research in New York City, focused on the activation of a particular immune response called the interferon pathway. This pathway is more active among lupus patients with the most serious disease.
The researchers knew that activation of the type I interferon pathway also triggers abnormally high expression of the "interferon-inducible" family of genes (IFIGs).
The researchers collected blood samples from 77 lupus patients; 22 people with either rheumatoid arthritis or another immune disorder, autoimmune uveitis; and 28 healthy people. They then checked the blood samples for levels of IFIG expression.
Overall, lupus patients scored higher than the other participants for activation of the type I interferon pathway. Among those with lupus, the highest scores were associated with increased disease severity and activity and a greater likelihood of kidney disease.
"Our data have defined a subgroup of SLE patients who have more severe disease, with frequent kidney involvement, and more active disease, as measured by complement activation, suggesting that determination of IFIG expression may prove a useful approach to selection of patients for clinical studies," study co-author Dr. Kyriakos A. Kirou said in a prepared statement.
The marker might someday help doctors spot lupus patients at high risk for severe disease, and treat them appropriately. It may also help researchers better understand interferon's role in the illness, Kirou said.
"Our next challenge will be to plan clinical studies to validate the measurement of IFIG as a biomarker for active lupus," Kirou said.
The study appears in the May issue of Arthritis & Rheumatism.
More information
The U.S. National Institute of Arthritis and Musculoskeletal and Skin Diseases has more about lupus.
