Posted on October 19, 2004 at 12:00 p.m.
BIRMINGHAM, AL — Genetics may help explain why some patients with rheumatoid arthritis are at higher risk for common infections, according to a recent study by researchers at the University of Alabama at Birmingham (UAB). Dr. Laura Hughes, assistant professor of medicine with UAB’s division of clinical immunology and rheumatology, presented details of findings this week at the American College of Rheumatology Annual Scientific Meeting in San Antonio, Texas.
Rheumatoid arthritis, an autoimmune disease that causes inflammation in the joints and other organs of the body, predisposes patients to common infections, such as upper respiratory and urinary tract infections. “We found genetics may play an important role in defining this increased susceptibility,” Hughes said.
The year-long study involved 632 patients with early rheumatoid arthritis enrolled in an clinical trail testing methotrexate and etanercept, two prescribed disease modifying anti-rheumatic drugs (DMARDs). “This was the first study of a large number of patients with early rheumatoid arthritis to investigate the link between genetics and increased risk of common infections,” Hughes said.
Serious infections were rare, but 62 percent of patients reported at least one infection, most commonly in the respiratory or urinary tract. Genotyping, or testing to determine genetic make up, was done on 457 patients. “It revealed upper respiratory infections and urinary tract infections occurred more often in patients with variations in particular genes known to be important for immune function,” Hughes said.
While researchers did not compare the frequency of infections in patients taking DMARDs to those not taking DMARDs, upper respiratory infections were more common in patients being treated with methotrexate than in those being treated with etanercept.
“These findings are preliminary and need to be corroborated in additional studies to assess the clinical usefulness of this information in treating patients with rheumatoid arthritis and other inflammatory diseases,” Hughes said.
Other UAB investigators who collaborated on the study are Dr. S. Louis Bridges, Jr., Dr. Larry W. Moreland, Dr. Robert P. Kimberly, Dr. T. Mark Beasley and Dr. Jeffrey C. Edberg.