Genetic Profiles and Risks of Common Infections for Rheumatoid Arthritis Patients

Newswise — Identifiable genetic factors may pre-dispose rheumatoid arthritis patients to common infections, according to research presented this week at the American College of Rheumatology Annual Scientific Meeting in San Antonio, Texas.

In the largest reported analysis of associations between genetic variations and risks of common infection, researchers studied data on 632 patients with early rheumatoid arthritis who were taking part in a clinical trial of methotrexate versus the TNF inhibitor etanercept. Serious infections were found to be rare, but 62 percent of patients reported at least one common infection during the year-long study. Analysis of the 457 patients who consented to genotyping revealed that upper respiratory infections and urinary tract infections occurred more often in those patients with particular variants in genes known to be important for immune function.

Rheumatoid arthritis, which causes inflammation in joints and other organs of the body, is an autoimmune disease that leaves patients more prone to common infections than the general population. This study demonstrates that genetics may play an important role in defining this susceptibility to common infections in patients with early rheumatoid arthritis. While researchers did not compare the frequency of infections in subjects taking disease modifying anti-rheumatic drugs (DMARDs) to participants not on DMARD therapy, upper respiratory infections were found to be more common in those being treated with methotrexate than in those treated with etanercept.

"This study is the first to use data on a large number of patients with early rheumatoid arthritis and demonstrates that a combination of genotypes predispose those patients to common infections such as upper respiratory and urinary tract infections," said S. Louis Bridges, Jr., MD, PhD, University of Alabama at Birmingham, Division of Clinical Immunology and Rheumatology, Birmingham, Alabama, and an investigator in the study. "These findings are preliminary and need to be corroborated in additional studies to assess the clinical utility of this genetic information in rheumatoid arthritis and other inflammatory diseases."

The American College of Rheumatology is the professional organization for rheumatologists and health professionals who share a dedication to healing, preventing disability and curing arthritis and related rheumatic and musculoskeletal diseases. For more information on the ACR's annual meeting, see http://www.rheumatology.org/annual.