Severity of Arthritis Linked to Gene

The number and similarity of a particular gene linked to rheumatoid arthritis helps determine how severely the disease will afflict a person, according to a study published today.

Those at the highest risk for the most severe form of rheumatoid arthritis have two identical copies of the gene, HLA-DRB1, the Mayo Clinic study showed. The risk goes down for people with two non-identical HLA-DRB1 genes or just one of the genes, it said.

The discovery could help physicians identify patients who may need more aggressive treatment and stronger medicine, the Mayo Clinic researchers reported in the Annals of Internal Medicine.

“This is an important landmark in the management of rheumatoid arthritis,” said Dr. Frank Arnett, chief rheumatologist at the University of Texas in Houston. “It changes the way we’re going to treat patients.”

Rheumatoid arthritis, which afflicts about 7 million people in the United States, results from a shortcoming in a person’s immune system. An afflicted person’s white blood cells, which normally patrol the body in search of microbes and cancer, also attack and destroy the lining of a person’s joints.