Blood Test Could Improve Medication Treatment Decisions for Rheumatoid Arthritis Patients

A molecule in the blood shows promise as a marker to predict whether individual rheumatoid arthritis patients are likely to benefit from biologic medications or other drugs should be tried, a Mayo Clinic-led study shows. The protein, analyzed in blood tests, may help avoid trial and error with medications, sparing patients treatment delays and unnecessary side effects and expense. The research is among several Mayo Clinic studies presented at the American College of Rheumatology annual meeting in Boston.

Researchers tested blood samples taken before rheumatoid arthritis treatment was given. The patients then were treated with anti-inflammatory biologic drugs, tumor necrosis factor-alpha inhibitors, a new class of rheumatoid arthritis drugs. They found that a protein made by the immune system, type 1 interferon, appears to serve as a valid marker to tell whether individual rheumatoid arthritis patients will respond to biologics, or other medications should be tried.

“We are trying to personalize therapy for rheumatoid arthritis. One of the main problems rheumatologists have had is that it’s hard to choose the right drug for the right person,” says senior author Timothy Niewold, M.D. (I ’04), a rheumatologist at Mayo Clinic in Rochester, Minn.

“Each new drug works for some people and not others. It’s not trivial, because the disease causes damage in the joints and if it takes a year or two to find the right treatment, then damage can accrue,” Dr. Niewold says. “In the study, we looked at markers in the immune system that might help.”

Methotrexate is often the first drug tried for rheumatoid arthritis. If that doesn’t work, biologics are often next. Those carry side effects including risk of infection, and people should be tested for tuberculosis before taking them.

Getting rheumatoid arthritis under control is important not only to prevent the damage it causes directly, but to reduce the risk of other serious conditions, such as heart disease. Rheumatoid arthritis patients are twice as likely to develop heart disease as the average person, and previous Mayo research has found that the severity of the rheumatoid arthritis is a factor. People for whom methotrexate doesn’t work tend to have more severe rheumatoid arthritis, Dr. Niewold noted.

More research is needed before use of the marker becomes standard practice, Dr. Niewold says. A larger trial involving several institutions is under way. Future studies may examine whether the marker can also help guide medication decisions for other conditions treated with biologics, such as psoriatic arthritis, psoriasis and inflammatory bowel disease, he says.

This information first appeared on the Mayo Clinic News Network on Nov. 17, 2014.