'Biomarkers' may help point patients to the best treatment. / Masterfile
New research has found a tool that could help take trial and error out of prescribing one type of medicine for rheumatoid arthritis. Most people with RA take some type of medicine to relieve pain, reduce inflammation and prevent or slow joint damage. RA is caused by the body's own immune system attacking finger, wrist, knee, hip and other joints.
One of the newest classes of medicines used to treat RA is called “biologics,” short for biologic response modifiers. They work by interrupting the chemical chain of events the immune system uses in its attacks. The most commonly prescribed medicines and other biologics are also used to treat other autoimmune diseases.
They work well for many RA patients, but they're expensive and they don't work for everyone, says rheumatologist Mary K. Crow, physician in chief and senior scientist at the Hospital for Special Surgery in New York City. Researchers have been studying various factors in the bodies of people with RA in the hope of finding a way to predict who will be helped by the drugs and who won't. Now they've found a clue.
A study of 35 RA patients found that people who had the highest levels of an immune system protein called type I interferon in their bodies also had the best response to biologics, but RA patients who had lower levels of that protein in their bodies had only moderate or no response to the medicines. The protein could be used as a “biomarker” (a biological identifier, like a bar code on a product label or an ID tag) to help doctors decide whether to prescribe biologics for someone with RA or try something else.
“RA is a complicated disease,” Crow says, but such biomarkers would help “predict which patients will respond best to one kind of treatment or another.” Her team is working on collecting more patient samples to investigate further.