Blood protein predicts future response to rheumatoid arthritis therapy

This study investigated whether MRP8/14 protein levels can predict rheumatoid arthritis patient response to biologic drug treatment.

Rheumatoid arthritis is an inflammatory disease affecting the joints, the connections between bones. The goal of drug therapy is remission: a time when the disease is not active and damage to the joints is limited. Disease-modifying anti-rheumatic drugs (DMARDs) can slow the progression of rheumatoid arthritis. TNF inhibitors, also known as biologics, block the activity of a protein that causes inflammation. These drugs are often used in patients who haven’t responded to or who were not able to tolerate other DMARDs. However, a significant number of patients do not respond to biologic treatment. Being able to predict who will respond may help to determine the best treatment and reduce cost.

The authors aimed to find a protein that may predict outcome in rheumatoid arthritis patients taking biologics.

This study involved 170 rheumatoid arthritis patients who did not respond to methotrexate (Trexall), a DMARD therapy. The next step was to try a biologic drug. Patients were divided into three different treatment groups: adalimumab (Humira) 86 patients, infliximab (Remicade) 60 patients and rituximab (Rituxan) 24 patients. Levels of the MRP8/14 protein were measured in the blood before treatment, and 4 and 16 weeks after the start of treatment.

Overall, 123 patients responded to the biologic treatment, while 47 did not. The authors found that the responders had significantly higher levels of MRP8/14 before the start of treatment, compared to non-responders. MRP8/14 levels were most helpful in determining the response to rituxan, followed by remicade and humira. 

The authors conclude that serum MRP8/14 is a promising proetin marker to predict response to biological therapy in rheumatoid arthritis patients. 

The authors admit that their definition of “high” MRP8/14 was chosen at random. More research is needed to determine exactly the level of MRP8/14 which may the best predictor.

If you are concerned about the effectiveness of a biologic drug, chat to your doctor about the potential to predict future responses using protein markers in the blood.