Looking to Primates for Help in Treating Rheumatoid Arthritis

A primate mostly found in Asia may hold the key to better treatment of rheumatoid arthritis (RA), according to findings from a new study conducted by researchers at the Keck School of Medicine of USC. The monkeys carry a peptide, θ-defensin 1 (RTD-1), that the team found effective in halting and reversing the progression of RA in rat models. Study author Michael Selsted, MD, PhD, chair and professor of pathology at the Keck School, commented, “Previous studies have shown that RTD-1 modulates lethal inflammation in animal models of infection, and we predicted that RTD-1’s protective mechanism in those models would translate to rheumatoid arthritis, a disease in which chronic inflammation produces irreversible joint damage.” The findings were published last week in the journal PLOS ONE.

RA, an autoimmune disease, impacts around 1.5 million Americans, with the resulting chronic inflammation leading to irreversible joint damage. In their study, the researchers worked with rats afflicted with both moderate and severe arthritis. A cohort with moderate arthritis was administered RTD-1 for 11 days and compared to a control group who did not receive the peptide. The treated group had significantly lower arthritis progression after 24 hours of first dose, and lower arthritis severity scores after the treatment interval. In rats with severe arthritis, RTD-1 produced better outcomes than the current gold standard treatments for RA, methotrexate and etanercept, with rapid lessening of arthritis severity within 48 hours of administration and complete resolution of the disease by day 15. Dr. Selsted concluded “Our findings strongly suggest that RTD-1 has potential as a completely new agent for treating rheumatoid arthritis. RTD-1-like molecules may also be effective in the treatment of other inflammatory diseases and cancer.”

Read more about the discovery and implications for treating RA.

The journal article may be read here.