Potential New Target for RA Treatment

A potential way to halt the cartilage destruction that occurs with rheumatoid arthritis (RA) without suppressing the immune system has been identified by a new study supported by the National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS). The technique involves blocking a molecule, cadherin-11 (cad-11), that is found on cells of the synovium. In healthy joints, the membrane is thin and secretes lubricating substances; in persons with RA, the synovium becomes inflamed and enlarged and begins to destroy the cartilage.

Cadherin-11 makes fibroblasts in the synovium more degradative and invasive. Researchers affiliated with Harvard University found that treating mice with an antibody that blocks cad-11 reduces inflammation in the joints.

Treatment traditionally has involved suppressing the immune system, but current therapies do not work for everyone and suppressing the immune system leaves patients open to the risk of infection and increases the possibility of some cancers. These risks prompted researchers to look for a targeted, localized treatment aimed at protecting joint tissue directly.

Although the research to date has been confined to animals, the investigators hope that the findings will translate to persons with RA. An agent to block cad-11 that probably would be injected or infused is in development. The work was published in the Proceedings of the National Academy of Sciences USA.

For more information, visit the NIAMS Web site at http://www.niams.nih.gov. Or, contact the organization at National Institute of Arthritis and Musculoskeletal and Skin Diseases, 1 AMS Circle, Bethesda, MD 20892-3675; telephone: (301) 495-4484 or (toll-free): (877) 226-4267; fax: (301) 718-6366.