Spinal Injections May Ease Rheumatoid Arthritis

THURSDAY, Sept. 7 (HealthDay News) -- Drugs to treat rheumatoid arthritis were more effective when they were delivered into the central nervous system of rats, a new study finds.

Researchers at the University of California, San Francisco, used the drugs to block a protein called p38, which is involved in a number of cellular processes associated with the development of RA. It's believed that p38 is activated in the central nervous system in response to peripheral pain and inflammation.

Several substances that block the action of p38 have been shown to be effective in animal models of arthritis and are currently undergoing clinical trials in people with rheumatoid arthritis.

In this study, p38-blocking drugs were injected directly into the spinal cords of rats with arthritis. Compared to arthritic rats that received no active drug, the treated rats had substantially less inflammation, arthritis, and joint damage.

Rats that received the same amount of drugs through injections under the skin did not show any beneficial effect on the joints. This systemic treatment approach is currently being tested in human patients, but with much higher drug doses.

The researchers said their findings suggest that direct delivery into the spinal cord may reduce the side effects and possibly the costs of p38 inhibitors without reducing the benefits to patients.

The study was published in the September issue of PLoS Medicine.