While sitting in the waiting room of the dentist today, I noticed an article written by Catherine Price in the March 2010 issue of Popular Science[i] about rebooting the immune system of people with autoimmune diseases like type I diabetes, lupus, and rheumatoid arthritis. Naturally, the title grabbed my attention. Price has type I diabetes and participated in early clinical trials (she also writes a blog). Part of the interest is also personal as someone fighting rheumatoid arthritis. I’m also interested because someone from my church is fighting a rare autoimmune disease, aplastic anemia, and the proposed treatment is to wipe out his immune system and start over…a “rebooting” of the immune system.
Some success with using antibodies to reboot the immune systems of multiple sclerosis patients has been reported.[ii] Stem cell transplants have also been used.[iii] [iv] Stem cells are harvested from a patient and are then purified. The immune system is wiped out and the stem cells injected to restart the system. There are obvious dangers in such an approach and my friend from church will need to be isolated for many weeks in order to avoid contracting an infection.
Rituximab, or Rituxan, is a biological antibody originally designed to treat lymphomas and other cancers. This antibody inhibits B-cell lymphocytes (acting on the protein CD20) and is approved to treat rheumatoid arthritis usually after a patient does not respond to the more commonly used TNF blockers like Enbrel and Humira. Rituxan provides a form of immune system rebooting and is usually one of the last RA treatments attempted.
In the Popular Science article, researchers are working with other biological antibodies focusing on CD3 proteins which are receptors on T-cell lymphocytes. As Price notes, “…anti-CD3 monoclonal antibodies might be more like guided missiles than conventional immunosuppressive drugs.” Such specificity would be better than the general suppression of the entire immune system approach of current biological and chemical RA treatments. There is only one anti CD3 antibody approved for medical use by the FDA, muromonab. It is used for organ transplant patients to help them avoid rejection. There are anti CD3 antibodies being tested for other autoimmune diseases like Crohn’s and psoriasis and there’s hope that such biological treatments may one day become available to RA.
Perhaps sometime in the future we’ll be able to hit “control-alt-delete” on our immune systems and reboot them into a fresh start. Until then, I’ll keep taking Humira injections (even though it doesn’t seem to be doing a whole lot for me yet).