Rheumatoid arthritis patients have worn-out and prematurely aging immune systems, according to new findings from the Mayo Clinic. The results reverse earlier beliefs that these patients have overactive immune systems and could have implications for how the disease is treated.
“This study shows for the first time that patients with rheumatoid arthritis have prematurely aged immune systems,” said Cornelia Weyand, M.D., a Mayo Clinic rheumatologist and principal author of the study.
Doctors currently treat rheumatoid arthritis with medications aimed at controlling a theoretically overactive immune system. However, according to Weyand, scientists should instead look at developing mechanisms with the goal of regenerating a prematurely tired immune system.
“Until now we have thought that these patients had overactive immune systems, which is why we have aggressively treated the symptoms of rheumatoid arthritis with medications that suppress the immune system. While this practice offers relief of the painful symptoms, it also puts patients at greater risk for infections and cardiovascular disease,” stated Weyand.
The study, published in the August 1 edition of Proceedings of the National Academy of Sciences, compared the immune systems of 51 RA patients to the immune systems of 47 healthy patients of a similar age. Weyand discovered that RA patients aged 20 to 30 years not only had significantly fewer varieties of T-cells than healthy people, but the T-cells they did have looked like they belonged to people about 30 years older. T-cells are immune cells that recognize and attack foreign invaders such as bacteria and viruses.
Weyand theorizes that these patients were experiencing a defect in the thymus gland, the area where T-cells develop, and a deficiency in overall T-cell production. When normal immune cells are not properly produced, existing cells clone themselves and attack the body instead of protecting it against infection. Weyand predicts that in the future, doctors and scientists will increasingly focus their attention on how the immune system ages.
Rheumatoid arthritis is a systemic autoimmune disease potentially affecting the entire body and involving many different joints. It affects one-to-two percent of the population and appears to hit women the hardest, with an estimated 22.8 million female sufferers in the United States alone. Although it normally shows up between ages 20 and 40, rheumatoid arthritis can strike anytime.