What Causes an Overactive Immune System?

An overactive immune system, which is the source of autoimmune disease, is affected by sex hormones, according to a 2004 article by Vicki Brower in EMBO Reports. For instance, estrogen predisposes women to systemic lupus erythematosus. Infectious disease may also play a causal role, as immune cells that have been provoked by an infection interact with normal tissues, triggering a response that involves the entire immune system.

Autoimmune disease takes many forms. Some common related ailments include rheumatoid arthritis, multiple sclerosis, diabetes mellitus (type 1 diabetes) and inflammatory bowel disease, according to WebMD. In patients with autoimmune disease, immune cells attack healthy tissues, causing inflammation and damage to organs and tissues. Some autoimmunity exists in everyone but in people with autoimmune disease, it reaches a pathogenic state and involves all aspects of the immune system including antigens, lymphocytes, messenger molecules, cytokines and signaling molecules, explains Brower.

Treatment may consist of dampening the entire immune system, thus risking infection, or targeting one part of it. Autoimmune diseases have been treated with steroids, chemotherapy or major immunosuppressants, each of which carries risks and side effects. More refined treatments are expected with the discovery of new targets and more precisely tailored medications, states Brower.