An Attack on Self Tissues W hen the immune system mistakes self tissues for nonself and mounts an inappropriate attack, the result is an autoimmune disease. There are many different autoimmune diseases. Some examples are Wegener's granulomatosis, multiple sclerosis, type 1 diabetes mellitus, and rheumatoid arthritis. Autoimmune diseases can each affect the body in different ways. For instance, the autoimmune reaction is directed against the brain in multiple sclerosis and the gut in Crohn's disease.
Many autoimmune diseases are rare.
As a group, however, they afflict millions of Americans. Most autoimmune diseases strike women more often than men, particularly affecting women of working age and during their childbearing years. The genes people inherit contribute to their susceptibility for developing an autoimmune disease. Certain diseases such as psoriasis can occur among several members of the same family, suggesting that a specific gene or set of genes predisposes a family member to psoriasis. In addition, individual family members with autoimmune diseases may inherit and share a set of abnormal genes, although they may develop different autoimmune diseases.