what is an autoimmune disease definition
autoimmune disease, one of a large group of diseases characterized by altered function of the immune system of the body, resulting in the production of antibodies against the body's own cells.ome autoimmune disorders, such as Hashimoto's disease, are tissue specific, whereas others, such as SLE, affect multiple organs and systems. Both genetic and environmental triggers may contribute to autoimmune disease. About 5-8% of the U.S. population is affected by an autoimmune disease.