autoimmune -
This word refers to a disease in which the body's immune (protection or resistance) system attacks healthy cells.
Other autoimmune diseases include lupus, rheumatoid arthritis, celiac, sjogrens syndrome, multiple sclerosis, polymyalgia rheumatica, Type 1 diabetes, alopecia areata, vasculitis, and inflammatory bowel disease - there are more than 80 of them.