autoimmune disease, any of a number of abnormal conditions caused when the body produces antibodies antibody, protein produced by the immune system (see immunity ) in response to the presence in the body of antigens: foreign proteins or polysaccharides such as bacteria, bacterial toxins , viruses, or other cells or proteins.
..... Click the link for more information. to its own substances. In rheumatoid arthritis arthritis, painful inflammation of a joint or joints of the body, usually producing heat and redness. There are many kinds of arthritis. In its various forms, arthritis disables more people than any other chronic disorder.
..... Click the link for more information. , a group of antibody molecules called collectively RF, or rheumatoid factor, is complexed to the individual's own gamma globulin blood proteins; the circulating complex apparently causes tissue inflammation and muscle and bone deformities. In Hashimoto's thyroiditis, an inflammatory disease of the thyroid gland, antibodies are produced against the thyroid protein thyroglobulin. In some blood disorders, antibodies may be produced against the body's own red and white blood cells. Myasthenia gravis, a disease characterized by weakened muscles, is thought to have an autoimmune origin. In systemic lupus erythematosus it has been shown that individuals have antibodies to certain of their own body substances that for some reason are acting as antigens; these substances include the individual's own nucleic acids and cell organelles such as ribosomes and mitochondria. Lupus can cause dysfunction of many organs, including the heart, kidneys, and joints. Because lupus and certain diseases of probable autoimmune origin, e.g., scleroderma and dermatomyositis, affect collagen collagen (kŏl`əjən)
..... Click the link for more information. (connective tissue) throughout the body and blood vessels, they are referred to as collagen-vascular diseases. In rheumatic fever, the individual produces antibodies to antigens of streptococcal bacteria; it is believed that the streptococcal antigens are structurally similar to antigens of the heart and that antistreptococcal antibodies, combining with antigenic sites on the heart, damage the muscle and heart valves. Diseases of the immune system are currently treated by a variety of nonspecific immunosuppressive drugs immunosuppressive drug, any of a variety of substances used to prevent production of antibodies . They are commonly used to prevent rejection by a recipient's body of an organ transplanted from a donor.
..... Click the link for more information. and steroids steroids, class of lipids having a particular molecular ring structure called the cyclopentanoperhydro-phenanthrene ring system. Steroids differ from one another in the structure of various side chains and additional rings.
..... Click the link for more information. .

autoimmune disease

Any disease caused by an immune response (see immunity) against antigens in the tissues of one's own body. The immune system has two known ways to prevent such a response: destruction of lymphocytes in the thymus before they leave to attack one's own tissues and loss of ability to react to their target antigens by any such cells that do leave the thymus. Autoimmune diseases arise when these mechanisms fail and lymphocytes destroy host tissues; examples include type 1 diabetes mellitus, systemic lupus erythematosus, pernicious anemia, and rheumatoid arthritis. Treatment may replace the function of the affected tissue (e.g., insulin therapy for diabetes) or suppress the immune system (see immunosuppression). Allergy is another type of autoimmune reaction.