A group of autoantibodies that react against normal components of the cell nucleus. These antibodies are present in a variety of immunologic diseases, including systemic lupus erythematosus, progressive systemic sclerosis, Sjogren’s syndrome, scleroderma, polymyositis, and dermatomyositis, and in some patients taking hydralazine, procainamide, or isoniazid. In addition, ANA is present in some normal people. Tests for ANAs are used in the diagnosis and management of autoimmune disease.