Autoimmunity is a natural phenomenon which in some instances, such as response to cancer cells, may benefit the individual. However, immune mechanisms are not always protective or beneficial to the host. Under certain conditions they produce tissue injury and clinical disease.
It is sometimes undetermined whether the presence of autoantibodies is directly related to the etiology of disease or evolve as a result of tissue destruction. Therefore, the term "autoimmune" as used today, has a broad scope an connotes a disease associated with the development of autoantibodies, irrespective of whether or not these antibodies contribute to the disease process itself.