SINCE the earliest descriptions of the immune system, the ability of an individual to react to a wide variety of foreign and endogenous antigens, while not responding to one's own self, has intrigued researchers.
The first descriptions of autoimmune phenomena in the early 1900s aroused sufficient anxiety to cause Ehrlich to coin the term "horror autotoxicus" to describe the situation in which an individual would attempt to destroy himself or herself. This horror at physiological self-destructive mechanisms was certainly justified with the delineation of the many autoimmune disease states. What has changed since then, however, is the recognition that the production of autoimmunity is a common phenomenon, often under normal immune regulation, and that in some situations, such as the response to cancer cells, it may benefit the individual. There has also been speculation that autoantibodies are the markers by which the phagocytic system recognizes and removes old red blood
Condemi JJ. The Autoimmune Diseases. JAMA. 1992;268(20):2882-2892. doi:10.1001/jama.1992.03490200134015