Autoimmunity and the immunologic network.

Recent developments in autoimmunity suggest that there are three stages in the response to self, which can be called autorecognition, autoimmunity, and autoimmune disease. The first is physiologic and fundamental to a network theory of immunologic control that is based upon recognition of idiotypes and antigens related to the major histocompatibility complex. Many foreign antigens may be recognized immunologically only if they can be imposed upon an existing network of immunologic communication. The existence of anti-receptor autoimmune diseases (such as myasthenia gravis and Grave's disease) leads to the postulate that the immune network may normally function to help regulate hormone and other nonimmune cell surface receptors. Chronic autoimmune diseases may be caused either by genetically determined abnormalities in the immune network or by an antigenic perturbation of the network that results in unresponsiveness and tolerance of an offending agent.