The immune system has very powerful effector mechanisms that can eliminate a
wide variety of pathogens. Early in the study of immunity, it was realized that these
could, if turned against the host, cause severe tissue damage. Autoimmune
responses resemble normal immune responses to pathogens as specifically activated
by antigens, in this case self-antigens or auto-antigens, and give rise to auto-reactive
effector cells and to antibodies, called autoantibodies, against the self-antigen. When
reactions to self-tissues do occur and are then improperly regulated, they cause a
variety of chronic syndromes called autoimmune diseases.
Although individual autoimmune diseases are uncommon, collectively they affect
approximately 5% of the populations in United States, and their incidence is on the
rise. Nevertheless, their relative rarity indicates that the immune system has evolved
multiple mechanisms to prevent damage to self-tissues. The most fundamental
principle underlying these mechanisms is the discrimination of self from non self, but
this discrimination is not easy to achieve.
Find more information about autoimmunity at Creative Diagnostics.