Autoimmunity is the failure of the body's immune system to recognize its own tissues as self and induction of an immune response against them. Any disease that results from such an aberrant immune response is termed an autoimmune disease

Autoimmunity is the failure of the body's immune system to recognize its own tissues as self and induction of an immune response against them. Any disease that results from such an aberrant immune response is termed an autoimmune disease. The concept of autoimmunity was first presented at the beginning of 2o" century by Paul Ehrlich, the great German bacteriologist and immunologist, who described it as "Horror autotoxicus" or "the horror of self-toxicity" describing the body's innate aversion to immunological self-destruction. However, occasionally, immune system can attack itself and does so in the autoimmune diseases