Pathogenesis of type I (insulin-dependent) diabetes: possible mechanisms of autoimmune damage.

By definition, autoimmunity is a circumvention of self-tolerance. Considering the complex network of control mechanisms which initiate and regulate immune responses to foreign agents and maintain the natural state of self-tolerance, autoimmunity may result from a weakening of this delicate equilibrium at various levels. Several hypotheses have therefore been put forward to explain the 'active' immunization process against self-constituents which are normally tolerated.