The genetics of thyroiditis as a prototype of human autoimmune disease.

The predisposition to autoimmune disease has been termed an autoimmune diathesis. The genetic basis for this predisposition has been analyzed, using three different models: juvenile thyroiditis in humans, spontaneous thyroiditis in chickens, and experimental thyroiditis in mice. At least three different categories of genetic factors contribute to the development of autoimmunity. They include an increased immune response due to immunoregulatory genes associated with the major histocompatibility complex, the balance of thymus-derived lymphocyte population with helper/inducer vs suppressor properties, and intrinsic metabolic abnormalities of the target thyroid cells.