Autoimmunity and the Thyroid Gland

Abstract

Immunological mechanisms are critical for the occurrence and progression of autoimmune thyroiditis (AIT) and diffuse toxic goitre (Graves’ disease), with or without thyroid-associated ophthalmopathy (TAO) (see Chaps. 9 and 18).

As in other autoimmune diseases, the pathophysiological background of the development of autoimmune thyroid disease has not been entirely clarified. It’s likely that some individuals have a predisposition which, in conjunction with triggering factors, starts the process. In addition to genetic factors, predisposing factors can include reduced immunological tolerance, which could have arisen during maturation of the immune competent cells in the thymus.

It is thought that autoimmune reactions against the thyroid can develop in various directions. In AIT, the immunological process is dominated be a lymphocyte mediated cell-damaging processes, leading to destruction of follicular cells; in Graves’ disease the immunological process is dominated by synthesis and release of antibodies that stimulate the TSH receptor.