[Predisposition to thyroid autoimmune diseases]

Genetic predisposition is required for the expression of thyroid autoimmune disorder addition to the immune dysfunction and the environmental factors.

In order to evaluate the role of this genetic factor, we reported the results of immunological and hormonal investigations of 62 members (TD), belonging to a large Akr family, who are related to 40 patients with Graves' disease or Hashimoto's thyroiditis.

The hormonal analyses showed that 19 subjects exhibited an infraclinical hypothyroidism, subdivided into 7 members with pathological rates of TSH evocative of thyroid insufficiency and 12 others with compensative thyroid insufficiency. Seventeen subjects of the Akr family who had solely antithyroid autoantibodies were considered as potential candidates to develop thyroid autoimmune diseases. The clinical follow-up, during two years, confirmed the diagnosis of Hashimoto's thyroiditis in 3 members among 19 subjects with infraclinical hypothyroidism (TD05, TD28 and TD54) and in only 1 member out of the 17 potential candidates (TD03).

Our results showed that a serological study of hormones and/or autoantibodies directed against thyroid antigens, could allow the detection of predisposed subjects to develop a thyroid autoimmune pathology. The Akr family seems to be suitable for the study of the localization of susceptibility genes to TAID.