[The association between autoimmune thyroid diseases and rheumatic diseases: a review]

Although the association between autoimmune thyroid diseases (especially Graves' and Hashimoto's diseases) and rheumatic diseases has been well accepted, its precise mechanism is unclear. Autoreactive T cells may recognize autoantigens not only those expressed on thyroid but also those on other organs. Rheumatoid arthritis and psoriatic arthritis are among the examples of that suggested to occur with high incidence in association with positive anti-thyroid autoantibodies. Systemic lupus erythematosus and systemic sclerosis are also known to often coincide with autoimmune thyroid disease. Anticardiolipin antibody is suggested to be induced in the patients with thyroid autoimmunity. Overall, it would be important to analyze the pathogenic autoimmune response at the molecular level to further understand the relationship between thyroid and rheumatic autoimmune diseases.