Systemic Autoimmune Manifestations: When Should Underlying Thyroid Autoimmunity be Considered?

Autoimmune thyroid disease is among the most common autoimmune disorders affecting 10% of the population. It is characterized by diffuse lymphocytic infiltration of the thyroid gland, the presence of antithyroid antibodies and diffuse hypoechogenicity on thyroid ultrasound. Despite the fact that autoimmune thyroid disease is classically considered a localized disease of the thyroid gland, systemic features, such as musculoskeletal complaints, sicca symptomatology, pregnancy loss and even neurological manifestations are not uncommon. Although thyroid dysfunction could account for some of these features, concomitant autoimmune disorders or even thyroid autoimmunity itself could be involved. In the current report new clinical and laboratory data from our department are presented and the existing literature regarding the systemic/rheumatic features of autoimmune thyroid disease is reviewed.