Eleonore Fröhlich1,2 and Richard Wahl1*
1Internal Medicine (Department of Endocrinology and Diabetology, Angiology, Nephrology and Clinical Chemistry), University of Tuebingen, Tuebingen, Germany 2Center for Medical Research, Medical University Graz, Graz, Austria
Autoimmune diseases have a high prevalence in the population, and autoimmune thyroid disease (AITD) is one of the most common representatives. Thyroid autoantibodies are not only frequently detected in patients with AITD but also in subjects without manifest thyroid dysfunction. The high prevalence raises questions regarding a potential role in extra-thyroidal diseases. This review summarizes the etiology and mechanism of AITD and addresses prevalence of antibodies against thyroid peroxidase, thyroid-stimulating hormone receptor (TSHR), and anti-thyroglobulin and their action outside the thyroid.