Thyrotropin receptor autoantibody (TSHR autoantibody)

Thyrotropin receptor autoantibody (TSHR autoantibody) refers to a group of autoantibodies directed against the thyroid-stimulating hormone receptor (TSHR) on thyroid epithelial cells. These antibodies are a hallmark of autoimmune thyroid diseases, most notably Graves’ disease, where the stimulating form (TSI) aberrantly activates the TSHR, driving hyperthyroidism through unregulated thyroid hormone production. Other subtypes include blocking antibodies, which inhibit TSH binding and can cause hypothyroidism, and so-called “neutral” antibodies with non-canonical effects. TSHR autoantibody specificity and subclass involvement play major roles in the clinical phenotype[2][3]. Their presence in serum is used as a diagnostic and prognostic biomarker, especially for Graves’ disease and related conditions. These autoantibodies function by binding primarily to conformational epitopes in the TSHR extracellular domain, altering receptor signaling and modifying thyroid cell growth, function, and immune interactions[1][2][3][6].

Other names

Thyrotropin receptor antibodyTSH receptor antibodyTSHR-AbTSHR antibodyGraves' disease immunoglobulin (when referring to stimulatory variant)thyroid-stimulating immunoglobulin (TSI)

Stimulating antibodies: Mimic TSH, activate TSHR, increase cAMP, promote thyroid hormone production. Blocking antibodies: Inhibit TSH binding, reduce receptor activation, suppress thyroid hormone production. Neutral antibodies: May engage alternative signaling or induce apoptosis without affecting TSH binding.