Detection of TSH receptor RNA in cultured fibroblasts from patients with Graves' ophthalmopathy and pretibial dermopathy.

Fibroblasts are target cells for the autoimmune process in Graves' ophthalmopathy and pretibial dermopathy. Because the autoantigen involved in the hyperthyroidism of Graves' disease is the TSH receptor, we sought to determine whether RNA encoding this receptor might be present in retroocular and pretibial fibroblasts. RNA was reverse transcribed and the resulting cDNA was amplified by the polymerase chain reaction using primers spanning a region of the extracellular domain of the human TSH receptor. The predicted amplified product, verified by direct sequencing, was detected when RNA was derived from fibroblasts, but not from the nonfibroblast cells studied. The demonstration in fibroblasts of RNA encoding this important autoantigen in Graves' disease suggests that the TSH receptor might play a role in the pathogenesis of the connective tissue manifestations of this disease.