Transplantation of human hyperthyroid tissue to the nude mouse. An experimental model.

This study analyzes the outcome of human normal and hyperfunctioning thyroid tissue transplanted to the nude mouse. Thyroid fragments from 7 patients with Graves' disease were transplanted to nude mice (nu/nu). Before surgery, the patients had been treated with propranolol and iodine; none had received antithyroid therapy. The transplants were removed on the 12th day following transplantation and were studied by light microscopy and autohistoradiography. At this time, all immunologic disorders found on the operative samples had disappeared, and the tissue had lost its hyperfunctioning characteristics. In contrast, transplants from toxic adenoma remained hyperfunctioning, with elevated serum T3 and T4 levels. Similarly, transplants from normal thyroid tissue remained unchanged, and serum T3 and T4 levels remained within the normal range, as if under the influence of the hypothalamic and pituitary regulation of the mice. These findings emphasize the role of the extrathyroid immunologic environment in the regulation of Graves' disease, whereas toxic adenoma remains autonomous.