Experimental autoimmune thyroiditis in transplanted isologous tissue and attempts to produce parathyroid lesions.

Strictly inbred guinea-pigs immunized with isologous thyroid extract in complete Freund's adjuvant consistently developed thyroiditis in intramuscular transplants of isologous thyroid tissue, with reactions at least as severe as those seen in their in situ thyroid glands. Normal isologous thyroid tissue accurately reflected the severity of the systemic thyroiditis within 2 weeks after transplantation into a previously immunized guinea-pig. There was no correlation between the intensity of the histological reaction of experimental autoimmune thyroiditis and the absolute amount of thyroid tissue present in an immunized guinea-pig. Control animals without antigen–adjuvant immunization failed to demonstrate any thyroiditis after multiple thyroid isografts alone. Parallel immunization procedures with isologous parathyroid tissue extracts failed to produce any parathyroiditis or thyroiditis. The finding that the cellular reactivity of thyroid autoimmunity is an anatomically generalized phenomenon adds to the similarity of the process to other forms of delayed hypersensitivity such as homotransplantation immunity. Accessible transplants of specific target tissue may be used to monitor the natural course of experimental autoimmune disease or the effect of attempts to modify it.