In Vivo Effects of TSH Receptor Antibodies in Xenotransplanted Human Thyroid Tissue

: From the data presented it can be concluded that the xenotransplantation model is well suited for studies concerning pathogenesis, diagnosis and therapy of AITD. Human thyroid transplants of Graves' disease tissue, depending upon extrinsic stimulators, lose all signs of hyperfunction after transplantation into athymic nude mice, but hyperfunction can again be induced in the transplants by injections of sera or immunoglobulin fractions from patients with active Graves' disease, containing stimulating TSH receptor antibodies. Our data demonstrate that thyroid function and growth are independent phenomena and can be differentiated by means of the xenotransplantation model. Furthermore the presented results indicate that TSH receptor antibodies are able to alter the expression of gene products in human thyroid transplants of Graves' disease, emphasising their important role in inducing/perpetuating immune phenomena related to AITD.