Extrathyroidal sites of autoantibody synthesis in Graves' disease

Several potential sites of thyroid autoantibody production have been investigated using tissue obtained at thyroidectomy for Graves' disease. Spontaneous thyroglobulin and microsomal antibody synthesis was measured using a plaque forming cell assay or a short term culture system coupled to a direct enzyme linked immunoassay (ELISA); these techniques allow the evaluation of lymphocyte populations which have been activated in vivo. Lymphocytes from the cervical lymph nodes, thyroid and bone marrow all contributed to autoantibody production; in contrast no synthesis was demonstrated using cells obtained from the thymus or peripheral blood. Long term culture of the lymphocytes confirmed these findings. The effect of anti-thyroid treatment, with radioiodine, drugs or surgery, on autoantibody production in Graves' disease must be viewed in the light of these results.