Sites of autoantibody production in rats with thyroiditis.

We have developed a thyroglobulin-specific haemolytic plaque assay and investigated potential sites of autoantibody synthesis in good and poor responder strains of rats immunized with thyroglobulin and in rats subjected to thymectomy and sub-lethal irradiation which subsequently develop thyroiditis spontaneously. The bone marrow appears to be the most important site of thyroglobulin antibody synthesis in all groups, but spleen and cervical lymph nodes are also involved. No thyroglobulin plaque-forming cells could be found in the thyroid. These results imply widespread involvement of the humoral immune system in organ-specific autoimmune processes.