1606 Cellular Events Preceding Thyroiditis in Rabbits

Although experimental thyroiditis in various animals has been studied rather extensively (1-4), the immunological events at the cellular level have not been characterized. Investigations carried out at this level should provide the answer as to whether antibody to thyroglobulin is responsible for the initial damage to the thyroid gland before any significant lymphocytic infiltration occurs. Other studies: (2, 5) have implicated cell-mediated activity as a contributing mechanism to the infiltration of mononuclear cells observed in the thyroid. However, this may not prove to be the case in all species, as the successful transfer of thyroiditis to rabbits and mice with sera from appropriately immunized donors is possible (6, 7). The immunoglobulin that induces thyroiditis in these species is as yet uncharacterized. Furthermore, the pathological roles of specific types of antibody to thyroglobulin are not known, as total antibody levels contain a variety of immunoglobulins with. various biological capabilities (8).