Experimental thyroiditis in the rhesus monkey. IV. The role of thyroglobulin and cellular antigens

Abstract

Nine normal rhesus monkeys were injected with homologous thyroid preparations, consisting either of a crude extract, partially purified thyroglobulin, or enzymatically dispersed viable cells. One monkey was injected with a preparation of heterologous human thyroid microsomes. The course of the disease was followed by periodic biopsies of the thyroid gland and by circulating antibodies. The latter were detected by tanned cell haemagglutination, complement fixation and cytotoxicity. The serum was also examined for levels of complement and for thyroid hormones.

Injection of partially purified monkey thyroglobulin resulted in the production of antibody both to thyroglobulin and to the cellular antigen. Inoculation of enzymatically dispersed viable thyroid cells led to a greater production of cytoplasmic antibody with a small and delayed production of antibody to thyroglobulin. Heterologous immunization of a monkey with human thyroid microsomes resulted in the production of autoantibodies to thyroid and minimal thyroid damage. There was considerable variation in antibody response and degree of tissue injury in different monkeys although injected with a similar antigen. There was no consistent association between circulating antibodies and pathological changes in the thyroid gland. Levels of complement varied but showed a definitive decrease in some animals with thyroiditis. There was no correspondence between tissue damage and protein bound iodine or thyroxine iodine.