When rabbits were injected with 10.0 mg rabbit thyroglobulin in complete Freund's adjuvant, the earliest thyroid lesions were seen on day 5 and uniformly severe thyroid lesions were seen by day 14; these observations were not significantly different from the thyroid lesions observed at 1 and 2 months post-immunization. Pooled sera were obtained from immunized, thyroidectomized, and nonthyroidectomized donors on various days and transferred to normal recipient rabbits in different experiments. Successful transfer of thyroid lesions was seen when serum containing early antithyroglobulin antibody obtained from thyroidectomized donor animals at various times after immunization was injected into normal recipients in a sequential manner. Immunofluorescent studies of recipient thyroid glands showed focal fixation of rabbit γ-globulin and ß1C complement in thyroid follicles. When purified antibody to rabbit thyroglobulin obtained from thyroidectomized donor sera was transferred sequentially as above, significant thyroid lesions were seen in recipient rabbits. In contrast, no thyroid lesions were seen in recipient animals injected with rabbit sera containing late antithyroglobulin antibody from thyroidectomized donors or hyperimmune sera from guinea pigs.
No thyroid lesions were seen in recipient animals injected either with sera from donors given complete adjuvant without thyroglobulin or with globulin fraction of pooled sera containing early antithyroglobulin antibody obtained on various days from nonthyroidectomized donors. Similarly, rabbits rendered unresponsive to guinea pig γG-globulin and periodically injected with guinea pig anti-rabbit thyroglobulin showed no thyroid lesions.