Summary
Beef thyroid antisera and hog thyroid antisera produced by the rabbit contain, in addition to potent antibodies against their homologous antigen, antibodies against rabbit thyroid extract.
Beef thyroid and hog thyroid antisera when treated with the homologous antigen are completely deprived of their antibody content. Complete absorption with rabbit thyroid extract, on the other hand, removed only that part of the antibody spectrum which is directed against the rabbit thyroid extract but always left antibodies against the homologous thyroid antigen.
Rabbit thyroid antibodies in rabbit antisera produced by immunization with thyroid extracts of foreign species are demonstrable mainly by the tanned cell hemagglutination test and occasionally by the gel diffusion precipitation test. In addition, complement-fixing antibodies against rabbit thyroid extracts could be demonstrated in certain antisera against hog thyroglobulin following an intensive and prolonged course of immunization.
Histologic changes characteristic of immunologic thyroiditis were also observed in the thyroid glands of the rabbits intensively treated with hog thyroglobulin.