Suppression of thyroid lesions in rabbits by treatment with cyclophosphamide after the induction of thyroiditis.

An acquired immunologic unresponsive state to bovine thyroglobulin has been induced in adult rabbits following simultaneous injections of cyclophosphamide and bovine thyroglobulin. The acquired unresponsive state in some rabbits lasted at least 3 months after the last injection of bovine thyroglobulin. After induction of autoimmune thyroiditis by soluble injections of altered homologous arsanilsulphanil thyroglobulin or bovine thyroglobulin, a decrease in the incidence of thyroid lesions and the level of antithyroglobulin antibody production was observed following simultaneous injections of cyclophosphamide and native thyroglobulin.