Studies on auto-anti-idiotypic thyroid-stimulating antibodies.

We immunized rabbits with human (h) or bovine (b) thyroid-stimulating hormone (TSH), hTSH beta chains or human serum albumin. Serum from the rabbits was then assayed for thyroid-stimulating activity, using the thyroid-cell bioassay. Anti-idiotypic antibodies (anti-ID) to monoclonal anti-TSH were detected in these rabbit antisera after removal of rheumatoid factor by absorption with IgG. Anti-ID activity was detected in the serum of the rabbits immunized with bovine TSH. Thyroid-stimulating antibody (TSI) activity, too, was most prominent in the sera obtained from bTSH-immunized rabbits. Anti-ID activity seemed to arise sooner than did TSI, but both tended to peak 3 months after an initial series of immunizations. Since thyroid-stimulating immunoglobulins can develop following TSH immunization of rabbits, it is possible that a similar immunopathogenesis may be responsible for some instances of Graves' hyperthyroidism.