Detectability of thyroid anti-microsomal antibodies, changes in thyroid-stimulating immunoglobulins (TSI) and thyrotropin-binding-inhibiting immunoglobulins (TBII) during methimazole treatment of Graves' disease patients.

The prognostic value of determination of different antibodies in Graves' disease patients is questionable. The authors simultaneously assessed the generation of cAMP, the TSH-receptor binding inhibitory assay and the detectability of anti-microsomal antibodies by indirect immuno-fluorescence. The tests were performed before, during and after methimazole treatment. During a 12 months' medication all 22 patients became euthyroid. Six months after withdrawal of the drug, 15 patients were still euthyroid (Group A); 7 relapsed (Group B). Patients showing enhanced activities by all three methods, relapsed (5 out of 7 cases of Group B). The results indicate that simultaneous determination of TSI, TBII and anti-microsomal antibodies are of high prognostic value for relapses. These data should be taken into consideration for the further therapy.