[What is the recurrence rate for Basedow's disease treated with thyrostatic agents. Answers from a prospective study]

Graves' disease is an autoimmune disease whose development involves immunogenetic and exogenous factors such as viruses, bacteria and iodine excess. In a number of patients the disease follows a chronic recurrent course. A recurrence rate of 50% can be expected one year after the end of therapy. Based on the preliminary results of the prospective study presented here, this recurrence rate does not differ in groups where patients underwent long-term treatment with 10 or 40 mg thiamazole. Retrospectively obtained data suggest that the time at which euthyroidism occurs under low-dose treatment is dependent on the alimentary iodine supply. A number of groups have attempted to develop clinically applicable methods to identify patients at risk for recurrence at the end of treatment. All the studies yielded controversial results. A prospective multicenter study was undertaken to reinvestigate the importance of measuring TSH receptor antibodies and performing the TRH test and the suppression test at the end of therapy in connection with this problem. In 451 patients the recurrence rate was 50.3% one year after the end of treatment. The patients in the recurrence group had a significantly higher rate of persistent antibody activity, no increase in TSH after TRH (negative TRH test), no normal suppressibility of thyroid 123 iodine uptake (negative suppression test) and larger goiter. The calculation of sensitivities and specificities shows, however, that these differences are not large enough to be of clinical importance for the individual patient.