Thyrotropin Receptor Antibody Activities Significantly Correlate with the Outcome of Radioiodine (¹³¹I) Therapy for Hyperthyroid Graves' Disease

Abstract

The outcome of ¹³¹I therapy for 109 patients with Gravest disease was analysed according to pretreatment laboratory data including thyrotropin receptor antibody (TRAb) activities. Forty-five percent of patients became euthyroid, and 13% of patients became hypothyroid within one year after ¹³¹I therapy. Forty-two percent of patients remained hyperthyroid one year after ¹³¹1 therapy. Pretreatment values for serum T₄, T₃, and the estimated weight of the thyroid were significantly higher in the hyperthyroid group. The mean for the TRAb index of the hyperthyroid group was significantly higher than that of the euthyroid group. Life table analysis revealed a significant effect of the TRAb index on the rate of hyperthyroidism after 3 months or later. These results appear to suggest that the TRAb index is one of the factors which influence the outcome of 131I therapy for Graves' disease.