There are scarce reports regarding a functional prognostic value of thyroid-stimulating autoantibody (TSAb) levels using a thyroid-stimulating hormone receptor chimera (Mc4) in Graves’ disease (GD) in iodine sufficient area. The aim of this study was to investigate whether Mc4-TSAb can predict GD remission/relapse after antithyroid drug (ATD) treatment and to compare Mc4-TSAb with a binding assay using M22 monoclonal antibody (M22-TRAb) in GD patients. We retrospectively reviewed the results of M22-TRAb and Mc4-TSAb in GD patients treated with ATD for 12 months. GD patients who underwent ATD treatment for at least 12 months were included. We compared the predictive values of M22-TRAb and Mc4-TSAb for GD remission and relapse. Of the 92 patients, 60 (65.2 %) achieved remission and 32 (34.8 %) relapsed within 12 months. In receiver operating characteristic analysis, there were no significant differences in the area under the curves (AUCs) between Mc4-TSAb [AUC = 0.79 (95 % CI 0.69–0.89)] and M22-TRAb [AUC = 0.69 (95 % CI 0.58–0.81)]. The optimal predictive cut-off values of M22-TRAb and Mc4-TSAb were 2.23 IU/L and 230 %, respectively. At a high Mc4-TSAb cut-off, the better specificity of 85.0 % and positive predictive value (PPV) of 69.0 % were shown compared with those at the best cut-off for M22-TRAb. In conclusion, a high cut-off for an Mc4 assay may improve the predictive value of relapse with superior specificity and PPV compared with M22-TRAb in treated GD.
All Science Journal Classification (ASJC) codes
- Endocrinology, Diabetes and Metabolism