Remission in pediatric Graves' disease treated with antithyroid drug and the risk factors associated with relapse

Purpose: To evaluate the characteristics and frequency of remission in pediatric patients with Graves' disease (GD) treated with antithyroid drug (ATD) and to identify factors that may be associated with relapse. Methods: Medical records of patients younger than 19 years who presented to the Department of Pediatrics of Queen Elizabeth Hospital Hong Kong with newly diagnosed GD from 1st January 2007 to 31st December 2017 were retrospectively reviewed. Remission was defined as euthyroidism for 12 months or more after discontinuation of ATD treatment and no relapses during the follow-up period. Patients who successfully achieved remission were compared to those who suffered relapse. Factors that may predict occurrence of relapse after ATD treatments were studied, and their odds ratios (ORs) were calculated. Results: A total of 101 patients was included in this study. Eighty-one patients completed one course of ATD. Eighteen patients ( 17.8%) successfully achieved remission, and 58 patients (57.4%) experienced relapse after discontinuation of ATD. The remission group received a significantly longer course of ATD therapy than the relapse group (median, 28 months; interquartile range [IQR], 18-48 months in remission group vs. median, 21 months; IQR, 17-26; P=0.024). The OR for relapse was 0.971 ( 95% confidence interval [CI], 0.946-0.997) in univariate analysis and remained significant after adjustments in the multivariate regression model (OR, 0.961; 95% CI, 0.933-0.989; P=0.008). Conclusion: The remission rate in pediatric patients with GD treated with ATD was low. A longer ATD course was associated with a greater chance of remission in this population.