SAT-LB75 Thyroid Peroxidase Antibody Positivity Predicts Relapse Free Survival Following Anti-Thyroid Drug Treatment for Graves Disease

Objective: Graves disease is an autoimmune disease characterized by production of autoantibodies directed against the thyroid gland. Thyrotropin-receptor antibodies (TRABs) are clearly pathogenic, but the role of thyroid-peroxidase antibodies (TPOAb) in Graves disease is unknown. Design: We retrospectively studied whether TPOAb positivity reduced risk of relapse following anti-thyroid drug treatment in newly diagnosed Graves disease. Results: During follow-up of 204 patients with TRAB positive Graves disease, 107 (52%) relapsed following withdrawal of anti-thyroid medication. Mean age was 40.0 years and 82% were female. The average duration of anti-thyroid drug (ATD) treatment was 23.5 months and was not different between patients who relapsed and those with sustained remission. Absence of TPOAb significantly increased risk of Graves relapse (OR 2.21) and displayed a trend towards shorter time to relapse. Male sex and younger age were additional factors significantly associated with increased risk of relapse. Conclusion: TPO-antibody positivity significantly improves odds of remission following ATD treatment in newly diagnosed Graves disease.