ABSTRACT Objective: It is well established that serum levels of TSH receptor antibodies (TRAb) rise after radioiodine (131I) therapy for Graves’ disease (GD). However, it remains unclear whether these post-therapy autoantibodies are predominantly TSH receptorstimulating immunoglobulins (TSI) and how their persistence might affect treatment outcomes. Subjects and methods: In this prospective study, 39 patients with GD underwent 131I therapy. Serum TRAb (measured by competitive electrochemiluminescence, ECLIA) and TSI (measured by an IMMULITE® 2000/2000 XPi TSI assay) were evaluated at baseline […]