Clinical Changes and Autoantibody Level Changes in Thyroid Eye Disease Patients after Intravenous High-dose Steroid therapy

Purpose: To evaluate the effects of intravenous steroid therapy on the clinical activity score (CAS), exophthalmos, margin -reflex distance 1 (MRD1), and autoantibody levels in patients with thyroid eye disease. Methods: In this retrospective observational study, we enrolled 83 patients diagnosed with thyroid eye disease treated with intravenous steroid therapy. We assessed exophthalmos, MRD1, CAS, thyroid -stimulating antibody (TSAb), and thyroid -stimulating hormone receptor antibody (TSHR Ab) levels at baseline, 6 and 12 weeks after initiating therapy, and 2 months after therapy termination. Additionally, baseline serum selenium levels were examined to determine their impact on treatment efficacy. Results: TSAb, TSHRAb, and CAS levels showed a continuous decline from 443.22 to 341.03 specimen -to -reference control ratio (SRR%), 22.18 to 7.91 IU/L, and 3.37 to 1.88, respectively ( p < 0.0001), up to 2 months following therapy termination. Exophthalmos did not show significant changes at any assessed time point up to 2 months after therapy termination. MRD1 decreased until 12 weeks after therapy initiation but showed no significant change 2 months later. No correlation was found between baseline serum selenium levels and changes in exophthalmos, MRD1, TSAb, TSHR Ab, or CAS. Conclusions: Intravenous steroid therapy was effective in reducing TSAb, TSHR Ab, and CAS levels up to 2 months after therapy termination. However, it had limited positive impact on exophthalmos or eyelid retraction. Baseline selenium levels did not correlate with the changes in any of the examined parameters.