The prognostic value of thyroid-stimulating immunoglobulin in the management of Graves' disease

Yulin Zhou; Mengxi Zhou; Yicheng Qi; Weiqing Wang; Xinxin Chen; Shu Wang

doi:10.1177/20420188211044943

The prognostic value of thyroid-stimulating immunoglobulin in the management of Graves' disease

Ther Adv Endocrinol Metab. 2021 Sep 28:12:20420188211044943. doi: 10.1177/20420188211044943. eCollection 2021.

Authors

Yulin Zhou¹, Mengxi Zhou¹, Yicheng Qi¹, Weiqing Wang¹, Xinxin Chen², Shu Wang³

Affiliations

¹ Shanghai Clinical Center for Endocrine and Metabolic Diseases, Department of Endocrinology, Shanghai Institute of Endocrine and Metabolic Diseases, Ruijin Hospital, Shanghai Jiao Tong University School Medical School, Shanghai, P.R. China.
² Department of Endocrinology, Suzhou Municipal Hospital Affiliated to Nanjing Medical University, 26 Daoqian Road, Suzhou 215000, P.R. China.
³ Shanghai Clinical Center for Endocrine and Metabolic Diseases, Department of Endocrinology, Shanghai Institute of Endocrine and Metabolic Diseases, Ruijin Hospital, Shanghai Jiao Tong University School Medical School, 197 Ruijin 2nd Road, Shanghai 200025, P.R. China.

Abstract

Background: The bioassay of thyroid-stimulating immunoglobulin was reported to have a similar performance to the commonly used thyroid-stimulating hormone binding inhibition assay, also known as thyroid receptor antibody assay. The normal reference range of thyroid receptor antibody levels indicates the withdrawal of anti-thyroid drugs in the recent clinical guidelines.

Methods: A prospective, longitudinal observational study was conducted to evaluate the prognostic value of thyroid-stimulating immunoglobulin in patients with Graves' disease.

Results: A total of 77 patients with Graves' disease treated with anti-thyroid drugs were in a continuous follow-up until 1 year after anti-thyroid drugs discontinuation. Commercial kits of thyroid-stimulating immunoglobulin and M22-thyroid-stimulating hormone binding inhibition assay were used and compared. Thyroid-stimulating immunoglobulin was all negative in healthy controls, Hashimoto thyroiditis, and subacute thyroiditis. Thyroid-stimulating immunoglobulin value was highest in untreated patients with Graves' disease (p < 0.001). Under anti-thyroid drugs treatment, thyroid-stimulating immunoglobulin value decreased gradually. A total of 21 patients had positive thyroid-stimulating immunoglobulin at the end of treatment. According to clinical fate of patients with Graves' disease after withdrawal of anti-thyroid drugs, thyroid-stimulating immunoglobulin value and positivity in patients with relapse were significantly higher than that reported in patients with remission (p = 0.001, p < 0.001). After adjustment for age, gender, initial thyroid receptor antibody, initial thyroid-stimulating immunoglobulin, and thyroid receptor antibody at the end of treatment, the odds ratio of positive thyroid-stimulating immunoglobulin for the risk of relapse was 33.271 (95% confidence interval: 4.741-233.458, p < 0.001) and odds ratio of quantitative thyroid-stimulating immunoglobulin was 1.009 (95% confidence interval: 1.002-1.015, p < 0.001).

Conclusion: Thyroid-stimulating immunoglobulin is a good predictor of relapse in patients with Graves' disease treated with anti-thyroid drugs. It might be safer to discontinue anti-thyroid drugs when thyroid-stimulating immunoglobulin and thyroid receptor antibody were both negative.

Keywords: Graves’ disease; autoimmune thyroiditis; thyroid-stimulating immunoglobulin; thyrotoxicosis; thyrotropin receptor antibody.