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

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.

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The Prognostic Value of Thyroid Stimulating Immunoglobulin in the Management of Graves’ Disease

10.21203/rs.3.rs-26936/v1 ◽

2020 ◽

Author(s):

Xinxin Chen ◽

Yulin Zhou ◽

Mengxi Zhou ◽

Yicheng Qi ◽

Weiqing Wang ◽

...

Keyword(s):

Prognostic Value ◽

Hashimoto Thyroiditis ◽

Diagnostic Value ◽

Graves Disease ◽

Antibody Assay ◽

End Of Treatment ◽

Binding Inhibition ◽

Thyroid Receptor ◽

Commercial Kits

Abstract Background: The bioassay of thyroid-stimulating immunoglobulin (TSI) appears to be more sensitive than the commonly used TSH binding inhibition assay (TBII), also known as thyroid receptor antibody assay or TRAb.Methods: An observational study was conducted to evaluate the prognostic value of TSI in clinic. Patients with different etiologies of thyrotoxicosis were enrolled to verified the diagnostic value of TSI.Results: 77 Graves’ disease (GD) patients who were treated with anti-thyroid drug (ATD) were in a continuous follow-up until 1 year after ATD discontinuation. Commercial kits of TSI (Thyretain™) and M22-TBII were used and compared. TSI was all negative in healthy controls, Hashimoto thyroiditis, subacute thyroiditis. TSI value was highest in untreated GD patients (P < 0.001). Under ATD treatment, TSI value decreased gradually. 21 patients had positive TSI at the end of treatment. According to clinical fate of patients with GD after withdrawal ATD, TSI 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 TRAb, initial TSI, and TRAb at the end of treatment, the odds ratio (OR) of positive TSI for the risk of relapse was 33.271 (95% confidence interval [CI]: 4.741-233.458, P < 0.001) and OR of quantitative TSI was 1.009 (95% CI: 1.002–1.015, P < 0.001).Conclusions: TSI is a good predictor of relapse in patients with GD subjected to ATD treatment. It might be safer to discontinue ATD when TSI and TRAb were both negative.

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