Thyroid-stimulating immunoglobulin (TSI) may be a more informative marker than the standard thyrotropin receptor antibody (TRAb) test for monitoring Graves’ disease, according to a retrospective analysis of 330 patients treated at Guangzhou Red Cross Hospital between January 2023 and March 2026. The study, published in BMC Endocrine Disorders, compared the two antibodies across treatment outcomes, disease duration and thyroid function measures.
The research team stratified patients by their TSI and TRAb levels and by treatment outcome, grouping them into those who relapsed, those who stopped medication, and those who continued treatment without remission, then analyzed antibody levels, thyroid function and clinical data across these groups and across disease-duration strata.
The results pointed to differences between the two antibodies. In patients who were TRAb-negative but TSI-positive, median TRAb levels were higher than in patients negative for both antibodies, indicating that some discordance exists between the assays. Among patients positive for both antibodies, the TRAb-positive/TSI-positive group showed significantly higher free T3 levels and lower TSH levels than the TRAb-positive/TSI-negative group, suggesting that TSI positivity tracks more closely with active thyroid overactivity.
The clearest separation emerged in the treatment-outcome analysis. TSI levels were significantly higher in the relapse group than in the group that successfully withdrew from medication, whereas TRAb levels did not differ significantly between these two groups. In addition, higher TSI levels were associated with longer drug-withdrawal duration and longer overall disease duration among patients who relapsed, positioning TSI as a candidate marker for relapse risk assessment.
Across disease-duration groups, both TSI and TRAb levels were highest in patients within four months of diagnosis and were lower in groups with longer disease duration, a pattern consistent with declining antibody levels over the course of treatment. The authors conclude that TSI reflects response to antithyroid drug therapy and disease activity, and showed potential utility in guiding the timing of drug withdrawal and assessing relapse risk in this cohort.
The study’s authors caution that these findings require validation in larger, prospective studies. As a retrospective, single-center analysis, the work establishes associations within one cohort rather than demonstrating that TSI-guided decisions improve clinical outcomes, and the conclusions should be read in that context.
Subject of Research: Comparison of TSI and TRAb antibodies for monitoring Graves' disease, predicting relapse and guiding antithyroid drug withdrawal
Article Title: TSI vs. TRAb in Graves’ disease: treatment monitoring, relapse prediction, and drug withdrawal decisions
Article References: Zhou, X., Chen, H., Jiang, X., Ke, X., Liu, J., Chen, C., Zhu, P., Tan, R., & Ran, J. (2026). TSI vs. TRAb in Graves’ disease: treatment monitoring, relapse prediction, and drug withdrawal decisions. BMC Endocrine Disorders. https://doi.org/10.1186/s12902-026-02695-z
Image Credits: AI Generated
DOI: 10.1186/s12902-026-02695-z
Keywords: Graves' disease, TSI, TRAb, hyperthyroidism, antithyroid drugs, relapse prediction, drug withdrawal, thyroid function, retrospective study, BMC Endocrine Disorders, Graves, disease
News Source: Ophelia Keating. (October 29, 2026). TSI outperforms TRAb for tracking Graves’ disease activity and relapse risk in retrospective cohort. Scienmag.
