Graves’ hyperthyroidism is characterized by stimulation of the thyroid gland by thyroid-stimulating hormone receptor antibodies (TRAbs). Antithyroid drug (ATD) continuation is recommended as long as the thyroid gland is stimulated. Goiter size, thyroidal 123I uptake, serum thyroglobulin level, and TRAb positivity are reliable markers of thyroid stimulation. Attention must also be paid to the responsiveness of the thyroid gland due to the high prevalence of painless thyroiditis and spontaneous hypothyroidism during treatment. TRAbs disappeared at <5 years entering remission in 36.6% of patients (smooth-type), while re-elevation of TRAb activity occurred in 37.7% (fluctuating-type) and remained positive for >5 years in 21.1% (smoldering-type). Seven percent of patients remained positive for TRAbs for >30 years, requiring life-long ATD treatment. Remission occurred after median 6.8 years (interquartile range, 4.0 to 10.9) of ATD treatment in 55% of patients. However, late relapse may occur after stressful events (dormant type). In apparently intractable Graves’ disease (GD) with a large goiter (>40 g), 131I therapy should be considered. For initial and long-term ATD treatment, we must choose effective, safe, and economical drugs such as 100 mg potassium iodide (KI), although KI sensitivity varies in patients with GD. Thionamide, which has notorious side effects, is added only during the KI-resistant period.
Background To determine whether baseline thyroid-stimulating immunoglobulin (TSI) bioassay or its early response upon treatment with an anti-thyroid drug (ATD) can predict prognosis of Graves’ disease (GD) in real-world practice.
Methods This retrospective study enrolled GD patients who had previous ATD treatment with TSI bioassay checked at baseline and at follow-up from April 2010 to November 2019 in one referral hospital. The study population were divided into two groups: patients who experienced relapse or continued ATD (relapse/persistence), and patients who experienced no relapse after ATD discontinuation (remission). The slope and area under the curve at 1st year (AUC1yr) of thyroid-stimulating hormone receptor antibodies including TSI bioassay and thyrotropin-binding inhibitory immunoglobulin (TBII) were calculated as differences between baseline and second values divided by time duration (year).
Results Among enrolled 156 study subjects, 74 (47.4%) had relapse/persistence. Baseline TSI bioassay values did not show significant differences between the two groups. However, the relapse/persistence group showed less decremental TSI bioassay in response to ATD than the remission group (–84.7 [TSI slope, –198.2 to 8.2] vs. –120.1 [TSI slope, –204.4 to –45.9], P=0.026), whereas the TBII slope was not significantly different between the two groups. The relapse/persistence group showed higher AUC1yr of TSI bioassay and TBII in the 1st year during ATD treatment than the remission group (AUC1yr for TSI bioassay, P=0.0125; AUC1yr for TBII, P=0.001).
Conclusion Early changes in TSI bioassay can better predict prognosis of GD than TBII. Measurement of TSI bioassay at beginning and follow-up could help predict GD prognosis.
Citations
Citations to this article as recorded by
A Predictive Model for Graves’ Disease Recurrence After Antithyroid Drug Therapy: A Retrospective Multicenter Cohort Study Omar El Kawkgi, David Toro-Tobon, Freddy J.K. Toloza, Sebastian Vallejo, Cristian Soto Jacome, Ivan N. Ayala, Bryan A. Vallejo, Camila Wenczenovicz, Olivia Tzeng, Horace J. Spencer, Jeff D. Thostenson, Dingfeng Li, Jacob Kohlenberg, Eddy Lincango, Sneha M Endocrine Practice.2025; 31(4): 455. CrossRef
Microvascular Ultrasonography Vascularity Index as a Rapid and Simplified Assessment Tool for Differentiating Graves’ Disease from Destructive Thyroiditis and Managing Thyrotoxicosis Han-Sang Baek, Chaiho Jeong, Jeonghoon Ha, Dong-Jun Lim Endocrinology and Metabolism.2025; 40(3): 394. CrossRef
Enhanced predictive validity of integrative models for refractory hyperthyroidism considering baseline and early therapy characteristics: a prospective cohort study Xinpan Wang, Tiantian Li, Yue Li, Qiuyi Wang, Yun Cai, Zhixiao Wang, Yun Shi, Tao Yang, Xuqin Zheng Journal of Translational Medicine.2024;[Epub] CrossRef
Long-term Effect of Thyrotropin-binding Inhibitor Immunoglobulin on Atrial Fibrillation in Euthyroid Patients Jung-Chi Hsu, Kang-Chih Fan, Ting-Chuan Wang, Shu-Lin Chuang, Ying-Ting Chao, Ting-Tse Lin, Kuan-Chih Huang, Lian-Yu Lin, Lung-Chun Lin Endocrine Practice.2024; 30(6): 537. CrossRef
Dynamic Risk Model for the Medical Treatment of Graves’ Hyperthyroidism according to Treatment Duration Meihua Jin, Chae A Kim, Min Ji Jeon, Won Bae Kim, Tae Yong Kim, Won Gu Kim Endocrinology and Metabolism.2024; 39(4): 579. CrossRef