The Early Changes in Thyroid-Stimulating Immunoglobulin Bioassay over Anti-Thyroid Drug Treatment Could Predict Prognosis of Graves' Disease

• Published in: Endocrinology and metabolism (Seoul) 2023, 38(3), , pp.338-346
• Main Authors: Yu, Jin, Baek, Han-Sang, Jeong, Chaiho, Jo, Kwanhoon, Lee, Jeongmin, Ha, Jeonghoon, Kim, Min Hee, Lee, Jungmin, Lim, Dong-Jun
• Format: Article
• Language: English
• Subjects: antithyroid agents; Autoantibodies; Biological Assay; graves disease; Graves Disease - drug therapy; Humans; hyperthyroidism; immunoglobulins, thyroid-stimulating; Immunoglobulins, Thyroid-Stimulating - therapeutic use; Original; Prognosis; Receptors, Thyrotropin; recurrence; Retrospective Studies; thyrotropin-binding inhibitory immunoglobulin; 내과학
• ISSN: 2093-596X; 2093-5978
• DOI: 10.3803/EnM.2023.1664

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. 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). 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). 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.