Clinical outcomes of thyroid function in patients with thyrotropin receptor blocking antibody-positive hypothyroidism
Rei Hirose, Jaeduk Yoshimura Noh, Natsuko Watanabe, Tatsuya Iida, Toshino Suzuki, Masahiro Ichikawa, Masakazu Koshibu, Nami Suzuki, Masako Matsumoto, Miho Fukushita, Ai Yoshihara, Kiminori Sugino, Koichi ItoAbstract
Context
Thyrotropin receptor blocking antibodies (TBAbs) are uncommon but not rare cause of hypothyroidism. However, clinical outcomes of thyroid function in patients with TBAb-positive hypothyroidism remain unclear.
Objective
To explore the clinical outcomes of thyroid function in patients with TBAb-positive hypothyroidism and investigate factors associated with hypothyroidism outcomes.
Methods
A single-center retrospective observational study conducted from 2024 to 2025. Overall, 137 patients with TBAb-positive hypothyroidism without Graves’ disease (Non-GD group) and 181 with TBAb-positive hypothyroidism during or after antithyroid drug therapy for Graves’ disease (Prior GD group), almost all Japanese, were included. Thyroid functional outcomes were assessed in all patients; serial TBAb measurements were available for 31% and 36% of the patients, respectively. The main outcome was thyroid function at the final visit after a median follow-up period of 6.8 years. Clinical factors associated with hypothyroidism outcomes were analyzed using logistic regression analysis.
Results
Hypothyroidism persisted in 84% and 43% of the patients in the Non-GD and Prior GD groups, respectively. In both groups, persistent TBAb positivity was associated with hypothyroid outcomes (Non-GD: univariate analysis, odds ratio [OR], 3.51; 95% confidence interval [CI], 1.14–40.6; p = 0.013; Prior GD: univariate analysis, OR, 6.75; 95% CI, 1.87–24.4; p = 0.0016; multivariate analysis, OR, 6.88; 95% CI, 1.89–25.1; p = 0.0015).
Conclusions
Most patients with TBAb-positive hypothyroidism remain hypothyroid over the long term, whereas outcomes are more heterogeneous in patients with prior Graves’ disease who develop TBAb-positive hypothyroidism. Persistent TBAb positivity is associated with the hypothyroidism outcomes.