Test Utilization for Thyroid Stimulating Hormone Receptor Antibody and Thyroid Stimulating Immunoglobulin Assays in Korea.

BACKGROUND: We aimed to investigate test utilization of the competition-based M22 thyroid-stimulating hormone receptor antibody (M22-TSH Rc Ab) and thyroid stimulating immunoglobulin (TSI) bioassay in Korea. METHODS: We retrospectively reviewed data on M22-TSH Rc Ab assays and TSI assays from the laboratory information system between January 1, 2015, and June 30, 2020. RESULTS: During the study period, 175,448 TSH-Rc Ab tests and including M22-TSH Ab assays and TSI assays were performed on 99,350 Korean adults (26,251 men and 73,099 women). Among 160,880 M22-TSH Rc Ab tests, 1,992 (1.2%) specimens from 1,771 Korean adults had undergone concurrent measurement with M22-TSH Rc Ab and TSI assays. The overall agreement between the M22-TSH-Rc Ab assay and TSI assay was 88.8% (95% confidence interval 87.3 - 90.1). CONCLUSIONS: The results of this study provide basic information regarding test utilization of the M22-TSH-Rc Ab assay and TSI assay in Korean patients.