Method Performance Verification of Anti-GAD65 and Anti-Insulin antibody Assays.

Background: The aim of this study was to evaluate the performance of chemiluminescence immunoassays for anti-GAD65 and anti-insulin antibodies following user verification guidelines.

Methods: The analytical performance of anti-GAD65 and anti-insulin antibodies using a MAGLUMI 2000 analyzer was verified following user verification guidelines by the Clinical and Laboratory Standards Institute.

Results: Performance specifications including precision, linearity, carry-over, cutoffs for positive results, reference intervals, and comparability with pre-existing commercially available radioimmunoassays using patient specimens and certified reference material were verified (coefficients of variation for precision of anti-GAD65 and anti-insulin antibodies were 2.

Utilization of Anti-Thyroid Peroxidase Antibody in Local Clinics and Hospitals and Intraindividual Changes in Korean Patients.

Background: Limited data are available for test utilization and intraindividual changes in anti-thyroid peroxidase antibodies (anti-TPO Ab) in Korean patients.

Methods: Using a laboratory information system, we retrospectively investigated longitudinally measured anti-TPO Ab along with thyroid function test (TFT) in Korean patients visiting local clinics.

Results: During the two-year study period, 542 test results from 183 Korean patients were requested from 51 local clinics and hospitals.

Association Among Glycemic Biomarkers in Korean Adults: Hemoglobin A1c, Fructosamine, and Glycated Albumin.

Background: We aimed to investigate the associations between glycemic biomarkers (hemoglobin A1c [HbA1c], fructosamine, and glycated albumin [GA]) in Korean adults.

Methods: We retrospectively reviewed data for HbA1c, fructosamine, and glycated albumin between August 28, 2017, and June 30, 2020, to investigate the association between HbA1c and fructosamine and between HbA1c and GA.

Results: Overall, 961 fructosamine and 142 GA tests concurrently measured HbA1c.

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).

Seroprevalence of CMV IgG and IgM in Korean women of childbearing age.

Background: The aim of this study was to investigate the seroprevalence of cytomegalovirus (CMV) infection using the serologic status of CMV IgG and IgM antibodies in Korean women of childbearing age.

Methods: We retrospectively reviewed CMV IgG and IgM test results from Korean women aged 15-49 years who underwent testing between January 2009 and December 2019. Seroprevalence of CMV IgG and IgM by year and age was investigated.

Evaluation of the Serum Mac-2 Binding Protein Glycosylation Isomer Test used for Diagnosis and Monitoring of Liver Fibrosis and the Correlation of Mac-2 Binding Protein Glycosylation Isomer with Hemoglobin A1c.

Background: Our aims in this study were to evaluate the performance of the Mac-2 binding protein glycosylation isomer (M2BPGi), a liver fibrosis marker, using Sysmex HISCL following user verification guidelines before clinical use. We also evaluated the correlation between M2BPGi and hemoglobin A1c (HbA1c) because HbA1c is known as another biomarker associated with glycosylation.

Methods: The analytical performance of M2BPGi was verified following user verification guidelines by the Clinical and Laboratory Standards Institute.