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.

Recent trends in seroprevalence of rubella in Korean women of childbearing age: a cross-sectional study.

OBJECTIVES: The aim of this study was to investigate the immunity against rubella using the serological status of rubella-specific IgG antibodies (antirubella IgG) in Korean women of childbearing age (15-49 years). DESIGN: Retrospective cross-sectional study. SETTING: Population-based cross-sectional study in South Korea. PARTICIPANTS: Between January 2010 and December 2017, test results from Korean women aged 15-49 years who had visited an obstetric private clinic (nationwide institutions) and had requested rubella-specific IgG antibody tests from Green Cross Laboratories were obtained from the laboratory information system. RESULTS: Between 2010 and 2017, antirubella IgG test results from 328 426 Korean women aged 15-49 years who had visited private obstetric clinics (1438 institutions nationwide) were retrospectively analysed by tested year, age, cohort and geographic regions. Over the 8-year study period, the rate of unimmunised women ranged from 7.8% to 9.7%. Multivariable-adjusted logistic regression models showed that the odds of being immune to rubella (positive and equivocal results of antirubella IgG test) were lower in 2017 compared with 2010, in women in their 40s, in a pre-catch-up cohort and in women living in Incheon, Busan, South Gyeongsang, North and South Jeolla and Jeju provinces (p<0.0001). CONCLUSIONS: In consideration of the factors associated with prevalence of women unimmunised to rubella, future public health efforts should be focused on catch-up activities. The results of this study could be used to strengthen disease control and prevent rubella, including a nationwide immunisation programme.

Understanding the patient population and test utilization for hepatitis B virus testing.

BACKGROUND: Hepatitis B virus (HBV) infection remains a global concern with different epidemiologies due to several factors including migration, vaccination policies, and new antiviral treatment regimens. It is important to understand the characteristics of a patient population, including the prevalence of diseases, and to assess test utilization to understand and evaluate the clinical performance of laboratory tests and to improve the quality of clinical laboratories. MATERIALS AND METHODS: In this study, we evaluated serologic and virologic laboratory tests including hepatitis B surface antigen, hepatitis B surface antibody, hepatitis B envelope antigen (HBeAg), hepatitis B envelope antibody, and HBV DNA in Korean adults who were exposed to HBV. RESULTS: During the 1-year study period, we obtained 22 750 specimens from 17 523 adult Korean patients (>18.0 years; 9894 males and 7629 females) with a median age of 50.1 years (interquartile range, 42.2-58.2 years). Among them, five serologic and virologic laboratory tests were performed for 1340 (5.9%) specimens from 1172 adult Korean patients (>18.0 years; 647 males and 525 females) with a median age of 46.8 years (range, 19.0-84.5 years). The prevalence of serologic and virologic tests indicating several clinical situations was evaluated. The correlation coefficient between HBV DNA and HBeAg was ρ = 0.85 (P < .0001). However, 51.9% (695/1340) of samples did not show agreement between the two test results. CONCLUSIONS: Analysis of the prevalence of patients categorized into five serologic and virologic laboratory results would be helpful to expand our knowledge about patient population characteristics and to improve test utilization.

Quantitation of 2-acetyl-1-pyrroline in aseptic-packaged cooked fragrant rice by HS-SPME/GC-MS.

Aseptic-packaged cooked rice (APCR) is a rice-based food product with a rapidly increasing market size, and APCR made of fragrant rice (FR) has recently appeared on the market. The fragrance of FR is produced by a combination of odoriferous compounds, among which 2-acetyl-1-pyrroline (2AP) has been identified as the most important contributor to overall aroma. This study describes the development of a method to quantify 2AP in FR-based APCR using headspace solid-phase microextraction (SPME) coupled with gas chromatography-mass spectrometry (GC-MS). The recovery of 2AP spiked into APCR was lower than 10%, which suggests significant matrix effects and inappropriateness of external standard-based calibration. For standard addition calibration method, up to 1,000 ng of 2AP were spiked into APCR containing 0% to 100% FR. Subsequent regression analyses of recovered peak area (Y) as a function of the amount of 2AP spiked (X) yielded highly linear calibration curves (R 2 > 0.9917) with consistent slopes (RSD = 2.7%), regardless of FR composition. Y-intercepts, however, which represent the amount of 2AP in APCR without spiking, increased linearly (R 2 = 0.9898) in proportion to the composition of FR in the APCR. The amount of 2AP in APCR, determined by extrapolating the standard addition calibration curves, also increased linearly (R 2 = 0.9963) as a function of FR composition. Practicality of developed method was tested by monitoring 2AP contents in APCR under realistic storage conditions, which successfully demonstrated 38% and 60% 2AP reductions in APCR of 20% FR after 1 and 2 months of storage at 25°C, respectively. The present study demonstrates that a standard addition method, whereby up to 1,000 ng of 2AP standard is spiked into 4 g of APCR containing 5%-100% FR in a 20-mL headspace vial followed by SPME/GC-MS, may serve as an effective means of quantitating 2AP in fragrant rice-based APCR.

Effects of milling on aromatics, lipophilic phytonutrients, and fatty acids in unprocessed white rice of scented rice 'Cheonjihyang-1-se'.

To understand effects of milling, scented rice 'Cheonjihyang-1-se' was milled from 10 to 140 s and changes in volatiles, phytonutrients, and fatty acids were evaluated. Among 43 identified odor-active compounds, four volatiles, including hexan-3-one, exhibited decreases of up to 78%, while four others including (E)-non-2-enal, increased following milling. Levels of 2-acetyl-1-pyrroline, the most distinctive popcorn-flavoring compound in scented rice, were not affected by the degree of milling (DM). Partial least squares discriminant analyses of volatiles were able to differentiate white rice according to the DM. Benzene and 2-pentylfuran showed the highest variable importance in projection scores, which could be applied in estimating the DM of rice. Milling significantly decreased tocopherols, tocotrienols, squalene, phytosterols contents and oleic acid composition, while palmitic acid composition was increased. These results suggest milling-dependent variations in phytonutrient levels and lipid composition, as well as changes in aroma and subsequent market quality, in 'Cheonjihyang-1-se' rice.

Pyrosequencing-based quantitative measurement of CALR mutation allele burdens and their clinical implications in patients with myeloproliferative neoplasms.

BACKGROUND: We developed a pyrosequencing-based method for the quantification of CALR mutations and compared the results using Sanger sequencing, fragment length analysis (FLA), digital-droplet PCR (ddPCR), and next-generation sequencing (NGS). METHODS: Method validation studies were performed using cloned plasmid controls. Samples from 24 patients with myeloproliferative neoplasms were evaluated. RESULTS: Among the 24 patients, 15 had CALR mutations (7 type 1, 2 type 2, and 6 other mutations). The type 1 or type 2 mutation-positive results from pyrosequencing exhibited 100% concordance with the Sanger sequencing results. One novel CALR mutation was not detected by pyrosequencing. The CALR mutation allele burdens measured by pyrosequencing were slightly lower than those measured by FLA but slightly higher than the results obtained using ddPCR. Pyrosequencing exhibited high correlations with both methods. The mutation allele burdens estimated by NGS were significantly lower than those measured by pyrosequencing. An increased CALR mutation allele burden was associated with overt primary myelofibrosis. Patients with >70% mutation allele burdens in myeloid cells had a significantly longer time from diagnosis (P = 0.007), more bone marrow fibrosis (P = 0.010), and lower hemoglobin (P = 0.007). CONCLUSIONS: Pyrosequencing was a useful rapid sequencing method to determine the burden of CALR mutations.