Editorial2023-03-01

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Editorial2023-03-01

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Guideline2023-03-01
Clinical Microbiology

Guidelines for the Laboratory Diagnosis of Monkeypox in Korea

Ki Ho Hong , M.D., Gab Jung Kim , Ph.D., Kyoung Ho Roh , M.D., Hyukmin Lee , M.D., Ok Kyu Park , M.S., Taek Soo Kim , M.D., Jae-Seok Kim , M.D., Jaehyeon Lee , M.D., Moon-Woo Seong , M.D., So Yeon Kim , M.D., Jae-Sun Park , Ph.D., Younhee Park , M.D., Hee Jae Huh , M.D., Namhee Ryoo , M.D., Hyun Soo Kim , M.D., Heungsup Sung , M.D., and Cheon Kwon Yoo , Ph.D.; On behalf of the Committee of Management of Laboratory Tests for Infectious Diseases, Korean Society for Laboratory Medicine, and the Bureau of Infectious Disease Diagnosis Control, Korea Disease Control and Prevention Agency

Ann Lab Med 2023; 43(2): 137-144

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Abstract : While the coronavirus disease 2019 pandemic is ongoing, monkeypox has been rapidly spreading in non-endemic countries since May 2022. Accurate and rapid laboratory tests are essential for identifying and controlling monkeypox. Korean Society for Laboratory Medicine and the Korea Disease Prevention and Control Agency have proposed guidelines for diagnosing monkeypox in clinical laboratories in Korea. These guidelines cover the type of tests, selection of specimens, collection of specimens, diagnostic methods, interpretation of test results, and biosafety. Molecular tests are recommended as confirmatory tests. Skin lesion specimens are recommended for testing in the symptomatic stage, and the collection of both blood and oropharyngeal swabs is recommended in the presymptomatic or prodromal stage.

Original Article2023-03-01
Diagnostic Hematology

Clinical, Mutational, and Transcriptomic Characteristics in Elderly Korean Individuals With Clonal Hematopoiesis Driver Mutations

Inki Moon , M.D., M.S., Min Gyu Kong , M.D., M.S., Young Sok Ji , M.D., M.S., Se Hyung Kim , M.D., Ph.D., Seong Kyu Park , M.D., Ph.D., Jon Suh , M.D., Ph.D., and Mi-Ae Jang , M.D., Ph.D.

Ann Lab Med 2023; 43(2): 145-152

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Abstract : Background: Clonal hematopoiesis of indeterminate potential (CHIP), which is defined as the presence of blood cells originating from somatically mutated hematopoietic stem cells, is common among the elderly and is associated with an increased risk of hematologic malignancies. We investigated the clinical, mutational, and transcriptomic characteristics in elderly Korean individuals with CHIP mutations. Methods: We investigated CHIP in 90 elderly individuals aged ≥60 years with normal complete blood counts at a tertiary-care hospital in Korea between June 2021 and February 2022. Clinical and laboratory data were prospectively obtained. Targeted next-generation sequencing of 49 myeloid malignancy driver genes and massively parallel RNA sequencing were performed to explore the molecular spectrum and transcriptomic characteristics of CHIP mutations. Results: We detected 51 mutations in 10 genes in 37 (41%) of the study individuals. CHIP prevalence increased with age. CHIP mutations were observed with high prevalence in DNMT3A (26 individuals) and TET2 (eight individuals) and were also found in various other genes, including KDM6A, SMC3, TP53, BRAF, PPM1D, SRSF2, STAG1, and ZRSR2. Baseline characteristics, including age, confounding diseases, and blood cell parameters, showed no significant differences. Using mRNA sequencing, we characterized the altered gene expression profile, implicating neutrophil degranulation and innate immune system dysregulation. Conclusions: Somatic CHIP driver mutations are common among the elderly in Korea and are detected in various genes, including DNMT3A and TET2. Our study highlights that chronic dysregulation of innate immune signaling is associated with the pathogenesis of various diseases, including hematologic malignancies.

Original Article2023-03-01
Clinical Chemistry

Comprehensive Evaluation of the NeoBase 2 Non-derivatized MSMS Assay and Exploration of Analytes With Significantly Different Concentrations Between Term and Preterm Neonates

Beomki Lee , M.D., Won Young Heo , M.D., Jee Ah Kim , M.D., Hyun-Seung Lee , M.D., Ph.D., Narae Hwang , M.D., Hyung-Doo Park , M.D., Ph.D., Se In Sung , M.D., Ph.D., Yun Sil Chang , M.D., Ph.D., Won Soon Park , M.D., Ph.D., and Soo-Youn Lee , M.D., Ph.D.

Ann Lab Med 2023; 43(2): 153-166

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Abstract : Background: Despite the popularity of the NeoBase 2 Non-derivatized MSMS assay (PerkinElmer, Turku, Finland), there are no reports of its comprehensive evaluation, including the ability to distinguish transient tyrosinemia of the newborn (TTN) from tyrosinemia type 1 (TYR 1) using succinylacetone (SUAC). No newborn screening (NBS) cutoffs for preterm neonates in the Korean population have been suggested. We evaluated the NeoBase 2 assay and identified analytes requiring different cutoffs in preterm neonates. Methods: Residual NBS dried blood spot samples and proficiency testing (PT) materials of the Newborn Screening Quality Assurance Program and the Korean Association of External Quality Assessment Service were used. Precision, accuracy, limit of detection (LOD), lower limit of quantification (LLOQ), linearity, recovery, carryover, and performance of SUAC were evaluated. Cutoffs were determined, and analytes requiring different cutoffs in preterm neonates were investigated. Results: Mean CVs for within-run and between-day precision were within 15%. Accuracy analysis indicated high agreement with in-house derivatized assay results and results of other PT participants. All analytes demonstrated acceptable LOD, LLOQ, and linearity. Recoveries were acceptable, except for SUAC. Carryover was negligible. Cutoffs were established for all analytes; Tyr, adenosine, and C20:0-lysophosphatidylcholine required different cutoffs in preterm neonates. Differential diagnosis of TYR 1 and TTN was successful with simultaneous Tyr and SUAC measurement. Conclusions: The NeoBase 2 assay demonstrated satisfactory performance. The additional analytes provide a wider diagnostic coverage, and the simultaneous measurement of Tyr and SUAC is efficient in excluding TYR 1. The new cutoffs for preterm neonates may decrease false-positive rates, without compromising diagnostic sensitivity.

Original Article2023-03-01
Clinical Chemistry

Performance Evaluation of the DxC 700 AU Chemistry Analyzer in Hemoglobin A1c Measurement

Yu Jeong Choi , M.D., Hyein Kang , M.D., Chan-Ik Cho , M.S., John Hoon Rim , M.D, Ph.D., Sang-Guk Lee , M.D., Ph.D., and Jong-Baeck Lim , M.D, Ph.D.

Ann Lab Med 2023; 43(2): 167-173

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Abstract : Background: Accurate measurement of glycated hemoglobin (HbA1c) is crucial for a diabetes diagnosis and subsequent patient management. The detection method and presence of variant Hb can interfere with HbA1c measurements. We evaluated the HbA1c-measuring performance of the DxC 700 AU (Beckman Coulter, Brea, CA, USA) immunoassay-based device in comparison with another immunoassay device and the reference method. Methods: A total of 120 normal and 14 variant Hb samples were analyzed using the Cobas c 513 (Roche Diagnostics, Mannheim, Germany) and DxC 700 AU analyzers. Variant Hb samples were also analyzed using the reference method, along with 20 normal samples. The accuracy, precision, linearity, and carryover were determined. Results: DxC 700 AU results strongly correlated with those of Cobas c 513 and exhibited accuracy in comparison with the reference method. The within-run, between-run, between-day, and total imprecision (%CV) values for the low- and high-concentration control materials were below 2%. The results of DxC 700 AU were linear over a wide HbA1c range (3.39%–18.30%). Although DxC 700 AU performed well in the presence of variant Hb, the HbA1c concentration was underestimated in the presence of fetal Hb. The possibility of interference from a high HbH proportion could not be ruled out. Conclusions: The overall analytical performance of DxC 700 AU was acceptable. The device is accurate, precise, and linear over a wide HbA1c concentration range. Although DxC 700 AU results highly correlated with those of Cobas c 513, caution should be exercised in cases of high HbF and HbH concentrations.

Original Article2023-03-01
Clinical Microbiology

Performance Comparison Between Fourier-Transform Infrared Spectroscopy–based IR Biotyper and Matrix-Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry for Strain Diversity

Son Young Jun , Ph.D., Young Ah Kim , M.D., Ph.D., Suk-Jun Lee , Ph.D., Woon-Won Jung , Ph.D., Hyun-Sook Kim , Ph.D., Sung-Soo Kim , Ph.D., Hyunsoo Kim , M.D., Dongeun Yong , M.D., and Kyungwon Lee , M.D.

Ann Lab Med 2023; 43(2): 174-179

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Abstract : Background: Development of an accessible method to routinely evaluate the clonality of strains is needed in microbiology laboratories. We compared the discriminatory power of the Fourier-transform infrared (FTIR) spectroscopy–based IR Biotyper (Bruker Daltonics GmbH, Bremen, Germany) to matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS), using whole-genome sequencing (WGS) as the reference method. Methods: Eighty-three extended-spectrum β-lactamase–producing Escherichia coli isolates were tested using WGS, MALDI-TOF MS, and IR Biotyper. Simpson’s diversity index (SDI), a statistical analysis for testing the homogeneity of a dendrogram, and the adjusted Rand index (aRI) were used to compare the discriminatory ability between typing tests. Results: The SDI (95% confidence interval) was 0.969 (0.952–0.985) for WGS, 0.865 (0.807–0.924) for MALDI-TOF MS, and 0.974 (0.965–0.983) for IR Biotyper. Compared with WGS, IR Biotyper showed compatible diversity, whereas MALDI-TOF MS did not. The concordance and aRI improved from 66.3% to 84.3% and from 0.173 to 0.538, respectively, for IR Biotyper versus MALDI-TOF MS with WGS as the reference method. IR Biotyper showed substantially improved performance in strain typing compared with MALDI-TOF MS. Conclusions: IR Biotyper is useful for diversity analysis with improved discriminatory power over MALDI-TOF MS in comparison with WGS as a reference method. IR Biotyper is an accessible method to evaluate the clonality of strains and could be applied in epidemiological analysis during an outbreak of a health care facility, as well as for research on the transmission of resistant bacteria in community settings.

Original Article2023-03-01
Clinical Microbiology

Comparative Analysis of the Molecular Characteristics of Group B Streptococcus Isolates Collected from Pregnant Korean Women Using Whole-genome Sequencing

Yangsoon Lee , M.D., Ph.D., Hye Gyung Bae , M.D., Ph.D., Dongju Won , M.D., Ph.D., Woobin Yun , M.S., Hyukmin Lee , M.D., Ph.D., Jong Rak Choi , M.D., Ph.D., Young Uh , M.D., Ph.D., and Kyungwon Lee , M.D., Ph.D.

Ann Lab Med 2023; 43(2): 180-186

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Abstract : Background: The incidence of early- and late-onset sepsis and meningitis in neonates due to maternal rectovaginal group B Streptococcus (GBS) colonization may differ with serotype distribution and clonal complex (CC). CC17 strains are associated with hypervirulence and poor disease outcomes. GBS serotypes are distinguished based on the polysaccharide capsule, the most important virulence factor. We determined the sequence type distribution of GBS isolates from pregnant women in Korea and validated whole-genome sequencing (WGS)-based prediction of antimicrobial susceptibility and capsular serotypes in GBS isolates. Methods: Seventy-five GBS isolates collected from pregnant Korean women visiting Wonju Severance Christian Hospital, Wonju, Korea between 2017 and 2019 were subjected to WGS using the NovaSeq 6000 system (Illumina, San Diego, CA, USA). Multilocus sequence types, serotypes, antimicrobial resistance genes, and hemolysin operon mutations were determined by WGS, and the latter three were compared with the results of conventional phenotypic methods. Results: The predominant lineage was CC1 (37.3%), followed by CC19 (32.0%), CC12 (17.3%), and CC17 (4.0%). All isolates were cps typeable (100%, (75/75), and 89.3% of cps genotypes (67/75) were concordant with serotypes obtained using latex agglutination. The cps genotypes of the 75 isolates were serotypes III (24.0%), V (22.7%), and VIII (17.3%). All isolates harboring intact ermB and tet were non-susceptible to erythromycin and tetracycline, respectively. Three non-hemolytic strains had 1-bp frameshift insertions in cylE. Conclusions: The low prevalence of CC17 GBS colonization may explain the low frequency of neonatal GBS infections. WGS is a useful tool for simultaneous genotyping and antimicrobial resistance determination.

Original Article2023-03-01
Transfusion and Cell Therapy

Common Data Model-based Analysis of Selective Leukoreduction Protocol Compliance at Three Hospitals

Sooin Choi , M.D., M.S., Soo Jeong Choi , M.D., Ph.D., Jeong Won Shin , M.D., Ph.D., and Young Ahn Yoon , M.D., Ph.D.

Ann Lab Med 2023; 43(2): 187-195

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Abstract : Background: The selective leukoreduction protocol (SLP) is limited in that patients who require it can be overlooked. We estimated SLP compliance (SLPC) using the Observational Medical Outcomes Partnership common data model (CDM). Methods: Patients were classified into eight groups: pre- and post-hematology disease (A and B), pre- and post-solid organ transplantation (C and D), solid cancer (E), immunodeficiency (F), anticancer therapy (G), and cardiovascular surgery (H). We examined the red blood cell (RBC) transfusion history from three hospital datasets comprising approximately three million patients over 20 years using CDM-based analysis. SLPC was calculated as the percentage of patients who received only leukoreduced RBCs in total patients transfused RBCs. Results: In total, 166,641 patients from three hospitals were enrolled in this study. From 2001 to 2021, SLPC in all groups, except H, tended to increase, although there were differences among the hospitals. Based on the most recent values (2017–2021), the SLPC in groups A, B, D, and G was maintained at ≥75% until 1,095 days before or after diagnosis or treatment. Groups E, F, and H had < 50% SLPC one day after diagnosis and treatment. Conclusions: CDM analysis supports the review of large datasets for SLPC evaluation. Although SLPC tended to improve in most patient groups, additional education and monitoring are needed for groups that continue to show low SLPC.

Brief Communication2023-03-01
Clinical Microbiology

Emergence of NDM-1–producing Pseudomonas aeruginosa Sequence Type 773 Clone: Shift of Carbapenemase Molecular Epidemiology and Spread of 16S rRNA Methylase Genes in Korea

Yu Jeong Choi , M.D., Young Ah Kim , M.D., Kim Junglim , B.D., Seok Hoon Jeong , M.D., Jong Hee Shin , M.D., Kyeong Seob Shin , M.D., Jeong Hwan Shin , M.D., Young Ree Kim , M.D., Hyun Soo Kim , M.D., Young Uh , M.D., and Nam Hee Ryoo , M.D.

Ann Lab Med 2023; 43(2): 196-199

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Abstract : Imipenemase (IMP)-6–producing Pseudomonas aeruginosa sequence type (ST) 235 is a dominant clone of carbapenemase-producing P. aeruginosa (CPPAE) in Korea. As part of the Antimicrobial Resistance Surveillance System in Korea, we found an increase in the carbapenem resistance rate of P. aeruginosa isolates from blood cultures and a shift in the molecular epidemiology of CPPAE. A total of 212 non-duplicated P. aeruginosa blood isolates were obtained from nine general hospitals and two nursing homes. Twenty-four isolates were identified as CPPAE. We observed the emergence of the NDM-1 P. aeruginosa ST 773 clone (N=10), mostly from Gyeongsang Province. The IMP-6 ST 235 clone (N=11) was detected in all provinces. CPPAE isolates showed very high resistance rates to amikacin, and all NDM-1 P. aeruginosa strains carried rmtB. This is the first nationwide surveillance of the recently emerged NDM-1–producing P. aeruginosa ST773 clone in Korea. Continuous surveillance is necessary to prevent the infection and transmission of carbapenem- and amikacin-resistant P. aeruginosa in Korea.

Letter to the Editor2023-03-01
Diagnostic Hematology

A Patient With CD20-positive T-cell Lymphoma Concurrently Exhibiting B-cell Neoplasm-related Genetic Abnormalities Shows Clonal Escape Post CD20-targeting Treatment

Jiyeon Kim , M.D., Miyoung Kim , M.D., Ph.D., Young-Uk Cho , M.D., Ph.D., Sang-Hyun Hwang , M.D., Ph.D., Seongsoo Jang , M.D., Ph.D., Eul-Ju Seo , M.D., Ph.D., Dok Hyun Yoon , M.D., Ph.D., Heounjeong Go , M.D., Ph.D., and Chan-Jeoung Park , M.D., Ph.D.

Ann Lab Med 2023; 43(2): 200-203

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Letter to the Editor2023-03-01
Diagnostic Hematology

The First Case of Acute Myeloid Leukemia With Underlying Fanconi Anemia due to FANCF Variants in Korea

Eunsang Suh , M.D., Sunghwan Shin , M.D., Hee Young Ju , M.D., Keon Hee Yoo , M.D., Ph.D., Hyun-Young Kim , M.D., Duck Cho , M.D., Ph.D., Sun-Hee Kim , M.D., Ph.D., and Hee-Jin Kim , M.D., Ph.D.

Ann Lab Med 2023; 43(2): 204-207

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Letter to the Editor2023-03-01
Diagnostic Hematology

Whole-mount Electron Microscopy to Quantitate Platelet Dense Granules: Reference Intervals for Healthy Controls in Korea

Jae-Ryong Shim , M.D., Miri Kang , M.T., Kwang-Sook Woo , M.D., Seo-Hee Rha , M.D., and Jin-Yeong Han , M.D.

Ann Lab Med 2023; 43(2): 208-210

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Letter to the Editor2023-03-01
Clinical Microbiology

Rapid Emergence of the Omicron Variant of Severe Acute Respiratory Syndrome Coronavirus 2 in Korea

Ae Kyung Park , Ph.D., Il-Hwan Kim , Ph.D., Chae Young Lee , B.S., Jeong-Ah Kim , Ph.D., Hyeokjin Lee , M.S., Heui Man Kim , Ph.D., Nam-Joo Lee , M.S., SangHee Woo , M.S., Jaehee Lee , B.S., JeeEun Rhee , Ph.D., Cheon-Kwon Yoo , Ph.D., and Eun-Jin Kim , Ph.D.

Ann Lab Med 2023; 43(2): 211-213

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Letter to the Editor2023-03-01
Diagnostic Immunology

Establishment of Reference Values for Non-HLA Antibodies in Patients With End-stage Renal Disease

Kyung-Hwa Shin , M.D., Ph.D., Hyun Ji Lee , M.D., Ph.D., Il Young Kim , M.D., Ph.D., Byung Hyun Choi , M.D., and Hyung-Hoi Kim , M.D., Ph.D.

Ann Lab Med 2023; 43(2): 214-216

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Letter to the Editor2023-03-01
Diagnostic Genetics

The First Korean Case of VEXAS Syndrome Caused by a UBA1 Somatic Variant

Jihoon G. Yoon , M.D., Ph.D., Seungbok Lee , M.D., Ph.D., Sheehyun Kim , M.D., Man Jin Kim , M.D., Ph.D., Yoon Hwan Chang , M.D., Ph.D., Jin Kyun Park , M.D., Ph.D., Dong-Yeop Shin , M.D., Ph.D., and Jangsup Moon , M.D., Ph.D.

Ann Lab Med 2023; 43(2): 217-220

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