Editorial2022-11-01

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Brief Communication2022-03-01 Diagnostic Genetics

Detection Methods and Status of CAT Interruption of ATXN1 in Korean Patients With Spinocerebellar Ataxia Type 1

Ja-Hyun Jang , M.D. Ph.D., Sun Joo Yoon , M.D., Sun-Kyung Kim , M.T., Jin Whan Cho , M.D., and Jong-Won Kim , M.D.

Ann Lab Med 2022; 42(2): 274-277

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Abstract : Spinocerebellar ataxia type 1 (SCA1) is an autosomal dominant disease caused by abnormal CAG repeat expansion in the ataxin 1 gene (ATXN1). The presence of CAT interruption(s) is important for diagnosing SCA1 in patients with 39–44 repeat alleles, as only uninterrupted alleles are considered abnormal. Determining the CAT interruption status might also be important for patients with >44 repeats, as the length of the longest uninterrupted CAG repeat stretch has been correlated with age at SCA1 onset. We detected CAT interruption(s) in the archived samples of Korean SCA1 patients using a traditional restriction enzyme method and validated the usefulness of a fluorescence-based tethering PCR procedure. Among the 2,312 alleles analyzed from 1,156 patients, we found 17 expanded alleles with ≥39 repeats, 71% of which harbored 39–44 repeats. Restriction enzyme method of six samples (four with 39–44 repeats and two with >44 repeats) revealed that none of the expanded alleles had CAT interruption(s). Tethering PCR showed the characteristic electropherogram pattern expected without CAT interruption(s). Along with the enzyme restriction method, tethering PCR can be applied to determine the number of allele repeats and provide information on CAT interruption(s) in clinical laboratories.

Original Article2022-11-01 Transfusion and Cell Therapy

Predictors of Red Blood Cell Transfusion in Elderly COVID-19 Patients in Korea

Hye Ryun Lee , M.D., Ph.D.

Ann Lab Med 2022; 42(6): 659-667

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Abstract : Background: Patients who experience clinical deterioration from coronavirus disease (COVID-19) require blood transfusion support. We analyzed blood component usage in COVID-19 patients and identified the predictors of red blood cell (RBC) transfusion in elderly (≥65 years) patients. Methods: Blood component usage in 882 COVID-19 patients hospitalized between January 24, 2020 and April 30, 2021 was analyzed. Elderly patients were categorized into transfused and non-transfused groups according to their RBC transfusion history; their demographic and clinical characteristics, disease severity, and outcomes were compared. Associations were determined using multiple logistic regression. Results: The overall transfusion rate was 8.3% (73/882), and the transfusion rate was 2.7% (14/524) in patients aged

Editorial2023-05-01

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Original Article2022-11-01 Diagnostic Genetics

Deciphering Epigenetic Backgrounds in a Korean Cohort with Beckwith–Wiedemann Syndrome

Hwa Young Kim , M.D., Ph.D., Choong Ho Shin , M.D., Ph.D., Young Ah Lee , M.D., Ph.D., Chang Ho Shin , M.D., Gu-Hwan Kim , Ph.D., and Jung Min Ko , M.D., Ph.D.

Ann Lab Med 2022; 42(6): 668-677

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Abstract : Background: Beckwith–Wiedemann syndrome (BWS) is a congenital overgrowth disorder caused by genetic or epigenetic alterations at two imprinting centers (ICs) in the 11p15.5 region. Delineation of the molecular defects is important for prognosis and predicting familial recurrence. We evaluated epigenetic alterations and potential epigenotype–phenotype correlations in Korean children with BWS. Methods: Forty children with BWS with proven genetic or epigenetic defects in the 11p15.5 region were included. The phenotype was scored using the BWS consensus scoring system. Methylation-specific multiplex ligation-dependent probe amplification (MS-MLPA), bisulfite pyrosequencing, a single-nucleotide polymorphism microarray, and CDKN1C sequencing were used for confirmative diagnosis. Results: Patients met the criteria for genetic testing, with a mean clinical score of 5.4±2.0. Methylation alterations were consistent between MS-MLPA and bisulfite pyrosequencing in all patients. Twenty-six patients (65.0%) had IC2 loss of methylation (IC2-LoM), 11 (27.5%) had paternal uniparental disomy (patUPD), and one (2.5%) had IC1 gain of methylation. Macroglossia and external ear anomalies were more common in IC2-LoM than in patUPD, and lateralized overgrowth was more common in patUPD than in IC2-LoM (all P

Letter to the Editor2022-07-01 Clinical Microbiology

The First Case of Clostridium saudiense Bacteremia in a Patient with Hepatocellular Carcinoma

Eungjun Yoon , M.D., Tae Yeul Kim , M.D., Won Young Heo , M.D., Onkyun Kang , M.T., Hui-Jin Yu , M.D., Joon Hyeok Lee , M.D., Ph.D., Jae-Hoon Ko , M.D., Ph.D., Nam Yong Lee , M.D., Ph.D., and Hee Jae Huh , M.D., Ph.D.

Ann Lab Med 2022; 42(4): 491-493

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Original Article2023-05-01 Clinical Chemistry

Prognostic Value of Combined Biomarkers in Patients With Heart Failure: The Heartmarker Score

Jonna A. van der Stam , M.Sc., Sjoerd Bouwmeester , M.D., Saskia L. M. van Loon , Ph.D., Natal A. W. van Riel , Ph.D., Lukas R. Dekker , Ph.D., Arjen-Kars Boer , Ph.D., Patrick Houthuizen , Ph.D., and Volkher Scharnhorst , Ph.D.

Ann Lab Med 2023; 43(3): 253-262

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Abstract : Background: Heart failure (HF) biomarkers have prognostic value. The aim of this study was to combine HF biomarkers into an objective classification system for risk stratification of patients with HF. Methods: HF biomarkers were analyzed in a population of HF outpatients and expressed relative to their cut-off values (N-terminal pro-B-type natriuretic peptide [NT-proBNP] >1,000 pg/mL, soluble suppression of tumorigenesis-2 [ST2] >35 ng/mL, growth differentiation factor-15 [GDF-15] >2,000 pg/mL, and fibroblast growth factor-23 [FGF-23] >95.4 pg/mL). Biomarkers that remained significant in multivariable analysis were combined to devise the Heartmarker score. The performance of the Heartmarker score was compared to the widely used New York Heart Association (NYHA) classification based on symptoms during ordinary activity. Results: HF biomarkers of 245 patients were analyzed, 45 (18%) of whom experienced the composite endpoint of HF hospitalization, appropriate implantable cardioverter-defibrillator shock, or death. HF biomarkers were elevated more often in patients that reached the composite endpoint than in patients that did not reach the endpoint. NT-proBNP, ST2, and GDF-15 were independent predictors of the composite endpoint and were thus combined as the Heartmarker score. The event-free survival and distance covered in 6 minutes of walking decreased with an increasing Heartmarker score. Compared with the NYHA classification, the Heartmarker score was better at discriminating between different risk classes and had a comparable relationship to functional capacity. Conclusions: The Heartmarker score is a reproducible and intuitive model for risk stratification of outpatients with HF, using routine biomarker measurements.

Editorial2023-01-01

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Original Article2023-05-01 Clinical Chemistry

Accuracy of the New Creatinine-based Equations for Estimating Glomerular Filtration Rate in Koreans

Tae-Dong Jeong , M.D., Ph.D., Jinyoung Hong , M.D., Woochang Lee , M.D., Ph.D., Sail Chun , M.D., Ph.D., and Won-Ki Min , M.D., Ph.D.

Ann Lab Med 2023; 43(3): 244-252

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Abstract : Background: New creatinine-based estimated glomerular filtration rate (eGFR) equations, including the 2021 Chronic Kidney Disease Epidemiology Collaboration (2021 CKD-EPI) and European Kidney Function Consortium (EKFC) equations, have been introduced recently. We assessed the performance of the 2021 CKD-EPI and EKFC equations in the Korean population. Methods: We analyzed 1,654 Korean patients aged ≥18 years who underwent chromium-51-ethylenediamine tetraacetic acid GFR measurements (mGFR). Bias (eGFR–mGFR), root mean square error (RMSE), and proportion of eGFR within 30% of mGFR (P30) of the 2009 CKD-EPI, 2021 CKD-EPI, and EFKC equations were compared. The concordance rate between eGFR and mGFR categories was evaluated. Both eGFR and mGFR categories were classified into six groups: ≥90, 89–60, 59–45, 44–30, 29–15, and

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.