Background: The accurate laboratory-based detection of respiratory viruses, including severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is essential for effective patient management and infection control in the post–coronavirus disease 2019 era. In this study, the performance of the PowerChek Respiratory Virus Panels 1–4 assay (Kogene Biotech) in detecting non-SARS-CoV-2 respiratory viruses and SARS-CoV-2 was compared with those of two established commercial assays. Methods: Residual clinical respiratory specimens collected between December 2023 and February 2024 were retested using the PowerChek assay. Of the 129 specimens retested, 80 had tested positive for 14 non-SARS-CoV-2 respiratory virus targets in the Allplex Respiratory Panels 1–3 assay (Seegene) and 49 had been tested using the Alinity m SARS-CoV-2 assay (Abbott; 20 positive and 29 negative for SARS-CoV-2). Agreement, Cohen’s kappa, and discordant results were assessed. Results: For the 14 non-SARS-CoV-2 respiratory virus targets, the virus-specific overall percent agreement (OPA) ranged from 95.0% to 100%, the positive percent agreement (PPA) ranged from 66.7% to 100%, and the negative percent agreement (NPA) ranged from 96.0% to 100%, with kappa values of 0.64–1.00. Lower agreements were observed for human coronavirus OC43 and influenza A virus. For SARS-CoV-2 detection, the OPA was 98.0% (PPA, 95.0%; NPA, 100%; kappa, 0.96). Conclusion The detection performance of the PowerChek assay was comparable to those of the established assays for most respiratory virus targets, with lower agreement observed for some targets. These features support its practical utility for the routine multiplex molecular detection of respiratory viruses, including SARS-CoV-2.

Background: Extended-spectrum β-lactamase (ESBL)-producing Escherichia coli is among the most important multidrug-resistant pathogens causing bloodstream infections (BSIs).Cefotaximase (CTX-M) enzymes are the most common and highly diverse ESBL family in E.coli. CTX-M-15 in group CTX-M-1 and CTX-M-14 in group CTX-M-9 are the most extensively disseminated enzymes. Multidrug-resistant E. coli strains complicate empirical therapy and increase healthcare burden globally and in Korea. We investigated the molecular epidemiology, sequence types (STs), and ESBL genotypes of E. coli bloodstream isolates in Korea and identified clinical risk factors for cefotaxime resistance. Methods: We collected all non-duplicated isolates of E. coli and related clinical information from patients with BSIs at eight sentinel hospitals in the Korean Global Antimicrobial Resistance Surveillance System (Kor-GLASS) collection network during 2017–2021. Duplicate isolates were removed to ensure representativeness of the data. Antimicrobial susceptibility was tested using disk diffusion tests, and multilocus sequence typing and betalactamase genotyping were performed. Results: Among 9,232 E. coli blood isolates, resistance rates to cefotaxime and ceftazidime were 36.4% and 11.4%, respectively. Among the clinical factors, age > 65 yrs (adjusted odds ratio [aOR], 1.36), hospital-origin infection (aOR, 2.55), and admission type (intensive care unit [ICU] vs. general ward; aOR, 1.34) were significant cefotaxime resistance risk factors. ST131 was the most prevalent among cefotaxime-resistant E. coli (64.8%, 2,180/3,363), followed by ST1193 (5.3%, N = 177), and ST69 (5.1%, N = 170).ST131, ST648, ST405, and ST410 cefotaxime-resistant E. coli isolates frequently harbored blaCTX-M-15, whereas ST1193 and ST68 showed a high proportion of blaCTX-M-27 carriers, and most ST457 and ST5150 isolates carried blaCTX-M-55. Conclusions Continuous monitoring of ESBL-producing E. coli is required to prevent further dissemination, guide empirical therapy, inform infection control policies, and ensure early detection of multidrug-resistant clones with the potential for widespread transmission.

Background: The 2020 European Society of Cardiology (ESC) 0-hr/1-hr algorithm using high-sensitivity cardiac troponin I (hs-cTnI) for non-ST-segment elevation acute coronary syndrome (NSTE-ACS) aims at early diagnosis and shorter emergency department (ED) stays. While this algorithm has been well-established in controlled studies, real-world implementation remains challenging. We evaluated the algorithm’s clinical performance and risk stratification capability in patients with chest pain or discomfort. Methods: We measured hs-cTnI in 4,678 patients suspected of NSTE-ACS between August 2022 and July 2023, using an Atellica IM Analyzer (Siemens Healthineers, Erlangen, Germany). We categorized patients into rule-in, observe, or rule-out groups according to the algorithm and assessed its diagnostic performance for NSTE-ACS. The final diagnosis of NSTE-ACS was adjudicated by two independent physicians. Additionally, we evaluated 30-day all-cause mortality, hazard risk, and ED length of stay across the three groups. Results: The algorithm categorized 3,408 (72.9%), 573 (12.2%), and 697 (14.9%) patients into the rule-out, observe, and rule-in groups, respectively. Among 90 patients diagnosed as having NSTE-ACS, none were falsely categorized into the rule-out group. Survival analysis revealed significant differences (P < 0.001), with Cox hazard ratios of 2.38 (95% confidence interval: 1.20–4.71) and 6.39 (3.45–11.86) in the observe and rule-in groups, respectively. ED stays shortened in the order of rule-out, observe, and rule-in groups (P < 0.001). Conclusions The 2020 ESC 0-hr/1-hr algorithm demonstrates excellent diagnostic accuracy without false rule-outs and effective risk stratification, and contributes to efficient ED throughput, supporting its clinical utility in real-world emergency settings.

Flow cytometric lymphocyte subset analysis (FCLSA) is essential for assessing immune status across various diseases and clinical settings. We surveyed current clinical laboratory practices related to FCLSA to establish a baseline reference for future standardization in Korea. Nine university hospitals actively performing FCLSA responded to the 22-question survey, which covered seven categories of laboratory practice. These hospitals used commercial reagent antibody kits from either Beckton Dickinson Biosciences (N = 4) or Beckman Coulter Diagnostics (N = 5). Most hospitals performed daily instrument setup and scheduled maintenance every 2–6 months. Two levels of commercial quality control materials were routinely used each day. Sample and reagent antibody volumes varied across hospitals, even when the same reagent kit was used. Acquired cell counts ranged from 5 × 10 3 to 5 × 10 4 cells, with two hospitals adjusting counts based on the cell type analyzed. Most laboratories reported percentages and general opinions; some additionally reported white blood cell and lymphocyte counts, along with lymphocyte percentages. This is the first comprehensive survey on the clinical laboratory practice of FCLSA in Korea.Standardization of FCLSA should be accelerated to ensure reliable and reproducible results.

Background: Lithium hydroxide (LiOH) is increasingly used in electric vehicle battery production; however, its health effects in the work environment remain underreported. This study characterizes the acute health effects on workers following accidental occupational exposure to LiOH at a Korean lithium plant in March 2024. Methods: We analyzed health effects from two LiOH exposure accidents on March 6 and 9, 2024, involving 50–100 kg powder spills. Two datasets were examined: acute symptoms from 115 workers who visited hospitals immediately after exposure, and a symptom severity survey from 474 workers conducted 2 weeks post-exposure. Workers were stratified by distance from the leak source (<10 m, 10–20 m, >20 m) and respirator use. Univariate general linear modeling was applied to analyze the relationship between symptom occurrence and both the distance from the exposure source and respirator use. Results: Among workers visiting hospitals immediately, local irritation symptoms predominated: sore throat (58.3%), cough (28.7%), and skin dermatoses (17.4%). Systemic symptoms included headache (45.2%), nausea (18.3%), chest tightness (12.2%), and dizziness (9.6%). Two-week follow-up revealed overall symptom improvement; severe cough decreased from 22.2% to 10.1%. However, despite general improvement, a significant portion of workers reported persistent respiratory issues, including cough (28.7%) and sputum production (31.0%). Symptom severity showed a significant dose-response relationship with proximity to the source (p < 0.001). While respirator use offered initial protection (p = 0.021), this effect was not statistically significant after 2 weeks. Conclusions Occupational LiOH exposure caused acute irritation and systemic symptoms, demonstrating immediate tissue damage consistent with its alkalinity and systemic toxicity upon absorption. As lithium battery production expands globally, these results emphasize the necessity for developing specific occupational exposure limits and medical surveillance guidelines for lithium compounds.

The Pheochromocytoma of the Adrenal Gland Scaled Score (PASS) is widely used for risk stratification in pheochromocytoma and paraganglioma (PPGL), but its clinical utility is limited by inter-observer variability of its parameters and inconsistent predictive performance. Methods: We conducted a multicenter retrospective study of 1,518 patients with PPGL from five tertiary referral centers in Korea. Prognostic utility of PASS system was assessed using logistic regression, Kaplan-Meier analysis, and receiver operating characteristic (ROC) curve analysis. Inter-observer variability was inferred by comparing area under the ROC curve (AUCs) across institutions. Simplified PASS systems were developed based on multivariable analysis of key histopathological parameters. Results: The PASS system was a significant predictor of adverse events and recurrence-free survival. Although the PASS system demonstrated only modest discriminative ability (AUC, 0.673), it showed a high negative predictive value (NPV, 0.885), supporting its usefulness as a screening tool for benign behavior. However, there was significant inter-institutional variability in PASS performance (AUC; range, 0.513 to 0.727; p < .05). The 3-factor Simple PASS, which incorporates necrosis, spindling, and mitotic figures, exhibited less inter-observer variation. The 4-factor Simple PASS, which adds vascular invasion to the 3-factor model, also showed reduced inter-observer variability and improved AUC and NPV compared to the original PASS system. Conclusions: In this multicenter cohort, the PASS system demonstrated high NPV and screening potential, but significant inter-observer variability remains a challenge. Simplification of the PASS system and enhanced pathologist training may improve reproducibility and clinical utility in PPGL risk stratification.

Myopia, particularly high myopia, is a significant risk factor for several ocular pathologies including cataract, glaucoma, and retinal detachment. Excessive axial elongation associated with high myopia can induce biomechanical stretching, increasing the risk of serious complications like posterior staphyloma and myopic maculopathy. Global meta-analyses estimate that approximately 10 million people were visually impaired due to myopic maculopathy in 2015, with 3 million being blind. Recent nationwide surveys in South Korea revealed a prevalence of 65.4% for myopia and 6.9% for high myopia in children and adolescents, highlighting the urgent need for effective management. Delaying the onset and slowing the progression of myopia during childhood and adolescence is crucial for reducing the potential lifetime risk of these complications. This consensus statement, prepared by the Korean Myopia Society for the Korean Association for Pediatric Ophthalmology and Strabismus (KAPOS), reviews the current evidence for myopia control interventions and provides management strategies applicable to the South Korean clinical setting. Key interventions covered include lifestyle modifications (outdoor time, near work adjustment), optical methods (myopia-control spectacle lenses, dual-focus soft contact lenses, orthokeratology), and pharmacologic treatment (low-concentration atropine), as well as combination therapies. The statement also addresses patient selection, treatment outcome evaluation using spherical equivalent and axial length changes, and the crucial aspects related to treatment cessation and the rebound effect.

Purpose: This study aimed to evaluate the association between peripapillary retinal nerve fiber layer thickness (pRNFLT) and health-related quality of life in Korean adults. Methods: A total of 4,614 adults aged 40 years or older from the 2019 Korea National Health and Nutrition Examination Survey were included in this study. Average pRNFLT was categorized into the thicker eye, thinner eye, and the mean value of both eyes. Complex sample ordinal logistic regression was performed for the five items of the EuroQol 5-Dimension (EQ-5D) and the eight items of the Health-related Quality of Life Instrument with 8 Items (HINT-8), while complex sample linear regression was used for the EQ-5D index. Results: In multivariable analysis adjusted for age and sex, a decrease in thinner eye-pRNFLT was significantly associated with ‘usual activities’ and ‘anxiety/depression’ in the EQ-5D. Furthermore, a decrease in both thinner eye-pRNFLT and mean pRNFLT were significantly associated with a lower EQ-5D index and the ‘vitality’ in the HINT-8. Conclusions Decreased thinner eye-pRNFLT and mean pRNFLT were independently associated with certain declines in health-related quality of life among Korean adults. These findings suggest that structural changes in the optic nerve, which connects the eye and the brain, may be linked to overall quality of life.

Genetic variation in the leptin receptor (LEPR) gene has been implicated in metabolic regulation, while the gut microbiome and circulating metabolites are increasingly recognized as mediators of host metabolic phenotype. However, the systems-level interactions among LEPR genotypes, gut microbial composition, and serum metabolomic profiles remain poorly understood, particularly in healthy individuals. We conducted a cross-sectional study involving 37 healthy Korean adults. Three LEPR single nucleotide polymorphisms (rs1137101, rs1173100, rs790419) were genotyped. Untargeted metabolomics of fasting serum was performed using gas chromatography–time-of-flight mass spectrometry, and gut microbiome composition was profiled by 16S rRNA gene sequencing. Statistical analysis included principal component analysis, Mann–Whitney U tests, and Spearman correlations. Network analysis integrating microbiome, metabolomic, and clinical phenotype data was conducted using Cytoscape. A total of 54 serum metabolites were identified. LEPR genotypes, particularly rs1137101 and rs1173100, were associated with differences in metabolites such as pimelic acid, malonic acid, and 2,4-dihydroxybutyric acid. Firmicutes negatively correlated with saturated fatty acids and organic acids, whereas Actinobacteria positively correlated with cholesterol and amino acids. Network analysis revealed indole-3-acetate and cholesterol as central nodes linking microbial taxa with body mass index and leptin levels. However, no direct molecular pathways connecting leptin or its receptor were identified. LEPR genetic variation is associated with distinct serum metabolomic patterns and microbiome–host networks in healthy adults. Although no direct leptin signaling links were found, network-level associations suggest indirect genetic influences on metabolic states through microbiome–metabolome interactions.These findings advance understanding of personalized metabolic regulation and gene–microbiome interplay.