Background: To investigate Korean neurologists' perceptions of the non-standard term ‘jayulsingyeongsiljo’ and their actual evaluation and management of such patients. Methods: We performed an anonymous web-based cross-sectional survey of board-certified Korean neurologists by Korean Society of Pain and Autonomic Disorders between August 13 and September 10, 2025. A questionnaire sent by e-mail asked about demographics, experience with patients labeled with ‘jayulsingyeongsiljo,’ use and perceived usefulness of autonomic function tests, the impact of coronavirus disease 2019, and opinions on terminology and the role of neurologists. Results: In total, 109 neurologists responded. Most reported that patients presenting for ‘jayulsingyeongsiljo’ were young or middle-aged adults and that their numbers had increased over the preceding 2 years. Referrals frequently originated from Korean medicine clinics and other non-neurology departments, often after stand-alone heart rate variability testing. Fatigue, orthostatic intolerance, palpitations, sweating abnormalities, gastrointestinal symptoms, and anxiety or insomnia were common, and autonomic testing was generally regarded as helpful. Eighty percent felt that the risks associated with ‘jayulsingyeongsiljo’ are overstated, and 95% preferred replacing the term with standardized expressions such as autonomic dysfunction. Conclusions Korean neurologists view ‘jayulsingyeongsiljo’ as an unrecognized and potentially misleading label and support society-led standardization of terminology and guidance to improve autonomic dysfunction care and resource use.

Objectives: In alignment with the World Health Organization’s goal of eliminating hepatitis C, this study assessed the current treatment status and reasons for non-treatment among patients with hepatitis C in Jeonbuk State, Republic of Korea, to inform strategies for improving care engagement. Methods: Among 311 individuals diagnosed with hepatitis C and reported through the NationalNotifiable Infectious Disease Surveillance system between January 2023 and June 2024, 208 patients were surveyed after excluding those who had died or could not be contacted.Statistical analyses included the chi-square test, the Cochran-Armitage test for trend, and logistic regression. Results: Overall, 116 participants (55.8%) reported having received antiviral therapy. Among the 92 untreated individuals, the most common reason for non-treatment was the absence of symptoms (n = 23; 25.0%), followed by the burden of drug costs (n = 21; 22.8%). Conclusion These findings highlight suboptimal treatment uptake and key barriers that may hinder progress toward hepatitis C elimination. Expanding screening and strengthening linkage-to-care strategies, while addressing financial barriers, will be essential to achievingnational elimination targets.

Purpose: We aimed to analyze pediatric drowning cases to study age group-related clinical characteristics, such as causes, location, and outcomes, in an under-researched area in South Korea. Methods: From January 1, 2020 through July 20, 2025, we retrospectively analyzed medical records of patients aged 19 years or younger who had experienced drowning and visited Kangwon National University Hospital located in the northern Yeongseo region of Gangwon Province. Their clinical characteristics were compared between those with worse outcomes, defined as hospitalization to the intensive care unit or in-hospital mortality, and those with better outcomes. Results: During the period, 27 patients having undergone drowning accidents visited the hospital. The most frequent location was the bathtub at home in the patients younger than 1 year (all 4 patients), commercial swimming pools in those aged 1-14 years (12 of the 16 patients), and rivers in those aged 15-19 years (all 7 patients). Of the 27 cases, 11 had worse outcomes including 4 mortalities. Patients with worse outcomes had higher percentages of guardian’s negligence, altered mental status, pool or river as the location, implementation of oxygen therapy or positive pressure ventilation, and lower mean initial Korean Triage and Acuity Scale (i.e., higher acuity), as well as higher mean concentrations of glucose, urea nitrogen, aspartate aminotransferase, and base deficit. Conclusion This study on pediatric drowning patients in the under-researched area showed age-related differences in the primary causes of drowning and clinical features related to the worse outcomes. These findings need to be considered for prompting increased parental vigilance and more comprehensive societal preventive measures.

Background/Aims: We investigated whether patients with inflammatory bowel disease (IBD) in Korea have an increased risk of hepatitis A virus (HAV) and hepatitis C virus (HCV) infections and sought to identify the risk factors for these infections. Methods: We performed a nationwide population-based study using 2013–2021 data from the Korean National Health Insurance Claims Database. We calculated the incidence rates and standardized incidence ratios (SIRs) of HAV and HCV infections in patients with IBD compared with the overall Korean population. Results: A total of 43,513 patients were included in this study. A total of 317 cases of HAV were identified in 276,007 perdison- years, while 297 cases of HAV developed in the Korean general population. The SIR of HAV in the patients with IBD was 1.07 (95% confidence interval [CI], 0.96–1.19) and the increase of HAV infection in patients with IBD was not statistically significant. A total of 289 cases of HCV infection were identified in 276,538 person-years, while 242 cases of HCV infection developed in the Korean general population. The SIR of HCV in patients with IBD was 1.19 (95% CI, 1.06–1.34) and the increase of HCV infection in patients with Crohn's disease (SIR, 1.63; 95% CI, 1.31–2.04). Corticosteroid use was identified as a risk factor for HAV and HCV infections in patients with IBD. Conclusions HCV showed an increasing trend in Korean patients with IBD, especially those with Crohn's disease. Corticosteroids use is a risk factor for hepatitis in patients with IBD.

Background: s/Aims: Phase angle (PhA), as measured by bioelectrical impedance analysis, provides insights into hydration and nutritional status, making it a prognostic indicator of frailty. While low preoperative PhA has been linked to postoperative complications in cancer patients, its predictive value in individuals undergoing pancreaticoduodenectomy (PD) has not been thoroughly investigated.This study aims to evaluate the clinical utility of preoperative PhA in predicting postoperative complications for patients undergoing PD. Methods: Among 41 patients who underwent PD at Seoul National University Hospital between September and December 2024, 35 were included in the analysis after excluding 6 patients who had concomitant blood vessel or other organ resections. Patients were divided into low (Comprehensive Complication Index [CCI] ≤ 20) and high (CCI > 20) complication groups based on the CCI, derived from the Clavien–Dindo classification. The differences in PhA between the two groups were analyzed, and logistic regression was performed to assess the relationship between PhA and CCI. Results: The mean PhA was significantly lower in the high-CCI group compared to the low-CCI group (5.7° vs. 6.7°, p = 0.025). Multivariate logistic regression analysis indicated that PhA (odds ratio: 0.17; 95% confidence interval: 0.04–0.68; p = 0.012) was an independent predictor of high CCI. A low preoperative PhA was associated with an increased risk of postoperative complications following PD. Conclusions Preoperative PhA may serve as a valuable predictive indicator of postoperative complications after PD, enabling the identification of patients who could benefit from preoperative prehabilitation, including nutritional support.

Background: Current guidelines recommend factor IIa- or Xa-specific inhibitors over warfarin analogs for preventing thromboembolic stroke in patients with atrial fibrillation (AF).However, their plasma concentrations in Korean patients are not well understood. Methods: We conducted a single-center laboratory study to determine the distribution ranges of peak and trough concentrations of three factor Xa inhibitors (apixaban, edoxaban, and rivaroxaban) prescribed for preventing strokes in patients with AF. Patients receiving one of these drugs and undergoing blood specimen collection for laboratory tests were screened. Blood specimens were obtained from patients who had adhered to the prescribed drug regimen consistently for at least 1 week. Drug plasma concentrations were measured using heparin liquid-reagent technology-based anti-Xa chromogenic assays. Results: We selected 459 patients who were taking standard or on-label-reduced doses of apixaban (N = 252), edoxaban (N = 182), or rivaroxaban (N = 25). The 5th–95th percentile ranges of the peak concentrations were 84–414 ng/mL (apixaban), 72–424 ng/mL (edoxaban), and 97–517 ng/mL (rivaroxaban). The respective 5th–95th percentile ranges of the trough concentrations were 44–237 ng/mL, 23–93 ng/mL, and 13–219 ng/mL. Approximately 19.6% (apixaban), 33.3% (edoxaban), and 64.0% (rivaroxaban) of patients in each group had peak concentrations out of the predicted distribution ranges based on pharmacokinetic data. Approximately 7.3%, 52.8%, and 8.3% of patients had trough concentrations out of the predicted distribution ranges. Conclusions A considerable proportion of Korean patients with AF taking factor Xa inhibitors may require population-specific reference ranges to guide therapeutic monitoring.

Background: Mycoplasma pneumoniae is a major cause of community-acquired pneumonia (CAP) in children, with a rising incidence of macrolide resistance. Early diagnosis is crucial for reducing the disease burden; however, current diagnostic tools have limitations.We evaluated the diagnostic accuracy of serological assays and their performance based on symptom onset in children with CAP. Methods: From September 2023 to September 2024, we prospectively enrolled children with CAP, classified as M. pneumoniae pneumonia (MPP) or non-MPP, from 16 hospitals in Korea. Serological testing included chemiluminescence immunoassay (CLIA) and ELISA for detecting IgM and IgG, along with particle agglutination (PA) for total antibody measurements. Serological responses were analyzed at different times after symptom onset (0–4, 5–9, and 10–21 days). Results: Among 472 children with CAP (362 MPP, 110 non-MPP), 138 (29.2%) underwent PA testing, and 334 (70.8%) underwent IgM testing. PA at a 1:640 cutoff showed 48.0% sensitivity and 100% specificity. CLIA and ELISA showed comparable sensitivities (69.1% vs. 69.2%) and specificities (76.9% vs. 66.7%) for IgM testing. Seropositivity increased significantly with time since symptom onset (P for trend < 0.001), reaching 97.9% for IgM, 62.5% for IgG, and 94.7% for PA at 10–21 days. Conclusions The time post-symptom onset significantly influenced the diagnostic utility of serological tests for pediatric MPP, which showed limited value during the early stage of illness. These findings emphasize the importance of symptom onset-based interpretation of serological test results and their utility in complementing PCR when optimizing MPP diagnosis in children.

Background: Recent advancements in large language models (LLMs) have accelerated their integration into clinical domains, including laboratory medicine. The performance of LLMs in answering board-level laboratory medicine questions has not been comprehensively evaluated. Given the importance of diagnostic accuracy in this field, rigorous and objective evaluations of LLM capabilities are essential. Methods: We assessed 12 LLMs from OpenAI, Anthropic, and Google using 320 Korean Residency Examination questions (2021–2024) spanning six laboratory medicine subspecialties. Standardized prompts were provided via their application programming interfaces under deterministic settings (temperature = 0). Questions were administered thrice to assess response reproducibility. Outputs were compared with validated answers and analyzed for accuracy, reasoning quality, and error typology. Results: Google’s Gemini 2.0 Pro achieved the highest accuracy (80.0%), followed by OpenAI’s GPT-4.5 (77.2%) and Anthropic’s Claude 3.7 Sonnet (74.1%). Accuracy decreased as the difficulty of questions increased (78.0% for easy vs. 45.1% for challenging). Subspecialty performance varied. Al models underperformed on questions on transfusion medicine (mean accuracy: 38.8%), primarily because of limitations in domain-specific and regional knowledge representations. Incorrect answers primarily resulted from reasoning errors. Reproducibility exceeded 95% for most models; however, some residual non-determinism appeared even with greedy decoding (temperature = 0). Conclusions LLMs demonstrated substantial potential for integration into laboratory medicine, particularly in clinical chemistry and immunology. Performance inconsistencies (particularly for high-difficulty questions) and knowledge gaps (notably for transfusion medicine) highlight the necessity for further development—potentially including domain-specific fine-tuning and retrieval-augmented generation integration—and robust expert oversight before clinical application.