Janus kinase (JAK) inhibitors are an important treatment option for ulcerative colitis, providing rapid onset of action, oral administration, and efficacy even after biologic failure. The 3 approved agents—tofacitinib, filgotinib, and upadacitinib—differ in JAK isoform selectivity, leading to clinically meaningful differences in efficacy and safety. Evidence from network meta-analyses, clinical trials, and real-world studies consistently shows that upadacitinib provides the highest efficacy for induction and maintenance of remission, whereas filgotinib demonstrates the most favorable safety profile. The strong efficacy of upadacitinib and tofacitinib is particularly relevant in patients with severe disease, including acute severe ulcerative colitis, and upadacitinib maintains high efficacy regardless of prior advanced therapy exposure. JAK inhibitors also benefit extraintestinal manifestations. Although risks such as herpes zoster, serious infection, thromboembolism, and major cardiovascular events differ among agents, long-term data suggest generally acceptable safety when used appropriately. Intraclass JAK-to-JAK cycling is feasible, with about half of patients achieving steroid-free clinical remission in retrospective cohorts. Based on mechanistic, clinical, and real-world evidence, filgotinib may be a first-line option for patients with lower disease activity or when safety is a priority, whereas upadacitinib or tofacitinib may be preferred in higher disease activity. Strategically selecting agents may improve durability and outcomes.

Background: The Act on Decisions on Life-Sustaining Treatment (LST) has been implemented in Korea since 2018, yet data on its application in neurocritical care units remain scarce. This study aimed to evaluate the clinical characteristics and outcomes of LST withdrawal or withholding in the neurocritical care unit. Methods: This study was a retrospective analysis conducted at a tertiary university hospital in Busan, South Korea. Among patients admitted to the neurocritical care unit between February 2018 and August 2023, those with documented decisions for LST withdrawal or withholding were enrolled. Demographic and clinical characteristics, underlying and combined conditions, reasons for LST decisions, measures taken, and time from LST withdrawal to death were extracted from medical records. Results: A total of 69 patients were included, with a median age of 67 years, and 38 (55%) were male. Cerebrovascular disease (62%) and traumatic brain injury (22%) were the most common underlying diagnoses. The primary reason for LST decisions was irreversible neurological damage (71%), followed by systemic complications (19%). Mechanical ventilation cessation (91%) and extubation (86%) were most frequently used measures for LST withdrawal. The median time from LST withdrawal to death was 22 minutes. Conclusions Our study demonstrates that LST decisions in the neurocritical care unit predominantly occur among patients with cerebrovascular disease or traumatic brain injury, mostly triggered by neurological deterioration. Most patients died shortly after withdrawal. These findings provide important insight into current LST withdrawal practices in neurocritical care and may assist clinical and ethical decision making in similar settings.

Purpose: To propose improvements for promoting eyeball donation and managing donated corneas, this study analyzed the current system in Korea and reviewed relevant Korean laws, international standards, and foreign practices. Methods: To understand the current situation in Korea, annual reports published by the Korean Network for Organ Sharing and existing Korean laws were examined. For the international context, references were made to the National Organ Transplant Act, 21 CFR Part 1271 (Code of Federal Regulations Title 21 Part 1271), Current Good Tissue Practice guidelines of the Food and Drug Administration, and the Medical Standards of the Eye Bank Association of America in the United States. Opinions on promoting eyeball donation, improving the monitoring system for donated corneas and revising laws related to cornea management were gathered. The perspectives of 31 experts affiliated with the Korea Cornea Society were collected through a survey. Results: Currently, there are no laws or regulations that can be appropriately applied to the cornea which has properties of both organs and tissue. Additionally, there is no law regulating imported corneas. Therefore, there is a need to legislate or revise the current law; all experts who conducted the survey agreed on this. Furthermore, the current system faces limitations in the efficient procurement, stable supply, and management of donor corneas, as well as in donation promotion. To address these issues, the establishment of independent legislation for managing donated corneas and a National Central Eye Bank was proposed. This central body would oversee continuous personnel training, education, and monitoring, along with ensuring stable procurement, processing, and supply of corneas within a structured management system. Sixty-eight percent of the surveyed experts agreed with this proposal. Conclusions To establish a safe and efficient Korean corneal supply and demand system, it is imperative to enact cornea-specific laws, including the establishment of a National Central Eye Bank.

Background: Laser procedures are integral to dermatologic practice, yet safety measures- particularly regarding ocular protection and plume control- are poorly studied in real-world settings. Objective: To evaluate current practices in eye protection, infection control, and occupational risk awareness among Korean dermatologists performing laser treatments. Methods: A cross-sectional survey was conducted among board-certified dermatologists at the 2024 Korean Society for Dermatologic Laser Surgery meeting. The questionnaire covered demographics, laser frequency, use of goggles and masks, infection control strategies, ophthalmologic monitoring, and history of warts or cancer. Results: Seventy-nine respondents completed the survey. All reported using protective goggles, but only 26.6% and 22.8% did so for CO 2 and erbium-doped yttrium aluminium garnet lasers, respectively. Only 24.1% underwent regular eye exams, and 13.9% reported eye conditions after starting laser practice. While 89.9% used masks, 40.8% used dental masks, which are inadequate for plume protection. Suction devices were used by 94.9%, though performance specifications were unclear. Warts were reported by 46.8% of respondents; two reported cancer diagnoses after initiating laser work. Conclusion Despite high overall adherence to basic safety practices, critical gaps remain. Our findings highlight the need for standardized guidelines and long-term occupational health monitoring to ensure safe laser practice.

Background: Rosacea is a chronic inflammatory skin disorder characterized by erythema, papules, ocular symptoms, and heightened sensitivity. Patients with neurogenic symptoms such as burning or stinging remain particularly difficult to manage. Current guidelines often underrepresent energy-based devices (EBDs), pigmentary sequelae, psychosocial burden, and ocular comorbidities. Objective: To examine Korean dermatologists’ expert perspectives on rosacea management, focusing on skin sensitivity, neurogenic symptoms, pigmentary changes, psychosocial impact, ocular involvement, and EBD use. Methods: A web-based, 29-item survey was administered to 25 board-certified Korean dermatologists (May–June 2025). Quantitative and qualitative responses were analyzed. Results: Erythematotelangiectatic and papulopustular phenotypes with sensitivity skin predominated. EBDs (pulsed dye laser, intense pulsed light) were frequently used but limited by cost and sensitivity issues. Neurogenic symptoms were recognized but rarely treated with neuromodulators. Post-inflammatory hyperpigmentation was infrequent, yet monitoring was inconsistent.Psychosocial and ocular aspects were acknowledged but seldomly systematically addressed.Respondents expressed interest in emerging adjunctive treatments such as cold plasma, skin boosters, and holistic care approaches. Conclusion Korean dermatologists adopt individualized strategies for rosacea, yet practice gaps remain regarding neurogenic symptoms, pigmentary complications, and psychosocial and ocular comorbidities. Findings support the need for updated multidisciplinary, phenotype-driven guidelines aligned with real-world practice.

Background: Older patients aged ≥75 years are underrepresented in major statin trials, leaving the optimal statin intensity after acute ischemic stroke (AIS) undefined. We aimed to compare functional outcomes and short-term safety between high-intensity statin therapy (HIST) and moderate-intensity statin therapy (MIST) in patients aged ≥75 years with AIS or transient ischemic attack. Methods: Using a prospective stroke registry at a single tertiary center (2019–2022), we retrospectively analyzed 337 patients aged ≥75 years with AIS or transient ischemic attack who maintained statin therapy for 3 months (HIST n=117; MIST n=220). The primary outcome was a favorable 3-month functional outcome (modified Rankin Scale score 0–2). Secondary outcomes included stroke recurrence, adverse effects, and statin discontinuation. Multivariable logistic regression with pre-specified sensitivity analyses was performed. Results: Favorable outcomes at 3 months were more frequent with HIST (70.9% vs. 55.9%; p=0.010). After multivariable adjustment, HIST was independently associated with a favorable outcome (adjusted odds ratio [aOR]=2.03, 95% confidence interval [CI] 1.17–3.53), consistent across sensitivity analyses: per-protocol (aOR=3.48, 95% CI 1.97–6.17) and atrial fibrillation-adjusted (aOR=2.21, 95% CI 1.26–3.89). No significant differences were observed in statin discontinuation, stroke recurrence, or adverse effects. Conclusion In older patients with AIS, HIST was independently associated with better functional outcomes without evidence of increased harm, broadly consistent with current guideline recommendations for HIST when tolerated. Prospective studies are needed to confirm a causal relationship.

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: Current reference intervals for lymphocyte subpopulations are primarily based on Western populations, with limited data available for Korean children, particularly for extended subsets. We determined absolute cell counts and percentages of lymphocyte subpopulations in Korean children, according to age and sex. Methods: Samples from 92 children—stratified into two age groups, groups 1 (5–9 yrs) and 2 (10–17 yrs)—were obtained. Immunophenotyping was performed via flow cytometry using the Primary Immunodeficiency Orientation Tube (PIDOT) panel, primarily classifying the cells into T, B, and natural killer cell populations. T lymphocytes were divided into CD4+ , CD8+ , and CD4– CD8– subsets; T and B cells were further subdivided according to their maturation stage. Results: Children in group 1 exhibited higher absolute counts of total B cells, unswitched memory B cells/plasma cells, total T cells, CD4+ naïve cells, and TCRγδ+ T cells than those in group 2. In contrast, Group 2 children showed higher absolute counts of CD4+ effector memory (EM) T cells. Males had higher absolute counts of total B cells, particularly pregerminal center B cells, CD4+ EM cells, and CD8+ terminally differentiated T cells, whereas females showed higher proportions of CD4+ , CD4+ naïve, and CD8 + central memory/transitional memory T cells. Conclusions To the best of our knowledge, this study is the first to establish reference values for extended lymphocyte subsets in Korean children using the PIDOT panel. Age, sex, and laboratory-related factors influenced lymphocyte subset distributions. These findings may serve as reference data for immune disorders and immunotherapy in pediatric populations.

Background: Warm ischemia is a major contributor to ischemic cholangiopathy and non-anastomotic biliary strictures (NAS) after liver transplantation, particularly in donation-after-circulatory-death grafts. However, the isolated impact of warm ischemia on peribiliary fibrosis is difficult to delineate because clinical settings involve overlapping effects of cold ischemia, reperfusion injury, and alloimmunity. This study aimed to establish a non-transplant rat model that isolates warm ischemic biliary injury and to compare the antifibrotic effects of rapamycin and tacrolimus. Methods: Warm ischemia was induced in Sprague–Dawley rats by ligating both ends of the peribiliary vascular plexus and the hepatic artery, followed by 30 minutes of portal vein clamping. Rats were randomly assigned to control, tacrolimus (1 mg/kg/day), or rapamycin (1 mg/kg/day) groups (n=15 per group). Serum alanine aminotransferase, alkaline phosphatase, gamma-glutamyl transferase, and total bilirubin were measured serially. Hematoxylin and eosin (H&E) and Sirius red staining were performed at 1, 3, and 6 weeks. Peribiliary fibrosis was quantified using digital image analysis of collagen area fraction. Results: Warm ischemia induced acute hepatobiliary injury with transient enzyme elevations, but no significant intergroup differences were observed. Histologically, biliary epithelial proliferation and collagen deposition increased progressively and became prominent at 6 weeks. At this time point, fibrosis ratios differed significantly (overall p=0.002): controls showed the highest fibrosis (4.8%), followed by tacrolimus (2.4%) and rapamycin (1.7%). Both immunosuppressants significantly reduced fibrosis compared with controls (p<0.05), whereas the difference between tacrolimus and rapamycin was not significant. Conclusion This warm ischemia model demonstrates that isolated ischemic injury alone can induce progressive peribiliary fibrosis. Rapamycin and tacrolimus attenuated fibrosis, with rapamycin producing the lowest collagen deposition. These findings provide mechanistic insight into ischemic cholangiopathy after liver transplantation—particularly in donation after circulatory death grafts—and underscore the need for further studies using models that incorporate cold ischemia, reperfusion, and alloimmune factors.

Purpose: Weight reduction (WR) can reduce liver volume, affecting the graft-to-recipient weight ratio (GRWR). This study aimed to evaluate the decrease in liver volume after WR and analyze risk factors affecting liver volume reduction in potential liver donors with steatosis. Methods: We retrospectively reviewed data of 147 potential liver donors with steatosis who participated in a WR program prior to liver transplantation between January 2016 and December 2021. Total liver volume (TLV) was measured using CT and MRI. Risk factors for large liver volume reduction (≥10%) were analyzed using multivariate logistic regression. Results: Ninety-seven donors (66.0%) underwent donor hepatectomy after WR. Liver volumes showed a statistically significant decrease (from 1,399.6 ± 315.4 mL to 1,283.6 ± 271.2 mL, P < 0.05). Thirty-eight donors (42.7%) showed large liver volume reduction. There was a more significant reduction in weight, AST, and ALT in the large liver volume reduction group than in the small liver volume reduction group (all P < 0.05). WR percentage and ALT abnormalities were independent risk factors for large liver volume reduction (odds ratio, 1.184 [95% confidence interval, 1.054–1.329] and odds ratio, 5.502 [95% confidence interval, 1.660–18.229], respectively; all P < 0.05). Conclusion Potential liver donors with 7% or more WR or ALT abnormality require liver volume/GRWR remeasurement after WR to ensure adequate graft size and prevent small-for-size syndrome.