Background/Aims: This study investigated the clinical efficacy of low-dose mepolizumab (100 mg) in controlling severe eosinophilic asthma, aiming to induce eosinophilic granulomatosis with polyangiitis (EGPA) remission and reduce systemic steroid usage. Additionally, we constructed a basic frame for our longitudinal EGPA cohort by collecting serial blood samples before, during, and after mepolizumab treatment in EGPA patients. Methods: We conducted a 2-year prospective observational cohort study in patients with uncontrolled severe eosinophilic asthma and refractory EGPA who used systemic steroids (≥ 7.5 mg/day of prednisolone) or other immunosuppressant drugs for at least 6 months. All patients were treated with 100 mg of mepolizumab every 4 weeks for 1 year to control severe eosinophilic asthma and then were followed for an additional 1 year to monitor their disease course. We analyzed total systemic steroid use and EGPA remission/relapse during the study period. Results: Three EGPA patients were included in this study and completed 16 study visits over a 2-year period. After 1 year of treatment with mepolizumab (100 mg monthly), all 3 patients were able to reduce their maintenance dose of systemic steroids, with 2 patients completely discontinuing use. These 2 patients achieved EGPA remission during mepolizumab treatment, and their remission status remained stable for 1 year after they stopped receiving the medication. Conclusions Low-dose mepolizumab treatment demonstrated clinical efficacy in reducing the maintenance dose of systemic steroids required for severe refractory EGPA. While not all patients achieved EGPA remission with low-dose mepolizumab, some did, and their remission persisted even after treatment discontinuation.

Background: Psoriasis is a chronic inflammatory skin disorder typified by well-demarcated erythematous plaques with scales. While considered an immune-driven condition, its underlying molecular triggers remain insufficiently defined. Cold-inducible RNA-binding protein (CIRP), a stress-response protein, has recently been recognized as a damage-associated molecular pattern that can stimulate immune responses. Objective: This study aimed to explore the potential association between circulating CIRP levels and the clinical as well as histological characteristics of psoriasis. Methods: Serum CIRP concentrations were analyzed in 67 individuals diagnosed with psoriasis and 20 healthy controls. Relationships between CIRP expression and various clinical and histological indices were also examined. Results: Patients with psoriasis exhibited significantly elevated serum CIRP levels compared to healthy individuals. Although correlations were observed between CIRP and certain clinical and histological indicators, CIRP levels did not significantly differ based on disease severity (Psoriasis Area and Severity Index score), joint involvement, or nail changes. Conclusion Our findings support the notion that CIRP may be involved in the immunopathogenesis of psoriasis and could be considered a prospective target for therapeutic modulation.

Background: Alitretinoin, a pan-retinoid receptor agonist approved for chronic hand eczema, exhibits immunomodulatory effects that may benefit alopecia areata (AA). However, clinical evidence for its use in AA is limited. Objective: To evaluate alitretinoin's clinical efficacy and immunological mechanism in patients with AA. Methods: We reviewed retrospectively twenty-one patients with AA who were treated with alitretinoin, either as monotherapy (n=9) or add-on therapy (n=12). Treatment response was assessed using the Severity of Alopecia Tool (SALT) scores, and in vitro studies used human outer root sheath cells stimulated with interferon-γ and polyinosinic:polycytidylic acid to investigate the drug’s effects on inflammatory pathways. Results: Both groups showed significant reductions in SALT scores (p=0.04 and p=0.02, respectively). Patients with baseline SALT scores below 50 demonstrated superior improvement.Adverse events were mild, with headache (33.3%) and cheilitis (4.8%) being the most common. In vitro, alitretinoin suppressed interleukin-6 and tumor necrosis factor-α expression, decreased phosphorylation of signal transducer and activator of transcription (STAT) 1/STAT3, and downregulated major histocompatibility complex class I expression, suggesting restoration of hair follicle immune privilege. Conclusion Alitretinoin appears to be a safe and potentially effective treatment for patients with mild to moderate AA unresponsive to conventional therapies. Its role as a monotherapy or adjunctive option in selected cases warrants further investigation through larger controlled studies.

Background: Erythema multiforme (EM) is typically a self-limited, acute hypersensitivity reaction. However, a subset of patients experiences chronic, recurrent episodes, for which clinical features and treatment strategies differ depending on the underlying etiology, especially in herpes simplex virus (HSV)-associated cases. Objective: To investigate the clinical and phenotypic features of chronic recurrent EM and assess treatment responses, with a focus on differences based on HSV association. Methods: This retrospective study included pathology-confirmed cases of suspected EM from 2010 to 2023. Forty patients with chronic EM (≥3 recurrences or persistent disease for ≥12 months) were included. Clinical, histopathologic, and serologic data were analysed.Patients were stratified into herpes simplex virus-associated erythema multiforme (HAEM) and non-HAEM groups. Clustering analysis was performed to identify clinical phenotypes.Treatment responses to antivirals and immunomodulators were evaluated. Results: Of the 40 patients, 24 (60%) were classified as HAEM. HAEM patients showed more mucosal involvement, smaller targetoid lesions, and acral predominance, while nonHAEM patients had larger, coalescing lesions with more trunk involvement. Cluster analysis supported HSV as the major discriminating factor. Antiviral agents were effective in 87.5% of HAEM cases but ineffective in 76.9% of non-HAEM patients. Immunosuppressants such as cyclosporine and mycophenolate mofetil showed variable responses. Baricitinib induced complete remission in all 3 refractory cases. Conclusion HSV association defines a distinct clinical subtype of chronic recurrent EM, with differences in lesion morphology, distribution, and treatment response. Recognizing these patterns may guide targeted therapeutic strategies, including the potential use of Janus kinase inhibitors in refractory cases.

Background/Aims: Endoscopic anti-reflux therapy is a therapeutic option for gastroesophageal reflux disease (GERD), providing durable effects. However, clinical data from Korea remain limited. This study evaluates the clinical outcomes of endoscopic radiofrequency Stretta therapy in Korean patients. Methods: A retrospective analysis was conducted on 71 patients with GERD who underwent Stretta therapy at 2 tertiary hospitals in Korea between November 2015 and July 2021. Clinical outcomes, including patient satisfaction, medication cessation or reduction, and complications, were evaluated. Pre- and post-procedural esophageal manometry and 24-hour pH monitoring test results were also analyzed. Results: Patient satisfaction rates at 1, 6, and 12 months post-procedure were 54.7% (35/64), 70.0% (28/40), and 75.0% (21/28), respectively. Medication cessation or reduction was achieved in 31.2% (20/64) at 1 month, 70.0% (28/40) at 6 months, and 67.9% (19/28) at 12 months. Esophageal manometry (n = 21) showed no significant changes in mean lower esophageal sphincter pressure (18.7 mmHg [2.5-52.9] vs 17.4 mmHg [0.0-43.0], P = 0.702) or mean integrated relaxation pressure (8.2 mmHg [0.0-28.0] vs 10.1 mmHg [0.0-31.0], P = 0.840). The 24-hour pH monitoring (n = 18) demonstrated a nonsignificant decrease in acid exposure time (pH < 4) from 2.3% (0.0-8.4) to 1.6% (0.0-7.3) (P = 0.182). Similarly, the DeMeester score decreased non-significantly from 8.4 (0.8-27.7) to 6.6 (0.8-21.8) (P = 0.352). No procedure-related complications occurred. Conclusion Endoscopic radiofrequency Stretta therapy appears to be a safe treatment option for GERD and may provide favorable patient satisfaction and medication reduction.

Gastroesophageal reflux disease (GERD) is a chronic and relapsing gastrointestinal disorder characterized by the reflux of gastric contents into the esophagus, leading to troublesome symptoms and/or complications. Since the publication of the 2020 Seoul Consensus on GERD, significant new evidence has emerged, particularly regarding acid-suppressive therapies and diagnostic approaches. This 2025 focused update aims to refine GERD management strategies by incorporating the latest evidence on acid suppressive therapies and regional considerations in Asian populations. This study builds on the 2020 Seoul Consensus by integrating systematic reviews, meta-analyses, and expert consensuses to offer updated recommendations for the definition and medical treatment of GERD. These guidelines incorporate recent advances in acid-suppressive therapies, particularly potassium-competitive acid blockers, and adopt updated diagnostic frameworks in accordance with the Lyon Consensus 2.0. Key clinical questions were identified and structured using the following format: Population, Intervention, Comparator, Outcome. The resulting recommendations address the initial treatment, long-term maintenance strategies, and role of personalized therapy based on disease severity, such as the grade of reflux esophagitis. Six key statements are presented: updated definition and classification of GERD (Statement 1); initial and long-term treatment strategies tailored to GERD phenotypes, such as non-erosive reflux disease, mild erosive esophagitis, and severe erosive esophagitis (Statements 2-5); and dose optimization strategies for long-term safety (Statement 6). These guidelines aim to support gastroenterologists and general healthcare providers in making individualized evidence-based decisions for GERD management.

Dietary protein is a crucial macronutrient for systemic homeostasis, and the global interest in protein supplements has surged because of their roles in muscle synthesis, immune function, and sarcopenia prevention. In South Korea, the proportion of energy derived from protein has increased steadily over the past decade, reflecting a significant shift in dietary patterns toward greater reliance on protein. Concurrently, a wide range of protein- and amino acidbased processed foods and dietary supplements has been developed and actively consumed.Nevertheless, comprehensive data on the prevalence of protein supplement users, their characteristics across different life stages, and the contribution of supplements to total daily protein requirements are lacking. Unlike other macronutrients, the human body lacks a dedicated reservoir for protein storage, necessitating a continuous dietary supply to support protein turnover, particularly for older adults facing anabolic resistance and individuals with high physical demands. Although clinical evidence highlights that protein supplementation, particularly when combined with resistance exercise, effectively improves muscle mass and physical performance, the magnitude of these benefits remains inconsistent across different life stages and protein sources. Conversely, emerging concerns about the potential metabolic risks from chronic overconsumption suggest that the validity and safety of protein supplementation are unclear, highlighting the need for a precision nutrition approach. Thus, this review evaluates the status of protein supplement intake among Koreans, synthesizes evidence on its physiological benefits and drawbacks and examines international trends and regulatory frameworks. Developed as part of the technical assessment for the 2025 revision of the Dietary Reference Intakes for Koreans, this review addresses the current lack of longterm safety data on chronic protein overconsumption. It provides a foundational framework for evidence-based dietary guidelines and serves as a critical scientific basis for establishing future tolerable upper intake levels and nutrition policies for protein supplement use in Korea.

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.

Objective: This study aims to compare the incidence of active tuberculosis (TB) among Korean patients with rheumatoid arthritis (RA) initiating treatment with tumor necrosis factor inhibitors (TNFi) or tofacitinib. Methods: Using the Korean National Health Insurance database, we conducted a nationwide, retrospective cohort study of RA patients who started TNFi or tofacitinib therapy between 2015 and 2018. We calculated the incidence rates of active TB based on the treatment type and results from latent tuberculosis infection (LTBI) screening tests. A multivariable Cox proportional hazards model was employed to evaluate the risk of active TB in RA patients beginning TNFi or tofacitinib treatment. Results: Among 3,382 RA patients (596 on tofacitinib and 2,786 on TNFi), LTBI screening was predominantly conducted using the IGRA (interferon-gamma release assays) test. Of these patients, 624 (18.5%) with a positive LTBI test received prophylactic treatment. No cases of active TB occurred in tofacitinib users, while 32 cases were observed in TNFi users. The adjusted hazard ratio for active TB in LTBI-positive patients was 5.47 (95% confidence interval 2.74 to 10.92) compared to LTBI-negative patients.In subgroup analyses, TB incidence was significantly higher among individuals aged over 65 years. Conclusion Despite LTBI treatment, active TB remains prevalent among RA patients on TNFi therapy and in those with positive LTBI tests.