Background/Aims: The absence of standardized clinical minimum inhibitory concentration (MIC) breakpoints for Helicobacter pylori infection has resulted in inconsistent resistance definitions, even within the same research group in Korea. Therefore, establishing epidemiological cutoff values (ECOFFs) is essential for standardization. Methods: The MIC distributions for antibiotics commonly used against H. pylori infection in South Korea were analyzed from 2015 to 2023. A total of 5,925 primary H. pylori isolates were collected from five data sources, and MIC values were determined using the serial 2-fold agar dilution method. The ECOFFinder program was used to establish ECOFFs for six antibiotics. Results: The tentative ECOFFs for amoxicillin and clarithromycin were 0.125 μg/mL. The ECOFFs for levofloxacin, metronidazole, and tetracycline were 0.5, 8.0, and 0.25 μg/mL, respec-tively. The ECOFF for rifabutin could not be determined due to insufficient data. On the basis of these ECOFFs, the resistance rate was 17.9% for amoxicillin, 31.9% for clarithromycin, 40.9% for levofloxacin, 24.7% for metronidazole, and 11.5% for tetracycline. Conclusions This comprehensive analysis defined regional antibiotic resistance patterns and established Korea-specific ECOFFs, providing a foundation for determining clinical breakpoints and optimizing H. pylori eradication strategies.

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.

Purpose: To assess long-term outcomes of vesicostomy on bladder capacity (BC) and voiding function in non-neurogenic bladder, and explore the association between kidney ultrasonographic findings and renal function. Materials and Methods: Thirty-four patients under 2 years at the time of vesicostomy formation (2005–2020) with ≥3 years of follow-up were reviewed. Patients were further stratified based on neurogenic bladder status. Twenty-one patients were nonneurogenic. A subgroup analysis of 7 patients under 3 months with primary vesicoureteral reflux (VUR) and compromised renal function was conducted. Results: The median age at vesicostomy formation was 1.0 months (interquartile range [IQR] 0.0–3.5); the median duration of vesicostomy was 16.0 months (IQR 8.0–21.0). At a median age of 93.0 months (IQR 59.5–117.5), all patients achieved spontaneous micturition and continence. Eleven patients (52.4%) showed bell-shaped voiding patterns. Five patients showed interrupted (n=2) or plateau (n=3) patterns. With the exemption one patient, all patients with primary VUR showed bell-shaped curves. None initiated clean intermittent catheterization during follow-up. The median BC-to-estimated BC in patients with non-neurogenic bladder and primary VUR was 0.9 (IQR 0.7–1.1) and 0.9 (IQR 0.8–1.1), respectively. Three patients underwent revision due to prolapse. The glomerular filtration rate (GFR) was improved by 68.9% compared to the baseline (p=0.045). Parenchymal abnormalities on kidney ultrasonography were associated with decrease in GFR. Conclusions Vesicostomy in non-neurogenic bladder patients was associated with recovery of BC, preservation of continence, and improved renal function. Parenchymal abnormalities on ultrasonography predicted lower GFR.

Purpose: We present a rare case of acute visual acuity loss following intravitreal ganciclovir injection for the treatment of cytomegalovirus (CMV) retinitis.Case summary: A 35-year-old woman receiving immunosuppressive therapy for systemic lupus erythematosus developed CMV retinitis in the left eye. Oral valganciclovir was initiated but discontinued due to cytopenia and treatment was switched to intravitreal ganciclovir injections (2 mg/0.04 mL). One year later, CMV retinitis developed in the right eye and the same regimen was initiated. Although receiving bilateral injections at two-week intervals, the patient experienced a sudden decrease in visual acuity in the right eye one day after injection, 10 months after treatment initiation. Optical coherence tomography and fluorescein angiography revealed inner retinal edema and focal macular leakage. Treatment was switched to intravenous foscarnet resulting in resolution of macular edema; however, central retinal thinning persisted. Owing to recurrent retinitis, intravitreal ganciclovir injections are currently being continued at a reduced dose (1 mg/0.02 mL). Conclusions Acute visual acuity loss may rarely occur following intravitreal ganciclovir injection in patients with CMV retinitis. Careful consideration of potential mechanical injury and drug-induced retinal toxicity is needed during treatment.

Background/Aims: Gastric antral vascular ectasia (GAVE) is a rare but important cause of gastrointestinal (GI) bleeding. The clinical course of GAVE is not well-known, and recurrent bleeding from GAVE is a therapeutic challenge. Therefore, we investigated the clinical course of GAVE and identified the risk factors for bleeding from it. Methods: We retrospectively reviewed the records of patients diagnosed with GAVE using upper GI endoscopy at Asan Medical Center between January 2004 and December 2019 and evaluated the clinical course and risk factors for bleeding from GAVE. Results: Of the 348 patients (mean age, 62.3 ± 10.7 years; male, 62%), bleeding from GAVE occurred in 123 (35%) patients during follow-up (median, 17.3 months; interquartile range [IQR], 4.2–46.6). GI bleeding from GAVE was significantly associated with Child–Pugh class B or C liver cirrhosis (odds ratio [OR], 2.55; 95% confidence interval [CI], 1.57–4.16), chronic kidney disease (CKD) (OR, 2.77; 95% CI, 1.52–5.07), use of antithrombotic agents (OR, 2.34; 95% CI, 1.13–4.82), and involvement of the duodenal bulb (OR, 3.21; 95% CI, 1.76–5.86). Rebleeding occurred in 39 of 123 patients (32%), in whom CKD (OR, 2.55; 95% CI, 1.12–5.81) was significantly associated with rebleeding. Endoscopic hemostasis was most commonly performed using argon plasma coagulation, and the median number of endoscopic hemostasis performed was 2 (IQR, 1–3). Conclusions A careful follow-up for bleeding is needed in GAVE patients with liver cirrhosis, CKD, use of antithrombotic agents, and duodenal bulb involvement.

The gut microbiome is not just a bystander of colorectal carcinogenesis but is an active driver of colorectal cancer (CRC). CRC-associated microbiome contributes in the tumorigenesis through chronic inflammation, formation of toxic metabolite and genotoxins, oncogenic signal activation, immune evasion, and barrier disruption—all reinforcing a tumor microenvironment. In contrast, beneficial microbiome supports the barrier-immune-metabolic axis by maintaining mucosal integrity and balanced immune tone. Despite extensive studies of microbiome-based CRC biomarkers, microbiome-based CRC biomarkers have not been yet ready for routine clinical use due to variation across populations and lack of standardization of key steps such as sampling, analysis, cutoffs, and interpretation. Microbiome-based therapies aim to change the overall intestinal ecosystem rather than simply adding or removing single strains. At present, dietary modulation and prebiotics are considered supportive measures, while probiotics or synbiotics are in preclinical stage. Fecal microbiota transplantation (FMT) still faces important challenges in effectiveness, standardization and safety. By its role in reshaping the tumor–host immune environment, FMT is viewed as a potential option for cancer therapy after further development through well-controlled clinical trials with careful safety monitoring.

Rectal cancer, which accounts for approximately 40% of colorectal cancers, remains a major clinical concern. Recent advances in diagnostic imaging, surgical techniques, radiotherapy, and systemic treatment have steadily improved rectal cancer outcomes. Considering this, the Korean Rectal Cancer Multidisciplinary (KRCM) Committee has aimed to provide clinicians and policymakers with up-to-date, evidence-based clinical practice guidelines to support optimal decision-making, reflecting current evidence, the Korean healthcare context, and patient values and preferences. The Clinical Practice Guidelines for Rectal Cancer version 2.0 were developed through multidisciplinary collaboration with related academic societies, building upon and updating the KRCM Clinical Practice Guidelines version 1.0 (titled “Multidisciplinary guidelines for the management of rectal cancer”). These consensus guidelines of the KRCM were established based on a comprehensive literature review, evidence synthesis, with recommendation development guided by the GRADE (Grading of Recommendations Assessment, Development and Evaluation) methodology, and consideration of applicability in real-world clinical practice under the national health insurance system. Each recommendation has been presented with its strength and level of evidence.

Purpose: Esophagojejunal anastomotic leakage (EJAL) represents a severe postoperative complication following total or proximal gastrectomy. Treatment strategies include conservative management, endoscopic interventions, and surgery; however, comparative data remain limited. This study aimed to compare clinical outcomes of different strategies to identify the optimal approach based on anastomotic defect size. Materials and Methods: This retrospective study reviewed 100 patients diagnosed with EJAL between January 2015 and October 2024. Patients were categorized into four groups:conservative management, endoscopic vacuum-assisted closure (E-VAC), other endoscopic treatments, and surgery. The primary outcomes were leakage duration and length of hospital stay after EJAL diagnosis, whereas the secondary outcome was time to C-reactive protein normalization. Subgroup analyses were performed according to defect size. Results: Among the 100 patients, 76 were male and 24 were female, with a mean age of 65.7 years. Conservative treatment was the most common modality (53%), followed by other endoscopic treatments (19%), E-VAC (14%), and surgery (14%). In patients with a defect size <1 cm, conservative treatment was associated with significantly shorter leakage duration (P=0.035) and earlier resumption of diet (P=0.029) compared with endoscopic treatment.Among those with defects ≥2 cm, E-VAC demonstrated the most favorable median outcomes across all variables; however, statistical significance was not achieved because of the small sample size. Conclusions Conservative treatment appears to be the most effective treatment strategy for EJAL with anastomotic defects <1 cm. For larger defects (≥2 cm), E-VAC may offer clinical benefit, although further studies are needed to confirm its efficacy. These findings highlight the importance of individualized treatment selection based on defect size.

Objective: Janus kinase (JAK) inhibitors are widely used to treat rheumatoid arthritis (RA); however, comparative analyses regarding their adverse events remain limited. This study aimed to compare the effects of different JAK inhibitors (tofacitinib, baricitinib, and upadacitinib) on hematological parameters in patients with RA in a real-world setting. Methods: This retrospective analysis included 552 patients with RA treated with JAK inhibitors between August 2015 and February 2024. Hematological parameters, including absolute neutrophil count (ANC) and platelet count, were assessed at baseline and after 6 months of treatment. Statistical analysis was performed to evaluate changes over time, and logistic regression analysis identified factors associated with hematologic alterations. Results: The 552 patients were divided into three groups: tofacitinib (n=264), baricitinib (n=143), and upadacitinib (n=145). No significant differences in baseline hematological parameters were observed across the groups. After 6 months, ANC decreased in all groups without significant differences among them (p=0.465). Patients receiving baricitinib had significantly higher platelet counts than those receiving tofacitinib (Pillai’s trace value of 0.063, p<0.001) or upadacitinib (Pillai’s trace value of 0.029, p<0.001).Multivariate analysis revealed that baricitinib was significantly associated with increased platelet counts (odds ratio, 2.009; 95% confidence interval, 1.212~3.331; p=0.007). Conclusion Although all three JAK inhibitors reduced ANC, baricitinib was associated with a substantial increase in platelet counts. These findings highlight the differences in adverse effect profiles among JAK inhibitors, emphasizing the importance of tailored monitoring in RA management.