Characteristics and outcomes of portal vein thrombosis in patients with inflammatory bowel disease in Korea.

Background/aims: Portal vein thrombosis (PVT) frequently occurs in patients with inflammatory bowel disease (IBD), particularly when influenced by factors such as abdominal infections, IBD flare-ups, or surgical procedures. The implications of PVT range from immediate issues such as intestinal ischemia to long-term concerns including portal hypertension and its complications. However, there is a notable gap in comprehensive studies on PVT in IBD, especially with the increasing incidence of IBD in Asia.

Nonlesional ileal transcriptome in Crohn's disease reveals alterations in immune response and metabolic pathway.

Background And Aim: We aimed to assess the gene expression profiles of nonlesional small bowels in patients with Crohn's disease (CD) to identify its accompanying molecular alterations.

Methods: We performed RNA sequencing of the uninflamed small bowel tissues obtained from 70 patients with ileal CD and 9 patients with colon cancer (non-CD controls) during bowel resection. Differentially expressed gene (DEG) analyses were performed using DESeq2.

Mapping tumor habitats in isocitrate dehydrogenase -wild type glioblastoma: Integrating MRI, pathologic, and RNA data from the Ivy Glioblastoma Atlas Project.

Background: The goal of the study was to spatially validate intratumoral subregions (tumor habitat) using physiologic magnetic resonance imaging (MRI) on the pathology of the isocitrate dehydrogenase (IDH)-wild-type whole-glioblastoma sample.

Methods: Data from 20 patients (168 slides) were obtained from the Ivy Glioblastoma Atlas Project. On MRI, tumor habitats were defined using voxel-wise clustering of the apparent diffusion coefficient and cerebral blood volume maps for contrast-enhancing lesions (CEL) and non-enhancing lesions (NEL).

Transcriptomic Profiling and Cellular Composition of Creeping Fat in Crohn's disease.

Background And Aims: Creeping fat [CF] is a poorly understood feature of Crohn's disease [CD], characterized by the wrapping of mesenteric adipose tissue [MAT] around the inflamed intestine. The aim of this study was to investigate the transcriptional profile and compositional features of CF.

Methods: We collected 59 MAT samples: 23 paired samples from patients with CD (CF [CD-CF] and MAT around the uninflamed intestine [CD-MAT]) and 13 MAT samples from non-CD patients [Con-MAT].

Sex-Dimorphic Analyses Identify Novel and Sex-Specific Genetic Associations in Inflammatory Bowel Disease.

Background: Sex is an integral variable often overlooked in complex disease genetics. Differences between sexes have been reported in natural history, disease complications, and age of onset in inflammatory bowel disease (IBD). While association studies have identified >230 IBD loci, there have been a limited number of studies investigating sex differences underlying these genetic associations.

Genetic architecture of the inflammatory bowel diseases across East Asian and European ancestries.

Inflammatory bowel diseases (IBDs) are chronic disorders of the gastrointestinal tract with the following two subtypes: Crohn's disease (CD) and ulcerative colitis (UC). To date, most IBD genetic associations were derived from individuals of European (EUR) ancestries. Here we report the largest IBD study of individuals of East Asian (EAS) ancestries, including 14,393 cases and 15,456 controls.

Impact of Sarcopenia on Clinical Course of Inflammatory Bowel Disease in Korea.

Background And Aims: Reduced body muscle mass is a poor prognostic factor for inflammatory bowel disease (IBD). In this study, we investigated the prevalence of sarcopenia at diagnosis and its clinical significance in Korean patients with IBD.

Methods: The prevalence of sarcopenia in IBD patients between June 1989 and December 2016 was investigated using a well-characterized referral center-based cohort.

Case-case genome-wide association analysis identifying genetic loci with divergent effects on Crohn's disease and ulcerative colitis.

Crohn's disease (CD) and ulcerative colitis (UC), two major subtypes of inflammatory bowel disease, show substantial differences in their clinical course and treatment response. To identify the genetic factors underlying the distinct characteristics of these two diseases, we performed a genome-wide association study (GWAS) between CD (n = 2359) and UC (n = 2175) in a Korean population, followed by replication in an independent sample of 772 CD and 619 UC cases. Two novel loci were identified with divergent effects on CD and UC: rs9842650 in CD200 and rs885026 in NCOR2.

Clinical and Genetic Characteristics of Korean Patients Diagnosed with Chronic Enteropathy Associated with Gene: A KASID Multicenter Study.

Background/aims: Chronic enteropathy associated with gene (CEAS), an inherited disease characterized by nonspecific intestinal ulcers, has emerged in the Japanese population via loss-of-function mutations in the gene. We aimed to investigate the clinical and genetic characteristics of Korean patients diagnosed with CEAS.

Methods: From July 2018 to July 2021, we performed Sanger sequencing of the gene in 46 patients with chronic intestinal ulcers.

Identification of shared loci associated with both Crohn's disease and leprosy in East Asians.

Genome-wide association studies (GWAS) of Crohn's disease (CD) in European and leprosy in Chinese population have shown that CD and leprosy share genetic risk loci. As these shared loci were identified through cross-comparisons across different ethnic populations, we hypothesized that meta-analysis of GWAS on CD and leprosy in East Asian populations would increase power to identify additional shared loci. We performed a cross-disease meta-analysis of GWAS data from CD (1621 cases and 4419 controls) and leprosy (2901 cases 3801 controls) followed by replication in additional datasets comprising 738 CD cases and 488 controls and 842 leprosy cases and 925 controls.

Insufficient vaccination and inadequate immunization rates among Korean patients with inflammatory bowel diseases.

This study aimed to evaluate self-reported vaccination rates, immunity, knowledge of and attitudes toward vaccination among Korean patients with inflammatory bowel disease (IBD) as well as to identify factors associated with proper vaccination.Between November 2013 and February 2015, consecutive patients with IBD were invited to complete a standardized questionnaire on vaccination. Moreover, immune status for common vaccine-preventable diseases was evaluated via serologic tests.

Risk and characteristics of tuberculosis after anti-tumor necrosis factor therapy for inflammatory bowel disease: a hospital-based cohort study from Korea.

Background: Anti-tumor necrosis factor (TNF) treatment for inflammatory bowel disease (IBD) increases the risk of tuberculosis (TB) infection. In the present study, we analyzed the clinical characteristics and risks of TB in Korean patients with IBD who received anti-TNF treatment.

Methods: The study included patients with IBD who were treated using anti-TNF agents between January 2001 and June 2018 at the Asan Medical Center.

The Clinical Features of Inflammatory Bowel Disease in Patients with Obesity.

Methods: We retrospectively reviewed the medical records of IBD patients who visited Asan Medical center. We used a large, well-characterized referral center-based cohort. The clinical features of IBD patients with body mass index (BMI) over 30 and matched controls with BMI under 30 were compared.

Clinical Characteristics and Long-term Outcomes of Pediatric Ulcerative Colitis: A Single-Center Experience in Korea.

Background/aims: : Although pediatric ulcerative colitis (UC) has a different phenotype and clinical course than adult UC, its clinical features and outcomes are poorly defined, especially in Asian populations. This study investigated the clinical features and long-term outcomes of pediatric UC in a Korean population.

Methods: We retrospectively analyzed 208 patients aged <18 years diagnosed with UC between 1987 and 2013.

High Risk of Fractures Within 7 Years of Diagnosis in Asian Patients With Inflammatory Bowel Diseases.

Background & Aims: In this nationwide population-based study, we investigated the risk of vertebral and hip fractures in patients with inflammatory bowel disease (IBD).

Methods: Using data from the Korean National Health Insurance claims database gathered between 2007 and 2016, we calculated the incidence rate ratios (IRRs) of vertebral and hip fractures in patients with newly diagnosed IBD (n = 18,228; 64.1% male, 65.

Identification of Three Novel Susceptibility Loci for Inflammatory Bowel Disease in Koreans in an Extended Genome-Wide Association Study.

Background And Aims: Genome-wide association studies [GWAS] of inflammatory bowel disease [IBD] in multiple populations have identified over 240 susceptibility loci. We previously performed a largest-to-date Asian-specific IBD GWAS to identify two new IBD risk loci and confirm associations with 28 established loci. To identify additional susceptibility loci in Asians, we expanded our previous study design by doubling the case size with an additional dataset of 1726 cases and 378 controls.

Prostaglandin E receptor PTGER4-expressing macrophages promote intestinal epithelial barrier regeneration upon inflammation.

Objective: Dysfunctional resolution of intestinal inflammation and altered mucosal healing are essential features in the pathogenesis of inflammatory bowel disease (IBD). Intestinal macrophages are vital in the process of inflammation resolution, but the mechanisms underlying their mucosal healing capacity remain elusive.

Design: We investigated the role of the prostaglandin E (PGE) receptor PTGER4 on the differentiation of intestinal macrophages in patients with IBD and mouse models of intestinal inflammation.

Prevalence and risk factors of bowel symptoms in Korean patients with ulcerative colitis in endoscopic remission: a retrospective study.

Background: Many patients with ulcerative colitis (UC) in clinical remission frequently complain of bowel symptoms such as increased stool frequency (SF) and rectal bleeding (RB). However, studies on these patient-reported outcomes in patients with inactive UC are limited, especially in Korea. Therefore, we investigated the prevalence and risk factors of bowel symptoms in Korean patients with inactive UC.

Clinical outcomes and long-term prognosis of perianal Crohn's disease in an Asian population.

Background And Aim: The clinical impact of perianal Crohn's disease (CD) (pCD), a well-known poor prognostic factor of CD, has not been fully evaluated in Asian patients. We investigated the outcomes of CD in Korean patients according to the presence of pCD at CD diagnosis.

Methods: Using 2010-2014 data from the national health insurance claims database, we evaluated the disease course of CD according to the presence of pCD at CD diagnosis.

Inflammatory bowel disease and Parkinson's disease: common pathophysiological links.

Inflammatory bowel disease and Parkinson's disease are chronic progressive disorders that mainly affect different organs: the gut and brain, respectively. Accumulating evidence has suggested a bidirectional link between gastrointestinal inflammation and neurodegeneration, in accordance with the concept of the 'gut-brain axis'. Moreover, recent population-based studies have shown that inflammatory bowel disease might increase the risk of Parkinson's disease.

Molecular Changes in the Non-Inflamed Terminal Ileum of Patients with Ulcerative Colitis.

Ulcerative colitis is a chronic inflammatory disease confined to the colon. Although the etiopathogenesis remains unknown, small bowel dysfunctions like histological and permeability alterations have been described in ulcerative colitis. We evaluated the molecular gene signature in the non-inflamed terminal ileum of 36 ulcerative colitis patients (7 active, with Mayo endoscopic subscore ≥2, and 29 inactive) as compared to 15 non-inflammatory bowel disease controls.

Expression Quantitative Trait Loci (eQTL) Mapping in Korean Patients With Crohn's Disease and Identification of Potential Causal Genes Through Integration With Disease Associations.

Background: Expression quantitative trait loci (eQTL) datasets have extensively been used to help interpret genome-wide association study signals. Most eQTL analyses have been conducted with populations of European ancestry.

Objective: To determine the most functionally relevant genes at the Crohn's disease (CD) loci identified in genome-wide association studies (GWAS) involving Asian populations and to find novel disease-associated genes, we conducted an eQTL analysis.