Stem-like T cells are associated with the pathogenesis of ulcerative colitis in humans.

To understand the role of T cells in the pathogenesis of ulcerative colitis (UC), we analyzed colonic T cells isolated from patients with UC and controls. Here we identified colonic CD4 and CD8 T lymphocyte subsets with gene expression profiles resembling stem-like progenitors, previously reported in several mouse models of autoimmune disease. Stem-like T cells were increased in inflamed areas compared to non-inflamed regions from the same patients.

Amerindian ancestry proportion as a risk factor for inflammatory bowel diseases: results from a Latin American Andean cohort.

Background And Aims: Latin American populations remain underrepresented in genetic studies of inflammatory bowel diseases (IBDs). Most genetic association studies of IBD rely on Caucasian, African, and Asian individuals. These associations have yet to be evaluated in detail in the Andean region of South America.

Genotype Prevalence of Lactose Deficiency, Vitamin D Deficiency, and the Vitamin D Receptor in a Chilean Inflammatory Bowel Disease Cohort: Insights from an Observational Study.

Lactose intolerance (LI) and vitamin D deficiency (VDD) have been linked to inflammatory bowel disease (IBD). We conducted an observational study in 192 Chilean IBD patients to investigate the prevalence of a specific gene variant (LCT-13910 CC genotype) associated with LI and the prevalence of VDD/Vitamin D Receptor (VDR) gene variants. Blood samples were analyzed using Illumina's Infinium Global Screening Array.

Modulation of the Acute Inflammatory Response Induced by the Lipopolysaccharide through the Interaction of Pentoxifylline and Florfenicol in a Rabbit Model.

Background: Experimental reports have demonstrated that florfenicol (FFC) exerts potent anti-inflammatory effects, improving survival in a murine endotoxemia model. Considering the anti-inflammatory and immunomodulatory properties of pentoxifylline (PTX) as an adjuvant to enhance the efficacy of antibiotics, the anti-inflammatory effects of the interaction FFC/PTX over the Lipopolysaccharide (LPS)-induced acute inflammatory response was evaluated in rabbits.

Methods: Twenty-five clinically healthy New Zealand rabbits (3.

CD4-mediated colitis in mice is independent of the GPR183 and GPR18 pathways.

Colitis is characterized by an exacerbated intestinal immune response, but the genetic and other mechanisms regulating immune activation remain incompletely understood. In order to identify new pathways leading to colitis, we sought to identify genes with increased expression in the colons of patients that also are near loci identified by genome wide association studies (GWAS) associated with IBD risk. One such SNP, rs9557195 was of particular interest because it is within an intron of , known to be important for lymphocyte migration.

Ethnicity influences phenotype and clinical outcomes: Comparing a South American with a North American inflammatory bowel disease cohort.

Inflammatory bowel disease (IBD), including ulcerative colitis (UC) and Crohn disease (CD), has emerged as a global disease with an increasing incidence in developing and newly industrialized regions such as South America. This global rise offers the opportunity to explore the differences and similarities in disease presentation and outcomes across different genetic backgrounds and geographic locations. Our study includes 265 IBD patients.

Metabolic activation and colitis pathogenesis is prevented by lymphotoxin β receptor expression in neutrophils.

Inflammatory bowel disease is characterized by an exacerbated intestinal immune response, but the critical mechanisms regulating immune activation remain incompletely understood. We previously reported that the TNF-superfamily molecule TNFSF14 (LIGHT) is required for preventing severe disease in mouse models of colitis. In addition, deletion of lymphotoxin beta receptor (LTβR), which binds LIGHT, also led to aggravated colitis pathogenesis.

Inherent Immune Cell Variation Within Colonic Segments Presents Challenges for Clinical Trial Design.

Background And Aims: Intestinal biopsy sampling during IBD trials represents a valuable adjunct strategy for understanding drug responses at the tissue level. Given the length and distinctive embryonic origins of the proximal and distal colon, we investigated whether inherent regional differences of immune cell composition could introduce confounders when sampling different disease stages, or pre/post drug administration. Here, we capitalise on novel mass cytometry technology to perform deep immunophenotyping of distinct healthy colonic segments, using the limited numbers of biopsies that can be harvested from patients.

Implementation of Mass Cytometry as a Tool for Mechanism of Action Studies in Inflammatory Bowel Disease.

Background: Novel therapeutics for inflammatory bowel disease (IBD) are under development, yet mechanistic readouts at the tissue level are lacking. Techniques to assess intestinal immune composition could represent a valuable tool for mechanism of action (MOA) studies of novel drugs. Mass cytometry enables analysis of intestinal inflammatory cell infiltrate and corresponding molecular fingerprints with unprecedented resolution.

Increasing efficiency of MRE for diagnosis of Crohn's disease activity through proper sequence selection: a practical approach for clinical trials.

Purpose: To derive the best magnetic resonance enterography (MRE) approach for detecting activity and severe lesions in Crohn's disease (CD) to use for selecting patients and measuring response to treatment in clinical trials.

Methods: We compared the accuracies of MRE (T2-weighted sequences, DWI (b = 800 s/mm) sequences, combined T2-weighted and DWI sequences, combined T2-weighted or DWI sequences, and MaRIA score based on T2-weighted and contrast-enhanced T1-weighted sequences) versus ileocolonoscopy (SES-CD) performed within 1 month. Bowel segments were classified as inactive (SES-CD < 2), active (SES-CD ≥ 2), or active with severe lesions (ulcers seen at endoscopy).

Comparison of three magnetic resonance enterography indices for grading activity in Crohn's disease.

Background: Magnetic resonance enterography (MRE) is an accurate examination for assessing activity in Crohn's disease (CD). Various MRE indices have been developed for that purpose, but have not been directly compared. The aim of the study was to compare the diagnostic accuracy of three MRE indices for detecting and grading disease activity in CD, using endoscopy as gold standard.

Incidence, Clinical Characteristics, and Management of Psoriasis Induced by Anti-TNF Therapy in Patients with Inflammatory Bowel Disease: A Nationwide Cohort Study.

Background: Psoriasis induced by anti-tumor necrosis factor-α (TNF) therapy has been described as a paradoxical side effect.

Aim: To determine the incidence, clinical characteristics, and management of psoriasis induced by anti-TNF therapy in a large nationwide cohort of inflammatory bowel disease patients.

Methods: Patients with inflammatory bowel disease were identified from the Spanish prospectively maintained Estudio Nacional en Enfermedad Inflamatoria Intestinal sobre Determinantes genéticos y Ambientales registry of Grupo Español de Trabajo en Enfermedad de Croh y Colitis Ulcerosa.