Intestinal CD4CD8αβTCRαβ T cells function as tolerogenic antigen presenting cells in mice.

The intestinal mucosa harbors diverse lymphocyte populations, including double negative CD4CD8αβTCRαβ T (DNT) cells, in the intraepithelial compartment and the lamina propria. Here we report that DNT cells in mouse small intestines are motile and reach across the epithelial barrier to capture luminal antigens (Ags). DNT cells then migrate to mesenteric lymph nodes (MLN) and upregulate MHC-II, as evidenced by a sizeable fraction of mouse DNT cells in Peyer's patches (PP) and MLN expressing MHC-II but little or no co-stimulatory molecules.

Evolving Role of Artificial Intelligence in Endoscopic Management of Inflammatory Bowel Disease: Diagnosis, Surveillance, and Assessment.

Inflammatory bowel disease (IBD), including Crohn's disease and ulcerative colitis, presents substantial diagnostic and management challenges because of its variable clinical course and the limitations of conventional endoscopy. Although endoscopic procedures are crucial for diagnosis and surveillance, their inherent subjectivity and inter-observer variability complicate disease assessment. Recent advances in artificial intelligence (AI) offer promising solutions to these challenges by enabling automated, precise, and objective image analysis.

Comparative short-term efficacy of upadacitinib versus tofacitinib for ulcerative colitis: a 24-week real-world study in Japan.

Background/aims: Tofacitinib and upadacitinib are small-molecule compounds that inhibit the Janus kinase pathway for the treatment of refractory ulcerative colitis. Only a few reports have compared the efficacy and safety of these 2 drugs in real-world practice. We aimed to show our real-world evidence of these drugs and compare the efficacy and safety profiles in the treatment of ulcerative colitis.

Prevalence and predictability of the Chicago Classification of Pouchitis in ulcerative colitis: a multicenter study in Japan.

Background: Endoscopic phenotypes of pouchitis according to the Chicago Classification have been reported to be associated with poor pouch outcomes in ulcerative colitis (UC). Here, we aimed to assess the prevalence of endoscopic phenotypes and their predictability for pouch outcomes.

Methods: This retrospective multicenter study included UC patients aged 18 years or older who underwent total colectomy between January 2000 and March 2020.

Guidelines for endoscopic diagnosis and treatment of inflammatory bowel diseases.

In recent years, we have seen a considerable increase in the number of patients with inflammatory bowel diseases of unknown etiology, including both Crohn's disease and ulcerative colitis. Inflammatory bowel diseases can cause intestinal lesions throughout the gastrointestinal tract, necessitating gastrointestinal endoscopy for examining all relevant aspects, especially lesion characteristics, for differential diagnosis and histological diagnosis, to select the appropriate treatment options, determine treatment effectiveness, etc. Specific guidelines are necessary to ensure that endoscopy can be performed in a safe and more tailored and efficient manner, especially since gastrointestinal endoscopy, including enteroscopy, is a common procedure worldwide, including in Japan.

Diagnostic accuracy and cut-off values of serum leucine-rich alpha-2 glycoprotein for Crohn's disease activity in the small bowel.

Background: Small bowel (SB) lesions in Crohn's disease (CD) are often asymptomatic despite being highly active. Fecal calprotectin (FC) is the most widely used biomarker of CD activity, but its drawbacks include a large intra-individual sample variability and the burden of collecting stool samples. Meanwhile, serum leucine-rich alpha-2 glycoprotein (LRG) has recently attracted attention as a biomarker that can address the limitations of FC.

Combination of white-light imaging-based and narrow-band imaging-based artificial intelligence models during colonoscopy in patients with ulcerative colitis.

Background And Aims: The long-term treat-to-target (T2T) approach in ulcerative colitis (UC) aims for endoscopic remission, but variability among endoscopists and a lack of precision in relapse prediction both limit its clinical usefulness. A recently reported white-light imaging (WLI) artificial intelligence (AI) model helps standardize diagnosis, although challenges remain. Therefore, we attempted to combine a narrow-band imaging (NBI) AI model with the WLI AI model to determine whether these challenges can be overcome.

First-line biologics as a treatment for ulcerative colitis: a multicenter randomized control study.

Background: Despite the availability of several biologics for ulcerative colitis (UC), there remains a critical need to identify first-line treatment biologics. The superiority of infliximab (IFX) over vedolizumab (VED) and ustekinumab (UST) was evaluated as initial UC treatments in patients with biologic-naïve UC.

Methods: This multicenter, randomized control trial was conducted across 20 Japanese medical institutions.

Inadequate Efficacy of Biologics for Treating Proximal Ileal Lesions in Crohn's Disease; A Prospective Multicenter Study.

Background & Aims: Although biologic therapy has revolutionized the treatment of Crohn's disease (CD), surgery remains unavoidable in cases involving ileal complications. We aimed to evaluate the efficacy of biologics on proximal ileal lesions using balloon-assisted enteroscopy (BAE).

Methods: This open-label multicenter prospective study was conducted at tertiary referral centers in Japan.

Long-term efficacy and safety of tofacitinib in patients with ulcerative colitis: 3-year results from a real-world study.

Background/aims: The efficacy and safety of tofacitinib for the treatment of refractory ulcerative colitis (UC) has been demonstrated in clinical trials. Although, a series of reports with real-world evidence of its short-term efficacy and safety profiles have already been published, reports of long-term real-world data have been limited. We aimed to show our 3-year evidence on the clinical use of tofacitinib for the treatment of UC, focusing on its efficacy and safety profiles.

White Blood Cell Counts and Future Relapse in Ulcerative Colitis under Low-Dose Thiopurine Treatment in Real-World Practice: A 3-Year Japanese Multi-Center Retrospective Cohort Study.

Introduction: Whether white blood cell (WBC) counts are predictors for the effectiveness of thiopurine treatment in ulcerative colitis (UC) has been inconclusive in previous studies with small sample sizes. We investigated the association between WBC counts and future relapses in UC patients in a large-scale multi-center study.

Methods: This retrospective cohort study enrolled a total of 723 UC patients in remission from 33 hospitals and followed up for 3 years.

Combination of leucine-rich alpha-2 glycoprotein and fecal markers detect Crohn's disease activity confirmed by balloon-assisted enteroscopy.

Background/aims: Endoscopic activity confirmed by enteroscopy is associated with poor clinical outcome in Crohn's disease (CD). We investigated which of the existing biomarkers best reflects endoscopic activity in CD patients including the small bowel, and whether their combined use can improve accuracy.

Methods: One hundred and four consecutive patients with ileal and ileocolonic type CD who underwent balloon-assisted enteroscopy (BAE) from October 2021 to August 2022 were enrolled, with clinical and laboratory data prospectively collected and analyzed.

Serum Leucine-Rich α2 Glycoprotein: A Novel Biomarker for Transmural Inflammation in Crohn's Disease.

Introduction: Leucine-rich alpha-2 glycoprotein (LRG) is a newly studied biomarker for inflammatory diseases. This study aimed to investigate whether LRG can be used for evaluating transmural activity in patients with Crohn's disease (CD).

Methods: We performed magnetic resonance enterography (MRE) in 227 consecutive patients with CD from June 2020 to August 2021.

Hemorrhagic gastric ulcer in a patient with Behcet's disease successfully treated with infliximab.

Behcet's disease (BD) is a multisystem immune-mediated inflammatory disorder that occasionally involves the gastrointestinal tract. Reports on gastrointestinal involvement of BD are relatively rare, of which gastroduodenal involvement is particularly rare. Endoscopic features of gastroduodenal lesions are unknown, and treatment strategies have not been established.

A case of venous stasis colitis possibly caused by eplerenone.

A 50-year-old man was referred to our hospital for colitis with abdominal pain and diarrhea that had persisted for more than 8 months. 9 months earlier, he had been treated for fulminant eosinophilic myocarditis. During steroid therapy, ulceration appeared in the esophagus, stomach and large intestine.

Motility Mapping Quantification Using the Classical Optical Flow Algorithm for Small Bowel Crohn's Disease: Comparison with Balloon-assisted Enteroscopy Findings.

Purpose: To quantify bowel motility shown on cine MRI using the classical optical flow algorithm and compare it with balloon-assisted enteroscopy (BAE) findings in patients with Crohn's disease (CD).

Methods: This retrospective study included 29 consecutive patients with CD who had undergone MR enterocolonography (MREC) and BAE between March and May 2017. We developed computer software to present motion vector magnitudes between consecutive cine MR images as bowel motility maps via a classical optical flow algorithm using the Horn-Schunck method.

Mucosal healing of small intestinal stricture is associated with improved prognosis post-dilation in Crohn's disease.

Background: Small intestinal stricture is a major cause for surgery in Crohn's disease (CD). Endoscopic balloon dilation (EBD) is performed for small intestinal strictures to avoid surgery, often repeatedly. However, factors that are associated with prognosis after EBD of small intestinal strictures remain poorly investigated.

Systematic review of artificial intelligence-based image diagnosis for inflammatory bowel disease.

Objectives: Diagnosis of inflammatory bowel diseases (IBD) involves combining clinical, laboratory, endoscopic, histologic, and radiographic data. Artificial intelligence (AI) is rapidly being developed in various fields of medicine, including IBD. Because a key part in the diagnosis of IBD involves evaluating imaging data, AI is expected to play an important role in this aspect in the coming decades.

Artificial Intelligence for Disease Assessment in Inflammatory Bowel Disease: How Will it Change Our Practice?

Artificial intelligence (AI) has arrived and it will directly impact how we assess, monitor, and manage inflammatory bowel disease (IBD). Advances in the machine learning methodologies that power AI have produced astounding results for replicating expert judgment and predicting clinical outcomes, particularly in the analysis of imaging. This review will cover general concepts for AI in IBD, with descriptions of common machine learning methods, including decision trees and neural networks.