Upadacitinib for Induction of Remission in Pediatric Ulcerative Colitis: An International Multi‑center Study.

Background And Aims: Data on upadacitinib therapy in children with ulcerative colitis (UC) or unclassified inflammatory bowel disease (IBD-U) are scarce. We aimed to evaluate the effectiveness and safety of upadacitinib as an induction therapy in pediatric UC or IBD-U.

Methods: In this multicenter retrospective study, children treated with upadacitinib for induction of remission of active UC or IBD-U from 30 centers worldwide were enrolled.

Serum cytokine panels in pediatric clinical practice.

Background: Cytokines are soluble signaling proteins that regulate inflammation and coordinate immune responses. Serum cytokine panels are increasingly used in medical practice, yet our understanding of cytokines as biomarkers for disease remains limited.

Objective: We sought to analyze real-world single-center use of a multiplexed cytokine panel, correlate its results with diagnosis and severity, and explore its use in pediatric practice.

The immunopathological landscape of human pre-TCRα deficiency: From rare to common variants.

We describe humans with rare biallelic loss-of-function variants impairing pre-α T cell receptor (pre-TCRα) expression. Low circulating naive αβ T cell counts at birth persisted over time, with normal memory αβ and high γδ T cell counts. Their TCRα repertoire was biased, which suggests that noncanonical thymic differentiation pathways can rescue αβ T cell development.

The intestinal microbiome of inflammatory bowel disease across the pediatric age range.

Dysbiosis is associated with pediatric and adult-onset inflammatory bowel disease (IBD), but the role of dysbiosis and the microbiome in very early onset IBD (VEO-IBD) has not yet been described. Here, we aimed to demonstrate the impact of age and inflammation on microbial community structure using shotgun metagenomic sequencing in children with VEO-IBD, pediatric-onset IBD, and age-matched pediatric healthy controls (HC) observed longitudinally over the course of 8 weeks. We found disease-related differences in alpha and beta diversity between HC and children with IBD or VEO-IBD.

Humoral immune response and safety of SARS-CoV-2 vaccination in very early onset inflammatory bowel disease.

Children with very early onset inflammatory bowel disease (VEO-IBD) may respond differently to coronavirus disease 2019 (COVID-19) immunization compared to healthy children or other patients with IBD. We recruited children with VEO-IBD <6 years of age and younger following receipt of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccine. Demographics, IBD characteristics, medication use, adverse events (AEs) and IBD exacerbations were collected.

Clinicopathologic Characterization of Lymphocytic Colitis in the Pediatric Population.

Background: Lymphocytic colitis (LC) in the pediatric population has been associated with immune dysregulation.

Methods: Single-center retrospective study of pediatric LC.

Results: 50 patients (35 female, 70%) with a median age of 12 years at diagnosis (interquartile range: 5.

Isolation of Epithelial and Stromal Cells from Colon Tissues in Homeostasis and Under Inflammatory Conditions.

Inflammation of the gastrointestinal tract is a prevalent pathology in diseases such as inflammatory bowel disease (IBD). Currently, there are no therapies to prevent IBD, and available therapies to treat IBD are often sub-optimal. Thus, an unmet need exists to better understand the molecular mechanisms underlying intestinal tissue responses to damage and regeneration.

Identification of Iatrogenic Perforation in Pediatric Gastrointestinal Endoscopy.

Objectives: Iatrogenic viscus perforation in pediatric gastrointestinal endoscopy (GIE) is a very rare, yet potentially life-threatening event. There are no evidence-based recommendations relating to immediate post-procedure follow-up to identify perforations and allow for timely management. This study aims to characterize the presentation of children with post-GIE perforation to better rationalize post-procedure recommendations.

Canakinumab for the treatment of autoinflammatory very early onset- inflammatory bowel disease.

Introduction: Therapeutic options are critically needed for children with refractory very early onset inflammatory bowel disease (VEO-IBD). Our aim was to evaluate clinical response to canakinumab, an anti-IL-1β monoclonal antibody, in patients with VEO-IBD whose phenotype resembles those with monogenic autoinflammatory disease.

Methods: This is a single center retrospective study of patients with VEO-IBD with autoinflammatory phenotype (AIP) in the absence of identified monogenic disease treated with canakinumab for >6 months.

Large-scale sequencing identifies multiple genes and rare variants associated with Crohn's disease susceptibility.

Genome-wide association studies (GWASs) have identified hundreds of loci associated with Crohn's disease (CD). However, as with all complex diseases, robust identification of the genes dysregulated by noncoding variants typically driving GWAS discoveries has been challenging. Here, to complement GWASs and better define actionable biological targets, we analyzed sequence data from more than 30,000 patients with CD and 80,000 population controls.

Multicenter Cohort Study of Infliximab Pharmacokinetics and Therapy Response in Pediatric Acute Severe Ulcerative Colitis.

Background & Aims: We aimed to model infliximab (IFX) pharmacokinetics (PK) in pediatric acute severe ulcerative colitis (ASUC) and assess the association between PK parameters, including drug exposure, and clinical response.

Methods: We studied a multicenter prospective cohort of hospitalized children initiating IFX for ASUC or IBD-unclassified. Serial IFX serum concentrations over 26 weeks were used to develop a PK model.

Clinical and laboratory predictors of monogenic very early onset inflammatory bowel disease.

Background: Inflammatory bowel disease (IBD) is a chronic inflammatory disease of the gastrointestinal tract. Treatment for patients who have a monogenic cause of their IBD, often the youngest children, known as very early onset IBD (VEO-IBD), can be different from standard treatment for polygenic cases. Yet, ascertainment of these patients is difficult.

β-Hydroxybutyrate suppresses colorectal cancer.

Colorectal cancer (CRC) is among the most frequent forms of cancer, and new strategies for its prevention and therapy are urgently needed. Here we identify a metabolite signalling pathway that provides actionable insights towards this goal. We perform a dietary screen in autochthonous animal models of CRC and find that ketogenic diets exhibit a strong tumour-inhibitory effect.

Very early-onset inflammatory bowel disease: Novel description in glycogen storage disease type Ia.

Although inflammatory bowel disease is a well-described feature of glycogen storage disease type Ib, it has been reported in only a small number of individuals with glycogen storage disease type Ia (GSDIa). We describe, to our knowledge, the first patient with GSDIa and very early-onset inflammatory bowel disease (VEO-IBD). Larger studies are needed to better understand this possible association, elucidate the mechanism of VEO-IBD in GSDIa, and inform management.

A Pattern-based Pathology Approach to Very Early-onset Inflammatory Bowel Disease: Thinking Beyond Crohn Disease and Ulcerative Colitis.

Very early-onset inflammatory bowel disease (VEO-IBD), IBD diagnosed in children younger than 6 years old, is phenotypically and genetically distinct from older onset IBD. Monogenic and digenic causative defects, particularly in primary immunodeficiency and intestinal epithelial barrier genes, have been identified in a subset of patients with VEO-IBD allowing for targeted therapies and improved outcomes. However, these findings are the minority, thus strategies to correctly diagnose patients, including identification of specific histopathologic findings with correlating clinical and laboratory features may provide critical and necessary insight into mechanisms of disease pathogenesis and subsequent therapeutic options.

Efficacy and Outcomes of Faecal Microbiota Transplantation for Recurrent Clostridioides difficile Infection in Children with Inflammatory Bowel Disease.

Background: Children with inflammatory bowel disease [IBD] are disproportionally affected by recurrent Clostridioides difficile infection [rCDI]. Although faecal microbiota transplantation [FMT] has been used with good efficacy in adults with IBD, little is known about outcomes associated with FMT in paediatric IBD.

Methods: We performed a retrospective review of FMT at 20 paediatric centres in the USA from March 2012 to March 2020.

Deficiency in X-linked inhibitor of apoptosis protein promotes susceptibility to microbial triggers of intestinal inflammation.

Inflammatory bowel disease (IBD) is characterized by inappropriate immune responses to the microbiota in genetically susceptible hosts, but little is known about the pathways that link individual genetic alterations to microbiota-dependent inflammation. Here, we demonstrated that the loss of X-linked inhibitor of apoptosis protein (XIAP), a gene associated with Mendelian IBD, rendered Paneth cells sensitive to microbiota-, tumor necrosis factor (TNF)–, receptor-interacting protein kinase 1 (RIPK1)–, and RIPK3-dependent cell death. This was associated with deficiency in Paneth cell–derived antimicrobial peptides and alterations in the stratification and composition of the microbiota.

Clostridioides difficile Infection in Pediatric Inflammatory Bowel Disease: A Clinician's Dilemma.

Clostridioides difficile infection (CDI) in children with inflammatory bowel disease (IBD) can present and manifest differently from the general population with CDI, and it can worsen the underlying disease course. Furthermore, current clinical assays used to test for CDI do not accurately distinguish between true CDI or colonization. This uncertainty leads to difficulty in identifying the etiology and therapy for symptomatic patients with IBD.

Ruxolitinib: Targeted Approach for Treatment of Autoinflammatory Very Early Onset Inflammatory Bowel Disease.

Very early onset inflammatory bowel disease (VEO-IBD), diagnosed <6 years old, can be genetically and phenotypically distinct and more refractory than older-onset IBD. Identified causal monogenic defects have been targeted therapeutically in a small subset of VEO-IBD; however, for most of these children, treatment strategies, such as phenotypic profiles, are critically needed to improve outcomes.

Pediatric Global Health in Children with Very Early-Onset Inflammatory Bowel Disease.

Objective: Children with very early-onset inflammatory bowel disease (VEO-IBD) represent a distinct group of patients with IBD with unique phenotypic and genetic characteristics; however, they are frequently omitted from psychosocial research. This study used a novel, brief measure of pediatric global health to assess (1) overall health-related quality of life (HRQOL) in children with VEO-IBD, (2) HRQOL compared to healthy children, and (3) whether gastrointestinal symptoms account for the differences in HRQOL between these groups.

Methods: Caregivers of 51 children with VEO-IBD (Mage = 4.

Mucosal Invariant T cells are Diminished in Very Early-Onset Inflammatory Bowel Disease.

Objectives: Very early-onset inflammatory bowel disease (VEO-IBD) arises in children less than 6 years old, a critical time for immunologic development and maturation of the intestinal microbiome. Non-conventional lymphocytes, defined here as mucosal-associated invariant T cells and innate lymphocytes, require microbial products for either development or expansion, aspects that could be altered in very early-onset inflammatory bowel disease. Our objective was to define conventional leukocyte and non-conventional lymphocyte populations in controls and patients using multiparameter flow cytometry to test the hypothesis that their frequencies would be altered in a chronic inflammatory state associated with significant dysbiosis.