Nucleotide-binding oligomerization domain-containing-2 (NOD2) acts as a bacterial sensor in dendritic cells (DCs), but it is not clear how bacterial recognition links with antigen presentation after ...NOD2 stimulation. NOD2 variants are associated with Crohn's disease, where breakdown in self-recognition of commensal bacteria leads to gastrointestinal inflammation. Here we show NOD2 triggering by muramyldipeptide induces autophagy in DCs. This effect requires receptor-interacting serine-threonine kinase-2 (RIPK-2), autophagy-related protein-5 (ATG5), ATG7 and ATG16L1 but not NLR family, pyrin domain containing-3 (NALP3).We show that NOD2-mediated autophagy is required for both bacterial handling and generation of major histocompatibility complex (MHC) class II antigen-specific CD4(+) T cell responses in DCs. DCs from individuals with Crohn's disease expressing Crohn's disease-associated NOD2 or ATG16L1 risk variants are defective in autophagy induction, bacterial trafficking and antigen presentation. Our findings link two Crohn's disease-associated susceptibility genes in a single functional pathway and reveal defects in this pathway in Crohn's disease DCs that could lead to bacterial persistence via impaired lysosomal destruction and immune mediated clearance.
ObjectiveTo evaluate the impact of mental health comorbidity in children and young adults with inflammatory bowel disease (IBD).DesignRetrospective observational study.SettingRepresentative ...population, routinely collected primary care data from the UK Optimum Patient Care Research Database (2015–2019).ParticipantsPatients with IBD aged 5–25 years with mental health conditions were compared with patients with IBD of the same age without mental health conditions.Primary and secondary outcome measuresOutcomes comprised quality-of-life indicators (low mood, self-harm, parasuicide, bowel symptoms, absence from school or work, unemployment, substance use and sleep disturbance), IBD interventions (medication, abdominal surgery, stoma formation and nutritional supplements) and healthcare utilisation (primary care interactions and hospital admissions).ResultsOf 1943 individuals aged 5–25 years with IBD, 295 (15%) had a mental health comorbidity. Mental health comorbidity was associated with increased bowel symptoms (adjusted incident rate ratio (aIRR) 1.82; 95% CI 1.33 to 2.52), sleep disturbance (adjusted HR (aHR) 1.63; 95% CI 1.02 to 2.62), substance use (aHR 3.63; 95% CI 1.69 to 7.78), primary care interactions (aIRR 1.33; 95% CI 1.12 to 1.58) and hospital admissions (aIRR 1.87; 95%CI 1.29 to 2.75). In individuals ≥18 years old, mental health comorbidity was associated with increased time off work (aHR 1.55; 95% CI 1.21 to 1.99).ConclusionsMental health comorbidity in children and young adults with IBD is associated with poorer quality of life, higher healthcare utilisation and more time off work. It is imperative that affected young patients with IBD are monitored and receive early mental health support as part of their multidisciplinary care.Trial registration numberThe study protocol was specified and registered a priori (ClinicalTrials.gov study identifier: NCT05206734).
Electronic virtual chromoendoscopy (EVC) can demonstrate ongoing disease activity in ulcerative colitis (UC), even when Mayo subscores suggest healing. However, applicability of EVC technology ...outside the expert setting has yet to be determined.
Fifteen participants across 5 centers reviewed a computerized training module outlining high-definition and EVC (iScan) colonoscopy modes. Interobserver agreement was then tested (Mayo score, Ulcerative Colitis Endoscopic Index of Severity UCEIS, and the Paddington International Virtual Chromoendoscopy Score PICaSSO for UC), using a colonoscopy video library (30 cases reviewed pretraining and 30 post-training). Knowledge sustainability was retested in a second round (42 cases; 9/15 participants), 6 months after training provision.
Pretraining intraclass correlation coefficients (ICC) were good for the Mayo endoscopic subscore (ICC, .775), UCEIS scoring erosions/ulcers (ICC, .770), and UCEIS overall (ICC, .786) and for mucosal (ICC, .754) and vascular components of PICaSSO (ICC, .622). For the vascular components of UCEIS, agreement was only moderate (ICC, .429) and did not enhance post-training (ICC, .417); conversely, use of PICaSSO improved post-training (mucosal ICC, .848; vascular, .746). Histologic correlation using the New York Mt. Sinai System was strong for both PICaSSO components (Spearman’s ρ for mucosal: .925; vascular, .873; P < .001 for both). Moreover, accuracy in specifically discriminating quiescent from mild histologic strata was strongest for PICaSSO (area under the receiver operating characteristic curve AUROC for mucosal, .781; vascular, .715) compared with Mayo (AUROC, .708) and UCEIS (AUROC for UCEIS overall, .705; vascular, .562; bleeding, .645; erosions/ulcers, .696). Inter-rater reliability for PICaSSO was sustained by round 2 participants (round 1 and 2 ICC for mucosal, .873 and .869, respectively; vascular, .715 and .783, respectively), together with histologic correlation (ρ mucosal, .934; vascular, .938; P < .001 for both).
PICaSSO demonstrates good interobserver agreement across all levels of experience, providing excellent correlation with histology. Given the ability to discriminate subtle endoscopic features, PICaSSO may be applied to refine stratified treatment paradigms for UC patients.
Despite the increasing array of medications available for the treatment of Crohn's disease and a focus on mucosal healing, approximately 35% of patients with Crohn's disease undergo bowel surgery at ...some stage. The importance of nutritional optimisation before Crohn's surgery is well-highlighted by surgical, nutritional, and gastroenterological societies with the aim of reducing complications and enhancing recovery. Surgical procedures are frequently undertaken when other treatment options have been unsuccessful, and, thus, patients may have lost weight and/or required steroids, and are therefore at higher risk of post-operative complications. EEN is used extensively in the paediatric population to induce remission, but is not routinely used in the induction of remission of adult Crohn's disease or in pre-operative optimisation. Large prospective studies regarding the role of pre-operative EEN are lacking. In this review, we evaluate the current literature on the use of EEN in pre-operative settings and its impact on patient outcomes.
Twin studies and large-scale population studies have confirmed an increased sibling risk for both Crohn's disease (CD) and ulcerative colitis (UC). Unlike single gene disorders, CD and UC are thought ...to result from a complex interplay of multiple genes and environmental factors. The confirmation of CARD15/NOD2 as a CD susceptibility gene in the late 1990s caused much excitement in the field of complex diseases in general and since then, the rapid rate of progress in molecular genetics, with the advent of large-scale affordable genotyping techniques, has resulted in large collaborations and the identification of over 30 inflammatory bowel disease (IBD)-associated genes. In particular, the importance of the innate immune system has been reaffirmed with the identification of IRGM and ATG16L1 genes in the autophagy pathway as CD susceptibility genes. Disturbance in the adaptive immune system, in particular the IL-23/Th17 axis, has also shown to be of importance for IBD overall. In this era of genome-wide association studies it may be possible to, at last, identify the multiple genes involved in IBD and thus improve our understanding of the genotype-phenotype correlation and improve treatment.
Clinical trials on novel drug therapies require clear criteria for patient selection and agreed definitions of disease remission. This principle has been successfully applied in the field of ...rheumatology where agreed disease scoring systems have allowed multi-centre collaborations and facilitated audit across treatment centres. Unfortunately in ulcerative colitis this consensus is lacking. Thirteen scoring systems have been developed but none have been properly validated. Most trials choose different endpoints and activity indices, making comparison of results from different trials extremely difficult. International consensus on endoscopic, clinical and histological scoring systems is essential as these are the key components used to determine entry criteria and outcome measurements in clinical trials on ulcerative colitis. With multiple new therapies under development, there is a pressing need for consensus to be reached.
Reduced expression of Paneth cell antimicrobial alpha-defensins, human defensin (HD)-5 and -6, characterizes Crohn's disease (CD) of the ileum. TCF-4 (also named TCF7L2), a Wnt signalling pathway ...transcription factor, orchestrates Paneth cell differentiation, directly regulates the expression of HD-5 and -6, and was previously associated with the decrease of these antimicrobial peptides in a subset of ileal CD. To investigate a potential genetic association of TCF-4 with ileal CD, we sequenced 2.1 kb of the 5' flanking region of TCF-4 in a small group of ileal CD patients and controls (n = 10 each). We identified eight single nucleotide polymorphisms (SNPs), of which three (rs3814570, rs10885394, rs10885395) were in linkage disequilibrium and found more frequently in patients; one (rs3814570) was thereby located in a predicted regulatory region. We carried out high-throughput analysis of this SNP in three cohorts of inflammatory bowel disease (IBD) patients and controls. Overall 1399 healthy individuals, 785 ulcerative colitis (UC) patients, 225 CD patients with colonic disease only and 784 CD patients with ileal involvement were used to determine frequency distributions. We found an association of rs3814570 with ileal CD but neither with colonic CD or UC, in a combined analysis (allele positivity: OR 1.27, 95% CI 1.07 to 1.52, p = 0.00737), which was the strongest in ileal CD patients with stricturing behaviour (allele frequency: OR 1.32, 95% CI 1.08 to1.62, p = 0.00686) or an additional involvement of the upper GIT (allele frequency: OR 1.38, 95% CI 1.03 to1.84, p = 0.02882). The newly identified genetic association of TCF-4 with ileal CD provides evidence that the decrease in Paneth cell alpha-defensins is a primary factor in disease pathogenesis.
Infant health outcomes are a key consideration in decisions regarding therapy for pregnant and breast-feeding women with inflammatory bowel disease (IBD). A recent study by Kanis et al reported ...outcomes from 1000 children born to mothers with IBD (196 exposed to anti-TNFs) with no increased risk of adverse outcomes associated with anti-TNF exposure.1 Anti-TNF therapy should be continued through all trimesters to avoid maternal flares and consequent adverse fetal outcomes.2 3 Discontinuation in the third trimester is not associated with a decrease in infant infection risks.2 As the infant will be exposed to anti-TNF by active placental transfer, live vaccinations for the infant should be delayed to avoid potentially fatal infant outcomes.3
Background and Aim
Dye‐based chromoendoscopy (DCE) with targeted biopsies is recommended for inflammatory bowel disease (IBD) surveillance. However, DCE has not yet been widely adopted into clinical ...practice. We evaluated quality indicators in IBD surveillance following introduction of structured changes in service delivery.
Methods
In August 2016, we introduced a number of changes to IBD surveillance practice in our endoscopy unit. These included training using interactive videos/images in a structured module, DCE as standard by using a foot‐pedal operated pump jet, allocation of 45‐minute procedure timeslots, targeted biopsies (except in high‐risk patients), scoring of endoscopic disease activity, and lesion detection/morphology characterization. All IBD surveillance colonoscopies were allocated to a small team of four DCE‐trained endoscopists. We compared quality measures for surveillance procedures carried out pre‐ and post‐August 2016. The two groups were compared using chi‐squared statistics
Results
A total of 598 IBD surveillance procedures (277 pre‐August 2016 and 321 post‐August 2016) were done and included in the study. Use of DCE increased (54.2% vs 76.0% P < 0.0005) whereas random biopsy surveillance decreased (12.3% vs 3.1% P < 0.0005). Use of Paris classification (26.1% vs 57.0% P < 0.0005) and Kudo pit pattern increased (21.7% vs 59.0% P < 0.0005). There was also an increase in lesion detection rate (24.9% vs 33.1% P < 0.05).
Conclusions
Implementation of extensive changes in practice of surveillance colonoscopy resulted in significant improvement in quality indicators within a short period of time. Training, education and audit may continue to facilitate the adoption of DCE and further improve quality of performance in IBD surveillance.
Ileal Crohn's Disease (CD), a chronic small intestinal inflammatory disorder, is characterized by reduced levels of the antimicrobial peptides DEFA5 (HD-5) and DEFA6 (HD-6). Both of these α-defensins ...are exclusively produced in Paneth cells (PCs) at small intestinal crypt bases. Different ileal CD-associated genes including NOD2, ATG16L1, and recently the β-catenin-dependant Wnt transcription factor TCF7L2 have been linked to impaired PC antimicrobial function. The Wnt pathway influences gut mucosal homeostasis and PC maturation, besides directly controlling HD-5/6 gene expression. The herein reported candidate gene study focuses on another crucial Wnt factor, the co-receptor low density lipoprotein receptor-related protein 6 (LRP6). We analysed exonic single nucleotide polymorphisms (SNPs) in a large cohort (Oxford: n = 1,893) and prospectively tested 2 additional European sample sets (Leuven: n = 688, Vienna: n = 1,628). We revealed an association of a non-synonymous SNP (rs2302685; Ile1062Val) with early onset ileal CD (OR 1.8; p = 0.00034; for homozygous carriers: OR 4.1; p = 0.00004) and additionally with penetrating ileal CD behaviour (OR 1.3; p = 0.00917). In contrast, it was not linked to adult onset ileal CD, colonic CD, or ulcerative colitis. Since the rare variant is known to impair LRP6 activity, we investigated its role in patient mucosa. Overall, LRP6 mRNA was diminished in patients independently from the genotype. Analysing the mRNA levels of PC product in biopsies from genotyped individuals (15 controls, 32 ileal, and 12 exclusively colonic CD), we found particularly low defensin levels in ileal CD patients who were carrying the variant. In addition, we confirmed a direct relationship between LRP6 activity and the transcriptional expression of HD-5 using transient transfection. Taken together, we identified LRP6 as a new candidate gene in ileal CD. Impairments in Wnt signalling and Paneth cell biology seem to represent pathophysiological hallmarks in small intestinal inflammation and should therefore be considered as interesting targets for new therapeutic approaches.
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