Outcomes of exclusive enteral nutrition in paediatric Crohn\u27s disease

Background/objectives: Exclusive enteral nutrition (EEN) is a safe and effective treatment modality for inducing remission in paediatric Crohn\u27s disease (CD). The primary aim of this study was to compare the outcomes of EEN to corticosteroid (CS) therapy in newly diagnosed, treatment-naïve patients with CD. A secondary aim was to describe the outcomes of EEN in a national cohort of paediatric CD patients over a 10-year period. Subjects/methods: A retrospective chart review was conducted at the Irish national referral centre for paediatric CD. A case-matched analysis was conducted on two cohorts matched for age, gender, disease location, disease behaviour and disease activity, who received CS or EEN as their initial treatment. Subsequently, cohort analysis was conducted on all patients who undertook a course of EEN therapy between 2004 and 2013. Results: The case-matched analysis found higher remission rates after treatment with EEN (24/28, 86%) compared with those with CS (15/28, 54%; P=0.02). Dietetic contacts were found to be pivotal to the success of treatment and the attainment of remission. In total, 59 patients completed EEN at some time-point in their disease course and were included in the cohort analysis. Sixty-nine per cent of this cohort entered clinical remission (41/59). EEN was found to be most effective when used as an initial treatment (P=0.004) and less effective in patients aged under 10 years (P=0.04). Conclusions: EEN should be strongly considered as a favourable primary treatment over CS, especially in those diagnosed over the age of 10 years

Vacuolating cytotoxin and variants in Atg16L1 that disrupt autophagy promote Helicobacter pylori infection in humans

Peer reviewedPreprin

Infliximab in young paediatric IBD patients : it is all about the dosing

Infliximab (IFX) is administered intravenously using weight-based dosing (5 mg/kg) in inflammatory bowel disease (IBD) patients. Our hypothesis is that especially young children need a more intensive treatment regimen than the current weight-based dose administration. We aimed to assess IFX pharmacokinetics (PK), based on existing therapeutic drug monitoring (TDM) data in IBD patients = 10 years). Median age was 8.3 years (IQR 6.9-8.9) in YP compared with 14.3 years (IQR 12.8-15.6) in OP at the start of IFX. At the start of maintenance treatment, 72% of YP had trough levels below therapeutic range (< 5.4 mu g/mL). After 1 year of scheduled IFX maintenance treatment, YP required a significantly higher dose per 8 weeks compared with OP (YP; 9.0 mg/kg (IQR 5.0-12.9) vs. OP; 5.5 mg/kg (IQR 5.0-9.3);p < 0.001). The chance to develop antibodies to infliximab was relatively lower in OP than YP (0.329 (95% CI - 1.2 to - 1.01);p < 0.001), while the overall duration of response to IFX was not significantly different (after 2 years 53% (n = 29) in YP vs. 58% (n = 45) in OP;p = 0.56). Conclusion: Intensification of the induction scheme is suggested for PIBD patients aged < 10 years. What is Known

High-Throughput Sequencing Reveals the Incomplete, Short-Term Recovery of Infant Gut Microbiota following Parenteral Antibiotic Treatment with Ampicillin and Gentamicin

peer-reviewedThe infant gut microbiota undergoes dramatic changes during the first 2 years of life. The acquisition and development of this population can be influenced by numerous factors, and antibiotic treatment has been suggested as one of the most significant. Despite this, however, there have been relatively few studies which have investigated the short-term recovery of the infant gut microbiota following antibiotic treatment. The aim of this study was to use high-throughput sequencing (employing both 16S rRNA and rpoB-specific primers) and quantitative PCR to compare the gut microbiota of nine infants who underwent parenteral antibiotic treatment with ampicillin and gentamicin (within 48 h of birth), 4 and 8 weeks after the conclusion of treatment, relative to that of nine matched healthy controls. The investigation revealed that the gut microbiota of the antibiotic-treated infants had significantly higher proportions of Proteobacteria (P = 0.0049) and significantly lower proportions of Actinobacteria (P = 0.00001) (and the associated genus Bifidobacterium [P = 0.0132]) as well as the genus Lactobacillus (P = 0.0182) than the untreated controls 4 weeks after the cessation of treatment. By week 8, the Proteobacteria levels remained significantly higher in the treated infants (P = 0.0049), but the Actinobacteria, Bifidobacterium, and Lactobacillus levels had recovered and were similar to those in the control samples. Despite this recovery of total Bifidobacterium numbers, rpoB-targeted pyrosequencing revealed that the number of different Bifidobacterium species present in the antibiotic-treated infants was reduced. It is thus apparent that the combined use of ampicillin and gentamicin in early life can have significant effects on the evolution of the infant gut microbiota, the long-term health implications of which remain unknown.Irish Research Council for Science, Engineering and Technology EMBARK scholarship; Teagasc Walsh Fellowship; Science Foundation Ireland (Investigator award 11/PI/1137); Science Foundation of Ireland-funded Centre for Science, Engineering and Technology, the Alimentary Pharmabiotic Centre

Escape of intracellular Shigella from autophagy requires binding to cholesterol through the type III effector, IcsB.

Type III secretion systems are present in many pathogenic bacteria and mediate the translocation of bacterial effectors into host cells. Identification of host targets of these effectors is crucial for understanding bacterial virulence. IcsB, a type III secretion effector, helps Shigella to evade the host autophagy defense system by binding to the autophagy protein, Atg5. Here, we show that IcsB is able to interact specifically with cholesterol. The cholesterol binding domain (CBD) of IcsB is located between residues 288 and 351. Specific mutations of single tyrosine residues Y297 or Y340 of IcsB by phenylalanine (F) slightly reduced cholesterol binding, whereas deletion of the entire CBD or double mutation Y297F-Y340F strongly abolished interactions with cholesterol. To determine whether Shigella expressing IcsB variants could evade autophagy as effectively as the wild-type Shigella, we infected MDAMC cells stably expressing the autophagy marker LC3 fused to GFP and bacterial autophagosome formation was quantified using fluorescence microscopy. Mutation Y297F or Y340F slightly impaired IcsB function, whereas complete removal of CBD or mutation Y297F-Y340F significantly impaired autophagy evasion. Furthermore, we report that BopA, the counterpart of IcsB in Burkholderia pseudomallei with similar autophagy-evading properties, contains the CBD domain and is also able to bind cholesterol.Journal ArticleResearch Support, Non-U.S. Gov'tSCOPUS: ar.jinfo:eu-repo/semantics/publishe

Persistent changes in circulating and intestinal γδ T cell subsets, invariant natural killer T cells and mucosal-associated invariant T cells in children and adults with coeliac disease.

Coeliac disease is a chronic small intestinal immune-mediated enteropathy precipitated by exposure to dietary gluten in genetically predisposed individuals. The only current therapy is a lifelong gluten free diet. While much work has focused on the gliadin-specific adaptive immune response in coeliac disease, little is understood about the involvement of the innate immune system. Here we used multi-colour flow cytometry to determine the number and frequency of γδ T cells (Vδ1, Vδ2 and Vδ3 subsets), natural killer cells, CD56(+) T cells, invariant NKT cells, and mucosal associated invariant T cells, in blood and duodenum from adults and children with coeliac disease and healthy matched controls. All circulating innate lymphocyte populations were significantly decreased in adult, but not paediatric coeliac donors, when compared with healthy controls. Within the normal small intestine, we noted that Vδ3 cells were the most abundant γδ T cell type in the adult epithelium and lamina propria, and in the paediatric lamina propria. In contrast, patients with coeliac disease showed skewing toward a predominant Vδ1 profile, observed for both adult and paediatric coeliac disease cohorts, particularly within the gut epithelium. This was concurrent with decreases in all other gut lymphocyte subsets, suggesting a specific involvement of Vδ1 cells in coeliac disease pathogenesis. Further analysis showed that γδ T cells isolated from the coeliac gut display an activated, effector memory phenotype, and retain the ability to rapidly respond to in vitro stimulation. A profound loss of CD56 expression in all lymphocyte populations was noted in the coeliac gut. These findings demonstrate a sustained aberrant innate lymphocyte profile in coeliac disease patients of all ages, persisting even after elimination of gluten from the diet. This may lead to impaired immunity, and could potentially account for the increased incidence of autoimmune co-morbidity