F.P. Giugliano

T300A Variant of Autophagy ATG16L1 Gene is Associated with Decreased Antigen Sampling and Processing by Dendritic Cells in Pediatric Crohn?s Disease

Background:The single-nucleotide polymorphism T300A of ATG16L1, a Crohns disease (CD)–associated gene, is responsible for decreased autophagy. This study aimed to investigate the effects of this single-nucleotide polymorphism on the uptake and processing of antigens by dendritic cells (DCs) and the interaction between DC and intestinal epithelium in pediatric patients with CD. Methods:Pediatric patients who homozygously carry either the protective (wild type, n = 7) or risk allele (risk, n = 13) of ATG16L1, as well as heterozygous patients (het, n = 13) were enrolled. The monocyte-derived DC were analyzed for phenotype, antigen sampling, and processing by flow cytometry, whereas the capability of DC to form transepithelial protrusions was determined by confocal microscopy. Results:DC generated from wild type patients showed higher bacteria sampling and antigen processing compared with risk patients. Additionally, after exposure to either bacteria particles or the antigen DQ-ovalbumin, wild type DC showed a significant increase in the expression of the HLA-DR and CD86 when compared with risk DC. Interestingly, also het patients showed an impairment in bacteria uptake and expression of activation marker when compared with the wild type. In the Caco2/DC coculture, the formation of transepithelial protrusions were less numerous in risk DC compared with wild type and the antigen uptake decreased. Conclusions:DC of pediatric patients with CD carrying the T300A allele showed a marked impairment of antigen uptake and processing and defective interactions between DC and intestinal epithelium. Collectively, our results suggest that an autophagy defect is associated with an impairment of intestinal innate immunity in pediatric CD.

Bifidobacteria Enhance Antigen Sampling and Processing by Dendritic Cells in Pediatric Inflammatory Bowel Disease.

Abstract:Bifidobacteria have been reported to reduce inflammation and contribute to intestinal homeostasis. However, the interaction between these bacteria and the gut immune system remains largely unknown. Because of the central role played by dendritic cells (DCs) in immune responses, we examined in vitro the effects of a Bifidobacteria mixture (probiotic) on DC functionality from children with inflammatory bowel disease. DCs obtained from peripheral blood monocytes of patients with Crohns disease (CD), ulcerative colitis, and noninflammatory bowel disease controls (HC) were incubated with fluorochrome-conjugated particles of Escherichia coli or DQ-Ovalbumin (DQ-OVA) after a pretreatment with the probiotic, to evaluate DC phenotype, antigen sampling and processing. Moreover, cell supernatants were collected to measure tumor necrosis factor alpha, interferon gamma, interleukin 17, and interleukin 10 production by enzyme-linked immunosorbent assay. DCs from CD children showed a higher bacteria particles uptake and DQ-OVA processing after incubation with the probiotic; in contrast, DC from both ulcerative colitis and HC showed no significant changes. Moreover, a marked tumor necrosis factor alpha release was observed in DC from CD after exposure to E. coli particles, whereas the probiotic did not affect the production of this proinflammatory cytokine. In conclusion, the Bifidobacteria significantly improved the antigen uptake and processing by DCs from patients with CD, which are known to present an impaired autophagic functionality, whereas, in DCs from ulcerative colitis and HC, no prominent effect of probiotic mixture was observed. This improvement of antigen sampling and processing could partially solve the impairment of intestinal innate immunity and reduce uncontrolled microorganism growth in the intestine of children with inflammatory bowel disease.

Impact of Environmental and Familial Factors in a Cohort of Pediatric Patients with Inflammatory Bowel Disease.

Objectives: The primary role of environment on inflammatory bowel disease (IBD) onset has been recently stressed. We aimed to investigate the effect of environmental factors in an IBD pediatric cohort. Methods: A total of 467 subjects (264 IBD and 203 controls) were enrolled. All patients underwent a questionnaire including 5 different groups of environmental risk factors: family history of IBD and autoimmune diseases, perinatal period, home amenities and domestic hygiene, childhood diseases and vaccinations, and diet. Results: In a multivariate model, mothers degree (odds ratio [OR]: 5.5; 2.5–11.6), duration of breast feeding >3rd month (OR: 4.3; 1.6–10.5), fathers employment (OR: 3.7; 1.2–8.7), gluten introduction <6th month (OR: 2.8; 1.5–5), number of siblings <2 (OR: 2.8; 1.5–5.3), and family history of autoimmune diseases (OR: 2.7; 1.4–5.3) were significant risk factors for Crohn disease. Low adherence to Mediterranean diet (OR: 2.3; 1.2–4.5), gluten introduction <6th month (OR: 2.8; 1.6–4.9), and number of siblings <2 (OR: 2; 1.1–3.6) were significant risk factors for ulcerative colitis. Owning pets (OR: 0.3; 0.1–0.7) and bed sharing (OR: 0.2; 0.1–0.6) were protective factors for Crohn disease, whereas owning pets (OR: 0.4; 0.2–0.8) and family parasitosis (OR: 0.07; 0.01–0.4) were protective factors for ulcerative colitis. Conclusions: Our study confirms that environmental factors are closely linked to IBD onset and may partly explain IBD rise in developed countries.

Periappendiceal inflammation in pediatric ulcerative colitis.

Background: An involvement of the appendiceal orifice as a distintive skip lesion in adults with left side ulcerative colitis (UC) has been reported. The aim of our prospective study was to evaluate, by endoscopy and histology, the prevalence of periappendiceal inflammation (PAI) in children affected by UC. Methods: Fifty of 77 consecutive children undergoing total colonoscopy, who had a diagnosis of UC not extended beyond the hepatic flexure were enrolled. Results: PAI was endoscopically present in 16 of 50 patients (32%) with UC. Patients were divided in 2 groups: group A included the 16 patients with PAI, whereas group B included 34 patients without PAI. We found that among the 2 groups, PAI was more frequent in patients with new diagnosis than in those with pre-existing UC (P = 0.016). At index colonoscopy, the patients of group A had a significant major extent of disease (P = 0.013). Moreover, the histologic grade of inflammation at the ascending colon was significantly higher in group A than in group B (P = 0.014). Clinical activity, measured by pediatric ulcerative colitis activity index, and use of medication did not show significant differences among groups (P = 0.464 and P = 0.723, respectively). The use of immunosuppressant was significantly higher in group A than in group B. Conclusions: PAI is a frequent skip lesion in children with UC. It seems more frequent in patients with new diagnosis, and it is associated with a major extent of the disease and with a higher grade of histologic inflammation at the ascending colon.

Does Azathioprine induce endoscopic and histologic healing in pediatric inflammatory bowel disease? A prospective, observational study

BACKGROUND The new concept of disease remission for pediatric inflammatory bowel diseases (IBD) implies the achievement of mucosal healing. AIMS We aimed to evaluate endoscopic and histologic healing in children with Ulcerative Colitis (UC) and Crohns disease (CD) in clinical remission after 52 weeks of Azathioprine. METHODS From December 2012 to July 2015 we prospectively enrolled IBD children starting Azathioprine. Enrolled patients in clinical remission underwent colonoscopy after 52 weeks. Macroscopic assessment was described with Mayo score and the simplified endoscopic score for UC and CD, respectively. For microscopic assessment, an average histology score was used. Data on inflammatory markers and fecal calprotectin were also collected. RESULTS Fourty-seven patients were included in the analysis. Endoscopic healing was detected in 20/26 (76.9%) UC children and 10/21 (47.6%) CD patients. Median Mayo score and simplified endoscopic score were significantly decreased at week 52 (p<0.001; p=0.005). Median average histology score was not significantly different at week 52 in both diseases. Fecal calprotectin was directly correlated with simplified endoscopic score (T0: r=0.4, p=0.05; T52: r=0.5, p=0.01), but not with Mayo score. No correlation was found between endoscopic and histologic scores. CONCLUSIONS IBD children under Azathioprine reach endoscopic healing, but not histological remission.

Disorders of Sucking and Swallowing

Functional feeding skills, which depend on the integrity of anatomic structures, undergo change based on neurologic maturation and experimental learning. Eating/feeding requires active effort by infants who must have exquisite timing and coordination of sucking, swallowing, and breathing to be efficient.