Disease-associated DNA methylation signatures in esophageal biopsies of children diagnosed with Eosinophilic Esophagitis.

Eosinophilic esophagitis (EoE) is a leading cause of dysphagia and food impaction in children and adults. The diagnosis relies on histological examination of esophageal mucosal biopsies and requires the presence of > 15 eosinophils per high-powered field. Potential pitfalls include the impact of biopsy sectioning as well as regional variations of eosinophil density. We performed genome-wide DNA methylation analyses on 30 esophageal biopsies obtained from children diagnosed with EoE (n = 7) and matched controls (n = 13) at the time of diagnosis as well as following first-line treatment. Analyses revealed striking disease-associated differences in mucosal DNA methylation profiles in children diagnosed with EoE, highlighting the potential for these epigenetic signatures to be developed into clinically applicable biomarkers.

Association between body positioning and gastroesophageal reflux in paediatric age.

AIM: Postural measures are frequently recommended for gastroesophageal reflux (GER) symptoms, despite limited evidence. This was the first study to assess the impact of upright and recumbent body positions on GER episodes in children and adolescents, not just infants. METHODS: We retrospectively assessed the pH-impedance parameters of paediatric patients referred for possible GER-related symptoms to two hospitals in Naples and Rome, Italy, from September 2016 to September 2018. Data were separately obtained for the time that the patients spent in upright and recumbent positions. RESULTS: Data from 187 patients under the age of 18 were collected, at a mean age of just over seven years. We found that the acid exposure time was stable irrespective of changes in body position (P > .05). The mean number of reflux episodes per hour was 2.99 during the upright position and 1.21 during the recumbent position (P < .05), and the mean oesophageal acid clearance time was 44.4 and 93.4 seconds, respectively (P < .05). CONCLUSION: Most paediatric patients experienced reflux in the upright rather than recumbent position, probably as a result of frequent transient lower oesophageal sphincter relaxations while they were awake. In particular, our findings provide new insights into postural measures for reflux in children and adolescents.

The Role of Inflammation in the Endothelial Dysfunction in a Cohort of Pediatric Patients With Inflammatory Bowel Disease.

OBJECTIVES: Chronic inflammation plays a central role in the etiology of endothelial damage. Endothelial dysfunction (ED) is the inability of the artery to dilate in response to an endothelial stimulus. We assessed the ED by measuring the reactive hyperaemia index (RHI) and the flow-mediated dilation (FMD) in a cohort of pediatric patients affected by inflammatory bowel disease (IBD) and comparing these parameters to a group of healthy controls (HC). METHODS: Forty-one patients were consecutive enrolled. ED was evaluated by both the plethysmographic RHI method and the measurement of the FMD of brachial artery after occlusion of the blood flow. Differences between patients and controls were assessed by the Mann-Whitney test. In each patient with IBD, the main inflammation markers were detected and correlated to RHI and FMD by a linear regression test. RESULTS: We enrolled 26 (59%) patients with IBD and 18 (41%) HC. When comparing FMD value at diagnosis it was significantly lower in IBD patients than in HC (P = 0.04). This result was confirmed at follow-up, when this difference became even more significant (P = 0.004). A significant indirect correlation was found between FMD and fecal calprotectin (r: 0.17; P = 0.04). No differences were found when comparing RHI. CONCLUSIONS: Our results suggest that inflammation could lead to ED assessed by ultrasound FMD. These data were not confirmed by RHI; however, this could be due to the lack of a standardized pediatric cut-off. More studies are necessary to confirm our data.

Clinical significance and sonographic evolution of enlarged abdominal lymph nodes in children.

AIM: Paediatric evidence about the clinical implications of enlarged abdominal lymph nodes (EALN) is not univocal. The main purpose of our study was to evaluate the clinical significance and the morphological evolution of enlarged abdominal nodes in children with recurrent abdominal pain. METHODS: All children with recurrent abdominal pain diagnosed with EALN were enrolled at the involved centres between September 2017 and June 2018. Number, size, localisation, shape and architecture of nodes were accurately recorded along with clinical and laboratory data at enrolment and after three and six months. RESULTS: A total of 38 children were enrolled. After the six-month study period, 58% of them had lymph nodes reduced in size, 13% had unchanged lymph nodes, and 29% had lymph nodes increased in size. Overall, we observed a gradual, albeit slight reduction in the average size of enlarged nodes over the six-month period. The extent of size changes was not correlated with any clinical parameter. CONCLUSION: Our data suggest that EALN are a non-specific finding, which is not worth a change in the diagnostic and therapeutic management of children with abdominal pain.

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 Crohn's 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.

The Changing Face of Pediatric Ulcerative Colitis: A Population-based Cohort Study.

OBJECTIVES: The aims of this retrospective study were to describe ulcerative colitis (UC) phenotype at diagnosis and follow-up and to identify possible predictors of severe disease course. METHODS: This was a retrospective, single-center study. We reviewed the charts of patients with UC diagnosed between 2 and 18 years at our referral center from January 2007 to January 2016. Laboratory and clinical features at diagnosis, such as disease extent, atypical phenotypes, extraintestinal manifestations, and therapies, and pattern changes during the follow-up, including relapse rate, disease extension, and the cumulative risk for colectomy were collected. RESULTS: One hundred eleven patients were enrolled. Atypical phenotypes were identified at diagnosis in 55 out of 111 patients (49.5%). Extraintestinal manifestations were detected in 16 out of 111 (14.4%) at the diagnosis. During the follow-up 60 out of 111 (54%) patients needed to start azathioprine, 9 out of 111 (8.1%) patients started biologic therapy and 10 out of 111 (patients underwent surgery, resulting in a cumulative risk of 8% at 5 years and 16% at 10 years. Steroid refractoriness (hazard ratio: 13.9) and starting of biologic therapy (hazard ratio: 25.3) represented the best predictors for surgery. The cumulative probability of first relapse was 47% at 6 months and 63% at 1 year. Disease extension was reported in 21 out of 70 patients (30%). CONCLUSION: Pediatric UC is associated with a severe phenotype and a high percentage of atypical features. Surgery rate seems to be decreased from early reports.

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

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 Crohn's 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.

Autophagy genes variants and paediatric Crohn's disease phenotype: a single-centre experience.

BACKGROUND AND AIMS: Little evidence demonstrating the correlation between several single nucleotide polymorphisms and a specific phenotype of Crohn's disease has been reported in children. We investigated the relationship between autophagy genes variants and clinical features in our children with Crohn's disease. METHODS: Genotyping for ATG16L1, NOD2/CARD15, and IRGM1 was performed in 80 consecutive patients with Crohn's disease (median age: 11 years; range: 0.7-17.9 years). Crohn's disease location and behaviour were classified using the Paris classification. Additional data were collected from clinical records on patients' demographics, age at symptom onset and diagnosis, extraintestinal manifestations, therapy, clinical relapses, and need of surgical intervention. RESULTS: Patients homozygous for the risk allele ATG16L1 (T300A) showed a trend towards switching to a stricturing phenotype during the course of disease compared to children either homozygous for the wild-type allele or heterozygous for the ATG16L1 single nucleotide polymorphism (p=0.01). Homozygosity for the ATG16L1 risk allele was associated with a major recurrence of clinical relapses and earlier introduction of immunosuppressants (p=0.006 and p=0.04, respectively). Heterozygosity for the NOD2 rs2066847 allele was associated with major ileal involvement (p=0.01). CONCLUSION: In patients carrying the T300A variant, Crohn's disease follows a more aggressive clinical course.

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 Crohn's 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.