Objective The influence of eosinophilic oesophagitis (EoE)-associated inflammation upon oesophageal epithelial biology remains poorly understood. We investigated the functional role of autophagy in oesophageal epithelial cells (keratinocytes) exposed to the inflammatory EoE milieu. Design Functional consequences of genetic or pharmacological autophagy inhibition were assessed in endoscopic oesophageal biopsies, human oesophageal keratinocytes, single cell-derived ex vivo murine oesophageal organoids as well as a murine model recapitulating EoE-like inflammation and basal cell hyperplasia. Gene expression, morphological and functional characterization of autophagy and oxidative stress were performed by transmission electron microscopy, immunostaining, immunoblotting, live cell imaging and flow cytometry. Results EoE-relevant inflammatory conditions promoted autophagy and basal cell hyperplasia in three independent murine EoE models and oesophageal organoids. Inhibition of autophagic flux via chloroquine treatment augmented basal cell hyperplasia in these model systems. Oesophageal keratinocytes stimulated with EoE-relevant cytokines, including tumor necrosis factor-α and interleukin-13 exhibited activation of autophagic flux in a reactive oxygen species-dependent manner. Autophagy inhibition via chloroquine treatment or depletion of Beclin-1 or ATG-7, augmented oxidative stress induced by EoE-relevant stimuli in murine EoE, oesophageal organoids and human oesophageal keratinocytes. Oesophageal epithelia of pediatric EoE patients with active inflammation displayed increased autophagic vesicle content compared to normal and EoE remission subjects. Functional flow cytometric analysis revealed autophagic flux in human oesophageal biopsies. Conclusions Our findings reveal for the first time that autophagy may function as a cytoprotective mechanism to maintain epithelial redox balance and homeostasis under EoE inflammation-associated stress, providing mechanistic insights into the role of autophagy in EoE pathogenesis.

Eosinophilic esophagitis (EoE) is a chronic Th2 and food antigen-mediated disease characterized by esophageal eosinophilic infiltration. Thymic stromal lymphopoetin (TSLP), an epithelial derived cytokine which bridges innate and Th2-type adaptive immune responses in other allergic conditions, is overexpressed in esophageal biopsies of EoE subjects. However, the triggers of TSLP expression in the esophageal epithelium are unknown. The objective of the current study was to characterize TSLP expression in human esophageal epithelium in EoE in vivo and to determine the role of food antigens upon epithelial TSLP expression in vitro. Using immunohistochemistry (IHC), we localized TSLP in esophageal biopsies of active EoE (≥15 eos/hpf), inactive EoE (<15 eos/hpf) and non-EoE control subjects, and found that TSLP expression was restricted to the differentiated suprabasal layer of the epithelium in actively inflamed EoE biopsies. Consistent with these results in vivo, inducible TSLP protein secretion was higher in CaCl2 differentiated telomerase-immortalized esophageal epithelial cells (EPC2-hTERT) compared to undifferentiated cells of the basal phenotype, following stimulation with the TLR3 ligand poly(I:C). To determine whether food antigens could directly induce epithelial TSLP secretion, differentiated and undifferentiated primary esophageal epithelial cells from EoE and non-EoE subjects were challenged with food antigens clinically relevant to EoE: Chicken egg ovalbumin (OVA), wheat, and milk proteins beta-lactoglobulin (blg) and beta-casein. Food antigens failed to induce TSLP secretion by undifferentiated cells; in contrast, only OVA induced TSLP secretion in differentiated epithelial cells from both EoE and control cell lines, an effect abolished by budesonide and NF-κb inhibition. Together, our study shows that specific food antigens can trigger innate immune mediated esophageal TSLP secretion, suggesting that esophageal epithelial cells at the barrier surface may play a significant role in the pathogenesis of EoE by regulating TSLP expression.

Objective To review the understanding of the pathogenesis of eosinophilic esophagitis (EoE) and the role of the immune system in the disease process. Data Sources Peer-reviewed articles on EoE from PubMed searching for “Eosinophilic Esophagitis and fibrosis” in the period of 1995 to 2013. Study Selection Studies on the clinical and immunologic features, pathogenesis, and management of EoE. Results Recent work has revealed that thymic stromal lymphopoietin and basophil have an increased role in the pathogenesis of disease. Additional understanding on the role of fibrosis in EoE is emerging. Conclusion The incidence of EoE is increasing like most atopic disease. Similar to other allergic diseases, EoE is treated with topical steroids and/or allergen avoidance.

No abstract

Eosinophilic Esophagitis (EoE) is a chronic allergic disorder, whose pathobiology is incompletely understood. Histamine-producing cells including mast cells and basophils have been implicated in EoE. However, very little is currently known about the role of histamine and histamine receptor (HR) expression and signaling in the esophageal epithelium. Herein, we characterized HR (H1R, H2R, H3R, and H4R) expression in human esophageal biopsies and investigate the role of histamine signaling in inducible cytokine expression in human esophageal epithelial cells in vitro. HR expression was quantified in esophageal biopsies from non-EoE control (N = 23), inactive EoE (<15 eos/hpf, N = 26) and active EoE (>15 eos/hpf, N = 22) subjects using qRT-PCR and immunofluorescent localization. HR expression and histamine-mediated cytokine secretion were evaluated in human primary and telomerase-immortalized esophageal epithelial cells. H1R, H2R, and H4R expression were increased in active EoE biopsies compared to inactive EoE and controls. H2R was the most abundantly expressed receptor, and H3R expression was negligible in all 3 cohorts. Infiltrating eosinophils expressed H1R, H2R, and H4R, which contributed to the observed increase in HR in active subjects. H1R and H2R, but not H3R or H4R, were constitutively expressed by primary and immortalized cells, and epithelial histamine stimulation induced GM-CSF, TNFα, and IL-8, but not TSLP or eotaxin-3 secretion. Epithelial priming with the TLR3 ligand poly (I:C) induced H1R and H2R expression, and enhanced histamine-induced GM-CSF, TNFα, and IL-8 secretion. These effects were primarily suppressed by H1R antagonists, but unaffected by H2R antagonism. Histamine directly activates esophageal epithelial cytokine secretion in vitro in an H1R dependent fashion. However, H1R, H2R and H4R are induced in active inflammation in EoE in vivo. While systemic antihistamine (anti-H1R) therapy may not induce clinical remission in EoE, our study suggests that further study of histamine receptor signaling in EoE is warranted and that targeting of additional histamine receptors may lead to novel treatment strategies for this important disease.

Introduction Kohlmeier-Degos (K-D) disease is a rare obliterative vasculopathy that can present as a benign cutaneous form or with potentially malignant systemic involvement. The gastrointestinal tract is most frequently involved in systemic disease and mortality is often related to bowel perforations. Herein, we provide information to providers and patients regarding gastrointestinal K-D symptomology, pathology, treatment, and diagnosis, with a focus on the importance of timely diagnostic laparoscopy. We present three new cases of gastrointestinal K-D to highlight varying disease presentations and outcomes. Body Based on reviewed reports, perforation is preceded by at least one gastrointestinal symptom: abdominal pain/cramping, anorexia/weight loss, vomiting, diarrhea, nausea, gastrointestinal bleeding, obstipation, constipation, and abdominal fullness. Perforation most commonly occurs in the small intestine and often results in sepsis and death. Although underutilized, laparoscopy is the most sensitive and specific diagnostic technique, demonstrating serosal porcelain plaques similar to those on the skin and characteristic for K–D. The combination of eculizumab and treprostinil is presently the most effective treatment option for gastrointestinal K–D. The pathology of gastrointestinal K-D is characterized by an obliterative intimal arteriopathy eventuating in occlusive acellular deposits of mucin and collagen along with an extravascular pauci-cellular sclerosing process resembling scleroderma confined to the subserosal fat. C5b-9 and interferon-alpha are both expressed in all caliber of vessels in the affected intestine. While C5b-9 blockade does not prevent the intimal expansion, enhanced type I interferon signaling is likely a key determinant to intimal expansion by, causing an influx of monocytes which transdifferentiate into procollagen-producing myofibroblast-like cells. Conclusion Prompt laparoscopic evaluation is necessary in any K–D patient with an abdominal symptom to facilitate diagnosis and treatment initiation, as well as to hopefully decrease mortality. Those with gastrointestinal K–D should start on eculizumab as soon as possible, as onset of action is immediate.

No abstract

Background Blenderized feeds consisting of whole food components are emerging as a preferred approach to enteral nutrition. However, there is limited evidence‐based guidance for this strategy in short bowel syndrome (SBS). We aimed to explore the tolerance and clinical outcome of blenderized feeds in patients with SBS. Method We conducted a single‐center, retrospective study of blenderized feeds in pediatric SBS. Of the 376 patients screened, 58 met inclusion criteria. Three patients were excluded because of a history of bowel transplant. Demographics, clinical history, and nutrition history were collected and analyzed. Result Patients had improved diarrhea though worsening gas while receiving blenderized feeds. There was no significant difference in small bowel length in patients who discontinued blends compared with those who continued. However, patients with colonic resection were more likely to discontinue the blends. In a subgroup of patients who lost weight despite improved diarrhea (n = 19), most had a history of ileocecal valve (ICV) and colonic resection, but no difference in small bowel length compared with those who did not lose weight. Conclusion Our cohort of patients with SBS experienced improved gastrointestinal symptoms and stool quality on blenderized feeds. Patients without an ICV and with colonic resection were more prone to weight loss. Stepwise titration of blenderized formula with previous formula regimen may be needed in a subset of patients to optimize tolerance and weight gain. Further study is warranted to understand factors contributing to variable tolerance and weight gain on blenderized formulas to guide their use in patients with SBS.