Early in the 1990s, several case series described adults suffering from dysphagia and children with refractory reflux symptoms, both accompanied by an eosinophil‐predominant infiltration, thereby ...conclusively distinguishing it from gastroesophageal reflux disease. Eosinophilic esophagitis (EoE) was recognized as its own entity in the adult and in the pediatric literature. In the last decade, evidence has accumulated that EoE represents a T‐helper (Th)2‐type inflammatory disease. Remodeling of the esophagus is a hallmark of EoE, leading to esophageal dysfunction and bolus impaction. Familial occurrence and disease association with single‐nucleotide polymorphisms underscore the influence of genetics in this disease. Eosinophilic esophagitis may affect individuals at any age, although the clinical presentation is highly age dependent. There is a significant allergic bias in the EoE population, with the majority of patients having concurrent allergic rhinitis, asthma, eczema, and/or a history of atopy. One noteworthy difference is that in children, EoE seems to be primarily a food antigen–driven disease, whereas in adults, mainly aeroallergen sensitization has been observed. Treatment modalities for EoE include the 3Ds: drugs, diet, and dilation. The crucial question of whether adult and pediatric EoE are different phenotypes of one single entity or whether we are confronted with two different diseases is still open. Here, we review similarities and differences between EoE in adults and children.
Central to inflammatory bowel disease (IBD) pathogenesis is loss of mucosal barrier function. Emerging evidence implicates extracellular adenosine signaling in attenuating mucosal inflammation. We ...hypothesized that adenosine-mediated protection from intestinal barrier dysfunction involves tissue-specific signaling through the A2B adenosine receptor (Adora2b) at the intestinal mucosal surface. To address this hypothesis, we combined pharmacologic studies and studies in mice with global or tissue-specific deletion of the Adora2b receptor. Adora2b(-/-) mice experienced a significantly heightened severity of colitis, associated with a more acute onset of disease and loss of intestinal epithelial barrier function. Comparison of mice with Adora2b deletion on vascular endothelial cells (Adora2b(fl/fl)VeCadCre(+)) or intestinal epithelia (Adora2b(fl/fl)VillinCre(+)) revealed a selective role for epithelial Adora2b signaling in attenuating colonic inflammation. In vitro studies with Adora2b knockdown in intestinal epithelial cultures or pharmacologic studies highlighted Adora2b-driven phosphorylation of vasodilator-stimulated phosphoprotein (VASP) as a specific barrier repair response. Similarly, in vivo studies in genetic mouse models or treatment studies with an Adora2b agonist (BAY 60-6583) recapitulate these findings. Taken together, our results suggest that intestinal epithelial Adora2b signaling provides protection during intestinal inflammation via enhancing mucosal barrier responses.
Summary
Background
Eosinophilic oesophagitis is a clinicopathological disease affecting both children and adults that is characterized by symptoms of gastro‐oesophageal reflux disease (feeding ...refusal, vomiting, heartburn, dysphagia and food impaction) and dense oesophageal eosinophilia both of which are unresponsive to proton pump inhibition.
Aim
To present a review of the recent literature examining the pathogenesis and treatments of eosinophilic oesophagitis.
Methods
We performed a PubMed search for eosinophilic oesophagitis, pathogenesis and treatments.
Results
Translational and basic studies suggest that this disease is sparked by food or by aeroallergens. To date, effective treatments include systemic/topical corticosteroids, specific food elimination or an elemental diet. While several studies identified oesophageal strictures as potential complications of unbridled eosinophilia, the natural history of the disease is still not certain. Recent studies suggest a role for interleukin‐5 and eotaxin‐3 in the pathogenesis of eosinophilic oesophagitis and suggest an impact of future targeted therapeutic agents.
Conclusions
Eosinophilic oesophagitis represents a immune‐mediated disease of undetermined pathogenesis. While many patients develop clinicopathological findings following ingestion of foods, others do not. Natural history studies will be critical to defining future treatment paradigms.
Summary
Background
The validity of the eosinophilic oesophagitis (EoE) histologic scoring system (EoEHSS) has been demonstrated, but only preliminary reliability data exist.
Aim
Formally assess the ...reliability of the EoEHSS and additional histologic features.
Methods
Four expert gastrointestinal pathologists independently reviewed slides from adult patients with EoE (N = 45) twice, in random order, using standardised training materials and scoring conventions for the EoEHSS and additional histologic features agreed upon during a modified Delphi process. Intra‐ and inter‐rater reliability for scoring the EoEHSS, a visual analogue scale (VAS) of overall histopathologic disease severity, and additional histologic features were assessed using intra‐class correlation coefficients (ICCs).
Results
Almost perfect intra‐rater reliability was observed for the composite EoEHSS scores and the VAS. Inter‐rater reliability was also almost perfect for the composite EoEHSS scores and substantial for the VAS. Of the EoEHSS items, eosinophilic inflammation was associated with the highest ICC estimates and consistent with almost perfect intra‐ and inter‐rater reliability. With the exception of dyskeratotic epithelial cells and surface epithelial alteration, ICC estimates for the remaining EoEHSS items were above the benchmarks for substantial intra‐rater, and moderate inter‐rater reliability. Estimation of peak eosinophil count and number of lamina propria eosinophils were associated with the highest ICC estimates among the exploratory items.
Conclusion
The composite EoEHSS and most component items are associated with substantial reliability when assessed by central pathologists. Future studies should assess responsiveness of the score to change after a therapeutic intervention to facilitate its use in clinical trials.
Linked ContentThis article is linked to Conner and Kirsch and Pai et al papers. To view these articles visit https://doi.org/10.1111/apt.14633 and https://doi.org/10.1111/apt.14658.
Epithelial cells which line mucosal surfaces are the first line of defense against bacterial invasion and infection. Recent studies have also indicated that epithelial cells contribute significantly ...to the orchestration of ongoing inflammatory processes. Here, we demonstrate that human epithelial cells express bactericidal/permeability-increasing protein (BPI), an antibacterial and endotoxin-neutralizing molecule previously associated with neutrophils. Moreover, we demonstrate that such BPI expression is transcriptionally regulated by analogs of endogenously occurring anti-inflammatory eicosanoids (aspirin-triggered lipoxins, ATLa). Initial studies to verify microarray analysis revealed that epithelial cells of wide origin (oral, pulmonary, and gastrointestinal mucosa) express BPI and each is similarly regulated by aspirin-triggered lipoxins. Studies aimed at localization of BPI revealed that such expression occurs on the cell surface of cultured epithelial cell lines and dominantly localizes to epithelia in human mucosal tissue. Functional studies employing a BPI-neutralizing anti-serum revealed that surface BPI blocks endotoxin-mediated signaling in epithelia and kills Salmonella typhimurium. These studies identify a previously unappreciated "molecular shield" for protection of mucosal surfaces against Gram-negative bacteria and their endotoxin.
Summary
Background
Knowledge about determinants of quality of life (QoL) in eosinophilic oesophagitis (EoO) patients helps to identify patients at risk of experiencing poor QoL and to tailor ...therapeutic interventions accordingly.
Aim
To evaluate the impact of symptom severity, endoscopic and histological activity on EoE‐specific QoL in adult EoE patients.
Methods
Ninety‐eight adult EoE patients were prospectively included (64% male, median age 39 years). Patients completed two validated instruments to assess EoE‐specific QoL (EoO‐QoL‐A) and symptom severity (adult EoE activity index patient‐reported outcome) and then underwent esophagogastroduodenoscopy with biopsy sampling. Physicians reported standardised information on EoE‐associated endoscopic and histological alterations. The Spearman's rank correlation coefficient was calculated to determine the relationship between QoL and symptom severity. Linear regression and analysis of variance was used to quantify the extent to which variations in severity of EoE symptoms, endoscopic and histological findings explain variations in QoL.
Results
Quality of life strongly correlated with symptom severity (r = 0.610, P < 0.001). While the variation in severity of symptoms, endoscopic and histological findings alone explained 38%, 35% and 22% of the variability in EoE‐related QoL, respectively, these together explained 60% of variation. Symptom severity explained 18–35% of the variation in each of the five QoL subscale scores.
Conclusions
Eosinophilic oesophagitis symptom severity and biological disease activity determine QoL in adult patients with eosinophilic oesophagitis. Therefore, reduction in both eosinophilic oesophagitis symptoms as well as biological disease activity is essential for improvement of QoL in adult patients. Clinicaltrials.gov number, NCT00939263.
Oesophagitis is characterised by basal cell hyperplasia and activated eosinophils, which release mediators including major basic protein (MBP). MBP and its mimetic polyarginine activate the calcium ...sensing receptor (CaSR) on oesophageal epithelium. Fibroblast growth factor 9 (FGF9) is implicated in epithelial homeostasis and proliferative response to injury, but has not been characterised in the oesophagus.
To characterise FGF9 in oesophageal epithelium and oesophagitis, as the result of MBP activation of the CaSR.
Human oesophageal epithelial cells (HET-1A) were used to compare affects of calcium, polyarginine and MBP-peptide on FGF9. HET-1A were transfected with interfering RNA (siRNA(CaSR)). FGF9, FGF receptors 2 and 3, bone morphogenetic protein (BMP)-2, BMP-4 and noggin mRNA expression were detected by reverse transcriptase polymerase chain reaction. FGF9 was measured from HET-1A and from normal, gastro-oesophageal reflux and eosinophilic oesophagitis (EoE) patient biopsies using ELISA and immunohistochemistry. HET-1A proliferation was studied using bromodeoxyuridine and MTT.
FGF9 was secreted by HET-1A cells treated with polyarginine and MBP-peptide, but not calcium. This effect was abrogated by siRNA(CaSR). FGF9 receptor mRNA was present. HET-1A cells proliferated following rhFGF9, but not MBP-peptide treatment, and rhFGF9 altered transcription of downstream proliferation-related genes (noggin, BMP-2 and BMP-4). FGF9 was increased in biopsies from patients with eosinophilic oesophagitis, which correlated with basal hyperplasia.
Eosinophil-released MBP acts on the CaSR to increase FGF9 in oesophageal epithelial cells, leading to proliferation. Increased FGF9 is found in biopsies of EoE patients and may play a role in the pathogenesis of oesophagitis.
Mucosal organs such as the intestine are supported by a rich and complex underlying vasculature. For this reason, the intestine, and particularly barrier-protective epithelial cells, are susceptible ...to damage related to diminished blood flow and concomitant tissue hypoxia. We sought to identify compensatory mechanisms that protect epithelial barrier during episodes of intestinal hypoxia. Initial studies examining T84 colonic epithelial cells revealed that barrier function is uniquely resistant to changes elicited by hypoxia. A search for intestinal-specific, barrier-protective factors revealed that the human intestinal trefoil factor (ITF) gene promoter bears a previously unappreciated binding site for hypoxia-inducible factor (HIF)-1. Hypoxia resulted in parallel induction of ITF mRNA and protein. Electrophoretic mobility shift assay analysis using ITF-specific, HIF-1 consensus motifs resulted in a hypoxia-inducible DNA binding activity, and loading cells with antisense oligonucleotides directed against the alpha chain of HIF-1 resulted in a loss of ITF hypoxia inducibility. Moreover, addition of anti-ITF antibody resulted in a loss of barrier function in epithelial cells exposed to hypoxia, and the addition of recombinant human ITF to vascular endothelial cells partially protected endothelial cells from hypoxia-elicited barrier disruption. Extensions of these studies in vivo revealed prominent hypoxia-elicited increases in intestinal permeability in ITF null mice. HIF-1-dependent induction of ITF may provide an adaptive link for maintenance of barrier function during hypoxia.
Background
Eosinophilic esophagitis (EoE) is a chronic antigen‐mediated clinicopathologic disease of the esophagus characterized by an eosinophil‐predominant inflammatory infiltrate. A clinical ...hallmark is extensive tissue remodeling including basal zone hyperplasia, fibrosis, and angiogenesis. However, the cellular mechanisms responsible for these processes are not fully defined. We hypothesized that targeting granulocyte‐macrophage colony‐stimulating factor (GM‐CSF; an agonist cytokine linked with eosinophil survival and activation) would be protective in a preclinical model of EoE.
Methods
Eosinophilic esophagitis‐like esophageal inflammation was induced in the L2‐IL5OXA EoE mouse model, and GM‐CSF production was assessed by mRNA and protein analyses. Granulocyte‐macrophage colony‐stimulating factor‐receptor‐alpha expression patterns were examined by flow cytometric and immunofluorescence analysis. L2‐IL5OXA EoE mice were treated with anti‐GM‐CSF neutralizing antibody or isotype control and assessed for histopathological indices of eosinophilia, epithelial hyperplasia, and angiogenesis by immunohistochemistry and RT‐PCR.
Results
Significantly increased levels of esophageal GM‐CSF expression was detected in the L2‐IL5OXA mouse EoE model during active inflammation. Granulocyte‐macrophage colony‐stimulating factor‐receptor‐alpha was predominantly expressed on esophageal eosinophils during EoE, in addition to select cells within the lamina propria. Anti‐GM‐CSF neutralization in L2‐IL5OXA EoE mice resulted in a significant diminution of epithelial eosinophilia in addition to basal cell hyperplasia and vascular remodeling. This treatment response was independent of effects on esophageal eosinophil maturation or activation.
Conclusion
Granulocyte‐macrophage colony‐stimulating factor is a potential therapeutic target to reduce esophageal eosinophilia and remodeling.
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