Subepithelial collagen deposition, profibrogenic cytokine gene expression, and changes after prolonged fluticasone propionate treatment in adult eosinophilic esophagitis: a prospective study

Amphiregulin-producing TH2 cells facilitate esophageal fibrosis of eosinophilic esophagitis

Background

Massive eosinophil infiltration into the esophagus is associated with subepithelial fibrosis and esophageal stricture in patients with eosinophilic esophagitis (EoE). However, the pathogenesis of esophageal fibrosis remains unclear.

Objective

We sought to elucidate the cellular and molecular mechanisms underlying the induction of esophageal fibrosis.

Methods

We established a murine model of EoE accompanied by fibrotic responses following long-term intranasal administration of house dust mite antigen. Using this murine model, we investigated the characteristics of immune cells infiltrating the fibrotic region of the inflamed esophagus using flow cytometry and histological analyses. We also analyzed the local inflammatory sites in the esophagus of patients with EoE using single-cell RNA sequencing, flow cytometry, and immunohistochemistry.

Results

Enhanced infiltration of both amphiregulin-producing and IL-5-producing TH2 cells was detected in the fibrotic area of the esophagus in mice subjected to repeated house dust mite exposure. Deletion of amphiregulin in CD4+ T cells ameliorates esophageal fibrosis. An analysis of human esophageal biopsy samples showed that the infiltration of amphiregulin-producing CD4+ T cells was higher in patients with EoE than in control patients. Furthermore, the number of infiltrated amphiregulin-producing CD4+ T cells was associated with the degree of esophageal fibrosis in patients with EoE.

Conclusions

Amphiregulin, produced by TH2 cells, contributes to esophageal fibrosis in EoE and may be a therapeutic target.

Eosinophilic esophagitis: Current concepts in diagnosis and management

ABSTRACT

Eosinophilic esophagitis is an antigen-mediated chronic inflammatory disorder that has risen in incidence and prevalence over the past 2 decades. The clinical presentation is variable and consists of mainly esophageal symptoms such as dysphagia, heartburn, food impaction, and vomiting. Current management relies on dietary elimination, proton-pump inhibitors, and topical corticosteroids with different response rates and relapses after treatment discontinuation. With a better understanding of the underlying pathophysiology, many molecules emerged recently as targeted treatment including dupilumab (IL4/IL13 blocker), as the first FDA-approved biological treatment, which has changed the management paradigm.

Esophageal remodeling in eosinophilic esophagitis

PURPOSE OF REVIEW

Eosinophilic esophagitis (EoE) is a Th2 immune/antigen-mediated disorder characterized by esophageal dysfunction and eosinophilic inflammation. Worsening dysphagia and food impactions are significant complications associated with esophageal remodeling and fibrostenotic disease. This review highlights the most recent research findings pertaining to mechanisms of sub-epithelial fibrosis in EoE, current diagnostic tools, and therapeutic approaches.

RECENT FINDINGS

Recent studies leveraging publicly available single cell sequencing databases and comparative proteomics have furthered our understanding of the mechanisms mediating fibrosis. Fibroblast crosstalk with the extracellular matrix and with epithelial, endothelial, and T cells have been implicated, with the likely existence of multiple fibroblast sub-types. Accurate diagnosis of remodeling with biopsies remains a challenge due to inadequate depth of sampling. Web-based tools incorporating epithelial findings show promise in predicting subepithelial fibrosis. Impedance planimetry with esophageal distensibility measurements are increasingly utilized tools to assess fibrostenotic severity. Immunostaining and luminal captured proteins associated with remodeling show promise as potential molecular markers of fibrosis. Anti-inflammatory therapy may improve esophageal fibrosis and distensibility, although specific fibrosis-targeted therapy is lacking.

SUMMARY

Recent studies highlight novel mechanisms of fibrosis in EoE. Improved understanding of these mechanisms may lead to novel diagnostic strategies and therapies, and thereby inform treatment decisions.

Pathophysiology and Clinical Impact of Esophageal Remodeling and Fibrosis in Eosinophilic Esophagitis

Most of the major clinical signs and consequences of eosinophilic esophagitis seem to be related to tissue remodeling. Important data on remodeling activity in patients with eosinophilic esophagitis are provided by a range of current and new biologic markers and diagnostics. To completely clarify the possible advantages and restrictions of therapeutic approaches, clinical studies should take into consideration the existence and reversibility of esophageal remodeling. The degree of mucosal or submucosal disease activity may not be reflected by epithelial eosinophilic inflammation, which is used to define one criterion of disease activity".

Pharmacologic Management of Eosinophilic Esophagitis

Proton pump inhibitors (PPIs), swallowed topical corticosteroids (STSs), and dupilumab are highly effective therapies for the treatment of eosinophilic esophagitis. Shared decision-making informs the choice of therapy and factors such as ease of use, safety, cost, and efficacy should be addressed. PPIs are the most common medication utilized early in the disease course; however, for nonresponders, STSs are an excellent alternative. Dupilumab is unlikely to replace PPIs or STSs as first-line therapy, except in highly specific circumstances. Identification of novel biologic pathways and the development of small molecules may lead to a wider range of treatment options in the future.

Fibrous Remodeling in Eosinophilic Esophagitis: Clinical Facts and Pathophysiological Uncertainties

Eosinophilic esophagitis (EoE) is a chronic, progressive, type 2 inflammatory disease with increasing global prevalence. An eosinophil-predominant inflammation that permeates the epithelium and deeper esophageal layers characterizes the disease. Several cytokines, mainly derived from inflammatory T-helper 2 (Th2) cells and epithelial cells, are involved in perpetuating inflammatory responses by increasing surface permeability and promoting tissue remodeling characterized by epithelial-mesenchymal transition (EMT) and collagen deposition. This leads to esophageal strictures and narrow caliber esophagi, which are proportional a patient's age and untreated disease length. Pathophysiological mechanisms leading to EoE have been described in recent years, and transforming growth factor beta (TGF)-beta have been involved in fibrotic phenomena in EoE. However, evidence on the dependence of these phenomena on TGF-beta is scarce and contradictory. This review provides state-of-the art knowledge on intimate mechanisms of esophageal fibrosis in EoE and its clinical consequences.

Mechanistic Insights into Eosinophilic Esophagitis: Therapies Targeting Pathophysiological Mechanisms

Eosinophilic esophagitis (EoE) is a chronic inflammatory disease characterized by eosinophilic infiltration of the esophagus. It arises from a complex interplay of genetic predisposition (susceptibility loci), environmental triggers (allergens and dietary antigens), and a dysregulated immune response, mainly mediated by type 2 T helper cell (Th2)-released cytokines, such as interleukin (IL)-4, IL-5, and IL-13. These cytokines control eosinophil recruitment and activation as well as tissue remodeling, contributing to the characteristic features of EoE. The pathogenesis of EoE includes epithelial barrier dysfunction, mast cell activation, eosinophil degranulation, and fibrosis. Epithelial barrier dysfunction allows allergen penetration and promotes immune cell infiltration, thereby perpetuating the inflammatory response. Mast cells release proinflammatory mediators and promote eosinophil recruitment and the release of cytotoxic proteins and cytokines, causing tissue damage and remodeling. Prolonged inflammation can lead to fibrosis, resulting in long-term complications such as strictures and dysmotility. Current treatment options for EoE are limited and mainly focus on dietary changes, proton-pump inhibitors, and topical corticosteroids. Novel therapies targeting key inflammatory pathways, such as monoclonal antibodies against IL-4, IL-5, and IL-13, are emerging in clinical trials. A deeper understanding of the complex pathogenetic mechanisms behind EoE will contribute to the development of more effective and personalized therapeutic strategies.

Clinical guidance for the use of dupilumab in eosinophilic esophagitis: A yardstick

The Joint Task Force for the American Academy of Allergy Asthma Immunology and American College of Allergy Asthma Immunology and the American Gastroenterology Association recently published guidelines for the management of eosinophilic esophagitis (EoE). Because the guideline was published, dupilumab became the first and only medication to gain regulatory approval for the treatment of EoE. This expert opinion document provides a framework for how the clinician can consider using dupilumab in the treatment strategy for patients with EoE.

Fibrotic remodeling and tissue regeneration mechanisms define the therapeutic potential of human muscular progenitors

Fibrosis is an intrinsic biological reaction toward the challenges of tissue injury that is implicated in the wound-healing process. Although it is useful to efficiently mitigate the damage, progression of fibrosis is responsible for the morbidity and mortality occurring in a variety of diseases. Because of lacking effective treatments, there is an emerging need for exploring antifibrotic strategies. Cell therapy based on stem/progenitor cells is regarded as a promising approach for treating fibrotic diseases. Appropriate selection of cellular sources is required for beneficial results. Muscle precursor cells (MPCs) are specialized progenitors harvested from skeletal muscle for conducting muscle regeneration. Whether they are also effective in regulating fibrosis has seldom been explored and merits further investigation. MPCs were successfully harvested from all human samples regardless of demographic backgrounds. The extracellular matrices remodeling was enhanced through the paracrine effects mediated by MPCs. The suppression effects on fibrosis were confirmed in vivo when MPCs were transplanted into the diseased animals with oral submucous fibrosis. The data shown here revealed the potential of MPCs to be employed to simultaneously regulate both processes of fibrosis and tissue regeneration, supporting them as the promising cell candidates for development of the cell therapy for antifibrosis and tissue regeneration.

Challenges in Inter-rater Agreement on Lamina Propria Fibrosis in Esophageal Biopsies

BACKGROUND

Mucosal biopsies in eosinophilic esophagitis (EoE) can exhibit lamina propria (LP) fibrosis, which may portend stenotic complications; however, the histologic diagnosis of LP fibrosis is subjective. We sought to assess and improve the consistency of LP fibrosis diagnosis among our pathologist group.

METHODS

At a large pediatric hospital, 25 esophageal biopsy slides from 19 patients (16 with EoE) exhibiting a wide spectrum of LP area, artifacts, and fibrosis severity were scanned into whole-slide images. Staff pediatric pathologists (n = 8) separate from the authors classified each biopsy by LP adequacy and fibrosis severity 1 month before and after completion of an educational tutorial. Consensus was defined as >70% agreement.

RESULTS

At baseline, 16/25 (64%) cases reached consensus for no fibrosis (n = 3), fibrosis (n = 7), or inadequate LP (n = 6); agreement was fair (α = 0.34). Post-tutorial, 13/25 (52%) cases reached consensus for no fibrosis (n = 2), fibrosis (n = 7), or inadequate LP (n = 4); agreement was again fair (α = 0.33). There was moderate agreement in grading of fibrosis severity (α = 0.54).

CONCLUSION

We document only fair-to-moderate agreement in the diagnosis of esophageal LP fibrosis and adequacy in a large pediatric pathologist group despite targeted education, highlighting a challenge in incorporating this feature into EoE research and clinical decision-making.

Breaking down the complex pathophysiology of eosinophilic esophagitis

Eosinophilic esophagitis (EoE) is a chronic and progressive immune-mediated disease of the esophagus associated with antigen-driven type 2 inflammation and symptoms of esophageal dysfunction. Our understanding of EoE pathophysiology has evolved since its initial recognition more than 20 years ago and has translated into diagnostic and novel therapeutic approaches that are affecting patient care. The mechanisms underlying disease development and progression are influenced by diverse factors, such as genetics, age, allergic comorbidities, and allergen exposures. Central to EoE pathophysiology is a dysregulated feed-forward cycle that develops between the esophageal epithelium and the immune system. Allergen-induced, type 2-biased immune activation by the esophageal epithelium propagates a cycle of impaired mucosal barrier integrity and allergic inflammation, eventually leading to tissue remodeling and progressive organ dysfunction. Herein, we review the current understanding of fundamental pathophysiological mechanisms contributing to EoE pathogenesis.

A meta-analysis on randomized controlled trials of treating eosinophilic esophagitis with budesonide

OBJECTIVE

Eosinophilic esophagitis (EoE) is a chronic, local immune-mediated inflammatory oesophageal disease. Although Budesonide is recommended as one of the first-line drugs for EoE treatment, its efficacy is still controversial in multiple studies. Due to the continuous emergence of new and reliable research evidence in recent years, we updated the meta-analysis using RCT trial results to evaluate the efficacy and safety of budesonide.

MATERIALS AND METHOD

Retrieve the data of the randomised controlled trial literature from 2000 to June 20, 2021, on using Budesonide in the treatment of eosinophilic esophagitis from the three major databases. Based on the results achieved with the Cochrane risk assessment tool, evaluate the quality of the included literature to extract the data, and perform the Meta-analysis with RevMan5.4 and Stata15.0.

RESULTS

A total of 958 articles were retrieved, with 10 articles finally included, thus forming a sample size of 712 cases. The main outcome indicators of the meta-analysis are as follows: (1) Histological remission: the Budesonide group performs better than the placebo control group when it comes to histological remission of injuries [RR = 23.82, 95%CI = (13.46, 42.21), p < .001]; (2) Eosinophil count: the Budesonide group is superior to the control group in terms of reduced eosinophil count [SMD = -1.34, 95%CI = (-1.52, -1.15), p < .001].

CONCLUSION

More and more high-quality randomised controlled trials show that oral budesonide in the treatment of eosinophils esophagitis was better than the placebo group. Mounting high-quality RCTs have confirmed the efficacy of oral budesonide in the treatment of eosinophilic esophagitis and that the effects of this drug may not be so dose-dependent. It is safe to take budesonide for a long time, and this drug is a relatively ideal option for drug treatment of eosinophilic esophagitis at present, so it is worthy of clinical application.Key MessagesWe used high-quality randomised controlled trials to meta-update the previous results to further confirm the clinical efficacy and safety of budesonide.Oral budesonide in the treatment of eosinophilic esophagitis is significantly better than the placebo control group. We have confirmed the value of its clinical application and promotion by including more high-quality randomised controlled trials.We also found that the efficacy of budesonide in patients is not dose-dependent, and more research is needed to confirm this.

Current treatment options and long-term outcomes in patients with eosinophilic esophagitis

INTRODUCTION

Dietary and pharmacological (proton pump inhibitors, swallowed topical corticosteroids) therapies are effective for induction of clinical and histological remission of eosinophilic esophagitis. However, data evaluating their long-term efficacy and safety is limited.

AREAS COVERED

Since eosinophilic esophagitis is chronic, clinical, endoscopic, and histological features usually recur when successful treatments are stopped. In untreated patients, persistent esophageal eosinophilic inflammation may progress to fibrostenosis over time, giving place to strictures and narrow-caliber esophagi. This article comprehensively reviews available data on long-term maintenance of eosinophilic esophagitis with pharmacological and dietary treatment. It also discusses limitations re: available literature and outlines data gaps on adherence to therapy and monitoring disease activity in the long-term.

EXPERT OPINION

Evidence indicates that long-term maintenance therapy may decrease the risk of esophageal stricture, food bolus impaction, and need for dilation in patients with eosinophilic esophagitis. Further knowledge on eosinophilic esophagitis phenotypes is needed to ascertain who will benefit best from sustained therapy. Unanswered questions include an adequate definition for sustained remission, best strategies for maintenance drugs and diets, enhancement of treatment adherence, and proper monitoring for long-term surveillance.

Type 2 Inflammation in Eosinophilic Esophagitis: From Pathophysiology to Therapeutic Targets

Eosinophilic esophagitis (EoE) is a chronic immune-mediated disease of the esophagus characterized clinically by symptoms related to esophageal dysfunction and histologically by eosinophil-predominant inflammation, whose incidence is rising. It significantly affects patients’ quality of life and, if left untreated, results in fibrotic complications. Although broad consensus has been achieved on first-line therapy, a subset of patients remains non-responder to standard therapy. The pathogenesis of EoE is multifactorial and results from the complex, still mostly undefined, interaction between genetics and intrinsic factors, environment, and antigenic stimuli. A deep understanding of the pathophysiology of this disease is pivotal for the development of new therapies. This review provides a comprehensive description of the pathophysiology of EoE, starting from major pathogenic mechanisms (genetics, type 2 inflammation, epithelial barrier dysfunction, gastroesophageal reflux, allergens, infections and microbiota) and subsequently focusing on the single protagonists of type 2 inflammation (involved cells, cytokines, soluble effectors, surface proteins and transcription factors) that could represent present and future therapeutic targets, while summarizing previous therapeutic approaches in literature.

Pathophysiology of Dysphagia in Eosinophilic Esophagitis: Causes, Consequences, and Management

Eosinophilic esophagitis (EoE) is a leading cause of food bolus impaction in children and adults. The mechanism of dysphagia in EoE, particularly non-obstructive dysphagia, remains incompletely understood. While fibrostenotic processes appear to be critical in the development of dysphagia, somatosensory dysfunction and dysmotility also contribute. This review considers potential mechanisms of dysphagia and evaluates the utility of current and future treatment strategies in this context.

Gene therapy for a murine model of eosinophilic esophagitis

BACKGROUND

Eosinophils are specialized granulocytic effector cells that store and release highly active mediators used in immune defense. Eosinophils are also implicated in the pathogenesis of allergic disorders, including eosinophilic esophagitis (EoE), a chronic disorder characterized by infiltration of eosinophils into the esophagus and release of mediators that damage tissue, resulting in gastrointestinal morbidity, food impaction, and dysphagia. Treatment with elimination diets and/or topical corticosteroid therapy slow disease progression, but are complicated by adverse effects, limited compliance, and loss of response to therapy. We hypothesized that a single administration of an adeno-associated virus (AAV) coding for an anti-eosinophil monoclonal antibody that induces eosinophil clearance (anti-Siglec-F) would treat on a persistent basis a murine model of EoE.

METHODS

A mouse model of peanut-induced EoE that mimics the human disease was established by sensitization and challenge with peanut extract. After challenge, these mice exhibited an EoE phenotype demonstrated by elevated levels of blood eosinophils, infiltration of eosinophils in the esophagus with associated esophageal remodeling and food impaction.

RESULTS

The mice were treated with a single intravenous administration (10¹¹ genome copies) of AAVrh.10mAnti-Eos, a serotype rh.10 AAV vector coding for an anti-Siglec-F monoclonal antibody. Vector administration resulted in persistent, high levels of anti-Siglec-F antibody expression. Administration of AAVrh.10mAnti-Eos to the mouse model of EoE reduced blood (P < 0.02) and esophageal eosinophil numbers (P < 0.002) protected from esophageal tissue remodeling and minimized food impaction.

CONCLUSION

These results suggest that a single treatment with AAVrh.10mAnti-Eos has the potential to provide persistent therapeutic benefit to patients with EoE.

Eosinophils Correlate with Epithelial-Mesenchymal Transition in Chronic Rhinosinusitis with Nasal Polyps

INTRODUCTION

Chronic inflammation and tissue remodeling always occur together in chronic rhinosinusitis (CRS). Epithelial-mesenchymal transition (EMT) plays a critical role in airway remodeling.

OBJECTIVE

Changes of epithelial cells in sinus mucosa in different subtypes of CRS, especially in eosinophilic chronic rhinosinusitis with nasal polyps, and the role of EMT and eosinophils (EOS) in airway remodeling are still unknown.

METHODS

We included 85 patients in this study. They were divided into 4 groups: a normal control (NC) group, a chronic rhinosinusitis without nasal polyps (CRSsNP) group, an eosinophilic chronic rhinosinusitis with nasal polyps (ECRSwNP) group, and a noneosinophilic chronic rhinosinusitis with nasal polyps (non-ECRSwNP) group. Clinical data were all collected and analyzed. Standard hematoxylin and eosin staining, immunohistochemical staining, and 2-color immunofluorescence staining were performed. Biomarkers of EMT, epithelial cadherin, and vimentin were labeled. The immunohistochemistry results of each group were counted and statistically analyzed.

RESULTS AND CONCLUSION

E-cadherin was downregulated, and vimentin was upregulated in epithelial tissue from the ECRSwNP group, compared with that from the control group and the other groups. The number of vimentin-expressing epithelial cells correlated with sinus CT imaging Lund-Mackay scores (r = 0.560, p < 0.001). Moreover, expression levels of vimentin in the epithelium were associated with numbers of infiltrating EOS in tissues (r = 0.710, p < 0.001) and the peripheral blood EOS ratio (r = 0.594, p < 0.001). EMT occurred in patients with CRSwNP, especially in those with ECRSwNP. Epithelial reprogramming correlates with eosinophil infiltration and disease severity. Eosinophils contributed to impairment of epithelial function and promoted EMT in CRSwNP.

Eosinophilic esophagitis-established facts and new horizons

Despite dramatic advances in our understanding of the pathogenesis and course of disease in the relatively short timeframe since the discovery and first description of eosinophilic esophagitis (EoE) less than three decades ago, many open questions remain to be elucidated. For instance, we will need to better characterize atypical clinical presentations of EoE and other forms of esophageal inflammatory conditions with often similar clinical presentations, nut fulfilling current diagnostic criteria for EoE and to determine their significance and interrelationship with genuine EoE. In addition, the interrelationship of EoE with other immune-mediated diseases remains to be clarified. Hopefully, a closer look at the role of environmental factors and their interaction with genetic susceptibility often in context of atopic predisposition may enable identifying the candidate substances/agents/allergens and potentially earlier (childhood) events to trigger the condition. It appears plausible to assume that in the end—comparable to current concepts in other immune-mediated chronic diseases, such as for instance inflammatory bowel disease or asthma bronchiale—we will not be rewarded with the identification of a “one-and-only” underlying pathogenetic trigger factor, with causal responsibility for the disease in each and every EoE patient. Rather, the relative contribution and importance of intrinsic susceptibility, i.e., patient-driven factors (genetics, aberrant immune response) and external trigger factors, such as food (or aero-) allergens as well as early childhood events (e.g., infection and exposure to antibiotics and other drugs) may substantially differ among given individuals with EoE. Accordingly, selection and treatment duration of medical therapy, success rates and extent of required restriction in dietary treatment, and the need for mechanical treatment to address strictures and stenosis require an individualized approach, tailored to each patient. With the advances of emerging treatment options, the importance of such an individualized and patient-centered assessment will increase even further.

Role of fibroblast growth factor signalling in hepatic fibrosis

Fibrotic remodelling is a highly conserved protective response to tissue injury and it is essential for the maintenance of structural and functional tissue integrity. Also hepatic fibrosis can be considered as a wound-healing response to liver injury, reflecting a balance between liver repair and scar formation. In contrast, pathological fibrosis corresponds to impaired wound healing. Usually, the liver regenerates after acute injury. However, if the damaging mechanisms persist, the liver reacts with progressive and uncontrolled accumulation of extracellular matrix proteins. Eventually, excessive fibrosis can lead to cirrhosis and hepatic failure. Furthermore, cirrhosis is the major risk factor for the development of hepatocellular cancer (HCC). Therefore, hepatic fibrosis is the most critical pathological factor that determines the morbidity and mortality of patients with chronic liver disease. Still, no effective anti-fibrogenic therapies exist, despite the very high medical need. The regulation of fibroblast growth factor (FGF) signalling is a prerequisite for adequate wound healing, repair and homeostasis in various tissues and organs. The FGF family comprises 22 proteins that can be classified into paracrine, intracrine and endocrine factors. Most FGFs signal through transmembrane tyrosine kinase FGF receptors (FGFRs). Although FGFRs are promising targets for the treatment of HCC, the expression and function of FGFR-ligands in hepatic fibrosis is still poorly understood. This review summarizes the latest advances in our understanding of FGF signalling in hepatic fibrosis. Furthermore, the potential of FGFs as targets for the treatment of hepatic fibrosis and remaining challenges for the field are discussed.

Improvements in Dysphagia and Pain With Swallowing in Patients With Eosinophilic Esophagitis Receiving Budesonide Oral Suspension

BACKGROUND & AIMS

Quantification of eosinophilic esophagitis (EoE) symptoms is crucial for assessing treatment outcomes. We aimed to explore the effect of budesonide oral suspension (BOS) on dysphagia and pain with swallowing.

METHODS

We performed a secondary analysis of data from a phase 2 multicenter, double-blind, trial (conducted from July 2012 through October 2014) of patients with EoE, 11-40 y old, who were randomly assigned to groups given placebo or BOS (2.0 mg twice daily) for 12 weeks. Symptoms were quantified using the Dysphagia Symptom Questionnaire (DSQ) from baseline to week 12 of therapy.

RESULTS

Overall, 93 patients were randomly assigned to groups; the prespecified modified intention-to-treat analysis set comprised 87 patients (38 from the placebo group and 49 from the BOS group). Improvements from baseline in least-squares mean (standard error) DSQ (Q2+Q3) scores were observed. The difference between groups was statistically significant only at week 12 (placebo vs BOS: week 4, -4.9 [1.7] vs -7.4 [1.5]; P = .265; week 8, -7.4 [2.1] vs -10.3 [1.8]; P = .288; week 12, -7.5 [1.9] vs -14.3 [1.7]; P = .01). Similar findings were observed for pain (Q4) scores (placebo vs BOS: week 4, -2.5 [0.8] vs -3.3 [0.7]; P = .484; week 8, -3.0 [0.8] vs -4.9 [0.7]; P = .066; week 12, -3.1 [0.8] vs -4.9 [0.7]; P = .109). More severe DSQ and DSQ+pain scores were associated with presence of other symptoms (such as regurgitation) and physician-rated severity. Improvements in DSQ and DSQ+pain scores were greater in patients with either a histologic or endoscopic response than in patients without a response.

CONCLUSIONS

In a secondary analysis of data from a phase 2 trial of patients with EoE, we found evidence for improvements in dysphagia and pain scores in patients who received BOS (2.0 mg twice daily) vs placebo. Pain with swallowing should be considered in the clinical assessment of patients with EoE. ClinicalTrials.gov no: NCT01642212.

Eosinophilic Esophagitis and Microbiota: State of the Art

Eosinophilic esophagitis (EoE) is a chronic, food-triggered, immune-mediated disease of the oesophagus, clinically characterized by symptoms referred to oesophagal dysfunction, and histologically defined by an eosinophil productive inflammation of the oesophagal mucosa, among other cell types. The involvement of an adaptive Th2-type response to food antigens in EoE was known since 2000; several cytokines and chemokines promote food-specific responses, during which local production of IgE, but also IgG4 derived from plasma cells in lamina propria of oesophagal mucosa might play an important role. Evidence pointing towards a possible role for the innate immunity in EoE has arisen recently. Together, this evidence gives rise to a potential role that the innate immune system in general, and also the microbial pattern recognition receptors (PRRs) might play in EoE pathogenesis. Among PRRs, Toll-like receptors (TLRs) are type-I transmembrane receptors expressed both on epithelial and lamina propria cells with the capacity to distinguish between pathogen and commensal microbes. As TLRs in the different intestinal epithelia represent the primary mechanism of epithelial recognition of bacteria, this evidence underlines that oesophagal TLR-dependent signaling pathways in EoE support the potential implication of microbiota and the innate immune system in the pathogenesis of this disease. The oesophagal mucosa hosts a resident microbiota, although in a smaller population as compared with other districts of the gastrointestinal tract. Few studies have focused on the composition of the microbiota of the normal oesophagus alone. Still, additional information has come from studies investigating the oesophagal microbiota in disease and including healthy patients as controls. Our review aims to describe all the evidence on the oesophagal and intestinal microbiota in patients with EoE to identify the specific features of dysbiosis in this condition.

Eosinophilic esophagitis: clinical, endoscopic, histologic and therapeutic differences and similarities between children and adults

In the absence of secondary causes, eosinophilic esophagitis (EoE) is a chronic, local, progressive, T-helper type 2 immune-mediated disorder characterized by symptoms of esophageal dysfunction and eosinophil-predominant inflammation. In the last 20 years, the incidence and prevalence of EoE have risen sharply, and the chances of encountering affected patients in clinics and endoscopy rooms have increased. Nevertheless, it is estimated that the mean diagnostic delay of EoE is 4-6 years in both children and adults. Unfortunately, the longer the disease stays unrecognized, the likelier it is for the patient to have persistent or increased esophageal eosinophilic inflammation, to complain of non-resolving symptoms, and to develop fibrotic complications. Early detection depends on the recognition of initial clinical manifestations that vary from childhood to adulthood and even among patients of the same age. The disease phenotype also influences therapeutic approaches that include drugs, dietary interventions, and esophageal dilation. We have herein reviewed epidemiologic, clinical, endoscopic, and histologic features and therapeutic options of EoE focusing on differences and similarities between children and adults that may certainly serve in daily clinical practice.

Red Between the Lines: Evolution of Eosinophilic Esophagitis as a Distinct Clinicopathologic Syndrome

Eosinophilic esophagitis (EoE) is characterized by eosinophilic infiltration of the esophageal mucosa and symptoms of esophageal dysfunction, including dysphagia. While EoE is still considered a rare disease, in practice it seems that more and more cases are diagnosed every week, research in the field is exploding, and the pipeline for treatments contains multiple agents, some of which are quite far along the development pathway. After only scattered cases and small series were published in the late 1970s and 1980, Stephen Attwood, Thomas Smyrk, Tom DeMeester, and James Jones, published in Digestive Diseases and Sciences in 1993 a seminal report that described a clinicopathologic syndrome of esophageal eosinophilia with dysphagia. This review details the origins of this paper and compares and contrast what was observed then and what is known now about multiple aspects of EoE, including the clinical presentation, diagnosis, epidemiology, natural history, and treatments and outcomes. Moreover, it will highlight how the paper presaged a number of controversies in the field that have yet to be resolved, as well as foreshadowed the collaborative, multidisciplinary approach that has led to rapid advances.

Recent insights on the use of topical steroids in eosinophilic esophagitis

INTRODUCTION

Eosinophilic Esophagitis (EoE) is an immune-mediated, chronic inflammatory disorder of the esophagus. Topical steroids have been used in the management of EoE for over 15 years. However, there are no Food and Drug Administration (FDA) approved drug therapies for EoE.

AREAS COVERED

This review discusses the current understanding of EoE and the role of topical steroids in the induction and maintenance of remission in patients with EoE. We performed a comprehensive review of the literature, summarized randomized control trials from 2006 to 2020, and provided a simplified management algorithm for EoE.

EXPERT OPINION

In patients with EoE, topical steroids are effective in inducing clinical and histologic remission. Formulations of topical steroids that maximize the exposure to esophageal mucosa have the highest efficacy. A majority of patients who achieve remission with topical steroids develop clinical and histologic relapse off therapy within a year. Current evidence suggests that maintenance therapy with long-term topical steroids decreases the risk of relapse and progression to fibrostenotic disease. While uncertainty over the dose and duration of maintenance topical steroids and their potential side effects exists, long-term maintenance therapy with topical steroids appears to be the way forward to improve long-term outcomes in patients with EoE.

Treatment of eosinophlic esophagitis with swallowed topical corticosteroids

Eosinophilic esophagitis (EoE) is an emerging chronic local immune-mediated disease of the esophagus. Beside proton pump inhibitors and food-restriction-diets swallowed topical corticosteroids (STC) can be offered as a first line therapy according to current guidelines. This review describes the background and practical management of STCs in EoE. So far, mainly asthma inhalers containing either budesonide or fluticasone have been administered to the esophagus by swallowing these medications “off label”. Recently esophagus-targeted formulations of topical steroids have been developed showing clinicopathological response rates up to 85% - an orodispersible tablet of budesonide has been approved as the first “in label” medication for EoE in Europe in June 2018. Whereas it was shown that disease remission induction of EoE by STCs is highly effective, there is still a lack of data regarding long-term and maintenance therapy. However, current studies on STC maintenance therapy add some movement into the game.

Efficacy of proton pump inhibitor therapy for eosinophilic oesophagitis in 630 patients: results from the EoE connect registry

BACKGROUND

Proton pump inhibitors (PPIs) are the most commonly used first-line therapy for patients with eosinophilic oesophagitis (EoE). However, many aspects related to PPIs in EoE are still unknown.

AIMS

To assess the effectiveness of PPI therapy for EoE in real-world practice.

METHODS

This cross-sectional study collected data on PPI efficacy from the multicentre EoE CONNECT database. Clinical remission was defined as a decrease of ≥50% in dysphagia symptom score; histological remission was defined as a peak eosinophil count below 15 eosinophils per high-power field. Factors associated with effectiveness of PPI therapy were identified by binary logistic regression multivariate analyses.

RESULTS

Overall, 630 patients (76 children) received PPI as initial therapy (n = 600) or after failure to respond to other therapies (n = 30). PPI therapy achieved eosinophil density below 15 eosinophils per high-power field in 48.8% and a decreased symptom score in 71.0% of patients. More EoE patients with an inflammatory rather than stricturing phenotype accomplished clinico-histological remission after PPI therapy (OR 3.7; 95% CI, 1.4-9.5); as well as those who prolonged treatment length from 8 to 12 weeks (OR 2.7; 95% CI, 1.3-5.3). After achieving clinico-histological remission of EoE, PPI dosage reduction was effectively maintained in 69.9% of patients, but tended to be less effective among those with a stricturing phenotype.

CONCLUSIONS

Inflammatory EoE phenotype and treatment duration up to 12 weeks correlated with greater chance for inducing remission of EoE. A stricturing phenotype decreased response rates to PPI therapy both initially and in the long term.

An anti-IL-13 antibody reverses epithelial-mesenchymal transition biomarkers in eosinophilic esophagitis: Phase 2 trial results

BACKGROUND

Fibrostenosis, the most serious eosinophilic esophagitis (EoE) complication, is mediated by epithelial-mesenchymal transition (EMT). Transitioned cells contribute to pathogenesis by overproducing extracellular matrix.

OBJECTIVE

Our aim was to determine whether RPC4046 (anti‒IL-13 mAb) modulates EMT biomarkers in biopsy samples from adults with active EoE in a substudy of a double-blind, placebo-controlled phase 2 trial.

METHODS

Baseline and week 16 esophageal biopsy samples were taken from 69 patients who were randomized to weekly treatment with subcutaneous RPC4046, 180 mg (n = 19), 360 mg (n = 26), or placebo (n = 24). Duplex immunofluorescence slides stained for E-cadherin and vimentin were digitally analyzed by mapping each epithelial cell and recording fluorescence intensities. End points included change from baseline to week 16 in percentage of vimentin-positive epithelial cells (primary), total E-cadherin expression, and vimentin-to-E-cadherin ratio per cell (an average of 47,000 cells per biopsy sample analyzed).

RESULTS

The mean percentage of vimentin-positive cells decreased by 0.94%, 2.75%, and 4.24% in the placebo, low-dose, and high-dose groups, respectively (P =.032 for the high-dose vs placebo group). Mean E-cadherin expression per cell increased 5.6-fold in both dose groups versus in the placebo group (high-dose group P = .047). The increases in E-cadherin expression per cell from baseline to week 16 were correlated with improvements in histology, eosinophil counts, endoscopic findings, and symptoms.

CONCLUSION

RPC4046 significantly reduced EMT markers in adults with active EoE, with greater effects at 360 mg. Together with results for eosinophil density and clinical end points from the main trial, these data support the hypothesis that pharmacologic IL-13 inhibition ameliorates both inflammatory and remodeling pathways and could potentially reduce the risk of fibrostenotic complications.

Budesonide Oral Suspension Significantly Improves Eosinophilic Esophagitis Histology Scoring System Results: Analyses From a 12-Week, Phase 2, Randomized, Placebo-controlled Trial

Budesonide oral suspension (BOS) is a novel topical corticosteroid, which has been shown to improve symptoms and endoscopic appearance, and reduce peak eosinophil counts in patients with eosinophilic esophagitis (EoE). This trial evaluated the effect of BOS or placebo on the severity (grade) and extent (stage) of 8 histopathologic features observed in EoE, using the validated eosinophilic esophagitis histologic scoring system (EoE HSS). Patients with EoE aged 11 to 40 years with dysphagia were randomized to receive either BOS (2.0 mg twice daily) or placebo for 12 weeks. Mean (SD) EoE HSS grade and stage total scores at baseline for placebo and BOS groups were: grade, 0.42 (0.16) and 0.49 (0.14), respectively; stage: 0.38 (0.14) and 0.46 (0.11), respectively. These scores significantly decreased (improved) from baseline for patients receiving BOS versus placebo (grade: least squares mean change [SE]: placebo vs. BOS, -0.04 [0.03] vs. -0.24 [0.02]; P<0.0001; stage: -0.01 [0.02] vs. -0.19 [0.02]; P<0.0001). EoE HSS total scores improved for 6 of the 8 and 5 of the 8 histopathologic features for grade and stage, respectively, versus placebo. Change in EoE HSS total scores correlated moderately but significantly with change in endoscopic severity (endoscopic reference score; grade: R=0.5349; stage: R=0.5416; both P<0.0001). Change in EoE HSS stage total score correlated weakly with change in Dysphagia Symptom Questionnaire scores (grade: R=0.1925; P=0.0740; stage: R=0.2135; P=0.0471). These data demonstrate that the EoE HSS is a valuable endpoint of treatment response in randomized clinical trials and should be considered for future trials for EoE.

Esophageal perforation in eosinophilic esophagitis: A systematic review on clinical presentation, management and outcomes

There is evidence of an increased fragility in the inflamed esophagus of patients with eosinophilic esophagitis (EoE). We performed a systematic review on presentation, management and outcomes of and surgical interventions for esophageal perforation in these patients, by searching in the MEDLINE, Embase and Scopus databases. Of the 599 references identified, 41 full-papers and 9 abstract met the inclusion criteria. Overall, 76 esophageal perforation episodes in 70 individual patients aged between 9 and 65 years were reported. 51 patients had not been diagnosed with EoE at the time of perforation; 14 patients had an untreated disease and the remaining were non responsive to therapy. Acute or progressive pain after long-lasting dysphagia and food impaction was the most common symptom leading to diagnosis in 42 patients who presented with Boerhaave syndrome. Pushing impacted food into the stomach led to perforation in 5 cases. Eight episodes appeared after dilation. CT scans demonstrated perforation in 82.4% of patients. Conservative management (including esophageal stenting) was used in 67.1% patients. The 25 remaining patients underwent surgery. Recovery was uneventful in the vast majority of patients. No death was reported. Active inflammation due to undiagnosed or untreated EoE was present in most cases of esophageal perforation. Conservative treatment of perforation should always be considered in EoE.

Clinical relevance of esophageal subepithelial activity in eosinophilic esophagitis

Esophageal subepithelial activity (ESEA) is an important determinant of disease severity and complications in eosinophilic esophagitis (EoE). Inflammation and fibrosis of the lamina propria and muscularis propria result in esophageal dysfunction and stricture formation that are clinically manifest by symptoms of dysphagia and food impaction as well as the need for esophageal dilation. Esophageal biopsies that are limited to the evaluation of the esophageal epithelium are an inadequate means to assess overall, clinical disease severity in EoE. Instruments for the assessment of subepithelial activity in EoE are both limited and/or underutilized and thus represent an important unmet clinical need. Studies using endoscopic features, endoscopic ultrasonography, and barium esophagography have demonstrated improvement in ESEA parameters with topical steroid therapy. Impedance planimetry is being evaluated as an objective and quantifiable measure of esophageal distensibility that is a consequence of ESEA. In conjunction with symptom and histologic assessment, evaluation of ESEA provides a more complete evaluation of disease activity in EoE that will enhance clinical care as well as provide insights into the strengths and limitations of therapeutic interventions.

Eosinophilic Esophagitis-A Primer for Otolaryngologists

Importance

Eosinophilic esophagitis (EoE) is a chronic, inflammatory condition of the esophagus. Prevalence of EoE is on the rise and, owing to its associated extragastrointestinal manifestations and comorbidities, otolaryngologists are increasingly encountering this condition in their practice.

Observations

Symptoms of EoE are vague and vary greatly based on patient's age. The gastrointestinal symptoms include dysphagia, food impaction, feeding difficulties, symptoms mimicking gastroesophageal reflux, abdominal pain, vomiting, and failure to thrive. Several otolaryngologic symptoms are associated with EoE including rhinosinusitis, chronic cough, recurrent croup, hoarseness, and other aerodigestive symptoms refractory to gastroesophageal reflux therapy. Eosinophilic esophagitis is also frequently associated with other atopic conditions, such as asthma, eczema, and food allergies. The diagnosis is made on endoscopy with biopsies that reveal eosinophil-predominant esophageal inflammation. There are 3 major treatment approaches to EoE, commonly referred to as the 3 Ds: diet, drugs, and dilation. Untreated inflammation of esophagus from EoE can result in irreversible structural damage to the esophagus, leading to fibrosis, strictures, and impaired esophageal function.

Conclusions and Relevance

Eosinophilic esophagitis is now a fairly prevalent condition with considerable morbidity. Otolaryngologists should be familiar with the various clinical presentations of this condition in different age groups. Early diagnosis and treatment of this condition is a key for avoiding or postponing its complications.

CD4+ T cells and TGFβ1/MAPK signal pathway involved in the valvular hyperblastosis and fibrosis in patients with rheumatic heart disease

The aim of this study was to investigate the roles of CD4⁺ T cells and transforming growth factor beta (TGFβ1) in the pathological process of valvular hyperblastosis and fibrosis of patients with rheumatic heart disease (RHD). A total of 151 patients were enrolled, among whom, 78 patients were with RHD, and 73 were age and gender matched RHD negative patients. Blood samples and valve specimens were collected for analysis. Pathological changes and collagen fibers contents of valves were analyzed using HE and Masson staining. Percentage of peripheral blood CD4⁺ T cells was tested through flow cytometry. TGFβ1 level in serum were identified by ELISA. CD4⁺ T cells infiltration and expression of TGFβ1, p-p38, p-JNK, p-ERK in valves were detected by immunohistochemistry. The mRNA and protein levels of p38, JNK, ERK, TGFβ1, I-collagen and α-SMA were detected by qRT-PCR and western blotting, respectively. The heart valve tissues of RHD patients showed higher degrees of fibrosis, calcification and lymphocytes infiltration, which were mainly CD4⁺ T cells. In addition, compared with control group, RHD patients had more total CD4⁺ T cells in peripheral blood and valve tissues. Expression of TGFβ1, phosphorylation of JNK and p38, and synthesis of I-collagen in valve tissues of RHD patients were also significantly increased. Furthermore, we found a strong positive correlation between TGFβ1 expression and phosphorylation of JNK and p38. CD4⁺ T cells, and fibrogenic cytokine TGFβ1, which activate the intracellular MAPK signaling pathway may participate in the fibrosis of heart valve in RHD patients.

Molecular basis and cellular mechanisms of eosinophilic esophagitis for the clinical practice

Eosinophilic esophagitis (EoE) is a chronic, allergen-driven inflammatory esophageal disease characterized by predominantly eosinophilic inflammation leading to esophageal dysfunction. Recent efforts to understand EoE have increased our knowledge of the disease. Areas covered: Multiple cells, molecules, and genes interplay with early life environmental factors in the pathophysiology of EoE to converge in the esophageal epithelium at the center of disease pathogenesis. Epithelial cells constitute a mayor cytokine source for TSLP and Calpain-14; an impaired epithelial barrier function allowing penetration of food and microbiota-derived antigens is involved in triggering and maintaining inflammation. Eosinophil and mast cell-derived products, including TGFβ, together with IL-1β and TNFα, promote epithelial mesenchymal transition in EoE, contributing to tissue remodeling by synthetizing and depositing extracellular matrix in subepithelial layers. This article aims to provide a state-of-the-art update on the pathophysiology of EoE applied to clinical practice, and latest research and developments with potential interest to improve the diagnosis and treatment of patients with EoE are revised. Expert commentary: Preliminary approaches have provided promising results toward incorporating minimally invasive methods for patient diagnosis and monitoring in clinical practice. Early diagnosis and optimized therapies will allow for personalized medicine in EoE.

Elevated Tryptase in EoE Is an Independent Phenomenon Associated with Extra-Esophageal Symptoms

BACKGROUND

Eosinophilic esophagitis (EoE) is a chronic disease characterized histologically by > 15 eosinophils per high-power field (eos/hpf). Esophageal mucosal mast cells have been implicated in EoE pathogenesis. The association of atopy with EoE has been established but has not been correlated with levels of serum tryptase. The lack of concurrent atopy in some patients suggests the possibility that atopy may either be the related subtype of EoE or may be a sign of comorbidities. No study has looked at whether patients present with different phenotypes/comorbid disease when they have evidence of elevated serum tryptase. We hypothesized that these patients differ with respect to presentation and comorbidities with more refractory GI disease.

AIMS

To examine whether elevations of serum tryptase associate with different, more severe clinical presentations in EoE patients which may be explained via mast cell activation.

MATERIALS AND METHODS

Retrospective chart review identified 72 patients with EoE with results for serum tryptase between 2015 and 2016. Patients were classified as Tryptase^HI (tryptase > 10.9 µg/l) and Tryptase^LO (< 10.9 µg/l). Clinical characteristics and treatment response were compared using univariate analysis and multivariate regression between the groups.

RESULTS

Out of 72 patients, 12 were tested as Tryptase^HI (16.7%, 95% CI 8.1-25.3%). Tryptase^HI was associated frequently with asthma (P = 0.0003), urticaria (P = 0.002), arthralgia (P = 0.005), sinusitis (P = 0.03), nausea/vomiting (P = 0.046), and eosinophilic gastrointestinal disease (P = 0.001). Asthma and arthralgia were found to be significantly associated with Tryptase^HI (P = 0.0013, P = 0.0098, respectively). Mucosal eosinophil counts and tryptase levels were not correlated (R² 0.095, P = 0.77). Tryptase did not resolve with resolution of esophageal eosinophilia.

CONCLUSIONS

We found that EoE patients with elevated tryptase levels more commonly presented with asthma, urticaria, arthralgia, nausea/vomiting, sinusitis, and more distal eosinophilia. This indicates that atopy in EoE patients warrants further exploration. The lack of correlation between histologic remission and reduction of serum tryptase levels post-treatment suggests that mast cell activation may be an independent, yet associated disease. More study into this unique association is warranted.

Pathophysiology of Eosinophilic Esophagitis

Eosinophilic esophagitis (EoE) is a chronic inflammatory disease of the esophagus associated with an atopic predisposition which appears to be increasing in prevalence over the last few decades. Symptoms stem from fibrosis, swelling, and smooth muscle dysfunction. In the past two decades, the etiology of EoE has been and is continuing to be revealed. This review provides an overview of the effects of genetics, environment, and immune function including discussions that touch on microbiome, the role of diet, food allergy, and aeroallergy. The review further concentrates on the pathophysiology of the disease with particular focus on the important concepts of the molecular etiology of EoE including barrier dysfunction and allergic hypersensitivity.

Medical and dietary treatments in eosinophilic esophagitis

Eosinophilic esophagitis (EoE) refers to a relatively new chronic inflammatory disease of the esophagus, which according to the current understanding underlies an immune-mediated pathogenesis driven by exposure to allergens. While several open questions remain regarding ethiopathogenesis as well as treatment options and their positioning, one thing has increasingly been recognized. The disease is on the rise and will increasingly be of importance in everyday's clinical practice, not only in expert physicians but also gastroenterologists with a broad clinical spectrum, allergologists and even general practitioners. The aim of this review is to provide a current overview on EoE treatment, including the rationale and endpoints of treatment in EoE, medical treatment options - providing the standard of current care, second-line options and outlook to emerging therapies - as well as dietary elimination approaches.

Eosinophilic Esophagitis and the Eosinophilic Gastrointestinal Diseases: Approach to Diagnosis and Management

The eosinophilic gastrointestinal diseases (EGIDs) represent disorders of the gastrointestinal (GI) tract that result from the local infiltration and aberrant activity of eosinophils and other immune cells. Eosinophilic esophagitis (EoE) is the most well-characterized EGID and is defined by the presence of intraepithelial eosinophils in the esophagus (≥15 eosinophils per high-powered field) and clinical symptoms associated with esophageal dysfunction. The other EGIDs are rare and lack strong data regarding pathogenesis and management. The incidence and prevalence of EoE are increasing, and EoE is now a major cause of upper GI morbidity. Management is multidisciplinary, with collaboration between gastroenterologists, allergists, pathologists, and dieticians, and is aimed at amelioration of symptoms and prevention of long-term complications such as esophageal stricture. Treatment options for EoE include proton pump inhibitors, swallowed topical corticosteroids, and elimination diets. Esophageal dilation is used when esophageal strictures or fibrostenotic changes are present. Additional therapies targeting eosinophils and other mediators of Th2 inflammation are under development and are promising. Treatment options for other EGIDs typically involve corticosteroids or dietary elimination.

Esophageal dilation in eosinophilic esophagitis: risks, benefits, and when to do it

PURPOSE OF REVIEW

For patients with eosinophilic esophagitis (EoE), endoscopic dilation has been used primarily to provide immediate symptomatic relief of dysphagia. This report reviews the current position of esophageal dilation in the therapeutic algorithm for EoE, including effectiveness and safety issues.

RECENT FINDINGS

Esophageal strictures in EoE develop as a consequence of long-lasting esophageal eosinophilia, with patient age and diagnostic delay as well established risk factors. Endoscopic dilation leads to immediate symptomatic improvement in 95% of EoE patients who have strictures or narrow caliber esophagus. As dilation has no effect on the underlying eosinophil inflammation, repeated procedures are usually needed to maintain symptoms in remission. Adding an effective drug or dietary-based EoE therapy reduces the need of further dilation. The high rate of severe complications from dilation reported in early literature has not been reproduced in most recent series, with mild postprocedural chest pain as the most common side effect. Current data suggest that the risk of esophageal perforation is less than 1%. Mucosal tears after dilation should no longer be considered a complication, but rather a marker of procedural success.

SUMMARY

Esophageal dilation should be considered in EoE patients with esophageal strictures or narrow caliber esophagus who have persistent dysphagia/food impaction despite an effective anti-inflammatory treatment.

Toll-like receptors-mediated pathways activate inflammatory responses in the esophageal mucosa of adult eosinophilic esophagitis

Objectives

Esophageal microbiota and regulation of adaptive immunity are increasingly being investigated in eosinophilic esophagitis (EoE). Toll-like receptors (TLRs) play a central role in the initiation and maintenance of innate immune activity. Our objective was to characterize the esophageal and duodenal innate immune response in EoE and its modulation by dietary therapy.

Methods

Esophageal and duodenal biopsy samples were collected from 10 adults with untreated EoE, before and after effective treatment with a six-food elimination diet (SFED), and 10 controls with normal esophagus. In all cases, bacterial load (by mRNA expression of 16S), TLRs, mucins, transcription factors, interleukins, components of the NKG2D system, and innate immunity effectors were assessed by qPCR. Protein expression of TLRs were also determined by immunofluorescence.

Results

Bacterial load and TLR1, TLR2, TLR4, and TLR9 were overexpressed on biopsies with active EoE compared with controls. Muc1 and Muc5B genes were downregulated while Muc4 was overexpressed. Upregulation of MyD88 and NFκB was found together with IL-1β, IL-6, IL-8, and IL-10 mediators and PER-1, iNOS, and GRZA effectors. NG-K2D components (KLRK1, IL-15, MICB) were also upregulated. In all cases, changes in active EoE were normalized following SFED and mucosal healing. Duodenal samples also showed increased expressions of TLR-1, TLR-2, and TLR-4, but not 16S or any other mediators nor effectors of inflammation.

Conclusions

Esophageal TLR-dependent signaling pathways in EoE support the potential implication of microbiota and the innate immune system in the pathogenesis of this disease.

Prominent Levels of the Profibrotic Chemokine CCL18 during Peritonitis: In Vitro Downregulation by Vitamin D Receptor Agonists

Peritoneal dialysis (PD) is used as a renal replacement therapy, which can be limited by peritoneal membrane ultrafiltration failure (UFF) secondary to fibrotic processes. Peritonitis, a frequent complication of PD, is a major risk factor for peritoneal membrane fibrosis and UFF. Low peritoneal levels of the chemokine CCL18 are associated with preservation of peritoneal membrane function in PD. Given that CCL18 is involved in fibrotic processes and recurrent peritonitis, it is a risk factor for peritoneal membrane failure; thus, we evaluated CCL18 concentrations in peritoneal effluents from patients undergoing peritonitis episodes. Pharmacological interventions aimed at diminishing the production of CCL18 were also explored. Fivefold higher CCL18 peritoneal concentrations were found during acute bacterial peritonitis, in parallel with the increased infiltration of macrophages. Unexpectedly, CCL18 was also highly (50-fold) increased during sterile eosinophilic peritonitis, and peritoneal eosinophils were found to express CCL18. In vitro treatment of peritoneal macrophages with the vitamin D receptor agonist paricalcitol was able to reduce the secretion and the expression of CCL18 in isolated peritoneal macrophages. In conclusion, our study suggests that the chemokine CCL18 can be a mediator of peritoneal membrane failure associated with peritonitis episodes as well as providing a new potential therapeutic target.

Eosinophilic Esophagitis: Relationship of Subepithelial Eosinophilic Inflammation With Epithelial Histology, Endoscopy, Blood Eosinophils, and Symptoms

OBJECTIVES

For technical reasons, the histologic characterization of eosinophilic esophagitis (EoE)-specific alterations is almost exclusively based on those found in the esophageal epithelium, whereas little is known about subepithelial abnormalities. In this study, we aimed to systematically assess the nature of subepithelial histologic alterations, and analyze their relationship with epithelial histologic findings, endoscopic features, and symptoms.

METHODS

Adult patients with established EoE diagnosis were prospectively included during a yearly follow-up visit. Patients underwent assessment of clinical, endoscopic, and histologic disease activity using EoE-specific scores.

RESULTS

We included 200 EoE patients (mean age 43.5±15.7 years, 74% males) with a median peak count of 36 intraepithelial eosinophils/hpf (IQR 14-84). The following histologic features were identified in the subepithelial layer: eosinophilic infiltration (median peak count of 20 eosinophils/hpf (IQR 10-51)), eosinophil degranulation (43%), fibrosis (82%), and lymphoid follicles (56%). Peak intraepithelial eosinophil counts were higher, identical, and lower when compared to the subepithelial layer in 62.5%, 7%, and 30.5% of patients, respectively. Anti-eosinophilic treatment at inclusion did not influence the relation between subepithelial and epithelial peak eosinophil counts. Subepithelial histologic activity correlated with epithelial histologic activity (rho 0.331, P<0.001), endoscopic severity (rho 0.208, P=0.003), and symptom severity (rho 0.179, P=0.011). Forty percent (21/52) of patients with <15 intraepithelial eosinophils/hpf had subepithelial peak counts of ≥15/hpf.

CONCLUSIONS

There is a significant but modest correlation between subepithelial histologic activity and epithelial histologic activity, endoscopic severity, and symptom severity. The long-term clinical impact of assessing subepithelial alterations in EoE needs to be further elucidated.

TGF-β1 alters esophageal epithelial barrier function by attenuation of claudin-7 in eosinophilic esophagitis

Barrier dysfunction has been implicated in the pathophysiology of eosinophilic esophagitis (EoE). Transforming growth factor-β1 (TGF-β1), a potent pleiotropic molecule, is increased in EoE; however, no study has evaluated its influence on esophageal epithelial barrier. We hypothesized that TGF-β1 regulates barrier dysfunction in EoE. We aimed to determine the role of TGF-β1 in the epithelial barrier in models of EoE. To examine the impact of TGF-β1 on esophageal barrier, immortalized human esophageal epithelial (EPC2-hTERT) cells were exposed to TGF-β1 during the three-dimensional air-liquid interface (3D-ALI) model in vitro. TGF-β1 exposure diminished EPC2-hTERT barrier function as measured by transepithelial electrical resistance (TEER) and 3 kDa Fluorescein isothiocyanate dextran paracellular flux (FITC Flux), and hematoxylin and eosin (H&E) assessment revealed prominent cellular separation. In analysis of epithelial barrier molecules, TGF-β1 led to the specific reduction in expression of the tight-junction molecule, claudin-7 (CLDN7), and this was prevented by TGF-β-receptor I inhibitor. Short hairpin ribonucleic acid (shRNA)-mediated CLDN7 knockdown diminished epithelial barrier function, whereas CLDN7 overexpression resulted in protection from TGF-β1-mediated barrier dysfunction. In pediatric EoE biopsies CLDN7 expression was decreased and altered localization was observed with immunofluorescence analysis, and the TGF-β1 downstream transcription factor, phosphorylated SMAD2/3 (pSMAD2/3), was increased. Our data suggest that TGF-β1 participates in esophageal epithelial barrier dysfunction through CLDN7 dysregulation.

Ankylosaurus back sign: novel endoscopic finding in esophageal eosinophilia patients indicating proton pump inhibitor response

BACKGROUND AND STUDY AIMS

Characteristic endoscopic findings, such as linear furrows, rings, and whitish exudates, indicate the presence of esophageal eosinophilia (EE), though no specific findings are known to distinguish eosinophilic esophagitis (EoE) from proton pump inhibitor-responsive esophageal eosinophilia (PPI-REE). Here, we present a novel endoscopic finding in some EE patients possessing a linear longitudinal arrangement of whitish nodules with the appearance of the back of an Ankylosaurus dinosaur, termed Ankylosaurus back sign (ABS), and evaluations of its significance in affected patients.

PATIENTS AND METHODS

Fifty-five patients diagnosed with EE (≥ 15 eosinophils/high power field) who were treated at our hospital and shown to evaluate a PPI response were enrolled. Endoscopic findings at baseline and clinical parameters were retrospectively reviewed. Furthermore, the clinicopathological features of patients with ABS, as well as the relationship between its presence and PPI response were evaluated.

RESULTS

 Fifty-five patients (47 males, 8 females) with EE (17 with EoE, 38 with PPI-REE) were evaluated, of whom 50 (90.9 %) had linear furrows, the most frequently found feature, while ABS was found in 9 (16.4 %). Inter-observer agreement was substantial for ABS (κ 0.77). Interestingly, all patients with ABS had PPI-REE. Our findings revealed that the presence of ABS was closely associated with reflux esophagitis (RE) in patients with PPI-REE.

CONCLUSIONS

 Although ABS was less frequent than typical endoscopic findings such as linear furrows in EE, this novel finding was closely associated with PPI-REE accompanied with RE. The clinical implications of ABS in patients with EE should be investigated further.

Pathophysiology of Eosinophilic Esophagitis

Eosinophilic esophagitis is an emerging disease that is distinguished from gastroesophageal reflux disease by the expression of a unique esophageal transcriptome and the interplay of early life environmental factors with distinct genetic susceptibility elements at 5q22 (TSLP) and 2p23 (CAPN14). Rare genetic syndromes have uncovered the contribution of barrier disruption, mediated in part by defective desmosomes and dysregulated transforming growth factor beta production and signaling, to eosinophilic esophagitis pathophysiology. Experimental modeling has defined a cooperative role of activated eosinophils, mast cells, and the cytokines IL-5 and IL-13, mediated by allergic sensitization to multiple foods. Understanding these processes is opening the way to better treatment based on disrupting allergic inflammatory and type 2 cytokine-mediated responses, including anti-cytokine therapeutics and dietary therapy.

Eosinophilic Esophagitis in Children and Adults

Adults and children with eosinophilic esophagitis (EoE) have distinct clinical and endoscopic presentations. Recognition of clinical signs, along with laboratory and endoscopic findings, is critical for the identification of patients with EoE because delay in diagnosis has been associated with esophageal remodeling and stricture formation. Clinical presentation varies considerably between adults and children. This is less due to differences in the disease and more due to patient differences. This article describes the similarities and differences in clinical presentation of children and adults with EoE, including areas of epidemiology, clinical and endoscopic presentation, pathophysiology, and treatment.

Noncanonical NF-κB signaling and the essential kinase NIK modulate crucial features associated with eosinophilic esophagitis pathogenesis

Eosinophilic esophagitis (EoE) is an allergic disease of the esophagus driven by T cell and eosinophil responses to dietary allergens, resulting in chronic mucosal inflammation. Few spontaneous animal models of esophageal eosinophilia exist, with most studies relying on artificial sensitization procedures. NF-κB-inducing kinase (NIK; MAP3K14) is a key signaling molecule of the noncanonical NF-κB (NFKB1) pathway, an alternative signaling cascade producing chemokines involved in lymphoid stroma development and leukocyte trafficking. Nik-/- mice have been shown to develop a hypereosinophilic syndrome in peripheral blood and major filtering organs; however, the gastrointestinal mucosa of these mice has not been well characterized. We show that Nik-/- mice develop significant, localized eosinophilic esophagitis that mimics human EoE, including features such as severe eosinophil accumulation, degranulation, mucosal thickening, fibrosis and basal cell hyperplasia. The remainder of the GI tract, including the caudal stomach, small intestine and colon, in mice with active EoE are unaffected, also similar to human patients. Gene expression patterns in esophageal tissue of Nik-/- mice mimics human EoE, with thymic stromal lymphopoetin (TSLP) in particular also elevated at the protein level. In gene expression data sets from human biopsy specimens, we further show that many genes associated with noncanonical NF-κB signaling are significantly dysregulated in EoE patients, most notably a paradoxical upregulation of NIK itself with concurrent upregulation of powerful protein-level destabilizers of NIK. These findings suggest that Nik-/- mice could be useful as a spontaneous model of specific features of EoE and highlight a novel role for noncanonical NF-κB signaling in human patients.