Hypoxia-inducible factor-1α mediates reflux-induced epithelial-mesenchymal plasticity in Barrett's oesophagus patients.

INTRODUCTION: Epithelial-mesenchymal plasticity (EMP), the process through which epithelial cells acquire mesenchymal features, is needed for wound repair but also might contribute to cancer initiation. Earlier, in vitro studies showed that Barrett's cells exposed to acidic bile salt solutions (ABS) develop EMP. Now, we have (1) induced reflux oesophagitis in Barrett's oesophagus (BO) patients by stopping proton pump inhibitors (PPIs), (2) assessed their biopsies for EMP and (3) explored molecular pathways underlying reflux-induced EMP in BO cells and spheroids. METHODS: 15 BO patients had endoscopy with biopsies of Barrett's metaplasia while on PPIs, and 1 and 2 weeks after stopping PPIs; RNA-seq data were assessed for enrichments in hypoxia-inducible factors (HIFs), angiogenesis and EMP pathways. In BO biopsies, cell lines and spheroids, EMP features (motility) and markers (vascular endothelial growth factor (VEGF), ZEB1, miR-200a&b) were evaluated by morphology, migration assays, immunostaining and qPCR; HIF-1α was knocked down with siRNA or shRNA. RESULTS: At 1 and/or 2 weeks off PPIs, BO biopsies exhibited EMP features and markers, with significant enrichment for HIF-1α, angiogenesis and EMP pathways. In BO cells, ABS induced HIF-1α activation, which decreased miR-200a&b while increasing VEGF, ZEB1 and motility; HIF-1α knockdown blocked these effects. After ABS treatment, BO spheroids exhibited migratory protrusions showing nuclear HIF-1α, increased VEGF and decreased miR-200a&b. CONCLUSIONS: In BO patients, reflux oesophagitis induces EMP changes associated with increased HIF-1α signalling in Barrett's metaplasia. In Barrett's cells, ABS trigger EMP via HIF-1α signalling. Thus, HIF-1α appears to play a key role in mediating reflux-induced EMP that might contribute to cancer in BO. TRIAL REGISTRATION NUMBER: NCT02579460.

Updates to the modern diagnosis of GERD: Lyon consensus 2.0.

The Lyon Consensus provides conclusive criteria for and against the diagnosis of gastro-oesophageal reflux disease (GERD), and adjunctive metrics that consolidate or refute GERD diagnosis when primary criteria are borderline or inconclusive. An international core and working group was assembled to evaluate research since publication of the original Lyon Consensus, and to vote on statements collaboratively developed to update criteria. The Lyon Consensus 2.0 provides a modern definition of actionable GERD, where evidence from oesophageal testing supports revising, escalating or personalising GERD management for the symptomatic patient. Symptoms that have a high versus low likelihood of relationship to reflux episodes are described. Unproven versus proven GERD define diagnostic strategies and testing options. Patients with no prior GERD evidence (unproven GERD) are studied using prolonged wireless pH monitoring or catheter-based pH or pH-monitoring off antisecretory medication, while patients with conclusive GERD evidence (proven GERD) and persisting symptoms are evaluated using pH-impedance monitoring while on optimised antisecretory therapy. The major changes from the original Lyon Consensus criteria include establishment of Los Angeles grade B oesophagitis as conclusive GERD evidence, description of metrics and thresholds to be used with prolonged wireless pH monitoring, and inclusion of parameters useful in diagnosis of refractory GERD when testing is performed on antisecretory therapy in proven GERD. Criteria that have not performed well in the diagnosis of actionable GERD have been retired. Personalisation of investigation and management to each patient's unique presentation will optimise GERD diagnosis and management.

Th2 cytokine signaling through IL-4Rα increases eotaxin-3 secretion and tension in human esophageal smooth muscle.

In esophageal epithelial cells in eosinophilic esophagitis (EoE), Th2 cytokines (IL-4, IL-13) signal through IL-4Rα, activating JAK to increase eotaxin-3 secretion, which draws eosinophils into the mucosa. We explored whether Th2 cytokines also might stimulate eotaxin-3 secretion and increase tension in esophageal smooth muscle (ESM), which might impair esophageal distensibility, and whether those events could be blocked by proton pump inhibitors (PPIs) or agents that disrupt IL-4Rα signaling. We established human ESM cell cultures from organ donors, characterizing Th2 cytokine receptor and P-type ATPase expression by qPCR. We measured Th2 cytokine-stimulated eotaxin-3 secretion by enzyme-linked immunosorbent assay (ELISA) and ESM cell tension by gel contraction assay, before and after treatment with omeprazole, ruxolitinib (JAK inhibitor), or IL-4Rα blocking antibody. CPI-17 (inhibitor of a muscle-relaxing enzyme) effects were studied with CPI-17 knockdown by siRNA or CPI-17 phospho(T38A)-mutant overexpression. ESM cells expressed IL-4Rα and IL-13Rα1 but only minimal H+-K+-ATPase mRNA. Th2 cytokines increased ESM eotaxin-3 secretion and tension, effects blocked by ruxolitinib and IL-4Rα blocking antibody but not consistently blocked by omeprazole. IL-13 increased ESM tension by increasing CPI-17 expression and phosphorylation, effects blocked by CPI-17 knockdown. Blocking IL-4Rα decreased IL-13-stimulated eotaxin-3 secretion, CPI-17 expression, and tension in ESM. Th2 cytokines increase ESM eotaxin-3 secretion and tension via IL-4Rα signaling that activates CPI-17. Omeprazole does not reliably inhibit this process, but IL-4Rα blocking antibody does. This suggests that ESM eosinophilia and impaired esophageal distensibility might persist despite elimination of mucosal eosinophils by PPIs, and IL-4Rα blocking agents might be especially useful in this circumstance.NEW & NOTEWORTHY We have found that Th2 cytokines increase eotaxin-3 secretion and tension in esophageal smooth muscle (ESM) cells via IL-4Rα signaling. Unlike esophageal epithelial cells, ESM cells do not express H+-K+-ATPase, and omeprazole does not inhibit their cytokine-stimulated eotaxin-3 secretion or tension. An IL-4Rα blocking antibody reduces both eotaxin-3 secretion and tension induced by Th2 cytokines in ESM cells, suggesting that an agent such as dupilumab might be preferred for patients with EoE with esophageal muscle involvement.

Vonoprazan Versus Lansoprazole for Healing and Maintenance of Healing of Erosive Esophagitis: A Randomized Trial.

BACKGROUND & AIMS: For decades, proton pump inhibitors (PPIs) have been the mainstay of treatment for erosive esophagitis. The potassium-competitive acid blocker vonoprazan provides more potent acid inhibition than PPIs, but data on its efficacy for erosive esophagitis are limited. METHODS: Adults with erosive esophagitis were randomized to once-daily vonoprazan, 20 mg, or lansoprazole, 30 mg, for up to 8 weeks. Patients with healing were rerandomized to once-daily vonoprazan, 10 mg, vonoprazan, 20 mg, or lansoprazole, 15 mg, for 24 weeks. Primary end points, percentage with healing by week 8 endoscopy, and maintenance of healing at week 24 endoscopy, were assessed in noninferiority comparisons (noninferiority margins, 10%), with superiority analyses prespecified if noninferiority was demonstrated. Analyses of primary and secondary end points were performed using fixed-sequence testing procedures. RESULTS: Among 1024 patients in the healing phase, vonoprazan was noninferior to lansoprazole in the primary analysis and superior on the exploratory analysis of healing (92.9 vs 84.6%; difference, 8.3%; 95% confidence interval [CI], 4.5%-12.2%). Secondary analyses showed vonoprazan was noninferior in heartburn-free days (difference, 2.7%; 95% CI, -1.6% to 7.0%), and superior in healing Los Angeles Classification Grade C/D esophagitis at week 2 (difference, 17.6%; 95% CI, 7.4%-27.4%). Among 878 patients in the maintenance phase, vonoprazan was noninferior to lansoprazole in the primary analysis and superior on the secondary analysis of maintenance of healing (20 mg vs lansoprazole: difference, 8.7%; 95% CI, 1.8%-15.5%; 10 mg vs lansoprazole: difference, 7.2%; 95% CI, 0.2%-14.1%) and secondary analysis of maintenance of healing Grade C/D esophagitis (20 mg vs lansoprazole: difference, 15.7%; 95% CI, 2.5%-28.4%; 10 mg vs lansoprazole: difference, 13.3%; 95% CI, 0.02%-26.1%). CONCLUSIONS: Vonoprazan was noninferior and superior to the PPI lansoprazole in healing and maintenance of healing of erosive esophagitis. This benefit was seen predominantly in more severe erosive esophagitis. (ClinicalTrials.gov: NCT04124926).

Comparison of Los Angeles Grades of Erosive Esophagitis Scored by Local Investigators vs Central Adjudicators in a Clinical Trial.

Approximately 30% of patients with typical gastroesophageal reflux disease (GERD) symptoms have endoscopic evidence of erosive esophagitis (EE).1 The severity of EE is commonly graded using the Los Angeles (LA) classification system as grade A (minimal) to D (very severe), depending on the extent of endoscopically visible mucosal breaks (Supplementary Figure 1).2 Accurate grading of EE severity is crucial in clinical trials of medical EE treatments, as EE severity strongly influences both initial rates of healing and the likelihood of recurrence during maintenance treatment.3,4 Almost all EE treatment studies have relied exclusively on local investigators' grading of EE severity to determine study eligibility and response to treatment. Those few studies that included central adjudication did not assess the reliability of grading by local investigators.5 Unlike typical studies of EE treatment, the phase III clinical trial of vonoprazan versus lansoprazole for the treatment of EE (NCT04124926) mandated central adjudication of endoscopic grading for study participation.6 The aim of the present investigation was to evaluate the rate of agreement between local investigators and central adjudicators for EE grading during screening for entrance into that clinical trial.

Achalasia is Strongly Associated With Eosinophilic Esophagitis and Other Allergic Disorders.

BACKGROUND & AIMS: Achalasia has been assumed to be an autoimmune disease targeting esophageal myenteric neurons. Recently, we proposed an alternative hypothesis that achalasia sometimes might be allergy-driven, caused by a form of eosinophilic esophagitis (EoE) in which activated eosinophils and/or mast cells infiltrating esophageal muscle release products that disrupt motility and damage myenteric neurons. To seek epidemiologic support for this hypothesis, we identified patients with achalasia in the Utah Population Database, and explored their frequency of having EoE and other allergic disorders. METHODS: We used International Classification of Diseases codes to identify patients with achalasia and allergic disorders including EoE, asthma, atopic dermatitis, contact dermatitis, allergic rhinitis, allergic conjunctivitis, hives/urticaria, and anaphylaxis. We calculated relative risk (RR) for each allergic disorder by comparing the number observed in patients with achalasia with the expected number in individuals matched for birthyear and sex, and we performed subanalyses for patients age ≤40 versus age >40 years. RESULTS: Among 844 patients with achalasia identified (55% female; median age at diagnosis, 58 years), 402 (47.6%) had ≥1 allergic disorder. Fifty-five patients with achalasia (6.5%) had EoE (1.67 EoE cases expected), for a RR of 32.9 (95% confidence interval, 24.8-42.8; P < .001). In 208 patients with achalasia age ≤40 years, the RR for EoE was 69.6 (95% confidence interval, 46.6-100.0; P < .001). RR also was increased significantly for all other allergic disorders evaluated (all greater than 3-fold higher than population rates). CONCLUSIONS: Achalasia is strongly associated with EoE and other allergic disorders. These data support the hypothesis that achalasia sometimes might have an allergic etiology.

Vonoprazan is Efficacious for Treatment of Heartburn in Non-erosive Reflux Disease: A Randomized Trial.

BACKGROUND & AIMS: Potassium-competitive acid blockers have documented efficacy for erosive esophagitis. We performed a randomized trial in United States subjects diagnosed with non-erosive reflux disease of vonoprazan vs placebo for 4 weeks, followed by a 20-week active-treatment extension. METHODS: Adult subjects with heartburn ≥4 days/week during screening without erosive esophagitis on endoscopy were randomized to placebo, vonoprazan 10 mg, or vonoprazan 20 mg. After 4 weeks, subjects on placebo were re-randomized to vonoprazan 10 mg or 20 mg, and those already on vonoprazan continued at the same dose for 20 weeks. Electronic diaries were completed twice daily. The primary endpoint was percentage of days without daytime or nighttime heartburn (24-hour heartburn-free days). RESULTS: Among 772 randomized subjects, the percentage of 24-hour heartburn-free days was 27.7% for placebo vs 44.8% for vonoprazan 10 mg (least squares mean difference, 17.1%; P < .0001) and 44.4% for vonoprazan 20 mg (least squares mean difference, 16.7%; P < .0001). Differences in percentage of subjects with a 24-hour heartburn-free day for vonoprazan 10 mg vs placebo and vonoprazan 20 mg vs placebo were 8.3% and 11.6% on day 1 and 18.1% and 23.2% on day 2. The mean/median percentages of 24-hour heartburn-free days over the extension period were similar across the 4 study arms: 61%-63%/76%-79%. CONCLUSIONS: Vonoprazan reduced heartburn symptoms in subjects diagnosed with non-erosive reflux disease, with the benefit appearing to begin as early as the first day of therapy. Treatment effect persisted after the initial 4-week placebo-controlled period throughout the 20-week extension period. The 2 vonoprazan doses (10 mg and 20 mg) were similar in efficacy. (ClinicalTrials.gov: NCT05195528).

An Endoscopic Scoring System for Achalasia: The CARS score.

BACKGROUND AND AIMS: The diagnosis of achalasia is associated with an average delay of two years. Endoscopic features may prompt an earlier diagnosis. We aimed to develop and test a novel endoscopic CARS score for the prediction of achalasia. METHODS: Part 1: Twenty endoscopic videos were taken from patients undergoing endoscopy for dysphagia or reflux. A survey with videos and endoscopic criteria options was distributed to 6 esophagologists and 6 general gastroenterologists. Inter-rater reliability (IRR) was measured and logistic regression was used to evaluate predictive performance. Three rounds of review were conducted to select the final score of four components. PART 2: A retrospective review was conducted for consecutive patients who had comprehensive esophageal testing. Each patient had a CARS endoscopic score calculated based on findings reported at endoscopy. RESULTS: From a video review and analysis of score components, IRR ranged from 0.23 to 0.57 for score components. The final CARS score was selected based on the following four components: Contents, Anatomy, Resistance, and Stasis. In a mixed effects model, the mean score across raters was higher for achalasia compared to non-achalasia subjects (4.44 vs. 0.87, p = < 0.01). In part 2 of the study, achalasia patients had a higher mean CARS score compared to those with no / ineffective motility disorder (mean 4.1 vs 1.3, p = < 0.01). CONCLUSIONS: We developed a CARS score based on reliability performance in a video-based survey and tested the score in clinical setting. The CARS score performed well in predicting achalasia.

Interrater Reliability of Functional Lumen Imaging Probe Panometry and High-Resolution Manometry for the Assessment of Esophageal Motility Disorders.

INTRODUCTION: High-resolution manometry (HRM) and functional lumen imaging probe (FLIP) are primary and/or complementary diagnostic tools for the evaluation of esophageal motility. We aimed to assess the interrater agreement and accuracy of HRM and FLIP interpretations. METHODS: Esophageal motility specialists from multiple institutions completed the interpretation of 40 consecutive HRM and 40 FLIP studies. Interrater agreement was assessed using intraclass correlation coefficient (ICC) for continuous variables and Fleiss' κ statistics for nominal variables. Accuracies of rater interpretation were assessed using the consensus of 3 experienced raters as the reference standard. RESULTS: Fifteen raters completed the HRM and FLIP studies. An excellent interrater agreement was seen in supine median integral relaxation pressure (ICC 0.96, 95% confidence interval 0.95-0.98), and a good agreement was seen with the assessment of esophagogastric junction (EGJ) outflow, peristalsis, and assignment of a Chicago Classification version 4.0 diagnosis using HRM (κ = 0.71, 0.75, and 0.70, respectively). An excellent interrater agreement for EGJ distensibility index and maximum diameter (0.91 [0.90-0.94], 0.92 [0.89-0.95]) was seen, and a moderate-to-good agreement was seen in the assignment of EGJ opening classification, contractile response pattern, and motility classification (κ = 0.68, 0.56, and 0.59, respectively) on FLIP. Rater accuracy for Chicago Classification version 4.0 diagnosis on HRM was 82% (95% confidence interval 78%-84%) and for motility diagnosis on FLIP Panometry was 78% (95% confidence interval 72%-81%). DISCUSSION: Our study demonstrates high levels of interrater agreement and accuracy in the interpretation of HRM and FLIP metrics and moderate-to-high levels for motility classification in FLIP, supporting the use of these approaches for primary or complementary evaluation of esophageal motility disorders.

The broad impact of functional lumen imaging probe panometry in addition to high-resolution manometry in an esophageal clinical practice.

High-resolution manometry (HRM) with the Chicago Classification (CC) is the standard paradigm to define esophageal motility disorders. Functional lumen imaging probe (FLIP) panometry utilizes impedance planimetry to characterize esophageal compliance and secondary peristalsis. The aim of this study was to explore the clinical impact of FLIP panometry in addition to HRM. A retrospective chart review was performed on FLIP panometry cases utilizing the 322N catheter. Cases with prior foregut surgeries or botulinum injection within 6 months of FLIP panometry were excluded. EGJ-diameter and distensibility index (DI) and secondary contraction patterns at increasing balloon volumes were recorded. An EGJ-DI of ≥2.8 mm2/mm Hg at 60 mL was considered as a normal EGJ distensibility. CC diagnosis, Eckhardt score, Brief Esophageal Dysphagia Questionnaire, and clinical outcomes were obtained for each FLIP case. A total of 186 cases were included. Absent contractility and achalasia types 1 and 2 showed predominantly absent secondary contraction patterns, while type 3 had a variety of secondary contractile patterns on FLIP panometry. Among 77 cases with EGJ outflow obstruction (EGJOO), 60% had a low EGJ-DI. Among those with no motility disorder or ineffective esophageal motility on HRM, 27% had a low DI and 47% had sustained contractions on FLIP, raising concern for an esophageal dysmotility process along the achalasia and/or spastic spectrum. FLIP panometry often confirmed findings on HRM in achalasia and absent contractility. FLIP panometry is useful in characterizing EGJOO cases. Spastic features on FLIP panometry may raise concern for a motility disorder on the spastic spectrum not captured by HRM. Further studies are needed on FLIP panometry to determine how to proceed with discrepancy with HRM and explore diagnoses beyond the CC.

Kyoto international consensus report on anatomy, pathophysiology and clinical significance of the gastro-oesophageal junction.

OBJECTIVE: An international meeting was organised to develop consensus on (1) the landmarks to define the gastro-oesophageal junction (GOJ), (2) the occurrence and pathophysiological significance of the cardiac gland, (3) the definition of the gastro-oesophageal junctional zone (GOJZ) and (4) the causes of inflammation, metaplasia and neoplasia occurring in the GOJZ. DESIGN: Clinical questions relevant to the afore-mentioned major issues were drafted for which expert panels formulated relevant statements and textural explanations.A Delphi method using an anonymous system was employed to develop the consensus, the level of which was predefined as ≥80% of agreement. Two rounds of voting and amendments were completed before the meeting at which clinical questions and consensus were finalised. RESULTS: Twenty eight clinical questions and statements were finalised after extensive amendments. Critical consensus was achieved: (1) definition for the GOJ, (2) definition of the GOJZ spanning 1 cm proximal and distal to the GOJ as defined by the end of palisade vessels was accepted based on the anatomical distribution of cardiac type gland, (3) chemical and bacterial (Helicobacter pylori) factors as the primary causes of inflammation, metaplasia and neoplasia occurring in the GOJZ, (4) a new definition of Barrett's oesophagus (BO). CONCLUSIONS: This international consensus on the new definitions of BO, GOJ and the GOJZ will be instrumental in future studies aiming to resolve many issues on this important anatomic area and hopefully will lead to better classification and management of the diseases surrounding the GOJ.

A human Barrett's esophagus organoid system reveals epithelial-mesenchymal plasticity induced by acid and bile salts.

The pathogenesis of subsquamous intestinal metaplasia (SSIM), in which glands of Barrett's esophagus (BE) are buried under esophageal squamous epithelium, is unknown. In a rat model of reflux esophagitis, we found that columnar-lined esophagus developed via a wound-healing process involving epithelial-mesenchymal plasticity (EMP) that buried glands under ulcerated squamous epithelium. To explore a role for reflux-induced EMP in BE, we established and characterized human Barrett's organoids and sought evidence of EMP after treatment with acidic bile salts (AB). We optimized media to grow human BE organoids from immortalized human Barrett's cells and from BE biopsies from seven patients, and we characterized histological, morphological, and molecular features of organoid development. Features and markers of EMP were explored following organoid exposure to AB, with and without a collagen I (COL1) matrix to simulate a wound-healing environment. All media successfully initiated organoid growth, but advanced DMEM/F12 (aDMEM) was best at sustaining organoid viability. Using aDMEM, organoids comprising nongoblet and goblet columnar cells that expressed gastric and intestinal cell markers were generated from BE biopsies of all seven patients. After AB treatment, early-stage Barrett's organoids exhibited EMP with loss of membranous E-cadherin and increased protrusive cell migration, events significantly enhanced by COL1. Using human BE biopsies, we have established Barrett's organoids that recapitulate key histological and molecular features of BE to serve as high-fidelity BE models. Our findings suggest that reflux can induce EMP in human BE, potentially enabling Barrett's cells to migrate under adjacent squamous epithelium to form SSIM.NEW & NOTEWORTHY Using Barrett's esophagus (BE) biopsies, we established organoids recapitulating key BE features. During early stages of organoid development, a GERD-like wound environment-induced features of epithelial-mesenchymal plasticity (EMP) in Barrett's progenitor cells, suggesting that reflux-induced EMP can enable Barrett's cells to migrate underneath squamous epithelium to form subsquamous intestinal metaplasia, a condition that may underlie Barrett's cancers that escape detection by endoscopic surveillance, and recurrences of Barrett's metaplasia following endoscopic eradication therapy.

Randomized Trial of Medical versus Surgical Treatment for Refractory Heartburn.

BACKGROUND: Heartburn that persists despite proton-pump inhibitor (PPI) treatment is a frequent clinical problem with multiple potential causes. Treatments for PPI-refractory heartburn are of unproven efficacy and focus on controlling gastroesophageal reflux with reflux-reducing medication (e.g., baclofen) or antireflux surgery or on dampening visceral hypersensitivity with neuromodulators (e.g., desipramine). METHODS: Patients who were referred to Veterans Affairs (VA) gastroenterology clinics for PPI-refractory heartburn received 20 mg of omeprazole twice daily for 2 weeks, and those with persistent heartburn underwent endoscopy, esophageal biopsy, esophageal manometry, and multichannel intraluminal impedance-pH monitoring. If patients were found to have reflux-related heartburn, we randomly assigned them to receive surgical treatment (laparoscopic Nissen fundoplication), active medical treatment (omeprazole plus baclofen, with desipramine added depending on symptoms), or control medical treatment (omeprazole plus placebo). The primary outcome was treatment success, defined as a decrease of 50% or more in the Gastroesophageal Reflux Disease (GERD)-Health Related Quality of Life score (range, 0 to 50, with higher scores indicating worse symptoms) at 1 year. RESULTS: A total of 366 patients (mean age, 48.5 years; 280 men) were enrolled. Prerandomization procedures excluded 288 patients: 42 had relief of their heartburn during the 2-week omeprazole trial, 70 did not complete trial procedures, 54 were excluded for other reasons, 23 had non-GERD esophageal disorders, and 99 had functional heartburn (not due to GERD or other histopathologic, motility, or structural abnormality). The remaining 78 patients underwent randomization. The incidence of treatment success with surgery (18 of 27 patients, 67%) was significantly superior to that with active medical treatment (7 of 25 patients, 28%; P = 0.007) or control medical treatment (3 of 26 patients, 12%; P<0.001). The difference in the incidence of treatment success between the active medical group and the control medical group was 16 percentage points (95% confidence interval, -5 to 38; P = 0.17). CONCLUSIONS: Among patients referred to VA gastroenterology clinics for PPI-refractory heartburn, systematic workup revealed truly PPI-refractory and reflux-related heartburn in a minority of patients. For that highly selected subgroup, surgery was superior to medical treatment. (Funded by the Department of Veterans Affairs Cooperative Studies Program; ClinicalTrials.gov number, NCT01265550.).

In Esophageal Squamous Cells From Eosinophilic Esophagitis Patients, Th2 Cytokines Increase Eotaxin-3 Secretion Through Effects on Intracellular Calcium and a Non-Gastric Proton Pump.

BACKGROUND & AIMS: In upper airway cells, T helper 2 cytokines that signal through interleukin-4 (IL-4) receptor-α have been shown to stimulate eotaxin-3 secretion via a nongastric proton pump (ngH+,K+ATPase). To seek novel targets for eosinophilic esophagitis (EoE) treatments, we evaluated ngH+,K+ATPase expression in EoE squamous cells, and explored molecular pathways involved in eotaxin-3 secretion by IL-4 receptor-α signaling. METHODS: ngH+,K+ATPase expression in EoE cells was evaluated by quantitative real-time polymerase chain reaction and Western blotting. IL-4-stimulated eotaxin-3 secretion was measured by enzyme-linked immunosorbent assay after treatment with omeprazole, SCH 28080 (potassium-competitive acid blocker), ethylene glycol-bis(ß-aminoethyl)-N,N,N',N'-tetraacetoxymethyl ester (calcium chelator), 2-aminoethoxydiphenyl borate (inhibitor of endoplasmic reticulum calcium release), verapamil, and diltiazem (L-type calcium channel inhibitors). Intracellular calcium transients were measured by Fluo-4 fluorescence. Key experiments were confirmed in EoE primary cells and in RNA sequencing datasets from mucosal biopsies of patients with EoE and controls. RESULTS: EoE cells expressed ngH+,K+ATPase messenger RNA and protein. Omeprazole and SCH 28080 decreased IL-4-stimulated eotaxin-3 secretion. IL-4 increased intracellular calcium transients, and IL-4-stimulated eotaxin-3 secretion was blocked by ethylene glycol-bis(ß-aminoethyl)-N,N,N',N'-tetraacetoxymethyl ester, 2-aminoethoxydiphenyl borate, verapamil, and diltiazem. The combination of omeprazole and verapamil suppressed IL-4-stimulated eotaxin-3 secretion more than either agent alone. EoE biopsies expressed higher ngH+,K+ATPase and exhibited more calcium signaling than controls. CONCLUSIONS: EoE cells express a nongastric proton pump that mediates T helper 2 cytokine-stimulated eotaxin-3 secretion. IL-4 induces calcium release from the endoplasmic reticulum and calcium entry via L-type calcium channels, increasing intracellular calcium that contributes to eotaxin-3 secretion by EoE cells. L-type calcium channel inhibitors block T helper 2 cytokine-stimulated eotaxin-3 secretion, suggesting a potential role for these agents in EoE treatment.

ACG Clinical Guideline for the Diagnosis and Management of Gastroesophageal Reflux Disease.

Gastroesophageal reflux disease (GERD) continues to be among the most common diseases seen by gastroenterologists, surgeons, and primary care physicians. Our understanding of the varied presentations of GERD, enhancements in diagnostic testing, and approach to patient management have evolved. During this time, scrutiny of proton pump inhibitors (PPIs) has increased considerably. Although PPIs remain the medical treatment of choice for GERD, multiple publications have raised questions about adverse events, raising doubts about the safety of long-term use and increasing concern about overprescribing of PPIs. New data regarding the potential for surgical and endoscopic interventions have emerged. In this new document, we provide updated, evidence-based recommendations and practical guidance for the evaluation and management of GERD, including pharmacologic, lifestyle, surgical, and endoscopic management. The Grading of Recommendations, Assessment, Development, and Evaluation system was used to evaluate the evidence and the strength of recommendations. Key concepts and suggestions that as of this writing do not have sufficient evidence to grade are also provided.

An Endoscopic and Histologic Study on Healing of Radiofrequency Ablation Wounds in Patients With Barrett's Esophagus.

INTRODUCTION: Radiofrequency ablation (RFA) of Barrett's esophagus (BE) inflicts a wound spanning 3 epithelial types (stratified squamous, Barrett's metaplasia, gastric epithelium), yet the esophageal injury heals almost completely with squamous epithelium. Knowledge of how this unique wound heals might elucidate mechanisms underlying esophageal metaplasia. We aimed to prospectively and systematically characterize the early endoscopic and histologic features of RFA wound healing. METHODS: Patients with nondysplastic BE had endoscopy with systematic esophageal photographic mapping, biopsy, and volumetric laser endomicroscopy performed before and at 1, 2, and 4 weeks after RFA. RESULTS: Seven patients (6 men; mean age 56.1 ± 10.9 years) completed this study. Squamous re-epithelialization of RFA wounds did not only progress exclusively through squamous cells extending from the proximal wound edge but also progressed through islands of squamous epithelium sprouting throughout the ablated segment. Volumetric laser endomicroscopy revealed significant post-RFA increases in subepithelial glandular structures associated with the squamous islands. In 2 patients, biopsies of such islands revealed newly forming squamous epithelium contiguous with immature-appearing squamous cells arising from esophageal submucosal gland ducts. Subsquamous intestinal metaplasia (SSIM) was found in biopsies at 2 and/or 4 weeks after RFA in 6 of 7 patients. DISCUSSION: RFA wounds in BE are re-epithelialized, not just by squamous cells from the proximal wound margin but by scattered squamous islands in which esophageal submucosal gland duct cells seem to redifferentiate into the squamous progenitors that fuel squamous re-epithelialization. SSIM can be found in most patients during the healing process. We speculate that this SSIM might underlie Barrett's recurrences after apparently successful eradication.

Timing of Resumption of Anticoagulation After Polypectomy and Frequency of Post-procedural Complications: A Post-hoc Analysis.

BACKGROUND: Optimal timing for anticoagulation resumption after polypectomy is unclear. We explored the association between timing of anticoagulation resumption and occurrence of delayed post-polypectomy bleeding (PPB) and thromboembolic (TE) events. METHODS: We performed a post-hoc analysis of patients in an earlier study whose anticoagulants were interrupted for polypectomy. We compared rates of clinically important delayed PPB and TE events in relationship to timing of anticoagulant resumption. Late resumption was defined as > 2 days after polypectomy. RESULTS: Among 437 patients, 351 had early and 86 late resumption. Compared to early resumers, late resumers had greater polypectomy complexity. PPB rate was higher (but not significantly) in the late versus early resumers (2.3% vs. 0.9%, 1.47% greater, 95% CI [- 2.58 to 5.52], p = 0.26). TE events were more frequent in late versus early resumers [0% vs. 1.2% at 30 days, 0% vs. 2.3%, 95% CI 0.3-8, (p = 0.04) at 90 days]. On multivariate analysis, timing of restarting anticoagulation was not a significant predictor of PPB (OR 0.97, 95% CI 0.61-1.44, p = 0.897). Significant predictors were number of polyps ≥ 1 cm (OR 4.14, 95% CI 1.27-13.66, p = 0.014) and use of fulguration (OR 11.43, 95% CI 1.35-80.80, p = 0.014). CONCLUSIONS: Physicians delayed anticoagulation resumption more commonly after complex polypectomies. The timing of restarting anticoagulation was not a significant risk factor for PPB and late resumers had significantly higher rates of TE events within 90 days. Considering the potentially catastrophic consequences of TE events and the generally benign outcome of PPBs, clinicians should be cautious about delaying resumption of anticoagulation after polypectomy.

Mast cell effects on esophageal smooth muscle and their potential role in eosinophilic esophagitis and achalasia.

Mast cells and eosinophils are the key effector cells of allergic disorders. Although most studies on eosinophilic esophagitis (EoE), an allergic disorder of the esophagus, have focused on the role of eosinophils, recent studies suggest a major role for mast cells in causing the clinical manifestations of this disease. Cellular and animal studies have demonstrated that mast cells can cause esophageal muscle cells to proliferate and differentiate into a more contractile phenotype, and that mediators released by degranulating mast cells such as tryptase and histamine can activate smooth muscle contraction pathways. Thus, activated mast cells in the esophageal muscularis propria might cause esophageal motility abnormalities, including the failure of lower esophageal sphincter relaxation typical of achalasia. In addition, mast cells have been implicated in the pathogenesis of a number of neurodegenerative disorders of the central nervous system such as Alzheimer's and Parkinson's diseases, because degranulating mast cells release proinflammatory and cytotoxic mediators capable of damaging neurons. Such mast cell degranulation in the myenteric plexus of the esophagus could cause the loss of enteric neurons that characterizes achalasia. In this report, we review the molecular mechanisms of esophageal smooth muscle contraction, and how mast cells products might affect that muscle and cause neurodegeneration in the esophagus. Based on these data, we present our novel, conceptual model for an allergy-induced form of achalasia mediated by mast cell activation in the esophageal muscularis propria.

Obesity and its effects on the esophageal mucosal barrier.

Obesity is associated with gastroesophageal reflux disease (GERD) and its complications including reflux esophagitis, Barrett's esophagus, and esophageal adenocarcinoma. Traditionally, these associations have been attributed to the mechanical effect of abdominal fat in increasing intra-abdominal pressure, thereby promoting gastroesophageal reflux and causing disruption of antireflux mechanisms at the esophagogastric junction. However, recent studies suggest that visceral adipose tissue (VAT) produces numerous cytokines that can cause esophageal inflammation and impair esophageal mucosal barrier integrity through reflux-independent mechanisms that render the esophageal mucosa especially susceptible to GERD-induced injury. In this report, we review mechanisms of esophageal mucosal defense, the genesis and remodeling of visceral adipose tissue during obesity, and the potential role of substances produced by VAT, especially the VAT that encircles the esophagogastric junction, in the impairment of esophageal mucosal barrier integrity that leads to the development of GERD complications.

Classifying Esophageal Motility by FLIP Panometry: A Study of 722 Subjects With Manometry.

INTRODUCTION: Functional luminal imaging probe (FLIP) panometry can evaluate esophageal motility in response to sustained esophageal distension at the time of sedated endoscopy. This study aimed to describe a classification of esophageal motility using FLIP panometry and evaluate it against high-resolution manometry (HRM) and Chicago Classification v4.0 (CCv4.0). METHODS: Five hundred thirty-nine adult patients who completed FLIP and HRM with a conclusive CCv4.0 diagnosis were included in the primary analysis. Thirty-five asymptomatic volunteers ("controls") and 148 patients with an inconclusive CCv4.0 diagnosis or systemic sclerosis were also described. Esophagogastric junction (EGJ) opening and the contractile response (CR) to distension (i.e., secondary peristalsis) were evaluated with a 16-cm FLIP during sedated endoscopy and analyzed using a customized software program. HRM was classified according to CCv4.0. RESULTS: In the primary analysis, 156 patients (29%) had normal motility on FLIP panometry, defined by normal EGJ opening and a normal or borderline CR; 95% of these patients had normal motility or ineffective esophageal motility on HRM. Two hundred two patients (37%) had obstruction with weak CR, defined as reduced EGJ opening and absent CR or impaired/disordered CR, on FLIP panometry; 92% of these patients had a disorder of EGJ outflow per CCv4.0. DISCUSSION: Classifying esophageal motility in response to sustained distension with FLIP panometry parallels the swallow-associated motility evaluation provided with HRM and CCv4.0. Thus, FLIP panometry serves as a well-tolerated method that can complement, or in some cases be an alternative to HRM, for evaluating esophageal motility disorders.