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.

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.

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.

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.

Frequent discrepancies among diagnostic tests for detecting lower esophageal sphincter-related obstruction.

BACKGROUND: There are frequent discrepancies among high-resolution manometry (HRM), functional lumen imaging probe (FLIP), and esophagram in identifying lower esophageal sphincter (LES)-related obstruction. We aimed to determine the frequency of those discrepancies and how they influenced clinical treatment/outcomes. METHODS: We identified patients who had all three tests (HRM, FLIP, and esophagram) and endoscopy performed for evaluation of esophageal symptoms in our Center for Esophageal Diseases. Discrepancies among the tests for the presence of LES obstruction were noted, and the performance of individual tests was compared against a consensus opinion rendered by a panel of esophagologists. Binary logistical regression was performed, and ROC curves were generated for prediction of the consensus clinical diagnosis of LES obstruction. KEY RESULTS: A total of 126 patients (mean age 57.9 ± 17.0 years; 67% female) met inclusion criteria. All three tests agreed on the presence or absence of LES obstruction in only 72 (57%) patients [no LES obstruction in 57 (45%), LES obstruction in 15 (12%)]. Thirteen patients (10%) had a change in management based on additional findings on FLIP +/- esophagram not seen on HRM with 69% having symptomatic improvement after LES-directed intervention. FLIP was the strongest predictor of a consensus diagnosis of LES obstruction by logistic regression and ROC (OR 23.36, AUC 0.796), followed by HRM (OR 15.41, AUC 0.764). CONCLUSIONS & INFERENCE: High-resolution manometry, functional lumen imaging probe, and esophagram each have considerable limitations for identifying LES obstruction, and discrepancies among these tests occur frequently. Multimodal testing is often required for adequate evaluation of LES-related obstruction.

Updates in the Management of Erosive Esophagitis.

Upon completion of this activity, participants will:Have increased knowledge regarding the Mechanistic differences between proton pump inhibitors (PPIs) and potassium-competitive acid blockers (PCABs) Evidence comparing PPIs with PCABs for the treatment of GERD and EE Have greater competence related to Selecting evidence-based treatments for EE.

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.

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).

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.

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.

Clinical role of ambulatory reflux monitoring in PPI non-responders: recommendation statements.

BACKGROUND: Optimal ambulatory reflux monitoring methodology in symptomatic reflux patients continues to be debated. AIMS: To utilise published literature and expert opinion to develop recommendation statements addressing use of ambulatory reflux monitoring in clinical practice METHODS: The RAND Appropriateness Method (RAM) was utilised among 17 experts with discussion, revision and two rounds of ranking of recommendation statements. Ambulatory reflux monitoring protocol, methodology and thresholds ranked as appropriate by ≥80% of panellists met the criteria for appropriateness. RESULTS: Prolonged (96-h recommended) wireless pH monitoring off proton pump inhibitor (PPI) was identified as the appropriate diagnostic tool to assess the need for acid suppression in patients with unproven gastro-oesophageal reflux disease (GERD) and persisting typical reflux symptoms despite once-daily PPI. Acid exposure time (AET) <4.0% on all days of monitoring with negative reflux-symptom association excludes GERD and does not support ongoing PPI treatment. Conversely, AET >6.0% across ≥2 days is conclusive evidence for GERD and supports treatment for GERD, while AET >10% across ≥2 days identifies severe acid burden that supports escalation of anti-reflux treatment. In previously proven GERD, impedance-pH monitoring on PPI is helpful in defining refractory GERD and mechanisms of continued symptoms; the presence of <40 reflux events, AET <2.0% and a negative reflux-symptom association does not support escalation of anti-reflux treatment. In contrast, AET > 4.0% and positive reflux-symptom association support escalation of anti-reflux treatment, including use of invasive therapeutics. CONCLUSIONS: Statements meeting appropriateness for average clinical care have been identified when utilising reflux monitoring in patients with typical reflux symptoms and PPI non-response.

Patient journey in erosive oesophagitis: real-world perspectives from US physicians and patients.

OBJECTIVE: Management of erosive oesophagitis (EE) remains suboptimal, with many patients experiencing incomplete healing, ongoing symptoms, and relapse despite proton pump inhibitor (PPI) treatment. The Study of Acid-Related Disorders investigated patient burden of individuals with EE in a real-world setting. DESIGN: US gastroenterologists (GIs) or family physicians (FPs)/general practitioners (GPs) treating patients with EE completed a physician survey and enrolled up to four patients with EE for a patient survey, with prespecified data extracted from medical records. RESULTS: 102 GIs and 149 FPs/GPs completed the survey; data were available for 73 patients (mean age at diagnosis, 45.4 years). Omeprazole was healthcare professional (HCP)-preferred first-line treatment (60.8% GIs; 56.4% FPs/GPs), and pantoprazole preferred second line (29.4% and 32.9%, respectively). Price and insurance coverage (both 55.5% HCPs) and familiarity (47.9%) key drivers for omeprazole; insurance coverage (52.0%), price (50.0%), familiarity (48.0%), initial symptom relief (46.0%), and safety (44.0%) key drivers for pantoprazole. Only 49.3% patients took medication as instructed all the time; 56.8% independently increased medication frequency some of the time. Despite treatment, 57.5% patients experienced heartburn and 30.1% regurgitation; heartburn was the most bothersome symptom. 58.9% patients believed that their symptoms could be better controlled; only 28.3% HCPs were very satisfied with current treatment options. 83.6% patients wanted long-lasting treatment options. Fast symptom relief for patients was a top priority for 66.1% HCPs, while 56.6% would welcome alternatives to PPIs. CONCLUSION: This real-world multicentre study highlights the need for new, rapidly acting treatments in EE that reduce symptom burden, offer durable healing and provide symptom control.

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.

Mechanisms and pathophysiology of Barrett oesophagus.

Barrett oesophagus, in which a metaplastic columnar mucosa that can predispose individuals to cancer development lines a portion of the distal oesophagus, is the only known precursor of oesophageal adenocarcinoma, the incidence of which has increased profoundly over the past several decades. Most evidence suggests that Barrett oesophagus develops from progenitor cells at the oesophagogastric junction that proliferate and undergo epithelial-mesenchymal transition as part of a wound-healing process that replaces oesophageal squamous epithelium damaged by gastroesophageal reflux disease (GERD). GERD also seems to induce reprogramming of key transcription factors in the progenitor cells, resulting in the development of the specialized intestinal metaplasia that is characteristic of Barrett oesophagus, probably through an intermediate step of metaplasia to cardiac mucosa. Genome-wide association studies suggest that patients with GERD who develop Barrett oesophagus might have an inherited predisposition to oesophageal metaplasia and that there is a shared genetic susceptibility to Barrett oesophagus and to several of its risk factors (such as GERD, obesity and cigarette smoking). In this Review, we discuss the mechanisms, pathophysiology, genetic predisposition and cells of origin of Barrett oesophagus, and opine on the clinical implications and future research directions.

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.