A synthesis and subgroup analysis of the eosinophilic esophagitis tissue transcriptome

BACKGROUND

Eosinophilic esophagitis (EoE) is a chronic immune mediated inflammatory disorder of the esophagus. It is still unknown why children and adults present differently, and there is little evidence about why it is more common in men than women.

OBJECTIVE

Our aim was to synthesize published and unpublished esophageal bulk RNA-sequencing (RNA-seq) data to gain novel insights into the pathobiology of EoE and examine the differences in EoE transcriptome by sex and age group.

METHODS

Esophageal bulk RNA-seq data from 5 published and 2 unpublished studies resulting in 137 subjects (EoE: N = 76; controls: N = 61) were analyzed. For overall analysis, combined RNA-seq data of patients with EoE were compared with those of controls and subgroup analysis was conducted in patients with EoE by age of the patient (children [<18 years] vs adults [≥18 years]) and sex (female vs male). Gene-set enrichment analysis, ingenuity pathway analysis (IPA), cell-type analysis, immunohistochemistry, and T-cell or B-cell receptor analysis were performed.

RESULTS

Overall analysis identified dysregulation of new genes in EoE compared with controls. IPA revealed that EoE is characterized by a mixed inflammatory response compared with controls. Cell-type analysis showed that cell composition varied with age: children had more mast cells, whereas adults had more macrophages. Finally, gene-set enrichment analysis and IPA revealed pathways that were differentially regulated in adults versus children and male versus female patients with EoE.

CONCLUSIONS

Using a unique approach to analyze bulk RNA-seq data, we found that EoE is characterized by a mixed inflammatory response, and the EoE transcriptome may be influenced by age and sex. These findings enhance insights into the molecular mechanisms of EoE.

Opioid Exposure Differentially Impacts Esophageal Body Contraction Over the Lower Esophageal Sphincter

BACKGROUND & AIMS

Studies with limited sample sizes have investigated association of chronic opioid use with motility disorders of esophagogastric junction and esophageal body peristalsis. Our aims were to use a large cohort of patients to assess (1) the impact of opioid exposure on clinical and manometric characteristics, and (2) the association of opioid exposure with higher long-term symptom burden.

METHODS

Patients recruited from a tertiary medical center who underwent high-resolution manometry (HRM) between 2007 and 2018 were included. Demographics, opiate exposure, clinical symptoms, and HRM parameters were compared. Patient-Reported Outcomes Measurement Information System-Gastrointestinal swallowing domain (PROMIS-GI swallowing domain) and Eckardt score were administered via phone interviews in patients with hypercontractile esophagus (HE) or distal esophageal spasm (DES) to determine long-term symptom burden between opioid and nonopioid users.

RESULTS

Our cohort included 4075 patients (869 with opiate exposure with median morphine milligram equivalent [interquartile range] of 30 [10-45]). Patients in the opioid group were significantly more likely to have dysphagia (65% vs 51%, P < .01) and diagnosis of DES (11% vs 5%, P < .01) and HE (9% vs 3%, P < .01). Partial opioid agonists were not associated with motility abnormalities. Patients on opioids had significantly higher symptom burden on median (interquartile range) follow-up of 8.9 years (5.8-10.4) post manometric diagnosis with median PROMIS-GI swallowing domain score of 21.5 (17-25) compared with the nonopioid group at 15 (9.8-21, P = .03).

CONCLUSIONS

Nearly 2 of 3 patients with opioid exposure undergoing HRM have dysphagia and more than 25% of them with dysphagia as the primary symptom have a diagnosis of either DES or HE. Opioid users with spastic disorders have higher symptom burden long-term compared with nonopioid users.

Impedance and Histologic Characteristics of the Sub-Laryngeal Esophagus Distinguish Eosinophilic Esophagitis From Other Esophageal Disorders

BACKGROUND & AIMS

The region of the esophagus 15-17 cm below the incisors, called the sub-upper esophageal sphincter (sub-UES), has not been characterized in adults with eosinophilic esophagitis (EoE) but appears different during endoscopy. We investigated how the sub-UES differs from the remaining esophagus in patients with EoE and aimed to determine whether these differences be used to distinguish patients with EoE from those with lichen planus.

METHODS

We performed a prospective study of 14 patients with EoE, 7 patients with lichen planus (based on presence of Civatte bodies, dysphagia, and/or narrow esophagus with thin esophageal mucosa without signs of EoE), and 20 patients undergoing upper endoscopy for upper gastrointestinal or with dysphagia but without features of EoE (controls) at a single medical center from 2015 through 2018. Biopsies from the distal, middle, and sub-UES regions of the esophagus were analyzed by histology, quantitative PCR, and immunohistochemistry. We measured mucosal impedance (MI) in all subjects at the sub-UES and 2 cm, 5 cm, and 10 cm from the gastro-esophageal junction.

RESULTS

Patients with EoE had significantly fewer eosinophils (median, 2 eosinophils/high-powered field [HPF]; range, 0-8 eosinophils/HPF) in sub-UES tissues compared with distal esophagus (median, 50 eosinophils/HPF; range, 22.5-60.8 eosinophils/HPF; P < .0001) or middle esophagus (median, 32 eosinophils/HPF; range, 19.3-60; P < .0001). Sub-UES tissues from patients with EoE had significantly less basal cell hyperplasia (P < .01), papillary elongation (P < .01), and dilated intercellular spaces (P < .01) than middle or and distal esophagus. MI in the sub-UES did not differ significantly between patients with EoE vs controls (P = .24), but was significantly lower in patients with lichen planus (median, 1344 ohms; range, 1046-1488) than patients with EoE (median, 2880 ohms; range, 2149-4858) (P < .001). mRNA and protein expression patterns did not differ significantly in the sub-UES of patients with EoE vs controls, except for expression of desmoglein-1, which was increased in sub-UES tissues from patients with EoE.

CONCLUSIONS

Sub-UES tissues from patients with EoE differ in numbers of eosinophils, histologic features, and MI compared to controls or patients with lichen planus. These features might help to distinguish these 2 diseases.

Measurements of Duodenal Mucosal Integrity Are Altered in Celiac Disease

Altered barrier function is a part of celiac disease (CeD) pathophysiology that we currently cannot reliably measure. Catheter-based mucosal integrity (MI) is an endoscopic technology that has identified altered esophageal barrier function in esophageal disease.¹ The aim of this study was to evaluate feasibility, safety, and clinical utility of measuring duodenal integrity with an MI catheter in patients with and without CeD.

Development and Validation of a Mucosal Impedance Contour Analysis System to Distinguish Esophageal Disorders

BACKGROUND & AIMS

Diagnostic testing for chronic esophageal disorders relies on histopathology analysis of biopsies or uncomfortable transnasal catheters or wireless pH monitoring, which capture abnormal intraluminal refluxate. We therefore developed a balloon mucosal impedance (MI) catheter system that instantly detects changes in esophageal mucosal integrity during endoscopy over a long segment of the esophagus. We performed a prospective study to evaluate the ability of a balloon-incorporated MI catheter to detect and evaluate esophageal disorders, including gastroesophageal reflux disease (GERD) and eosinophilic esophagitis (EoE).

METHODS

We performed a prospective study of 69 patients undergoing esophagogastroduodenoscopy with or without wireless pH monitoring. Patients were classified as having GERD (erosive esophagitis or abnormal pH; n = 24), EoE (confirmed with pathology analysis of tissues from both distal and proximal esophagus; n = 21), or non-GERD (normal results from esophagogastroduodenoscopy and pH tests; n = 24). Receiver operating characteristic curves and area under the operating characteristic curve (AUC) were used to compare the accuracy of balloon MI in diagnosis. Probabilities of assignment to each group (GERD, non-GERD, or EoE) were estimated using multinomial logistic regression. Association between MI patterns and diagnoses were validated using data from patients seen at 3 separate institutions.

RESULTS

MI pattern along the esophageal axis differed significantly (P < .01) among patients with GERD, EoE, and non-GERD. Patients with non-GERD had higher MI values along all measured segments. The MI pattern for GERD was easily distinguished from that of EoE: in patients with GERD, MI values were low in the distal esophagus and normalized along the proximal esophagus, whereas in patients with EoE, measurements were low in all segments of the esophagus. Intercept and rate of rise of MI value (slope) as distance increased from the squamocolumnar junction identified patients with GERD with an AUC = 0.67, patients with EoE with an AUC = 0.84, and patients with non-GERD with an AUC = 0.83 in the development cohort. One patient had an adverse event (reported mild chest pain after the procedure) and was discharged from the hospital without further events.

CONCLUSIONS

We developed a balloon MI catheter system that instantly detects changes in esophageal mucosal integrity during endoscopy and found it to be safe and able to identify patients with GERD, EoE, or non-GERD. We validated our findings in a separate cohort for patients. ClinicalTrials.gov ID NCT03103789.

Model to Select On-Therapy vs Off-Therapy Tests for Patients With Refractory Esophageal or Extraesophageal Symptoms

BACKGROUND & AIMS

It is not clear whether we should test for reflux in patients with refractory heartburn or extraesophageal reflux (EER) symptoms, such as cough, hoarseness, or asthma. Guidelines recommend testing patients by pH monitoring when they are on or off acid-suppressive therapies based on pretest probability of reflux, determined by expert consensus. However, it is not clear what constitutes a low or high pretest probability of reflux in these patients. We aimed to develop a model that clinicians can use at bedside to estimate pretest probability of abnormal reflux.

METHODS

We performed a prospective study of 471 adult patients with refractory heartburn (n = 214) or suspected EER symptoms (n = 257) who underwent endoscopy with wireless pH monitoring while they were off acid-suppressive treatment and assigned them to groups based on symptoms at presentation (discovery cohort). Using data from the discovery cohort, we performed proportional odds ordinal logistic regression to select factors (easy to obtain demographic criteria and clinical symptoms such as heartburn, regurgitation, asthma, cough, and hoarseness) associated with esophageal exposure to acid. We validated our findings in a cohort of 118 patients with the same features from 2 separate tertiary care centers (62% women; median age 59 years; 62% with cough as presenting symptom).

RESULTS

Abnormal pH (>5.5% of time spent at pH <4) was found in 56% of patients with heartburn and 63% of patients with EER (P = .15). Within EER groups, abnormal pH was detected in a significantly larger proportion (80%) of patients with asthma compared with patients with cough (60%) or hoarseness (51%; P < .01). Factors significantly associated with abnormal pH in patients with heartburn were presence of hiatal hernia and body mass index >25 kg/m². In patients with EER, the risk of reflux was independently associated with the presence of concomitant heartburn (odds ratio [OR] 2.0; 95% confidence interval [CI] 1.3-3.1), body mass index >25 kg/m² (OR 2.1; 95% CI 1.5-3.1), asthma (OR 2.0; 95% CI 1.2-3.5), and presence of hiatal hernia (OR 1.9; 95% CI 1.2-3.1). When we used these factors to create a scoring system, we found that a score of ≤2 excluded patients with moderate to severe reflux, with a negative predictive value of 80% in the discovery cohort and a negative predictive value of 85% in the validation cohort.

CONCLUSION

We developed a clinical model to estimate pretest probability of abnormal pH in patients who were failed by proton pump inhibitor therapy. This system can help guide clinicians at bedside in determining the most appropriate diagnostic test in this challenging group of patients.

Weight loss in achalasia is determined by its phenotype

Patients with achalasia present with dysphagia, regurgitation, and varying degrees of weight loss. However, despite it being a disorder of the lower esophageal sphincter with functional obstruction in all patients, it is unclear why certain patients lose significantly more weight compared to others. The aims of this study are to assess demographic, clinical, and manometric characteristics of a large cohort of patients with achalasia to determine potential correlates of weight loss in this population. Patients with diagnosis of achalasia referred to our center between 2009 and 2016 were evaluated. Demographic and physiologic tests between those with and without weight loss were compared. The cohort of patients with initial self-reported weight loss were studied to determine change in weight after intervention (pneumatic dilation or myotomy). The Kruskal-Wallis test was used for comparison of continuous variables between groups and Pearson's χ2 test was used for comparison of categorical variables between groups. 138 patients with achalasia were evaluated. 35 patients were excluded due to lack of manometric data and 3 from lack of documented weight resulting in the study population of 100 patients with achalasia [51% male, median age: 56 years]. Weight loss was reported in 51/100 (51%) patients. BMI was lower in patients who reported weight loss (25 vs. 31, P < 0.001) with a median weight loss of 28 lbs (14-40 lbs). There were no significant differences in age at diagnosis, gender, or symptom presentation (dysphagia, regurgitation, or chest pain) between the groups. However, more patients with type II achalasia (63%) reported weight loss as compared to other sub-types (P = 0.013). 73% of type III achalasia denied having weight loss. Patients who denied weight loss had symptoms for longer duration (24 vs. 12 months, P < 0.001) and had lower mean residual LES pressure (20 vs. 30 mmHg, P = 0.006). Postintervention 42% of patients reported no weight regain despite appropriate therapy for achalasia with median follow-up of 22 months (range: 6-90 months). Type II achalasia patients are most likely and type III achalasia are least likely to have weight loss compared to type I achalasia. Given that no other demographic/physiologic parameters predicted weight loss, the role of underlying inflammatory cascade in achalasia phenotypes deserves special attention.

Esophageal Mucosal Impedance Patterns Discriminate Patients With Eosinophilic Esophagitis From Patients With GERD

BACKGROUND & AIMS

It is a challenge to make a diagnosis of eosinophilic esophagitis (EoE) because its symptoms and histologic features overlap with those of gastroesophageal reflux disease (GERD). A minimally invasive device was recently developed to detect mucosal impedance (MI) that measures epithelial integrity during upper endoscopy. We aimed to quantify MI along the esophagus and identify patterns that differentiated patients with and without GERD from those with EoE, and determine whether MI values and patterns are sufficient to identify patients with EoE using histologic findings as a reference.

METHODS

We performed a retrospective analysis of 91 patients with upper gastrointestinal symptoms referred for diagnostic testing for GERD and EoE from 2012 through 2014 (discovery set). During the first endoscopy, MI measurements were obtained at 2, 5, and 10 cm from the squamocolumnar junction. GERD was confirmed by ambulatory pH tests, and histologic analyses of biopsies were used to confirm EoE. We then used statistical modeling to identify MI patterns along the esophagus (at 10 cm, 5 cm, and 2 cm) that associated with GERD vs EoE. We validated our findings in a prospective cohort of 49 patients undergoing elective upper endoscopy for dysphagia, from 2015 through 2016, testing the ability of MI patterns to identify patients with vs. without EoE.

RESULTS

We found patients with EoE to have a unique MI pattern, with low values along the esophageal axis. MI measurements at 5 cm could discern patients with normal vs abnormal mucosa with 83% sensitivity and 79% specificity, and patients with EoE vs GERD with 84% sensitivity and 70% specificity; these measurements differentiated the patient populations with the highest level of accuracy of any of the 6 measurements tested. In the validation study, a rater using the esophageal MI pattern identified patients with EoE with 100% sensitivity and 96% specificity.

CONCLUSION

We identified and validated a pattern of MI along the esophagus that can identify patients with EoE vs normal mucosa or GERD with high levels of sensitivity.

Symptom association probability does not reliably distinguish functional heartburn from reflux hypersensitivity

BACKGROUND

Symptom association probability (SAP) is thought to distinguish reflux hypersensitivity from functional disorders. A diagnosis of hypersensitive oesophagus (SAP-positive) indicates that gastro-oesophageal reflux disease (GERD) is the cause of continued symptoms.

AIM

To conduct an analysis of pH and symptom criteria that lead to a diagnosis of SAP-positivity METHODS: We calculated SAP for 205 patients with GERD symptoms refractory to proton pump inhibitor (PPI) therapy who underwent endoscopy with wireless pH monitoring from 2007 to 2014. Patients were divided into three groups: pH-negative with no oesophagitis (n = 45), pH-positive with no oesophagitis (n = 130), and patients with oesophagitis (n = 30). We constructed a 2 × 2 table of symptom and reflux event association and quantified the number of 2-minute intervals for each of the 2 × 2 variables that distinguished SAP-positive from SAP-negative. In a separate cohort of 58 patients who had undergone anti-reflux surgery, we evaluated the effects of pre-surgery SAP.

RESULTS

The difference in symptom association parameters that led to a diagnosis of an SAP-positive was small (2.98% in oesophagitis-positive; 1.56% in oesophagitis-negative/pH-positive; 0.48% in oesophagitis-negative/pH-negative). In the pH-negative/oesophagitis-negative group, a difference of 0.48% led to a diagnosis of hypersensitivity. There was significant variability in SAP values between day 1 and day 2 of pH testing in all groups, with the greatest in the oesophagitis-positive group, despite objective evidence for reflux (27% in oesophagitis-positive, 19% pH-positive/oesophagitis-negative, and 7% in pH-negative/oesophagitis-negative). Pre-surgery SAP was not associated with response to anti-reflux surgery.

CONCLUSION

In PPI-refractory GERD, SAP cannot accurately distinguish reflux hypersensitivity from functional oesophageal symptoms.

Association Between Response to Acid-Suppression Therapy and Efficacy of Antireflux Surgery in Patients With Extraesophageal Reflux

BACKGROUND & AIMS

The effectiveness of antireflux surgery (ARS) varies among patients with extraesophageal manifestations of gastroesophageal reflux disease (GERD). By studying a cohort of patients with primary extraesophageal symptoms and abnormal physiologic markers for GERD, we aimed to identify factors associated with positive outcomes from surgery, and compare outcomes to those with typical esophageal manifestations of GERD.

METHODS

We performed a retrospective cohort study to compare adult patients with extraesophageal and typical reflux symptoms who underwent de novo ARS from 2004 through 2012 at a tertiary care center. All 115 patients (79 with typical GERD and 36 with extraesophageal manifestations of GERD) had evidence of abnormal distal esophageal acid exposure based on pH testing or endoscopy. The principle outcome was time to primary symptom recurrence after surgery, based on patient reports of partial or total recurrence of symptoms at follow-up visits. Patients were followed up for a median duration of 66 months (interquartile range, 52-77 mo).

RESULTS

The median time to recurrence of symptoms in the overall cohort was 68 months (11.5 months in the extraesophageal cohort vs >132 months in the typical cohort). Symptom recurrence after ARS was associated with having primarily extraesophageal symptoms (adjusted hazard ratio, 2.34; 95% confidence interval, 1.31-4.17) and poor preoperative symptom response to acid-suppression therapy (AST) (hazard ratio, 3.85; 95% confidence interval, 2.05-7.22). Patients with primary extraesophageal symptoms who had a full or partial preoperative AST response experienced lower rates of symptom recurrence compared to patients with poor AST response (P < .01). The rate of symptom recurrence was lowest among patients with primary typical reflux symptoms who had a partial or full symptom response to AST (P < .01). The severity of acid reflux on pH testing, symptom indices, severity of esophagitis, and hiatal hernia size were not associated with symptom response.

CONCLUSIONS

In a retrospective study, we found the effectiveness of ARS to be less predictable in patients with extraesophageal symptoms of GERD than in patients with typical GERD. Response to AST before surgery was associated with ARS effectiveness in patients with extraesophageal reflux symptoms. Caution should be exercised when advocating ARS for patients with extraesophageal symptoms that do not respond to AST.

Randomized controlled trial comparing esophageal dilation to no dilation among adults with esophageal eosinophilia and dysphagia

The role of esophageal dilation in patients with esophageal eosinophilia with dysphagia remains unknown. The practice of dilation is currently based on center preferences and expert opinion. The aim of this study is to determine if, and to what extent, dysphagia improves in response to initial esophageal dilation followed by standard medical therapies. We conducted a randomized, blinded, controlled trial evaluating adult patients with dysphagia and newly diagnosed esophageal eosinophilia from 2008 to 2013. Patients were randomized to dilation or no dilation at time of endoscopy and blinded to dilation status. Endoscopic features were graded as major and minor. Subsequent to randomization and endoscopy, all patients received fluticasone and dexlansoprazole for 2 months. The primary study outcome was reduction in overall dysphagia score, assessed at 30 and 60 days post-intervention. Patients with severe strictures (less than 7-mm esophageal diameter) were excluded from the study. Thirty-one patients were randomized and completed the protocol: 17 randomized to dilation and 14 to no dilation. Both groups were similar with regard to gender, age, eosinophil density, endoscopic score, and baseline dysphagia score. The population exhibited moderate to severe dysphagia and moderate esophageal stricturing at baseline. Overall, there was a significant (P < 0.001) but similar reduction in mean dysphagia score at 30 and 60 days post-randomization compared with baseline in both groups. No significant difference in dysphagia scores between treatment groups after 30 (P = 0.93) or 60 (P = 0.21) days post-intervention was observed. Esophageal dilation did not result in additional improvement in dysphagia score compared with treatment with proton pump inhibitor and fluticasone alone. In patients with symptomatic esophageal eosinophilia without severe stricture, dilation does not appear to be a necessary initial treatment strategy.

Providing Hospitalized Patients With an Educational Booklet Increases the Quality of Colonoscopy Bowel Preparation

BACKGROUND & AIMS

Inadequate bowel preparation is a problem frequently encountered by gastroenterologists who perform colonoscopies on hospitalized patients. A method is needed to increase the quality of bowel preparation in inpatients. An educational booklet has been shown to increase the overall quality of bowel preparation for outpatients. We performed a prospective study to evaluate the effects of an educational booklet on the quality of bowel preparation in a group of hospitalized patients.

METHODS

We performed a randomized, single-blind, controlled trial of all inpatients at a tertiary care medical center scheduled for inpatient colonoscopy from October 2013 through March 2014. They were randomly assigned to groups that were (n = 45) or were not (controls, n = 40) given the booklet before bowel preparation the evening before their colonoscopy. All patients received a standard bowel preparation (clear liquid diet the day before the procedure, followed by split-dose GoLYTELY). At the colonoscopy, the Boston Bowel preparation scale (BBPS) was used to assess bowel preparation. The primary outcome measure was adequate bowel preparation (a total BBPS score ≥6 with all segment scores ≥2). Secondary outcomes assessed included total BBPS score, BBPS segment score, and a total BBPS score of 0.

RESULTS

There were no differences between the groups in age, race, sex, body mass index, history of colonoscopy, history of polyps, or time of colonoscopy. Twenty-eight patients who received the booklet (62%) and 14 who did not (35%) had an adequate bowel preparation (P = .012). The number needed to treat to attain adequate bowel preparation was 4. After adjusting for age and history of prior colonoscopies, the odds of achieving an adequate bowel preparation and a higher total BBPS score after receipt of the booklet were 3.14 (95% confidence interval, 1.29-7.83) and 2.27 (95% confidence interval, 1.05-4.88), respectively. Three patients in the booklet group and 9 in the no-booklet group had a BBPS score of 0 (P = .036). The mean BBPS segment score was greater for the booklet group than the no-booklet group (right colon, P = .097; transverse colon, P = .023; left colon, P = .045).

CONCLUSIONS

In a randomized controlled trial, we found that providing hospitalized patients with an educational booklet on colonoscopy preparation increases the odds of a quality bowel preparation more than 2-fold.

Airway Hypersensitivity, Reflux, and Phonation Contribute to Chronic Cough

BACKGROUND & AIMS

Although chronic cough is common, its etiology is often elusive, making patient management a challenge. Gastroesophageal reflux and airway hypersensitivity can cause chronic cough. We explored the relationship between reflux, phonation, and cough in patients with idiopathic chronic cough.

METHODS

We performed a blinded, cross-sectional study of nonsmoking patients with chronic cough (duration, >8 weeks) refractory to reflux treatment referred to the Digestive Disease Center at Vanderbilt University. All underwent 24-hour acoustic recording concurrently and temporally synchronized with ambulatory pH-impedance monitoring. Cough, phonation, and pH-impedance events were recorded. We evaluated the temporal relationship between cough and phonation or reflux events using Poisson and logistic regression.

RESULTS

Seventeen patients met the inclusion criteria (88% female; 100% white; median age, 63 years [interquartile age range, 52-66 years]; mean body mass index, 30.6 [interquartile range, 27.9-34.0]); there were 2048 analyzable coughing events. The probability of subsequent coughing increased with higher burdens of preceding cough, reflux, or phonation. Within the first 15 minutes after a cough event, the cough event itself was the main trigger of subsequent cough events. After this period, de novo coughing occurred with increases of 1.46-fold in association with reflux alone (95% confidence interval, 1.17-1.82; P < .001) and 1.71-fold in association with the combination of phonation and reflux events.

CONCLUSIONS

Antecedent phonation and reflux increased the rate of cough events in patients with idiopathic chronic cough. Reflux events were more strongly associated with increased rate of coughing. Our findings support the concept that airway hypersensitivity is a cause of chronic cough, and that the vocal folds may be an effector in chronic cough ClinicalTrials.gov number: NCT01263626.

Mucosal impedance discriminates GERD from non-GERD conditions

BACKGROUND & AIMS

Current diagnostic tests for gastroesophageal reflux disease (GERD) are suboptimal and do not accurately and reliably measure chronicity of reflux. A minimally invasive device has been developed to assess esophageal mucosal impedance (MI) as a marker of chronic reflux. We performed a prospective longitudinal study to investigate MI patterns in patients with GERD and common nonreflux conditions, to assess MI patterns before and after treatment with proton pump inhibitors and to compare the performance of MI and wireless pH tests.

METHODS

We evaluated MI in 61 patients with erosive esophagitis, 81 with nonerosive but pH-abnormal GERD, 93 without GERD, 18 with achalasia, and 15 with eosinophilic esophagitis. MI was measured at the site of esophagitis and at 2, 5, and 10 cm above the squamocolumnar junction in all participants. MI was measured before and after acid suppressive therapy, and findings were compared with those from wireless pH monitoring.

RESULTS

MI values were significantly lower in patients with GERD (erosive esophagitis or nonerosive but pH-abnormal GERD) or eosinophilic esophagitis than in patients without GERD or patients with achalasia (P < .001). The pattern of MI in patients with GERD differed from that in patients without GERD or patients with eosinophilic esophagitis; patients with GERD had low MI closer to the squamocolumnar junction, and values increased axially along the esophagus. These patterns normalized with acid suppressive therapy. MI patterns identified patients with esophagitis with higher levels of specificity (95%) and positive predictive values (96%) than wireless pH monitoring (64% and 40%, respectively).

CONCLUSIONS

Based on a prospective study using a prototype device, measurements of MI detect GERD with higher levels of specificity and positive predictive values than wireless pH monitoring. Clinical Trials.gov, Number: NCT01556919.

Preference of endoscopic ablation over medical prevention of esophageal adenocarcinoma by patients with Barrett's esophagus

BACKGROUND & AIMS

Endoscopic intervention or pharmacologic inhibition of cyclooxygenase might be used to prevent progression of Barrett's esophagus (BE) to esophageal adenocarcinoma (EAC). We investigated whether patients with BE prefer endoscopic therapy or chemoprevention of EAC.

METHODS

Eighty-one subjects with nondysplastic BE were given a survey that described 2 scenarios. The survey explained that treatment A (ablation), endoscopy, reduced lifetime risk of EAC by 50%, with 5% risk for esophageal stricture, whereas treatment B (aspirin) reduced lifetime risk of EAC by 50% and the risk of heart attack by 30%, yet increased the risk for ulcer by 75%. Subjects indicated their willingness to undergo either treatment A and/or treatment B if endoscopic surveillance were required every 3-5 years, every 10 years, or were not required. Visual aids were included to represent risk and benefit percentages.

RESULTS

When surveillance was required every 3-5 years, more subjects were willing to undergo treatment A than treatment B (78%, 63 of 81 vs 53%, 43 of 81; P < .01). There were no differences in age, sex, education level, or history of cancer, heart disease, or ulcer between patients willing to undergo treatment A and those willing to undergo treatment B. Altering the frequency of surveillance did not affect patients' willingness to undergo either treatment.

CONCLUSIONS

In a simulated scenario, patients with BE preferred endoscopic intervention over chemoprevention for EAC. Further investigation of the shared decision-making process regarding preventive strategies for patients with BE may be warranted.

The role of impedance monitoring in patients with extraesophageal symptoms

OBJECTIVES/HYPOTHESIS

Ambulatory esophageal impedance monitoring is commonly employed to assess for nonacid reflux in patients with extraesophageal reflux. We aimed to determine if on therapy impedance data can be predicted from off therapy upper endoscopy, manometry, or pH parameters.

STUDY DESIGN

Prospective Cohort Study.

METHODS

Patients with extraesophageal reflux symptoms and either partial- or nonresponders to twice-daily PPI underwent impedance monitoring on twice-daily PPI, as well as manometry, upper endoscopy, and 48-hour wireless pH monitoring off acid-suppressive medications for 1 week. Percent time pH < 4 and number of reflux episodes were obtained. Multivariable linear regression was used to determine association between the impedance data on therapy and upper endoscopy, manometry, and pH parameters measured off therapy.

RESULTS

Seventy-five patients (77% female, median BMI 29, 38% with hiatal hernia, and 19% with esophagitis) were studied both on and off therapy. Thirty-five percent had abnormal impedance monitoring on therapy and 84% had abnormal pH testing off therapy. There was no significant (P = 0.184) overall correlation between total number of impedance events and the baseline physiologic parameters of hiatal hernia, degree of acid reflux, or manometric findings, with only weak correlation (r = 0.54, P = 0.045) with % time pH < 4 among patients with esophagitis.

CONCLUSIONS

In patients with suspected extraesophageal reflux refractory to PPI therapy, impedance measures on therapy cannot be predicted from traditional baseline esophageal physiologic parameters. We recommend caution regarding over-interpretation of impedance data.

LEVEL OF EVIDENCE

2b.

Use of direct, endoscopic-guided measurements of mucosal impedance in diagnosis of gastroesophageal reflux disease

BACKGROUND & AIMS

Diagnostic tests for gastroesophageal reflux disease (GERD) are constrained because measurements are made at a single time point, so the long-term effects on the mucosa cannot be determined. We developed a minimally invasive system to assess changes in esophageal mucosal impedance (MI), a marker of reflux. We measured the extent of changes in MI along the esophagus and show that the device to assess MI can be used to diagnose patients with GERD.

METHODS

A single-channel MI catheter composed of a unique sensor array was designed to easily traverse the working channel of an upper endoscope. We performed a prospective longitudinal study of patients with erosive esophagitis (n = 19), nonerosive but pH-positive GERD (n = 23), and those without GERD (n = 27). MI was measured at the site of esophagitis as well as 2, 5, and 10 cm above the squamocolumnar junction. The MI values were compared among groups, at different levels along the esophageal axis.

RESULTS

Median MI values were significantly lower at the site of erosive mucosa (811 Ω; range, 621-1272 Ω) than other nonerosive regions (3723 Ω; range, 2421-4671 Ω; P = .001), and were significantly lower at 2 cm above the squamocolumnar junction in patients with GERD (2096 Ω; range, 1415-2808 Ω), compared with those without GERD (3607 Ω; range, 1973-4238 Ω; P = .008). There was a significant and graded increase in MI along the axis of the distal to proximal esophagus in patients with GERD that was not observed in individuals without reflux (P = .004).

CONCLUSIONS

Measurements of MI along the esophagus can be used to identify patients with GERD. ClinicalTrials.gov, number NCT01194323.