Concurrent abnormal non-acid reflux is associated with additional chronic rejection risk in lung transplant patients with increased acid exposure.

Acid reflux has been associated with allograft injury and rejection in lung transplant patients; however, the pathogenic role of non-acid reflux remains debated. We aimed to evaluate the impact of concurrent abnormal non-acid reflux with acid reflux on chronic rejection in lung transplant patients with acid reflux. This was a retrospective cohort study of lung transplant recipients who underwent pre-transplant combined impedance-pH study off acid suppression. Only subjects with acid exposure >4% were included. Non-acid reflux (pH > 4) episodes >27 was considered abnormal per prior normative studies. Chronic rejection was defined as chronic lung allograft dysfunction (CLAD) per International Society for Heart and Lung Transplantation criteria. Time-to-event analyses were performed using Cox proportional hazards and Kaplan-Maier methods, with censoring at death, anti-reflux surgery, or last follow-up. In total, 68 subjects (28 abnormal/40 normal non-acid reflux) met inclusion criteria for the study. Baseline demographic/clinical characteristics were similar between groups. Among this cohort of patients with increased acid exposure, subjects with concurrent abnormal non-acid reflux had significantly higher risk of CLAD than those without on Kaplan-Meier analysis (log-ranked P = 0.0269). On Cox multivariable regression analysis controlling for body mass index, age at transplantation, and proton pump inhibitor use, concurrent abnormal non-acid reflux remained independently predictive of increased CLAD risk (hazard ratio 2.31, confidence interval: 1.03-5.19, P = 0.04). Presence of concurrent abnormal non-acid reflux in lung transplant subjects with increased acid exposure is associated with additional risk of chronic rejection. Non-acid reflux may also contribute to pathogenicity in lung allograft injury/rejection, supporting a potential role for impedance-based testing in this population.

Baseline Peripheral Eosinophil Count Independently Predicts Proton Pump Inhibitor Response in Eosinophilic Esophagitis.

GOALS: To assess the predictive value of baseline peripheral absolute eosinophil counts (AECs) for proton pump inhibitor (PPI) response in eosinophilic esophagitis (EoE). BACKGROUND: PPI leads to histologic remission in ~50% of EoE patients, although there are few distinguishing clinical features between PPI-responsive (PPI-r-EoE) and nonresponsive (PPI-nr-EoE) diseases. Peripheral eosinophilia is present in ~50% of EoE cases and is associated with eosinophil density on esophageal biopsy and worse clinical outcomes. The association between peripheral eosinophilia and PPI-responsiveness in EoE remains unclear. STUDY: This is a retrospective cohort study of adult EoE patients at a tertiary center between 2012 and 2016. All patients underwent twice daily PPI trials for ≥8 weeks followed by repeat esophageal biopsies and were classified as PPI-r-EoE or PPI-nr-EoE based on histologic response (<15 eosinophils/high power field). Baseline peripheral AEC was obtained within 1 month before index endoscopy. Analyses were performed using Fisher exact/Student t test (univariate) and logistic regression (multivariable). RESULTS: One hundred eighty-three patients (91 PPI-nr-EoE and 92 PPI-r-EoE) were included. Mean peripheral AEC was higher among PPI-nr-EoE patients (0.41 vs 0.24 K/µL, P = 0.013). Baseline peripheral eosinophilia (>0.5 K/µL) was more prevalent among patients with PPI-nr-EoE (70.4% vs 45.5%, P = 0.023) and a history of food impaction (51.9% vs 23.7%, P = 0.0082). On multivariable analyses, peripheral eosinophilia remained an independent predictor for PPI response (adjacent odds ratio = 2.86, CI: 1.07-7.62, P = 0.036) and food impaction (adjacent odds ratio = 2.80, CI: 1.07-7.35, P = 0.037). CONCLUSIONS: Baseline peripheral eosinophilia independently predicts PPI nonresponse and food impaction in EoE patients. Peripheral AEC may help therapy selection in EoE and prevent delays in achieving histologic remission.

Abnormal bolus reflux on impedance-pH testing independently predicts 3-year pulmonary outcome and mortality in pulmonary fibrosis.

BACKGROUND AND AIM: Gastroesophageal reflux has been associated with idiopathic pulmonary fibrosis (IPF), although the directionality of the relationship has been debated. Data on the value of objective reflux measures in predicting IPF disease progression and mortality remain limited. We aimed to evaluate the association between multichannel intraluminal impedance and pH testing (MII-pH) and 3-year pulmonary outcomes in IPF patients. METHODS: This was a retrospective cohort study of adults with IPF who underwent pre-lung transplant MII-pH off acid suppression at a tertiary center. Patients were followed for 3 years after MII-pH for poor pulmonary outcomes (hospitalization for respiratory exacerbation or death). A secondary analysis was performed using mortality as outcome of interest. Time-to-event analyses using Kaplan-Meier and Cox regression were performed to evaluate associations between MII-pH and poor outcomes. RESULTS: One hundred twenty-four subjects (mean age = 61.7 ± 8 years, 62% male) were included. Increased bolus exposure time (BET) on MII-pH was associated with decreased time to poor pulmonary outcomes and death (log-ranked P-value = 0.017 and 0.031, respectively). On multivariable Cox regression analyses controlling for potential confounders including age, sex, smoking history, body mass index, proton pump inhibitor use, baseline pulmonary function, and anti-fibrotic therapy, increased BET was an independent predictor for poor pulmonary outcomes [hazard ratio 3.18 (95% confidence interval: 1.25-8.09), P = 0.015] and mortality [hazard ratio 11.3 (95% confidence interval: 1.37-63.9), P = 0.025] over 3 years. CONCLUSIONS: Increased BET on MII-pH is an independent predictor of poor pulmonary outcomes and mortality over 3 years in IPF patients. These findings also support a role for gastroesophageal reflux in IPF disease progression and the potential impact of routine reflux testing and treatment.

Pre-Lung transplant reflux testing demonstrates high prevalence of gastroesophageal reflux in cystic fibrosis and reduces chronic rejection risk.

BACKGROUND: Gastroesophageal reflux (GER) has been associated with poor outcomes after lung transplantation for chronic lung disease, including increased risk of chronic rejection. GER is common in cystic fibrosis (CF), but factors influencing the likelihood of pre-transplant pH testing, and the impact of testing on clinical management and transplant outcomes in patients with CF are unknown. AIM: To evaluate the role of pre-transplant reflux testing in the evaluation of lung transplant candidates with CF. METHODS: This was a retrospective study from 2007-2019 at a tertiary medical center that included all patients with CF undergoing lung transplant. Patients with pre-transplant anti-reflux surgery were excluded. Baseline characteristics (age at transplantation, gender, race, body mass index), self-reported GER symptoms prior to transplantation, and pre-transplant cardiopulmonary testing results, were recorded. Reflux testing consisted of either 24-h pH- or combined multichannel intraluminal impedance and pH monitoring. Post-transplant care included a standard immunosuppressive regimen, and regular surveillance bronchoscopy and pulmonary spirometry in accordance with institutional practice as well as in symptomatic patients. The primary outcome of chronic lung allograft dysfunction (CLAD) was defined clinically and histologically per International Society of Heart and Lung Transplantation criteria. Statistical analysis was performed with Fisher's exact test to assess differences between cohorts, and time-to-event Cox proportional hazards modeling. RESULTS: After applying inclusion and exclusion criteria, a total of 60 patients were included in the study. Among all CF patients, 41 (68.3%) completed reflux monitoring as part of pre-lung transplant evaluation. Objective evidence of pathologic reflux, defined as acid exposure time > 4%, was found in 24 subjects, representing 58% of the tested group. CF patients with pre-transplant reflux testing were older (35.8 vs 30.1 years, P = 0.01) and more commonly reported typical esophageal reflux symptoms (53.7% vs 26.3%, P = 0.06) compared to those without reflux testing. Other patient demographics and baseline cardiopulmonary function did not significantly differ between CF subjects with and without pre-transplant reflux testing. Patients with CF were less likely to undergo pre-transplant reflux testing compared to other pulmonary diagnoses (68% vs 85%, P = 0.003). There was a decreased risk of CLAD in patients with CF who underwent reflux testing compared to those who did not, after controlling for confounders (Cox Hazard Ratio 0.26; 95%CI: 0.08-0.92). CONCLUSION: Pre-transplant reflux testing revealed high prevalence of pathologic reflux in CF patients and was associated with decreased risk of CLAD. Systematic reflux testing may enhance outcomes in this patient population.

Ineffective esophageal motility is associated with acute rejection after lung transplantation independent of gastroesophageal reflux.

BACKGROUND: Gastroesophageal reflux is associated with poorer outcomes after lung transplant, likely through recurrent aspiration and allograft injury. Although prior studies have demonstrated a relationship between impedance-pH results and transplant outcomes, the role of esophageal manometry in the assessment of lung transplant patients remains debated, and the impact of esophageal dysmotility on transplant outcomes is unclear. Of particular interest is ineffective esophageal motility (IEM) and its associated impact on esophageal clearance. AIM: To assess the relationship between pre-transplant IEM diagnosis and acute rejection after lung transplantation. METHODS: This was a retrospective cohort study of lung transplant recipients at a tertiary care center between 2007 and 2018. Patients with pre-transplant anti-reflux surgery were excluded. Manometric and reflux diagnoses were recorded from pre-transplant esophageal function testing. Time-to-event analysis using Cox proportional hazards model was applied to evaluate outcome of first episode of acute cellular rejection, defined histologically per International Society of Heart and Lung Transplantation guidelines. Subjects not meeting this endpoint were censored at time of post-transplant anti-reflux surgery, last clinic visit, or death. Fisher's exact test for binary variables and student's t-test for continuous variables were performed to assess for differences between groups. RESULTS: Of 184 subjects (54% men, mean age: 58, follow-up: 443 person-years) met criteria for inclusion. Interstitial pulmonary fibrosis represented the predominant pulmonary diagnosis (41%). During the follow-up period, 60 subjects (33.5%) developed acute rejection. The all-cause mortality was 16.3%. Time-to-event univariate analyses demonstrated significant association between IEM and acute rejection [hazard ratio (HR): 1.984, 95%CI: 1.03-3.30, P = 0.04], confirmed on Kaplan-Meier curve. On multivariable analysis, IEM remained independently associated with acute rejection, even after controlling for potential confounders such as the presence of acid and nonacid reflux (HR: 2.20, 95%CI: 1.18-4.11, P = 0.01). Nonacid reflux was also independently associated with acute rejection on both univariate (HR: 2.16, 95%CI: 1.26-3.72, P = 0.005) and multivariable analyses (HR: 2.10, 95%CI: 1.21-3.64, P = 0.009), adjusting for the presence of IEM. CONCLUSION: Pre-transplant IEM was associated with acute rejection after transplantation, even after controlling for acid and nonacid reflux. Esophageal motility testing may be considered in lung transplant to predict outcomes.

Relationship Between Esophageal Disease and Pulmonary Fibrosis.

Esophageal disorders are prevalent among patients with chronic lung diseases, including idiopathic pulmonary fibrosis (IPF). Gastroesophageal reflux disease (GERD) has been associated with IPF prevalence, severity, and respiratory decline. The pathophysiologic relationship between GERD and IPF is likely bidirectional, with aspiration of refluxate leading to lung inflammation and fibrosis, while the restrictive pulmonary physiology may contribute to altered transdiaphragmatic pressure gradient and increased reflux. Esophageal symptoms are frequently absent and do not predict esophageal dysfunction or pathologic reflux in patients with IPF, and objective diagnostic tools including upper endoscopy, ambulatory reflux monitoring, and high-resolution manometry are often needed. Impedance-based testing that identifies both weakly/non-acidic and acid reflux may provide important additional diagnostic value beyond pH-based acid testing alone. Novel metrics and maneuvers, including advanced impedance measures on impedance-pH study and provocative testing on HRM, may hold promise to future diagnostic advancements. The main treatment options include medical therapy with acid suppressants and anti-reflux surgery, although their potential benefits in pulmonary outcomes of IPF require further validations. Future directions of research include identifying phenotypes of IPF patients who may benefit from esophageal testing and treatment, determining the optimal testing strategy and protocol, and prospectively assessing the value of different esophageal therapies to improve outcomes while minimizing risks. This review will discuss the pathophysiology, evaluation, and management of esophageal diseases, particularly GERD, in patients with IPF, as informed by the most recent publications in the field, in hopes of identifying targets for future study and research.

Assessment of Post-traumatic Stress Disorder Among Objective Esophageal Motility and Reflux Phenotypes in Symptomatic Veterans.

Prior research suggests post-traumatic stress disorder (PTSD) is associated with the development of esophageal symptoms. We aimed to evaluate the prevalence of PTSD in veterans with esophageal symptoms, and assess for differences in objective esophageal motility and reflux classifications. Consecutive veterans reporting esophageal symptoms (e.g., dysphagia and reflux) underwent clinical evaluation with standard reflux and motility testing. Relevant demographic, mental health, and clinical esophageal information was gathered. Patients were classified into "PTSD" and "Non-PTSD" groups based on the documentation of a clinician-confirmed diagnosis of PTSD in the medical chart. Of the 273 consecutive veterans (89% men, mean age: 62 years) that met inclusion criteria for the study, 34% had a clinician-confirmed diagnosis of PTSD. Differences existed between PTSD and non-PTSD groups on smoking, bipolar disorder, depression, ADHD, and opiate use. However, no differences existed in objectively determined motility or reflux phenotypes. While PTSD was highly prevalent among our sample of symptomatic veterans, the presence of PTSD was not associated with differences in motility classifications and reflux phenotypes. These findings are consistent with recent research in psychogastroenterology, which suggests psychological processes are important to consider across esophageal classifications.

Routine Reflux Testing Guides Timely Antireflux Treatment to Reduce Acute and Chronic Rejection After Lung Transplantation.

INTRODUCTION: Gastroesophageal reflux has been associated with poorer lung transplantation outcomes, although no standard approach to evaluation/management has been adopted. We aimed to evaluate the effect of timely antireflux treatment as guided by routine reflux testing on postlung transplant rejection outcomes. METHODS: This was a retrospective cohort study of lung transplant recipients at a tertiary center. All patients underwent pretransplant ambulatory pH monitoring. Timely antireflux treatment was defined as proton pump inhibitor initiation or antireflux surgery within 6 months of transplantation. Patients were separated into 3 groups: normal pH monitoring (-pH), increased reflux (+pH) with timely treatment, and +pH with delayed treatment. Rejection outcomes included acute rejection, bronchiolitis obliterans syndrome, and chronic lung allograft dysfunction per International Society for Heart and Lung Transplantation criteria. Time-to-event analyses using Cox proportional hazard models were applied. Patients not meeting outcomes were censored at death or last clinic visit. RESULTS: One hundred seventy-five patients (59% men/mean 56.3 yr/follow-up: 496 person-years) were included. On multivariable analyses, +pH/delayed treatment patients had higher risks of acute rejection (adjust hazard ratio [aHR]:3.81 [95% confidence interval [CI]: 1.90-7.64], P = 0.0002), bronchiolitis obliterans syndrome (aHR: 2.22 [95% CI: 1.07-4.58], P = 0.03), and chronic lung allograft dysfunction (aHR: 2.97 [95% CI: 1.40-6.32], P = 0.005) than +pH/timely treatment patients. Similarly, rejection risks were increased among +pH/delayed treatment patients vs -pH patients (all P < 0.05). No significant differences in rejection risks were noted between +pH/timely treatment patients and -pH patients. Failure/complications of antireflux treatment were rare and similar among groups. DISCUSSION: Timely antireflux treatment, as directed by pretransplant reflux testing, was associated with reduced allograft rejection risks and demonstrated noninferiority to patients without reflux. A standardized peri-transplant test-and-treat algorithm may guide timely reflux management to improve lung transplant outcomes.

Overlapping Transcriptional Profile in Proton Pump Inhibitor Responsive and Nonresponsive Eosinophilic Esophagitis.

INTRODUCTION: We compared esophageal mucosal gene transcript expression in proton pump inhibitor (PPI) responsive (PPI-R) eosinophilic esophagitis (EoE), PPI nonresponsive (PPI-NR) EoE, and healthy controls. METHODS: Transcript expression in midesophagus biopsies was determined using NanoString and a custom panel of EoE-specific genes. The top upregulated and downregulated genes with ≥2-fold difference in expression and statistically significant ( P < 0.05) were identified. RESULTS: Nearly all the top upregulated (17 of 20) and downregulated (5 of 5) genes in EoE, compared with healthy controls, were shared between the PPI-R and PPI-NR groups. DISCUSSION: Esophageal mucosal transcript expressions are remarkably similar in PPI-R EoE and PPI-NR EoE compared with healthy controls.

Artificial Intelligence-Based Assessment of Colorectal Polyp Histology by Elastic-Scattering Spectroscopy.

BACKGROUND: Colonoscopic screening and surveillance for colorectal cancer could be made safer and more efficient if endoscopists could predict histology without the need to biopsy and perform histopathology on every polyp. Elastic-scattering spectroscopy (ESS), using fiberoptic probes integrated into standard biopsy tools, can assess, both in vivo and in real time, the scattering and absorption properties of tissue related to its underlying pathology. AIMS: The objective of this study was to evaluate prospectively the potential of ESS to predict polyp pathology accurately. METHODS: We obtained ESS measurements from patients undergoing screening/surveillance colonoscopy using an ESS fiberoptic probe integrated into biopsy forceps. The integrated forceps were used for tissue acquisition, following current standards of care, and optical measurement. All measurements were correlated to the index pathology. A machine learning model was then applied to measurements from 367 polyps in 169 patients to prospectively evaluate its predictive performance. RESULTS: The model achieved sensitivity of 0.92, specificity of 0.87, negative predictive value (NPV) of 0.87, and high-confidence rate (HCR) of 0.84 for distinguishing 220 neoplastic polyps from 147 non-neoplastic polyps of all sizes. Among 138 neoplastic and 131 non-neoplastic polyps ≤ 5 mm, the model achieved sensitivity of 0.91, specificity of 0.88, NPV of 0.89, and HCR of 0.83. CONCLUSIONS: Results show that ESS is a viable endoscopic platform for real-time polyp histology, particularly for polyps ≤ 5 mm. ESS is a simple, low-cost, clinically friendly, optical biopsy modality that, when interfaced with minimally obtrusive endoscopic tools, offers an attractive platform for in situ polyp assessment.

Novel Advanced Impedance Metrics on Impedance-pH Testing Predict Lung Function Decline in Idiopathic Pulmonary Fibrosis.

INTRODUCTION: Gastroesophageal reflux has been associated with idiopathic pulmonary fibrosis (IPF). Mean nocturnal baseline impedance (MNBI) is a marker of esophageal mucosal integrity, whereas postreflux swallow-induced peristaltic wave (PSPW) index reflects esophageal chemical clearance. Both metrics offer novel ways to assess reflux burden on multichannel intraluminal impedance-pH testing (MII-pH), but their role in extraesophageal reflux remains unclear. We aimed to evaluate the relationship between these novel metrics and lung function decline in patients with IPF. METHODS: Adults with IPF undergoing prelung transplant MII-pH were enrolled. All patients completed pulmonary function testing (PFT) at the time of MII-pH and at the 1-year follow-up. MNBI was calculated by averaging baseline impedance at three 10-minute intervals (1 AM/2 AM/3 AM). PSPW index was the proportion of all reflux episodes, followed by a peristaltic swallow within 30 seconds. Univariate (Student t-test/Pearson correlation) and multivariable (general linear regression) analyses were performed. RESULTS: One hundred twenty-five subjects (mean age = 61.7 years, 62% men) were included. Forced expiratory volume in one second and forced vital capacity declined more significantly over 12 months in subjects with lower distal MNBI, proximal MNBI, and PSPW index (all P < 0.05). On multivariable analyses adjusting for age, sex, proton pump inhibitor use, and baseline lung function, distal MNBI (ß = -10.86, P = 0.024; ß = -8.03, P = 0.045), proximal MNBI (ß = -13.5, P = 0.0068; ß = -9.80, P = 0.025), and PSPW index (ß = -18.1, P = 0.010; ß = -12.55, P = 0.050) remained predictive of greater forced expiratory volume in one second and forced vital capacity decline. DISCUSSION: Low distal MNBI, proximal MNBI, and PSPW index independently predicted more severe lung function decline over 1 year in patients with IPF. These impedance metrics may have prognostic value and support a role for reflux in IPF pathogenesis.

Real-time artificial intelligence-based histologic classification of colorectal polyps with augmented visualization.

BACKGROUND AND AIMS: Artificial intelligence (AI)-based computer-aided diagnostic (CADx) algorithms are a promising approach for real-time histology (RTH) of colonic polyps. Our aim is to present a novel in situ CADx approach that seeks to increase transparency and interpretability of results by generating an intuitive augmented visualization of the model's predicted histology over the polyp surface. METHODS: We developed a deep learning model using semantic segmentation to delineate polyp boundaries and a deep learning model to classify subregions within the segmented polyp. These subregions were classified independently and were subsequently aggregated to generate a histology map of the polyp's surface. We used 740 high-magnification narrow-band images from 607 polyps in 286 patients and over 65,000 subregions to train and validate the model. RESULTS: The model achieved a sensitivity of .96, specificity of .84, negative predictive value (NPV) of .91, and high-confidence rate (HCR) of .88, distinguishing 171 neoplastic polyps from 83 non-neoplastic polyps of all sizes. Among 93 neoplastic and 75 non-neoplastic polyps ≤5 mm, the model achieved a sensitivity of .95, specificity of .84, NPV of .91, and HCR of .86. CONCLUSIONS: The CADx model is capable of accurately distinguishing neoplastic from non-neoplastic polyps and provides a histology map of the spatial distribution of localized histologic predictions along the delineated polyp surface. This capability may improve interpretability and transparency of AI-based RTH and offer intuitive, accurate, and user-friendly guidance in real time for the clinical management and documentation of optical histology results.

Coexisting Abnormal Esophageal Body Motility Predicts Clinical Symptoms and Bolus Transit in Patients With Esophagogastric Junction Outflow Obstruction (EGJOO).

GOAL: The goal of this study was to compare the clinical presentations of esophagogastric junction outflow obstruction (EGJOO) with coexisting abnormal esophageal body motility (EBM) to isolated EGJOO. BACKGROUND: The clinical significance and management of EGJOO remain debated, as patients may have varied to no symptoms. The effect of coexisting abnormal EBM in EGJOO is unclear. We hypothesized that a concomitant EBM disorder is associated with clinical symptoms of EGJOO. STUDY: This was a retrospective cohort study of consecutive adults diagnosed with EGJOO on high-resolution impedance-manometry (HRIM) at 2 academic centers in March 2018 to September 2018. Patients with prior treatment for achalasia, foregut surgery, or evidence of obstruction were excluded. Subjects were divided into EGJOO with abnormal EBM per Chicago classification v3.0 and isolated EGJOO. Statistical analyses were performed using Fisher-exact or Student t test (univariate) and logistic or linear regression (multivariate). RESULTS: Eighty-two patients (72% women, age 61.1±10.7 y) were included. Thirty-one (37.8%) had abnormal EBM, including 16 (19.5%) ineffective esophageal motility and 15 (18.2%) hypercontractile esophagus. Esophageal symptoms (heartburn, regurgitation, chest pain, dysphagia) were more prevalent among those with abnormal EBM (90.3% vs. 64.7%, P=0.01). On logistic regression adjusting for age, gender, body mass index, and opioid use, abnormal EBM remained predictive of esophageal symptoms (adjusted odds ratio [aOR] 7.51, P=0.007). On separate models constructed, HE was associated with chest pain (aOR 7.45, P=0.01) and regurgitation (aOR 4.06, P=0.046), while ineffective esophageal motility was predictive of heartburn (aOR 5.84, P=0.009) and decreased complete bolus transit (ß-coefficient -0.177, P=0.04). CONCLUSION: Coexisting abnormal EBM is associated with esophageal symptoms and bolus transit in patients with EGJOO.

Increased Acid Exposure on Pretransplant Impedance-pH Testing Is Associated With Chronic Rejection After Lung Transplantation.

GOAL: The goal of this study was to assess the relationship between pretransplant measures of reflux and longer-term outcomes of chronic allograft rejection in lung transplant recipients. BACKGROUND: Bronchiolitis obliterans syndrome (BOS) is a primary measure of morbidity and mortality following lung transplantation, and a manifestation of chronic lung allograft dysfunction (CLAD). Acid reflux has been associated with early allograft injury through a proposed mechanism of aspiration and activation of the inflammatory cascade, but its association with chronic rejection is unclear. STUDY: This was a retrospective cohort study of lung transplant recipients undergoing impedance-pH testing off proton pump inhibitor from 2007 to 2016. Patients with pretransplant antireflux surgery were excluded. Time-to-event analysis using the Cox proportional hazards model was applied to assess the relationship between pretransplant reflux measures and the development of BOS, defined histologically and clinically. A secondary analysis was completed using CLAD as the outcome variable. RESULTS: Fifty-one subjects (59% men, mean age: 56, mean follow-up: 2.2 y) met inclusion criteria for the study. The BOS endpoint was reached in 13 subjects (28%). In time-to-event analyses, BOS was associated with increased acid exposure, defined as >4.2% of time with pH<4 [hazard ratio (HR): 4.18; 95% confidence interval (CI): 1.31-13.4; P=0.01], and elevated DeMeester score >14.7 (HR: 3.08; 95% CI: 1.02-9.26; P=0.04), with confirmation from Kaplan-Meier analyses. The secondary analysis demonstrated a similar association between increased acid exposure and CLAD (HR: 3.28; 95% CI: 1.09-9.88; P=0.03), which persisted on multivariate models. CONCLUSION: Increased acid exposure on pretransplant reflux testing was associated with the development of BOS and CLAD, both measures of chronic allograft rejection, after lung transplantation, and may provide clinically relevant information to improve lung allograft survival through aggressive reflux management.

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.).

Abnormal Bolus Reflux Is Associated With Poor Pulmonary Outcome in Patients With Idiopathic Pulmonary Fibrosis.

BACKGROUND/AIMS: Gastroesophageal reflux (GER) is postulated to play a role in idiopathic pulmonary fibrosis (IPF). However, the value of objective GER measures in predicting IPF disease progression is unclear. We aim to evaluate the association between objective GER measures on multichannel intraluminal impedance and pH (MII-pH) testing and development of poor pulmonary outcomes within 1 year in prelung transplant IPF patients. METHODS: This was a retrospective cohort study of adults with IPF who underwent pre-lung transplant evaluation with MII-pH off proton pump inhibitors (PPI) at a tertiary care center from June 2008 to November 2015. Patients were followed for 1 year from time of MII-pH for poor pulmonary outcomes, defined by hospitalization for respiratory exacerbation or death. Univariate, multivariate and time-to-event analyses were performed to assess associations between baseline GER parameters on MII-pH and poor outcomes. RESULTS: Eighty-four subjects (mean age 61.1 years, 64.3% male) were included. Subjects with increased bolus exposure time (BET) had a higher incidence of 1-year poor pulmonary outcome vs normal BET (45.7% vs 15.2%, P = 0.006). Increased BET remained an independent predictor of poor outcome after controlling for age, gender, body mass index, smoking, lung disease severity, and PPI use (OR, 4.18; P = 0.030). Increased BET was also predictive of decreased time to poor pulmonary outcome (hazard ratio [HR], 4.88; P = 0.007). Subgroup analyses showed that increased BET remained independently associated with time to pulmonary hospitalization (HR, 4.00; P = 0.020), with a trend for 1-year mortality (HR, 2.19; P = 0.380). CONCLUSION: Increased BET on MII-pH is an independent predictor of poor pulmonary outcome over 1 year in IPF patients.

Proton Pump Inhibitors Independently Protect Against Early Allograft Injury or Chronic Rejection After Lung Transplantation.

BACKGROUND: Acid reflux has been associated with poor outcomes following lung transplantation. Unlike surgical fundoplication, the role of noninvasive, pharmacologic acid suppression remains uncertain. AIMS: To assess the relationship between post-transplant acid suppression with proton pump inhibitors (PPI) or histamine-2 receptor antagonists (H2RA) and onset of early allograft injury or chronic rejection following lung transplantation. METHODS: This was a retrospective cohort study of lung transplant recipients at a tertiary center in 2007-2014. Patients with pre-transplant antireflux surgery were excluded. Time-to-event analysis using the Cox proportional hazards model was applied to assess acid suppression therapy and onset of acute or chronic rejection, defined histologically and clinically. Subgroup analyses were performed to assess PPI versus H2RA use. RESULTS: A total of 188 subjects (60% men, mean age 54, follow-up 554 person-years) met inclusion criteria. During follow-up, 115 subjects (61.5%) developed rejection, with all-cause mortality of 27.6%. On univariate analyses, acid suppression and BMI, but not other patient demographics, were associated with rejection. The Kaplan-Meier curve demonstrated decreased rejection with use of acid suppression therapy (log-rank p = 0.03). On multivariate analyses, acid suppression (HR 0.39, p = 0.04) and lower BMI (HR 0.67, p = 0.04) were independently predicted against rejection. Subgroup analyses demonstrated that persistent PPI use was more protective than H2RA or no antireflux medications. CONCLUSIONS: Post-lung transplant exposure to persistent PPI therapy results in the greatest protection against rejection in lung transplant recipients, independent of other clinical predictors including BMI, suggesting that PPI may have antireflux or anti-inflammatory effects in enhancing allograft protection.

Role of gastroesophageal reflux disease in lung transplantation.

Lung transplantation is one of the highest risk solid organ transplant modalities. Recent studies have demonstrated a relationship between gastroesophageal reflux disease (GERD) and lung transplant outcomes, including acute and chronic rejection. The aim of this review is to discuss the pathophysiology, evaluation, and management of GERD in lung transplantation, as informed by the most recent publications in the field. The pathophysiology of reflux-induced lung injury includes the effects of aspiration and local immunomodulation in the development of pulmonary decline and histologic rejection, as reflective of allograft injury. Modalities of reflux and esophageal assessment, including ambulatory pH testing, impedance, and esophageal manometry, are discussed, as well as timing of these evaluations relative to transplantation. Finally, antireflux treatments are reviewed, including medical acid suppression and surgical fundoplication, as well as the safety, efficacy, and timing of such treatments relative to transplantation. Our review of the data supports an association between GERD and allograft injury, encouraging a strategy of early diagnosis and aggressive reflux management in lung transplant recipients to improve transplant outcomes. Further studies are needed to explore additional objective measures of reflux and aspiration, better compare medical and surgical antireflux treatment options, extend follow-up times to capture longer-term clinical outcomes, and investigate newer interventions including minimally invasive surgery and advanced endoscopic techniques.

Both Pre-Transplant and Early Post-Transplant Antireflux Surgery Prevent Development of Early Allograft Injury After Lung Transplantation.

BACKGROUND: Antireflux surgery (ARS) has been associated with improved lung transplant outcomes. Pre-transplant ARS has been shown in small studies to improve pulmonary function among transplant candidates with gastroesophageal reflux disease (GERD). Although early post-transplant ARS has been shown to be effective in reducing chronic rejection, the optimal timing of ARS in transplant recipients remains unclear. The aim of this study is to evaluate the time to early allograft injury among lung transplant recipients by timing of ARS. METHODS: This was a retrospective cohort study of lung transplant recipients undergoing ARS before or after transplantation at a tertiary care center since 2007, with at least 1-year follow-up. Early allograft injury was defined clinically and histologically as acute rejection or lymphocytic bronchiolitis, occurring within the first year after transplantation. In accordance with prior studies, the cutoff between early and late post-transplant ARS was set at 6 months. Time-to-event analysis using the Cox proportional hazards model was applied to assess the relationship between timing of surgery and early allograft injury. Subjects not meeting this outcome were censored at 1 year in the time-to-event analysis. Fisher's exact test for binary variables and Student's t test for continuous variables were performed to assess for differences among the three groups: ARS pre-transplant, ARS early post-transplant, and ARS late post-transplant. RESULTS: Forty-eight subjects (60% men, mean age 55) met the inclusion criteria for the study. Patient demographics, pre-transplant cardiopulmonary function, BMI, CMV status, and PPI exposure were similar between groups. Kaplan-Meier analysis demonstrated significantly increased early allograft injury in late post-transplant ARS patients compared with both pre-transplant (log-rank p = 0.007) and early post-transplant (log-rank p = 0.05) patients, as well as a significant trend across groups (log-rank p = 0.005). No significant difference between pre- and early post-transplant groups was noted. Three ARS failures were noted in the pre- and late post-transplant groups. Complications included one death due to aspiration pneumonia in a late post-transplant ARS recipient. No early post-transplant ARS patients experienced ARS failure or complications. CONCLUSION: Late post-lung transplant ARS resulted in increased risk of early allograft injury compared to pre-transplant and early post-transplant ARS. Both pre- and early post-transplant ARS appear equally safe and effective in improving lung transplant outcomes. These findings support consideration of aggressive reflux testing and application of antireflux measures before or soon after transplantation to minimize the impact of reflux on allograft injury.

Critical Assessment of Endoscopic Techniques for Gastroesophageal Reflux Disease.

Over the past 2 decades, a number of new endoscopic techniques have been developed for management of gastroesophageal (GE) reflux disease symptoms as alternatives to medical management and surgical fundoplication. These devices include application of radiofrequency treatment (Stretta), endoscopic plication (EndoCinch, Plicator, Esophyx, MUSE), and injection of bulking agents (Enteryx, Gatekeeper, Plexiglas, Duragel). Their goal was symptom relief through reduction of tissue compliance and enhancement of anatomic resistance at the GE junction. In this review, we critically assess the research behind the efficacy, safety, and durability of these treatments to better understand their roles in contemporary GE reflux disease management.