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

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.

Update on extraesophageal manifestations of gastroesophageal reflux

PURPOSE OF REVIEW

Symptoms/complications related to extraesophageal reflux (EER) are increasingly prevalent presentations and pose significant challenges for clinicians. We summarize and discuss clinical advances and developments in pathophysiology, testing and treatment algorithms of upper/lower airway manifestations of EER.

RECENT FINDINGS

Growing evidence supports likely multifactorial causes of laryngeal symptoms, including EER, oropharyngeal pathologies, allergic conditions, and cognitive-affective processes (brain-larynx interaction). Diagnostic paradigm for laryngopharyngeal reflux (LPR) is shifting towards a personalized approach with noninvasive strategies/prediction tools to risk-stratify patients for upfront reflux testing over empiric acid suppression trials. Management should be multipronged to include antireflux therapies and treatments targeting other causes. Lower airway complications of EER may result in lung dysfunction and poor transplant outcomes. Esophageal symptoms are often absent and routine esophageal/reflux testing to guide timely antireflux therapies may lead to improved outcomes. Modalities that leverage impedance technology may be important, given the potential role of nonacidic reflux. Novel impedance-based metrics such as mean nocturnal baseline impedance and postreflux swallow-induced peristaltic wave index may provide adjunctive diagnostic values.

SUMMARY

Standardized approach to diagnosis/management of EER should include multidisciplinary care teams and consider different phenotypes, nonreflux contributors, and the complex gut-airway relationships. Prompt antireflux therapies after careful candidate selection may improve outcomes of these airway complications.

Esophageal Function Testing Patterns in the Evaluation and Management of Lung Transplantation: Results of a National Survey

GOALS

We surveyed esophageal motility laboratories affiliated with adult pulmonary transplant centers to determine esophageal function testing (EFT) practices.

BACKGROUND

Gastroesophageal reflux and esophageal dysmotility are associated with worse lung transplant outcomes, yet no consensus guidelines for EFT exist in this population.

STUDY

A deidentified online survey was sent to gastrointestinal motility laboratory directors of 49 academic and community-affiliated medical centers that perform lung transplants. Practice characteristics, including annual lung transplant volume and institutional EFT practices pre-lung transplantation and post-lung transplantation were queried. Respondents were categorized by transplant volume into small and large programs based on median annual volume.

RESULTS

Among 35 respondents (71% response rate), the median annual transplant volume was 37, and there were 18 large programs. Institutional EFT protocols were used pretransplant by 24 programs (68.6%) and post-transplant by 12 programs (34.2%). Among small and large programs, 52.9% and 72.2% always obtained high-resolution manometry before transplant, respectively. Endoscopy before transplant was performed more often in small programs (n=17, 100%) compared with large programs (n=15,83.3%). Pretransplant endoscopy (P=0.04), barium esophagram (P<0.01), and high-resolution manometry (P=0.04) were more common than post-transplant. In contrast, post-transplant reflux monitoring off-therapy was more common than pretransplant (P=0.01). In general, pulmonologists direct referrals for EFT and gastroenterology consultation (n=28, 80.0%), with symptoms primarily prompting testing.

CONCLUSIONS

In the absence of established guidelines, substantial variability exists in pretransplant and post-transplant EFT, directed by pulmonologists. Standardized EFT protocols and gastroenterologist-directed management of esophageal dysfunction has potential to improve lung transplant outcomes.

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.

Laparoscopic fundoplication after lung transplantation does not appear to alter lung function trajectory

BACKGROUND

The primary aim of this study was to determine if allograft function in lung transplant (LTx) recipients improves or stabilizes after laparoscopic fundoplication (LF). The secondary aim was to examine the differences in forced expiratory volume in 1 second (FEV1) before and after LF for various subgroups to identify patients who obtained a superior respiratory outcome after LF, and potential predictive factors for this outcome.

METHODS

Retrospective analysis of consecutive LTx recipients undergoing LF at a single centre in Brisbane, Australia between 2004 and 2018. 149/431 proceeded to LF after clinical review and pH study. Regular pre- and post-fundoplication pulmonary function tests were collected from participants. Data were analyzed with linear mixed models, random intercept models, the Reliable Change Index (RCI), and graphical and visual analysis of the trajectory of FEV1.

RESULTS

There was 100% follow-up. After Bonferroni adjustment for multiple comparison was performed, none of the models demonstrated statistical significance. The Reliable Change Index showed one patient had a significant improvement in lung function across that time period, while nine had a significant reduction. The rate of change before and after LF was similar for the 132/149 patients for whom the first and last pre- and post-LF FEV1 values were available. A subset of patients had a considerable reduction in their FEV1 in the peri-operative period (i.e., a large difference between the first measurement post-LF and the final measurement pre-LF).

CONCLUSION

In the largest published cohort to date, LF performed in a high-volume center did not appear to alter the reduction in allograft function seen with time.

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.

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.

Nano-Enabled Reposition of Proton Pump Inhibitors for TLR Inhibition: Toward A New Targeted Nanotherapy for Acute Lung Injury

Toll-like receptor (TLR) activation in macrophages plays a critical role in the pathogenesis of acute lung injury (ALI). While TLR inhibition is a promising strategy to control the overwhelming inflammation in ALI, there still lacks effective TLR inhibitors for clinical uses to date. A unique class of peptide-coated gold nanoparticles (GNPs) is previously discovered, which effectively inhibited TLR signaling and protected mice from lipopolysaccharide (LPS)-induced ALI. To fast translate such a discovery into potential clinical applicable nanotherapeutics, herein an elegant strategy of "nano-enabled drug repurposing" with "nano-targeting" is introduced to empower the existing drugs for new uses. Combining transcriptome sequencing with Connectivity Map analysis, it is identified that the proton pump inhibitors (PPIs) share similar mechanisms of action to the discovered GNP-based TLR inhibitor. It is confirmed that PPIs (including omeprazole) do inhibit endosomal TLR signaling and inflammatory responses in macrophages and human peripheral blood mononuclear cells, and exhibits anti-inflammatory activity in an LPS-induced ALI mouse model. The omeprazole is then formulated into a nanoform with liposomes to enhance its macrophage targeting ability and the therapeutic efficacy in vivo. This research provides a new translational strategy of nano-enabled drug repurposing to translate bioactive nanoparticles into clinically used drugs and targeted nano-therapeutics for ALI.

Sorting out the Relationship Between Esophageal and Pulmonary Disease

The aim of this review is to explore the relationship between esophageal syndromes and pulmonary diseases considering the most recent data available. Prior studies have shown a close relationship between lung diseases such as asthma, chronic obstructive pulmonary disorders (COPD), Idiopathic pulmonary fibrosis (IPF), and lung transplant rejection and esophageal dysfunction. Although the association has long been demonstrated, the exact relationship remains unclear. Clinical experience has shown a bidirectional relationship where esophageal disease may influence the outcomes of pulmonary disease and vice versa. The impact of esophageal dysfunction on pulmonary disorders may also be related to 2 different mechanisms: the reflux pathway leading to microaspiration and the reflex pathway triggering vagally mediated airway reactions. The aim of this review is to further explore these relationships and pathophysiologic mechanisms. Specifically, we discuss the proposed hypotheses for the relationship between the 2 diseases, as well as the pathophysiology and new developments in clinical management.

Foregut Dysmotility in the Lung Transplant Patient

PURPOSE OF REVIEW

To explore the role of upper gastrointestinal disease in the clinical course of lung transplant patients - including its pathophysiology, diagnostic testing, and treatment options.

RECENT FINDINGS

Gastroesophageal reflux disease (GERD) and foregut motility disorders are more prevalent among end-stage lung disease patients and are associated with poorer outcomes in lung transplant recipients. A proposed mechanism is the exposure of the lung allograft to aspirated contents, resulting in inflammation and rejection. Diagnostic tools to assess for these disorders include multichannel intraluminal impedance and pH (MII-pH) testing, high resolution esophageal manometry (HREM), and gastric emptying scintigraphy. The main treatment options are medical management with acid suppressants and/or prokinetic agents and anti-reflux surgery. In particular, data support the use of early anti-reflux surgery to improve outcomes. Newer diagnostic tools such as MII-pH testing and HREM allow for the identification of both acid and non-acid reflux and esophageal motility disorders, respectively. Recent studies have demonstrated that early anti-reflux surgery within six months post-transplant better protects against allograft injury and pulmonary function decline when compared to late surgery. However, further prospective research is needed to evaluate the short and long-term outcomes of these diagnostic approaches and interventions.

Dysphagia and medicine regimes in patients following lung transplant surgery: A retrospective review

PURPOSE

Dysphagia is reported following lung transplantation. Characteristics and trajectory for dysphagia are poorly understood. This retrospective study explored dysphagia and medicine regimes in patients following lung transplant.

METHOD

Medical records and endoscopic recordings of 101 patients (M:50yrs, range 20-67yrs, SD 13yrs) were reviewed. Standardised endoscopic swallowing measures were reported. Discharge reports were analysed for medicines known to cause dysphagia.

RESULT

All patients received bilateral sequential single-lung transplant. Prevalence of referral to speech pathology was 65% with 37 requiring more than one instrumental assessment. Twenty-nine patients were referred to otorhinolaryngology with suspected laryngeal abnormalities. Seventy-five percent of patients (n = 49/65) who received an instrumental assessment aspirated; of whom 63% aspirated silently (31/49). Diet on first day transferred from Intensive Care Unit (ICU) was significantly associated with intubation duration, ICU and hospital length of stay, tracheostomy and vocal fold paralysis (p < 0.001). In contrast, pre-operative reflux was significantly associated with diet on discharge (p < 0.05). Only three patients remained enterally fed on discharge. Polypharmacy (concurrent use of 5+ medicines) was prevalent.

CONCLUSION

Endoscopic, radiographic and/or manometric assessment of dysphagia in patients prior to, and following, lung transplant may allow for early management and prevention of secondary complications. Teams must consider pre-surgical reflux, length of stay in ICU and current medicine regimes when managing patients.

Luminal Gastrointestinal Manifestations of Cystic Fibrosis

PURPOSE OF REVIEW

People with cystic fibrosis (CF) are living longer. General age-related and CF-specific gastrointestinal symptoms are increasingly recognized. In this article, we review the latest data on luminal gastrointestinal manifestations in CF.

RECENT FINDINGS

People with CF have increased incidence of gastroesophageal reflux disease symptoms and often prescribed proton-pump inhibitors (PPI). PPI use may increase risk of pulmonary exacerbations. Evidence to support gastric fundoplication to improve pulmonary outcomes is limited. Features of intestinal dysmotility are common. There are distinct differences in the gut microbiome in the CF population which may have clinical implications. CF is a possible hereditary digestive cancer syndrome, particularly in regard to colorectal cancer (CRC) with earlier incidence of CRC and advanced colonic neoplasia. Early screening colonoscopy is warranted in the CF population. Gastrointestinal manifestations in CF are prevalent across all digestive organs. More study on the effect of interventions for symptomatic treatment and cancer screening is needed.

Treatment of Gastroesophageal Reflux Disease After Lung Transplant Using Radiofrequency Ablation to the Lower Esophageal Sphincter (Stretta Procedure)

BACKGROUND

Gastroesophageal reflux disease (GERD) is associated with chronic lung allograft dysfunction after lung transplant. Treating GERD after lung transplant has been shown to improve lung allograft function. This case series describes the efficacy of the Stretta procedure to control GERD after lung transplant at our institution.

METHODS

Eleven patients underwent the Stretta procedure at our institution for GERD after lung transplant during the years 2016-2017. Pre- and post-Stretta reflux parameters were gathered. Pulmonary function was followed up until subsequent fundoplication surgery, death, or end of study observation.

RESULTS

Reflux on esophagram was noted in 9 patients before Stretta and 8 patients after Stretta. The median number of acid reflux events was 31.5 vs. 26 after Stretta (P = .95), and median percent time in reflux was 17.7% before vs. 14.5% after Stretta (P = .76). Median DeMeester score before Stretta was 65.5 (range: 33.2-169.8) vs. 42.5 (range: 19.2-109.8) after the procedure (P = .14). Median lower esophageal resting pressure was 20.7 mm Hg (n = 7) compared to 25.9 mm Hg (n = 9) on post-Stretta follow-up (P = .99). Median FEV₁% predicted was 84% (41-97%) before compared to 71% (23-108%) at 1 year after the procedure (P = .14). Seven patients required fundoplication surgery for continued reflux. All patients were on triple immunosuppression, most commonly prednisone, tacrolimus, and mycophenolate (n = 9).

DISCUSSION

The Stretta procedure did not provide expected results at our institution after lung transplant surgery. Based on our limited series, we do not recommend routine use of the Stretta procedure for management of GERD in lung transplant patients.

Gastroesophageal Reflux Disease and Idiopathic Lung Fibrosis. From Heartburn to Lung Transplant, and Beyond

Idiopathic pulmonary fibrosis (IPF) and gastroesophageal reflux disease (GERD) are undoubtedly related. Even though it is not clear yet which one is the primary disease, they certainly interact increasing each other's severity. Symptoms are unreliable to diagnose GERD in patients with IPF, and objective evaluation with pH monitoring and/or bronchoalveolar lavage analysis is mandatory. Pharmacological treatment with proton pump inhibitors (PPIs) may bring control of IPF in few patients, but PPIs do not control reflux but just change the pH of the gastric refluxate. Surgical therapy based on a fundoplication is safe and effective as it controls any type of reflux, independently from the pH of the gastric refluxate. In patients waiting for lung transplantation (if they can tolerate a laparoscopic operation under general anesthesia), a fundoplication before the operation might block the progression of IPF, while after transplantation it might prevent rejection by preventing the bronchiolitis obliterans syndrome.

Challenges in the use of highly effective modulator treatment for cystic fibrosis

The last decade has seen development of oral, small molecule therapies that address the basic cystic fibrosis transmembrane conductance regulator (CFTR) protein defect. Highly effective modulator treatment (HEMT) that is efficacious for a large majority of people living with cystic fibrosis (CF) promises to change the landscape of this chronic life-limiting disease. Some people living with CF have a CFTR genotype that renders them eligible for HEMT, but also have comorbidities that excluded them from the original Phase III clinical trials that led to US Food and Drug Administration approval. The purpose of this review is to address the use of HEMT in challenging situations, including initiation for those with advanced CF lung disease, and use after solid organ transplant, during pregnancy, and for individuals with CFTR-related disorders without a definitive diagnosis of CF.

Current therapies for gastro-oesophageal reflux in the setting of chronic lung disease: state of the art review

The inter-relationship between chronic respiratory disease and reflux disease in the airway reflux paradigm is extremely complex and remains poorly characterised. Reflux disease is reported to cause or contribute to the severity of a number of respiratory tract diseases including laryngeal disorders, sinusitis, chronic cough, asthma, COPD, idiopathic pulmonary fibrosis, cystic fibrosis, bronchiectasis and bronchiolitis obliterans post lung transplant. It is now appreciated that reflux disease is not simply caused by liquid acid reflux but rather by a variety of chemical refluxates originating from the stomach and duodenum due to a number of different mechanisms. Reflux disease can be challenging to diagnose, particularly proving its role in the causation of direct respiratory epithelial damage. Significant advances in oesophageal assessment and gastric biomarkers have emerged in recent years as our understanding increases. There are a number of treatments available for reflux disease, both medical and surgical, but there is a paucity of large randomised trials to evaluate their efficacy in the setting of chronic respiratory disease. Everyday clinical practice, however, informs us that treatment failure in reflux disease is common. This clinical review summarises associations between reflux disease in the setting of chronic respiratory diseases and examines available evidence regarding potential therapeutic strategies.

Gastro-oesophageal reflux disease is prevalent among patients with chronic respiratory disease. A number of medical and surgical treatment options are available for GORD. This review examines available evidence in the setting of chronic lung disease.https://bit.ly/34TcMJS

Esophageal Evaluation for Patients Undergoing Lung Transplant Evaluation: What Should We Do for Evaluation and Management

Lung transplantation is a high-risk, but lifesaving, procedure for patients with end-stage lung disease. Although 1-year survival is high, long-term survival is not nearly as high, due mainly to acute and chronic rejection. Bronchiolitis obliterans syndrome is the most common type of chronic rejection and often leads to poor outcomes. For this reason, esophageal testing in the lung transplant population has become a major issue, and this article discusses the evidence behind esophageal testing, the importance of esophageal dysmotility gastroesophageal reflux disease, both acidic and nonacidic reflux, and aspiration and the treatment of these findings.

Extraesophageal syndrome of gastroesophageal reflux: relationships with lung disease and transplantation outcome

Gastroesophageal reflux disease (GERD) is prevalent and may be associated with both esophageal and extraesophageal syndromes, which include various pulmonary conditions. GERD may lead to pulmonary complications through the "reflux" (aspiration) or "reflex" (refluxate-triggered, vagally mediated airway spasm) mechanisms. While GERD may cause or worsen pulmonary disorders, changes in respiratory mechanics due to lung disease may also increase reflux. Typical esophageal symptoms are frequently absent and objective assessment with reflux monitoring is often needed for diagnosis. Impedance monitoring should be considered in addition to traditional pH study due to the involvement of both acidic and weakly acidic/nonacidic reflux. Antireflux therapy may improve outcomes of some pulmonary complications of GERD, although careful selection of a candidate is paramount to successful outcomes. Further research is needed to identify the optimal testing strategy and patient phenotypes that would benefit from antireflux therapy to improve pulmonary outcomes.

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.

Jackhammer Esophagus After Lung Transplantation: Results of a Retrospective Multicenter Study

GOALS

We sought to determine the incidence of jackhammer esophagus (JE) after lung transplantation (LT) and identify potential risk factors for the development of JE after LT.

BACKGROUND

JE is a rare esophageal motility disorder, and its pathophysiology remains unclear. Lung transplantation has been implicated as a potential risk factor for JE, but the incidence of JE after LT is unknown.

STUDY

A retrospective cohort of adult patients who underwent LT at 2 tertiary care centers over 7.5 years was reviewed. Analysis was performed on patients who underwent a high-resolution esophageal manometry (EM) study before and after LT. JE was defined according to the latest Chicago classification, version 3.0.

RESULTS

A total of 57 patients without JE identified on pre-LT EM also underwent an EM study after LT. Fifteen (25.4%) were found to have new JE after LT. Patients with newly diagnosed JE after LT were older (61.3±5.3 y vs. 51.6±15.6 y; P=0.02) and more often had chronic obstructive pulmonary disease (COPD; 47.6% vs. 16.6%; P=0.03) compared with those without COPD. There was a trend toward increased risk for JE among female individuals (60% vs. 33.3%; P=0.07) and those with shorter surgical anastomosis times (75.8±12.2 min vs. 84.4±14.3; P=0.06). There was no significant difference between body mass index, opioid use, pretransplant EM findings, surgical ischemic time, occurrence of gastroparesis, or measured post-LT outcomes between the 2 groups.

CONCLUSIONS

JE occurs not uncommonly in patients after LT. Older age and COPD pre-LT may be significant risk factors.

Phenotypes of Gastroesophageal Reflux Disease: Where Rome, Lyon, and Montreal Meet

Gastroesophageal reflux disease (GERD) is now one of the most common diagnoses made in a gastroenterology practice. From a conventional pathophysiological perspective, GERD is conceptualized as incompetence of the antireflux barrier at the esophagogastric junction; the more severe that incompetence, the worse the disease. However, it is increasingly clear that many presentations of GERD represent distinct phenotypes with unique predisposing cofactors and pathophysiology outside of this paradigm. Three major consensus initiatives have grappled with this dilemma (the Montreal Consensus, The Rome Foundation, and the Lyon Consensus), each from a different perspective. Montreal struggled to define the disease, Rome sought to characterize its functional attributes, while Lyon examined its physiological attributes. Here, we merge the 3 perspectives, developing the concept that what has come to be known as GERD is actually a family of syndromes with a complex matrix of contributing pathophysiology. A corollary to this is that the concept of one size fits all to therapeutics does not apply, and that although escalating treatment with proton pump inhibitors (PPIs) may be pertinent to healing esophagitis, its applicability beyond that is highly questionable. Similarly, failing to recognize the modulating effects of anxiety, hypervigilance, and visceral and central hypersensitivity on symptom severity has greatly oversimplified the problem. That oversimplification has led to excessive use of PPIs for everything captured under the GERD umbrella and shown a broad spectrum of syndromes less amenable to PPI therapy in any dose. It is with this in mind that we delineate this precision medicine concept of GERD.

Esophageal contractility increases and gastroesophageal reflux does not worsen after lung transplantation

Gastroesophageal reflux and esophageal dysmotility are common in patients with advanced lung disease and are associated with allograft dysfunction after lung transplantation. The effect of transplantation on reflux and esophageal motility is unclear. The aim of this study was to describe the changes in esophageal function occurring after lung transplantation. A retrospective cohort study was performed on lung transplant candidates evaluated at a tertiary care center between 2015 and 2016. A total of 76 patients who underwent lung transplantation had high-resolution manometry and ambulatory pH-metry before and after transplant. Demographic data, esophageal function testing results, and clinical outcomes such as pulmonary function testing were collected and analyzed using appropriate statistical tests and multivariable regression. Of the 76 patients, 59 (78%) received a bilateral transplant. There was a significant increase in esophageal contractility posttransplant, with an increase in median distal contractile integral from 1470 to 2549 mmHg cm s (P < 0.01). There were 19 patients with Jackhammer esophagus posttransplant, including 15 patients with normal motility pretransplant. Nine patients with ineffective or fragmented peristalsis pretransplant had normal manometry posttransplant. Abnormal pH-metry was observed in 35 (46%) patients pretransplant and 29 (38%) patients posttransplant (P = 0.33). Patients with gastroesophageal reflux disease posttransplant had less improvement in pulmonary function at one year, as measured by forced expiratory volume (P = 0.04). These results demonstrate that esophageal contractility increases significantly after lung transplantation, with an associated change in motility classification. In comparison, gastroesophageal reflux does not worsen, but is associated with worse pulmonary function, posttransplant.