Prevalence of gastroesophageal reflux in end-stage lung disease candidates for lung transplant

The role of Staphylococcus aureus in cystic fibrosis pathogenesis and clinico-microbiological interactions

Cystic fibrosis (CF) is a progressive and inherited disease that affects approximately 70000 individuals all over the world annually. A mutation in the cystic fibrosis transmembrane conductance regulator (CFTR) gene serves as its defining feature. Bacterial infections have a significant impact on the occurrence and development of CF. In this manuscript, we discuss the role and virulence factors of Staphylococcus aureus as an important human pathogen with the ability to induce respiratory tract infections. Recent studies have reported S. aureus as the first isolated bacteria in CF patients. Methicillin-resistant Staphylococcus aureus (MRSA) pathogens are approximately resistant to all β-lactams. CF patients are colonized by MRSA expressing various virulence factors including toxins, and Staphylococcal Cassette Chromosome mec (SCCmec) types, and have the potential for biofilm formation. Therefore, variations in clinical outcomes will be manifested. SCCmec type II has been reported in CF patients more than in other SCCmec types from different countries. The small-colony variants (SCVs) as specific morphologic subtypes of S. aureus with slow growth and unusual properties can also contribute to persistent and difficult-to-treat infections in CF patients. The pathophysiology of SCVs is complicated and not fully understood. Patients with cystic fibrosis should be aware of the intrinsic risk factors for complex S. aureus infections, including recurring infections, physiological issues, or coinfection with P. aeruginosa.

Pulmonary and esophageal function in lung transplantation: Fundamental principles and clinical application

The lungs and esophagus have a close anatomical and physiological relationship. Over the years, reflux-induced pulmonary injury has gained wider recognition, but the full effects of pulmonary disease on esophageal function are still unknown. Intrathoracic pressure dynamics potentially affect esophageal function, especially in patients with end-stage lung disease, both obstructive and restrictive. Lung transplantation is the only viable option for patients with end-stage pulmonary disease and has provided us with a unique opportunity to study these effects as transplantation restores the intrathoracic environment. Esophageal and foregut functional testing before and after transplantation provide insights into the pathophysiology of the foregut-pulmonary axis, such as how underlying pulmonary disease and intrathoracic pressure changes affect esophageal physiology. This review summarizes the available literature and shares the research experience of a lung transplant center, covering topics such as pre- and posttransplant foregut function, esophageal motility in lung transplant recipients, immune-mediated mechanisms of graft rejection associated with gastroesophageal reflux, and the role of antireflux surgery in this population.

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.

Lung Transplantation: A Viable Option for Connective Tissue Disease?

Interstitial lung disease (ILD) and pulmonary hypertension (PH) caused by connective tissue disease (CTD) are one of the main causes of morbidity and death in patients. Although the International Society for Heart & Lung Transplant suggested that ILD and PH related to CTD are rare indications for lung transplantation in 2006, many lung transplantation centers are concerned that the multisystem involvement of CTD will affect survival outcomes after lung transplantation, and CTD is regarded as a relative contraindication for lung transplantation. However, long-term and short-term survival after lung transplantation in CTD patients is similar compared with survival in common indications for lung transplantation such as idiopathic pulmonary fibrosis (IPF), and no higher incidence of complications after transplantation in many lung transplant centers. This suggests that lung transplantation may be beneficial in CTD patients with disease that progresses to end-stage lung disease, and CTD should not be considered a contraindication for lung transplantation. In the future, more prospective studies are needed to analyze the risk factors of lung transplantation in CTD patients to improve survival rates and reduce the risk of complications. This narrative review summarizes the selection and evaluation of candidates for CTD before lung transplantation and describes the clinical outcomes in CTD after lung transplantation in large-capacity lung transplantation center. The purpose of this review is to help rheumatologists decide when to refer patients with CTD-related lung involvement to a lung transplantation center and the conditions to consider before transplantation and to provide confidence to lung transplant experts.

Acute transcutaneous electrical stimulation (TES) augments esophageal contractility in patients with weak peristalsis

BACKGROUND

Lung transplantation (LTx) remains controversial in patients with absent peristalsis (AP) given the increased risk for gastroesophageal reflux (GER), and chronic lung allograft dysfunction. Furthermore, specific treatments to facilitate LTx in those with AP have not been widely described. Transcutaneous Electrical Stimulation (TES) has been reported to improve foregut contractility in LTx patients and therefore we hypothesize that TES may augment the esophageal motility of patients with ineffective esophageal motility (IEM).

METHODS

We included 49 patients, 14 with IEM, 5 with AP, and 30 with normal motility. All subjects underwent standard high-resolution manometry and intraluminal impedance (HRIM) with additional swallows as TES was delivered.

RESULTS

TES induced a universal impedance change observable in real-time by a characteristic spike activity. TES significantly augmented the contractile vigor of the esophagus measured by the distal contractile integral (DCI) in patients with IEM [median DCI (IQR) 0 (238) mmHg-cm-s off TES vs. 333 (858) mmHg-cm-s on TES; p = .01] and normal peristalsis [median DCI (IQR) 1545 (1840) mmHg-cm-s off TES vs. 2109 (2082) mmHg-cm-s on TES; p = .01]. Interestingly, TES induced measurable contractile activity (DCI > 100 mmHg-cm-s) in three out of five patients with AP [median DCI (IQR) 0 (0) mmHg-cm-s off TES vs. 0 (182) mmHg-cm-s on TES; p < .001].

CONCLUSION

TES acutely augmented contractile vigor in patients with normal and weak/ AP. The use of TES may positively impact LTx candidacy, and outcomes for patients with IEM/AP. Nevertheless, further studies are needed to determine the long-term effects of TES in this patient population.

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.

Association Between Antibodies Against Lung Self-Antigens and Gastroesophageal Reflux in Lung Transplant Candidates

Gastroesophageal reflux (GER) and pretransplant antibodies against lung self-antigens (SAbs) collagen-V and/or k-alpha 1 tubulin are both independently associated with allograft dysfunction after lung transplantation (LTx). The role of GER in inducing lung injury and SAbs is unknown. We aimed to study the association between pre-LTx GER and SAbs. After IRB approval, we retrieved SAb assays conducted between 2015 and 2019 and collected 24 hour GER data for these patients. Patients were divided into 2 groups: no reflux (GER-) and pathologic reflux (GER+) to compare the prevalence of SAbs. Multivariate analysis was used to study the association between GER and SAbs in the whole cohort and in restrictive lung disease (RLD) and obstructive lung disease (OLD) subsets. Proximal esophageal reflux (PER) events ≥5 was considered abnormal. Patients (n = 134; 73 men) were divided into groups: GER- (54.5%, n = 73) and GER+ (45.5%, n = 61). The prevalence of GER was higher in the RLD than in the OLD subset (p < 0.001). The overall prevalence of SAbs was 53.7% (n = 72), higher in the GER+ than the GER- group (65.6% vs 43.8%, p = 0.012), but comparable between RLD and OLD subsets. Overall, SAbs were associated with GER (p = 0.012) and abnormal PER (p = 0.017). GER and abnormal PER increased the odds of SAbs in the RLD subset (OR [95% CI]: 2.825 [1.033-7.725], p = 0.040 and OR [95% CI]: 3.551 [1.271-9.925], p = 0.014, respectively) but not in the OLD subset. LTx candidates have a high prevalence of SAbs, which are significantly associated with GER and abnormal PER in patients with RLD.

Surgical considerations in cystic fibrosis: what every general surgeon needs to know

Cystic fibrosis (CF) is a complex multiorgan disease, which often affects the gastrointestinal tract. With improved CF specific therapies and multidisciplinary management, patients with CF are now living longer with a median life expectancy of around 50 years. This increased life expectancy has resulted in corresponding increase in presentations of the CF patient with comorbid surgical conditions that were never important considerations. Investigations and management of these conditions, such as distal intestinal obstruction syndrome and colorectal cancer warrant good clinical understanding of the unique challenges that CF patients present including chronic immunosuppression, impaired respiratory function and their multi-organ dysfunction. The purpose of this review is to provide general surgeons with a contemporary update on the CF related surgical issues as they are likely to become increasingly involved in the care of these complex patients and form an integral part of the multidisciplinary team.

Role of gastric per-oral endoscopic myotomy (G-POEM) in post-lung transplant patients: a multicenter experience

Background and study aims  Gastroparesis post-lung transplant (LTx) can lead to increased risk of gastroesophageal reflux (GER) and accelerated graft dysfunction. We aimed to evaluate the efficacy and safety of gastric per-oral endoscopic myotomy (G-POEM), a promising tool in patients with refractory gastroparesis, for managing refractory gastroparesis and GER in post-LTx patients. Patents and methods  This was a multicenter retrospective study on post-LTx patients who underwent G-POEM for management of gastroparesis and GER that were refractory to standard medical therapy. The primary outcome was clinical success post-G-POEM. Secondary outcomes included the rate of post-G-POEM objective esophageal pH exam normalization, rate of gastric emptying scintigraphy (GES) normalization, technical success, and adverse events. Results  A total of 20 patients (mean age 54.7 ± 14.1 years, Female 50 %) underwent G-POEM at a median time of 13 months (interquartile range 6.5-13.5) post-LTx. All G-POEM procedures were technically successful. Clinical success was achieved in 17 (85 %) patients during a median follow-up time of 8.9 (IQR: 3-17) months post-G-POEM. Overall GCSI and two of its subscales (bloating and postprandial fullness/early satiety) improved significantly following G-POEM. Two patients (10 %) developed post-procedural AEs (delayed bleeding 1, pyloric stenosis 1, both moderate in severity). Post-G-POEM GES improvement was achieved in 12 of 16 patients (75 %). All 20 patients were on proton pump inhibitors pre-G-POEM, as opposed to five post-G-POEM. Post-G-POEM PH study normalization was noted in nine of 10 patients (90 %) who underwent both pre- and post-G-poem pH testing. Conclusions  G-POEM is a promising noninvasive therapeutic tool for management of refractory gastroparesis and GER post-LTx.

Risk Factors and Outcomes for Gastroparesis After Lung Transplantation

BACKGROUND

Gastroparesis is common after lung transplantation and is associated with worse transplant outcomes, including the development of chronic lung allograft dysfunction (CLAD). This study sought to identify the prevalence, risk factors, and outcomes associated with a new diagnosis of gastroparesis after lung transplantation.

METHODS

This was a single-center retrospective study of patients who underwent lung transplantation in 2008-2018. The primary outcome was a new diagnosis of gastroparesis within 3 years of transplant. Secondary outcomes included a new diagnosis of gastroesophageal reflux and the association between gastroparesis and both post-transplant survival and CLAD-free survival. Multivariable logistic regression was used to compare diagnosis of gastroparesis and gastroesophageal reflux, while multivariable Cox proportional hazards models were used to analyze gastroparesis and post-transplant outcomes.

RESULTS

Of 616 patients with no prior history of gastroparesis, 107 (17.4%) were diagnosed with delayed gastric emptying within 3 years of transplant. On multivariable logistic regression, black race (OR 2.16, 95% CI 1.18-3.98, p = 0.013) was significantly associated with a new diagnosis of gastroparesis. Age, sex, history of diabetes, connective tissue disease, type of transplant, diagnosis group, renal function, and body mass index were not predictive of gastroparesis post-transplant. Gastroparesis was significantly associated with CLAD (HR 1.76, 95% CI 1.20-2.59, p = 0.004), but not with overall mortality (HR 1.16, p = 0.43).

CONCLUSION

While gastroparesis is common after lung transplantation, it remains difficult to predict which patients will develop these complications post-transplant. Black patients were more likely to be diagnosed with gastroparesis after adjusting for relevant confounders. Gastroparesis is associated with increased risk of CLAD, and further studies are needed to assess whether early detection and treatment can reduce the incidence of CLAD.

Delayed Gastric Emptying in Prelung Transplant Patients Is Associated With Posttransplant Acute Cellular Rejection Independent of Reflux

GOAL

The goal of this study was to evaluate the relationship between pretransplant delayed gastric emptying (DGE) and posttransplant acute cellular rejection (ACR) in lung transplant recipients.

BACKGROUND

DGE is very prevalent (23% to 91%) after lung transplantation but pretransplant prevalence has not been well studied. DGE may lead to poor posttransplant outcomes by predisposing to microaspiration. Pretransplant testing for DGE may help identify patients at risk for negative posttransplant outcomes including ACR.

MATERIALS AND METHODS

A retrospective review of a prospectively collected database of consecutive patients undergoing prelung transplant evaluation at a tertiary referral center from 2010 to 2015 was performed. Patients with pretransplant gastric emptying scintigraphy were included in the study. ACR diagnosis was made using International Society for Heart and Lung Transplantation (ISHLT) histologic criteria. Typical gastroparesis symptoms at the time of gastric emptying scintigraphy and pretransplant 24-hour pH impedance monitoring (MII-pH) data was collected. Logistic regression was used for multivariate analysis. Subgroup analyses were performed to account for gastroesophageal reflux (GER).

RESULTS

A total of 83 subjects (18 with DGE, 51.8% male, mean age: 53.6 y) met the criteria for inclusion. Patients with DGE were more likely to have typical symptoms of gastroparesis, though 61.1% of DGE patients were asymptomatic. ACR was more prevalent in patients with DGE (33.3% vs. 12.3%, P=0.04). This correlation was independent of GER as measured by MII-pH on subgroup analysis (75% vs. 14.3%, n=0.02).

DISCUSSION

Lung transplant recipients with pretransplant DGE have a higher incidence of ACR, independent of GER. Routine pretransplant testing for DGE may help identify patients at greater risk for adverse posttransplant outcomes as the majority of patients with DGE are asymptomatic.

Swallowing and laryngeal complications in lung and heart transplantation: Etiologies and diagnosis

Despite continued surgical advancements in the field of cardiothoracic transplantation, post-operative complications remain a burden for the patient and the multidisciplinary team. Lesser-known complications including swallowing disorders (dysphagia), and voice disorders (dysphonia), are now being reported. Such disorders are known to be associated with increased morbidity and mortality in other medical populations, however their etiology amongst the heart and lung transplant populations has received little attention in the literature. This paper explores the potential mechanisms of oropharyngeal dysphagia and dysphonia following transplantation and discusses optimal modalities of diagnostic evaluation and management. A greater understanding of the implications of swallowing and laryngeal dysfunction in the heart and lung transplant populations is important to expedite early diagnosis and management in order to optimize patient outcomes, minimize allograft injury and improve quality of life.

Different clinical symptom patterns in patients with reflux micro-aspiration

Background

Pulmonary manifestation of gastro-oesophageal reflux disease (GORD) is a well-recognised entity; however, little primary reported data exists on presenting symptoms of patients in whom reflux micro-aspiration is confirmed. The aim of this study is to report symptoms and presenting patterns of a large group of patients with confirmed reflux micro-aspiration.

Patients and methods

Data was extracted from a prospectively populated database of patients referred to a tertiary specialist centre with severe, refractory or atypical reflux. Patients with reflux micro-aspiration on scintigraphy were included in this study. A separate group included patients with evidence of proximal reflux to the level of pharynx when supine and/or upright.

Results

Inclusion criteria were met by 243 patients with confirmed reflux micro-aspiration (33% males; mean age 59). Most common symptoms amongst patients with micro-aspiration were regurgitation (72%), cough (67%), heartburn (66%), throat clearing (65%) and dysphonia (53%). The most common two-symptom combinations were heartburn/regurgitation, cough/throat clearing, regurgitation/throat clearing, cough/regurgitation and dysphonia/throat clearing. The most common three-symptom combinations were cough/heartburn/regurgitation, cough/regurgitation/throat clearing and dysphonia/regurgitation/throat clearing. Cluster analysis demonstrated two main symptom groupings, one suggestive of proximal volume reflux symptoms and the other with motility/inflammatory bowel syndrome-like symptoms (bloat, constipation).

Conclusion

The combination of typical symptoms of GORD such as heartburn or regurgitation and a respiratory or upper aero-digestive complaint such as cough, throat clearing or voice change should prompt consideration of reflux micro-aspiration.

Patients with reflux micro-aspiration most commonly present with a combination of regurgitation and/or heartburn and cough and/or throat clearinghttps://bit.ly/3GM8cNS

Cough in Idiopathic Pulmonary Fibrosis

Chronic cough is experienced by most patients with idiopathic pulmonary fibrosis (IPF). It is often the first symptom and is associated with reduced quality of life, increased rates of depression and anxiety, more severe physiological impairment, and disease progression. Although not fully understood, recent gains in understanding the pathophysiology of chronic cough in IPF have been made. The pathophysiology is likely multifactorial and includes alterations in mucous production and clearance, architectural distortion, and increased cough reflex sensitivity, suggesting a role for targeted therapies and multidisciplinary treatment. Modifiable comorbidities can also induce cough in patients with IPF. There is a renewed emphasis on measuring cough in IPF, with clinical trials of novel and repurposed therapies for chronic cough emerging in this population. This review provides an update on the clinical characteristics, pathophysiology, and measurement of chronic cough in patients with IPF and summarizes recent developments in non-pharmacological and pharmacological therapies.

Fundoplication after lung transplantation in patients with systemic sclerosis-related end-stage lung disease

INTRODUCTION

Gastroesophageal reflux and aspiration are risk factors for chronic lung allograft dysfunction in lung transplant recipients. Patients with systemic sclerosis are at an increased risk of aspiration due to esophageal dysmotility and an ineffective lower esophageal sphincter. The aim of this study is to understand the effect of fundoplication on outcomes in systemic sclerosis recipients.

METHODS

Between 2001 and 2019, 168 systemic sclerosis patients were referred for lung transplantation-51 (30.3%) were listed and 36 (21.4%) were transplanted. Recipients were stratified whether they underwent a fundoplication (n = 10, 27.8%) or not (n = 26, 72.2%). Freedom from chronic lung allograft dysfunction and survival were analyzed using log-rank test. Multivariable analysis for known risk factors was performed using a Cox-proportional hazards model.

RESULTS

Median time to fundoplication after transplantation was 16.4 months (interquartile range: 9.6-25.1) and all were laparoscopic (Dor 50%, Nissen 40%, Toupet 10%). There were no differences in acute rejection ⩾ A1 (26.9% vs 30%), or primary graft dysfunction grades 2-3 at 72 h (42.3% vs 40%) between groups. Recipients with fundoplication had an increased freedom from chronic lung allograft dysfunction (p = 0.035) and overall survival (p = 0.01). Fundoplication was associated with a reduced risk of mortality adjusting for other comorbidities (hazard ratio = 0.13; 95% confidence interval = 0.02-0.65; p = 0.014). Double and single lung transplant did not have different post-transplant survival.

CONCLUSION

Fundoplication in systemic sclerosis lung transplant recipients is associated with greater freedom from chronic lung allograft dysfunction and overall survival. Screening for reflux and aspiration followed by early fundoplication may delay graft deterioration in this population.

Identification of Lung Transplant Recipients with a Survival Benefit after Fundoplication

BACKGROUND

Gastroesophageal reflux disease (GERD) and aspiration of enteric contents is associated with worse outcomes after lung transplant. The purpose of this study is to elucidate populations that benefit the most from fundoplication after lung transplant.

METHODS

Lung transplants from 2001-2019 (n=971) were retrospectively reviewed and stratified by a fundoplication before (n=128) or after (n=24) chronic lung allograft dysfunction (CLAD) development vs those who didn't. Patients with a fundoplication prior to CLAD were propensity-matched to those without a fundoplication. The primary outcome of interest was post-transplant survival. Time-to-event rates were calculated using a multivariable Cox proportional hazards model and Kaplan-Meier functions.

RESULTS

A fundoplication prior to CLAD improved post-transplant survival before and after propensity-matching, and remained a significant predictor after adjusting for baseline characteristics (HR:0.57, 95% CI:0.4-0.8, P=0.001). Recipients with a restrictive disorder (HR: 0.46, 95% CI:0.3-0.73, P=0.001), age <65 (HR:0.48, 95% CI:0.32-0.71, P<0.001), and both single (HR:0.47, 95% CI:0.28-0.79, P=0.005) or double (HR:0.55, 95% CI:0.32-0.93, P=0.027) lung transplants had a significant decrease in mortality after fundoplication. The effect was present after excluding early deaths and/or CLAD diagnoses. GERD diagnosed by pH, impedance or EGD was not associated with worse outcomes. Among patients with CLAD, a fundoplication was an independent predictor of post-CLAD survival (HR:0.27, 95% CI:0.12-0.61, P=0.002).

CONCLUSIONS

A fundoplication before or after CLAD development is an independent predictor of survival. Younger patients with restrictive disease, independent of the type of transplant, have a survival benefit. GERD diagnosed by conventional methods was not associated with worse survival.

Systems Biology and Bile Acid Signalling in Microbiome-Host Interactions in the Cystic Fibrosis Lung

The study of the respiratory microbiota has revealed that the lungs of healthy and diseased individuals harbour distinct microbial communities. Imbalances in these communities can contribute to the pathogenesis of lung disease. How these imbalances occur and establish is largely unknown. This review is focused on the genetically inherited condition of Cystic Fibrosis (CF). Understanding the microbial and host-related factors that govern the establishment of chronic CF lung inflammation and pathogen colonisation is essential. Specifically, dissecting the interplay in the inflammation–pathogen–host axis. Bile acids are important host derived and microbially modified signal molecules that have been detected in CF lungs. These bile acids are associated with inflammation and restructuring of the lung microbiota linked to chronicity. This community remodelling involves a switch in the lung microbiota from a high biodiversity/low pathogen state to a low biodiversity/pathogen-dominated state. Bile acids are particularly associated with the dominance of Proteobacterial pathogens. The ability of bile acids to impact directly on both the lung microbiota and the host response offers a unifying principle underpinning the pathogenesis of CF. The modulating role of bile acids in lung microbiota dysbiosis and inflammation could offer new potential targets for designing innovative therapeutic approaches for respiratory disease.

Bilateral Lung Transplant for a Connective Tissue Disorder: Esophageal Motility and 3-year Survival

Connective tissue disorders (CTDs) are associated with esophageal dysmotility and gastroesophageal reflux disease, which may diminish survival after lung transplantation (LTx). We studied LTx outcomes in patients with a CTD stratified by esophageal motility. We identified patients who underwent bilateral LTx from 2012 to 2017. Patients with a CTD were classified by pre-LTx diagnosis: absent esophageal motility (AEM), ineffective esophageal motility (IEM), or preserved esophageal motility (PEM). The primary endpoint was 3-year survival. Sub-analysis compared survival between the AEM group and a propensity-matched (lung allocation score), non-CTD control group. Kaplan-Meier method and log-rank test were used. In total, 495 patients underwent LTx; 33 (6.7%) had a CTD. Median (IQR) age was 62 years (55.5-67.0); 24 (72.7%) were women. Survival trended lower for recipients with a CTD than without a CTD at 1-year (84.8% vs 91.8%; p = 0.2) and 3-years (66.7% vs 73.5%; p = 0.5). Within the CTD cohort, 1- and 3-year survival was significantly higher in the PEM (100%, 87.5%) and IEM (100%, 85.7%) groups than in the AEM group (50%, 20%; p < 0.001). The AEM group had significantly lower survival at 1-year (50% vs 92.5%) and 3-years (20% vs 65%) than a lung allocation score-matched cohort of patients without a CTD. LTx recipients with a CTD and AEM had significantly lower survival than those with PEM or IEM as well as significantly lower survival than that of a propensity-matched cohort of patients without a CTD. Patients with a CTD and AEM should be considered for LTx with extreme caution and counseled appropriately.

Aspiration of conjugated bile acids predicts adverse lung transplant outcomes and correlates with airway lipid and cytokine dysregulation

INTRODUCTION

Duodeno-gastroesophageal reflux aspiration is associated with chronic lung allograft dysfunction (CLAD). Reflux aspirate can contain bile acids (BA), functional molecules in the gastro-intestinal tract with emulsifying properties. We sought to determine and quantify the various BA species in airways of the lung transplant recipients to better understand the various effects of aspirated BA that contribute to post-transplantation outcomes.

METHODS

Bronchial washings (BW) were prospectively collected from lung transplant recipients and subsequently assayed by liquid chromatography-mass spectrometry for 13 BA and 25 lipid families. Patients were monitored for CLAD, rejection, inflammation and airway infections.

RESULTS

Detectable BA were present in 45/50 patients (90%) at 3 months after transplant. Elevated BA and predominance of conjugated species were independent predictors of CLAD (hazard ratio 7.9; 95% confidence interval 2.7-23.6; p < 0.001 and 7.3; 2.4-22; p < 0.001, respectively) and mortality (hazard ratio 4.4; 1.5-12.7; p = 0.007 and 4.8; 1.4-15.8; p = 0.01, respectively). High BA associated with increased positive bacterial cultures (60% vs 25%, p = 0.02). Primary conjugated species independently correlated with the rate of bacterial cultures during the first-year post-transplant (Beta coefficient: 0.77; 0.28-1.26; p = 0.003) and changes in airway lipidome and cytokines.

CONCLUSIONS

Higher BA levels and predominance of conjugated BA are independent predictors of chronic lung allograft dysfunction, mortality and bacterial infections. Primary conjugated BA are related to distinct changes in airway lipidome and inflammatory cytokines. This elucidates novel evidence into the mechanism following BA aspiration and proposes novel markers for prediction of adverse post-transplant outcomes.

Esophageal disease in lung transplant patients

There is a very well-established and complex interplay between gastroesophageal reflux and lung disease. This is particularly true in end-stage lung disease and post-lung transplant patients. Numerous studies have shown that in patients who are undergoing pre-lung transplant evaluations for diseases such as idiopathic pulmonary fibrosis (IPF), emphysema, connective tissue disease, there is a high prevalence of gastroesophageal reflux and esophageal dysmotility. Post-lung transplant, many of the reflux issues persist or worsen, and there is some evidence to suggest that this leads to worsened long-term allograft function and bronchiolitis obliterans. Anti-reflux operations in patients with lung disease have been shown to be safe in both the pre and post-lung transplant setting and lead to improved reflux symptoms, as well as protecting against reflux induced allograft dysfunction in the post-lung transplant patients. Barrett’s esophagus and esophageal malignancy are also not unheard of in these patients, and select patients may benefit from operative intervention. This review discusses the links between gastroesophageal reflux and lung transplant patients in both the pre and post-transplant setting. We also review the approach to the workup of esophageal disease in the pre-lung transplant setting as well as the surgical management of this unique group of 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.

Factors associated with esophageal motility improvement after bilateral lung transplant in patients with an aperistaltic esophagus

OBJECTIVES

We reported that esophageal peristalsis can improve after lung transplant (LTx), even in patients with pretransplant esophageal aperistalsis. This improvement was associated with better outcomes. We analyzed preoperative factors and sought to predict persistent aperistalsis or motility improvement in patients with pre-LTx esophageal aperistalsis.

METHODS

Patients with esophageal aperistalsis who underwent LTx between January 2013 and December 2016 were included. Preoperative barium esophagrams were blinded and re-examined; subjective scores were assigned to motility and dilation patterns. Postoperative high-resolution manometry was used to divide patients into 2 groups: persistent esophageal aperistalsis (PEA) or improved esophageal peristalsis (IEP).

RESULTS

We identified 29 patients: 20 with restrictive lung disease, 7 with obstructive lung disease, and 2 with pulmonary arterial hypertension. Post-LTx, 10 patients had PEA and 19 had IEP (mean age, 53.3 ± 6.6 years and 61.2 ± 10.6 years, respectively; P = .04). All 9 patients (100%) with obstructive lung disease or pulmonary arterial hypertension but only 10 of 20 patients (50%) with restrictive lung disease had IEP post-LTx (P = .01). All 4 patients with scleroderma had PEA. Nearly absent contractility on preoperative esophagrams was more prevalent in the PEA group than in the IEP group (100% vs 58.8%; P = .06). No further differences were observed between the groups.

CONCLUSIONS

Patients with esophageal aperistalsis and obstructive lung disease or pulmonary arterial hypertension, but not patients with restrictive lung disease and scleroderma, are likely to have IEP post-LTx. Additional studies may determine whether subjective esophagram assessment can help predict IEP post-LTx in patients with restrictive lung disease without scleroderma.

Pathological Implications of Swallow-Associated Transient Lower Esophageal Sphincter Elevation

BACKGROUND

The lower esophageal sphincter (LES) overlaps the crural diaphragm (CD) in patients without hiatal hernia (HH). Swallowing induces esophageal peristalsis with longitudinal esophageal shortening, causing transient elevation of the LES above the CD. This phenomenon, visible on high-resolution manometry (HRM), is called swallow-induced transient HH (tHH).

METHODS

We assessed pathological implications of swallow-induced LES elevation. We included patients who underwent 24-h pH monitoring and HRM between January 1, 2017 and June 30, 2018. Patients with manometric HH were excluded. Patients were divided into 3 groups: persistent tHH, which indicated significant LES-CD separation (i.e., ≥ 1cm in ≥ 30% swallows, or ≥ 2cm in ≥ 10% swallows) at the second inspiration after the conclusion of swallow-induced esophageal peristalsis; incidental tHH, which indicated significant LES-CD separation at the first inspiration after peristalsis without meeting persistent tHH criterion; and non-tHH.

RESULTS

In total, 107 patients were included. There were 18 patients in the persistent tHH group, 54 in the incidental tHH group, and 35 in the non-tHH group. No differences were observed in esophageal body motility or LES antireflux barrier parameters among groups. However, patients with persistent tHH had significantly higher DeMeester scores, longer acid exposure time, and poorer acid clearance. Prevalence of pathological reflux was 83.3% in the persistent tHH cohort. Esophagogastroduodenoscopy showed that 76.9% of patients with persistent tHH had no HH. Endoscopic findings of the esophagogastric junction were similar among groups.

CONCLUSIONS

Persistent tHH seems to be a pathological finding associated with pathological reflux.

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.

Esophageal Function Tests are Not Associated with Barium Swallow Findings in Advanced Lung Disease

Gastroesophageal reflux disease and esophageal dysmotility are common in patients with advanced lung disease (ALD) and are associated with worse outcomes. Assessing esophageal function in these patients is relevant for determining pulmonary transplant eligibility and prognosticating post-transplant outcomes. Barium Swallow (BaS) is a non-invasive testing modality often performed as a complement to formal esophageal function tests (EFTs), but its role and clinical utility in this context is unknown. Therefore, we aimed to determine the relationship between BaS and EFTs with high-resolution manometry (HRM) and 24-h ambulatory pH-metry in patients with ALD. We performed a retrospective study of 226 consecutive patients undergoing evaluation for lung transplantation at a single center. All patients underwent EFTs and BaS independent of clinical history or symptoms per institutional protocol. Appropriate statistical tests were performed to evaluate the relationship between EFTs and BaS. Mucosal, reflux and motility findings were categorized. Abnormal motility was reported in 133 (59%) patients by BaS and 99 (44%) by HRM, with a significant difference in the proportions of patients with abnormal studies (p < 0.01). There were 7 (26%) patients with abnormal barium tablet passage who had normal HRM. The sensitivity (35%) and specificity (77%) for detecting pathologic reflux with BaS was poor. Inducibility of reflux and barium column height were not associated with pH-metry results. No clinically significant luminal irregularities were identified. In conclusion, while BaS can non-invasively assess esophageal mucosa, its findings are not associated with EFTs in patients with ALD.

Gastroesophageal Reflux and Microaspiration in Lung Transplant Recipients: The Utility of a Single Esophageal Manometry and pH Probe Monitoring Study

BACKGROUND

Gastroesophageal reflux (GER) in recipients of lung transplant (LTX) is associated with chronic allograft rejection, presumably via microaspiration that damages airway epithelium. Most LTX programs perform a single post-LTX esophageal study to evaluate for GER; the efficacy of this test is unclear.

METHODS

Patients with 1 year of post-LTX follow-up, including routine bronchoscopies with bronchoalveolar lavage fluid (BALF) samples as well as high-resolution esophageal manometry and pH probe monitoring (HREMpH), were evaluated. BALF samples were analyzed with competitive enzyme-linked immunosorbent assay to detect bile salts, which are indicative of aspiration. These results were compared to results of HREMpH studies post LTX.

RESULTS

Ninety BALF samples were analyzed for bile salts and acted as disease positive for this evaluation. Of the 13 HREMpH cases, 8 were positive for GER, but only 3 were positive for bile salts via assay. Of the 5 HREMpH-negative cases, 2 experienced aspiration. A solitary HREMpH study had 60.0% sensitivity and 37.5% specificity with positive and negative likelihood ratios: 0.96 and 1.07, respectively.

CONCLUSION

Microaspiration appears to be an intermittent phenomenon, and HREMpH screening poorly correlates with BALF evidence of aspiration; which may not be adequate. As aspiration detection is crucial in this population, further analysis is warranted.

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.

Bile acids inhibit cholinergic constriction in proximal and peripheral airways from humans and rodents

Duodenogastroesophageal reflux (DGER) is associated with chronic lung disease. Bile acids (BAs) are established markers of DGER aspiration and are important risk factors for reduced post-transplant lung allograft survival by disrupting the organ-specific innate immunity, facilitating airway infection and allograft failure. However, it is unknown whether BAs also affect airway reactivity. We investigated the acute effects of 13 BAs detected in post-lung-transplant surveillance bronchial washings (BW) on airway contraction. We exposed precision-cut slices from human and mouse lungs to BAs and monitored dynamic changes in the cross-sectional luminal area of peripheral airways using video phase-contrast microscopy. We also used guinea pig tracheal rings in organ baths to study BA effects in proximal airway contraction induced by electrical field stimulation. We found that most secondary BAs at low micromolar concentrations strongly and reversibly relaxed smooth muscle and inhibited peripheral airway constriction induced by acetylcholine but not by noncholinergic bronchoconstrictors. Similarly, secondary BAs strongly inhibited cholinergic constrictions in tracheal rings. In contrast, TC-G 1005, a specific agonist of the BA receptor Takeda G protein-coupled receptor 5 (TGR5), did not cause airway relaxation, and Tgr5 deletion in knockout mice did not affect BA-induced relaxation, suggesting that this receptor is not involved. BAs inhibited acetylcholine-induced inositol phosphate synthesis in human airway smooth muscle cells overexpressing the muscarinic M3 receptor. Our results demonstrate that select BAs found in BW of patients with lung transplantation can affect airway reactivity by inhibiting the cholinergic contractile responses of the proximal and peripheral airways, possibly by acting as antagonists of M3 muscarinic receptors.

Idiopathic pulmonary fibrosis and GERD: links and risks

Gastroesophageal reflux disease (GERD) and idiopathic pulmonary fibrosis (IPF) are two pathological conditions often strictly related, even if a clear relationship of causality has not been demonstrated. GERD is a frequent comorbidity in IPF patients, as demonstrated using combined multichannel intraluminal impedance-pH, despite being mostly clinically silent. According to that, it has been hypothesized that microaspiration of gastric material may play a fundamental role in the fibrotic transformation of pulmonary parenchyma. In contrast, it cannot be excluded that IPF may favor GERD by increasing the negative intrathoracic pressure. Therefore, this relationship is uncertain as well as not univocal. Nevertheless, the latest international guidelines recommend the use of proton pump inhibitors (PPIs) in IPF based on several data showing that PPIs can stabilize lung function, reduce disease flares and hospitalizations. On the contrary, recent studies not only question the relevance of these results, but also associate the use of PPIs with an increased risk of lung infections and a negative prognostic outcome. The aim of this review is to analyze the possible links between GERD and IPF and their possible therapeutic implications, trying to translate this scientific evidence into useful information for clinical practice.

Single-centre study of therapeutic drug monitoring of posaconazole in lung transplant recipients: factors affecting trough plasma concentrations

Objectives

This study describes therapeutic drug monitoring (TDM) of posaconazole suspension and modified release (MR) tablets in lung transplant (LTx) recipients and evaluates factors that may affect posaconazole trough plasma concentration (Cmin).

Methods

A single-centre, retrospective study evaluating posaconazole Cmin in LTx recipients receiving posaconazole suspension or MR tablets between January 2014 and December 2016.

Results

Forty-seven LTx patients received posaconazole suspension, and 78 received the MR tablet formulation; a total of 421 and 617 Cmin measurements were made, respectively. Posaconazole was concurrently administered with proton pump inhibitor in ≥ 90% of patients. The median (IQR) of initial posaconazole Cmin following 300 mg daily of posaconazole tablet was significantly higher than that of 800 mg daily of posaconazole suspension [1.65 (0.97-2.13) mg/L versus 0.81 (0.48-1.15) mg/L, P < 0.01]. Variability in posaconazole Cmin was apparent regardless of the formulations prescribed and dose adjustments were routinely undertaken to maintain therapeutic Cmin. A clear dose-response relationship was observed in patients receiving posaconazole MR tablets. Non-specific adverse events (fatigue, tremor, lethargy, sweating, nausea/vomiting and weight loss) were reported in 3/78 (4%) patients receiving posaconazole MR tablets. Posaconazole Cmin in these three patients was determined to be 9.6, 6.2 and 2.3 mg/L.

Conclusions

The current study has provided clinically important insights into the TDM of posaconazole in LTx recipients. Routine TDM should be undertaken in LTx recipients receiving posaconazole suspension and/or MR tablets.

Prevalence and Natural History of Barrett's Esophagus in Lung Transplant: A Single-Center Experience

BACKGROUND

Barrett's esophagus (BE)-intestinal metaplasia in the esophagus-may progress to low-grade dysplasia (LGD), high-grade dysplasia (HGD), and ultimately, invasive esophageal adenocarcinoma (EAC). The course of BE in immunosuppressed lung transplant recipients is unknown.

METHODS

This study retrospectively reviewed the records of patients who underwent lung transplant at a single center, Norton Thoracic Institute in Phoenix, Arizona, between January 1, 2010 and October 31, 2016. Pretransplant esophagram, esophagogastroduodenoscopy, 24-hour pH monitoring, high-resolution manometry, and gastric emptying studies were analyzed.

RESULTS

Of the 466 patients who underwent lung transplant during the study period, 54 (11.59%) had BE on pretransplant esophagogastroduodenoscopy. Of these, 1 patient had HGD before lung transplant. The median age of patients was 64 years (interquartile range, 58.25 to 68.75 years); 66.7% were men. Median follow-up duration was 29.48 months (interquartile range, 19.69 to 37.98 months). Sixteen of 54 patients (29.62%) underwent antireflux surgery after lung transplant. LGD or EAC developed in 3 patients during posttransplant surveillance. One patient had a diagnosis of HGD 24 months after retransplant. She underwent complete endoscopic ablation and was dysplasia-free for 5 months, but ultimately the condition recurred, and she underwent esophagectomy for invasive cancer. Two patients had a diagnosis of LGD 7 and 13 months after lung transplant and were successfully treated with radiofrequency ablation. The rate of progression to dysplasia or EAC was 2.3% per patient-year.

CONCLUSIONS

BE seems to be more prevalent in lung transplant recipients than in the general population. The study findings suggest that patients with BE have a higher risk of BE-to-EAC progression after lung transplant and that HGD may progress rapidly in immunosuppressed patients. More intensive surveillance endoscopy may be required in patients with BE after lung transplant.

Reflux in idiopathic pulmonary fibrosis: treatment informed by an integrated approach

Despite recent therapeutic advances, the prognosis for patients with idiopathic pulmonary fibrosis (IPF) remains poor. The link with gastro-oesophageal reflux disease (GORD) has been identified as a research priority, as GORD appears to be common in IPF and may be associated with adverse outcomes [1]. GORD is often clinically silent in IPF, so detection is challenging [2].

After MDT work-up and review, gastro-oesophageal reflux and pulmonary aspiration were found to be common in IPF patients; surgery was recommended in only 10%http://ow.ly/rO3T30lU17o

Perioperative Management of the Lung Graft Following Lung Transplantation

Perioperative management of patients undergoing lung transplantation is one of the most complex in cardiothoracic surgery. Certain perioperative interventions, such as mechanical ventilation, fluid management and blood transfusions, use of extracorporeal mechanical support, and pain management, may have significant impact on the lung graft function and clinical outcome. This article provides a review of perioperative interventions that have been shown to impact the perioperative course after lung transplantation.

Gastroesophageal Reflux Disease in Idiopathic Pulmonary Fibrosis: Uncertainties and Controversies

The mechanisms of idiopathic pulmonary fibrosis (IPF), a rare, devastating disease with a median survival of 3-5 years, are not fully understood. Gastroesophageal reflux disease (GERD) is a frequent comorbidity encountered in IPF. Hypothetically, GERD-associated microaspiration may lead to persistent inflammation impairing lung infrastructure, thereby possibly accelerating the progression of IPF. IPF may increase intrathoracic pressure, which can aggravate GERD and vice versa. On the basis of the possible beneficial effects of antireflux or antacid therapy on lung function, acute exacerbation, and survival, the recent international IPF guideline recommends antacid therapies for patients with IPF, regardless of symptomatic GERD. However, due to newer conflicting data, several national guidelines do not support this recommendation. Elucidation of these questions by further clinical and bench-to-bedside research may provide us with rational clinical diagnostic and therapeutic approaches concerning GERD in IPF. The present review aims to discuss the latest data on the controversial association of IPF and GERD.

Thoracoabdominal pressure gradient and gastroesophageal reflux: insights from lung transplant candidates

Advanced lung disease is associated with gastroesophageal reflux disease (GERD). The thoracoabdominal pressure gradient (TAPG) facilitates gastroesophageal reflux, but the effects of TAPG on gastroesophageal reflux in patients with pulmonary disease have not been well defined. Patients diagnosed with end-stage lung disease are expected to have the most extreme derangement in respiratory mechanics. The aim of this study is to explore the relationship between TAPG and reflux in lung transplant (LTx) candidates. We reviewed LTx recipients who underwent pretransplant esophageal high-resolution manometry and a 24-hour pH study. Patients were excluded if they were undergoing redo LTx, had manometric hiatal hernia, or had previously undergone foregut surgery. TAPG was defined as the intra-abdominal pressure minus the intrathoracic pressure during inspiration. Adjusted TAPG was calculated by the TAPG minus the resting lower esophageal sphincter (LES) pressure (LESP). Twenty-two patients with normal esophageal function tests (i.e., normal esophageal motility with neither manometric hiatal hernia nor pathological reflux on 24-hour pH monitoring) were selected as the pulmonary disease-free control group. In total, 204 patients underwent LTx between January 2015 and December 2016. Of these, 77 patients met inclusion criteria. We compared patients with obstructive lung disease (OLD, n = 33; 42.9%) and those with restrictive lung disease (RLD, n = 42; 54.5%). 2/77 patients (2.6%) had pulmonary arterial hypertension. GERD was more common in the RLD group than in the OLD group (24.2% vs. 47.6%, P = 0.038). TAPG was similar between the OLD group and the controls (14.2 vs. 15.3 mmHg, P = 0.850); however, patients in the RLD group had significantly higher TAPG than the controls (24.4 vs. 15.3 mmHg, P = 0.002). Although TAPG was not correlated with GERD, the adjusted TAPG correlated with reflux in all 77 patients with end-stage lung disease (DeMeester score, rs = 0.256, P = 0.024; total reflux time, rs = 0.259, P = 0.023; total number of reflux episodes, rs = 0.268, P = 0.018). Additionally, pathological reflux was seen in 59.1% of lung transplant candidates with adjusted TAPG greater than 0 mmHg (i.e., TAPG exceeding LESP); GERD was seen in 30.9% of patients who had an adjusted TAPG ≤ 0 mmHg. In summary, TAPG varies based on the underlying cause of lung disease. Higher adjusted TAPG increases pathological reflux, even if patients have normal antireflux anatomy and physiology (i.e., no hiatal hernia and manometrically normal LES function). Adjusted TAPG may provide further insights into the pathophysiology of GERD.

Association of methacholine challenge test with diagnosis of chronic lung allograft dysfunction in lung transplant patients

BACKGROUND

Chronic lung allograft dysfunction (CLAD) is a complication of lung transplantation. We sought to determine whether bronchial hyperresponsiveness detected by the methacholine challenge test (MCT) at 3 months after lung transplant (LT) predicts the development of CLAD.

METHODS

We performed a retrospective cohort study of 140 LT patients between 1/2008 and 6/2014 who underwent MCT at 3 months after LT. Pearson's chi-squared test and Kruskal-Wallis test were used to compare categorical and continuous variables, respectively. Cox proportional hazards modeling was used to evaluate the association between CLAD and MCT.

RESULTS

Methacholine challenge test+ was associated with the development of overall CLAD (adjusted hazards ratio [aHR]: 3.47; 95% confidence interval [95% CI]: 1.71, 7.03; P = 0.001) and CLAD within 3 years (aHR: 4.98; 95%CI: 1.84, 13.48; P = 0.002). Subgroup analysis showed that MCT (+) is associated with overall CLAD in single lung transplant (SLT) (aHR: 8.18; 95% CI: 2.22, 30.09; P = 0.002), double lung transplant (DLT) (aHR: 3.27; 95% CI: 1.22, 8.78; P = 0.02) and CLAD within 3 years in DLT patients (aHR: 6.76; 95% CI: 1.71, 26.74; P = 0.01).

CONCLUSION

Methacholine challenge test+ at 3 months after LT is associated with the development of overall CLAD. Positive MCT could predict the development of early CLAD within 3 years in DLT patients.

Meta-analysis of Gastroesophageal Reflux Disease and Idiopathic Pulmonary Fibrosis

BACKGROUND

The relationship between gastroesophageal reflux disease (GERD) and idiopathic pulmonary fibrosis (IPF) is controversial. Current guidelines recommend that clinicians use regular antacid treatment, while two recent meta-analyses of antacid therapy in IPF were inconclusive. The objective of this study was to examine the evidence regarding the association between GERD and IPF through a systematic review and a meta-analysis, with special reference to the methodologic quality of the observational studies.

METHODS

The MEDLINE, EMBASE, Ovid, and Web of Science (1966-May 2018) databases were searched for original articles published in any language, and we then systematically reviewed the bibliographies of the retrieved articles. Observational studies (cohort and case-control studies) were selected if they allowed the calculation of a measure of association relating GERD to IPF.

RESULTS

Eighteen case-control studies including 3,206 patients with IPF and 9,368 control subjects met the inclusion criteria of the meta-analysis. The meta-analysis indicated that GERD is associated with IPF (OR, 2.94 [95% CI, 1.95-4.42]; P homogeneity < .0001). Overall, the results remained consistent whatever the data source (clinical studies vs databases) or the type of control subject (healthy volunteers, patients with respiratory diseases other than interstitial lung disease, or patients with non-IPF interstitial lung disease). In a meta-regression, after controlling for smoking, GERD and IPF were not related.

CONCLUSIONS

GERD and IPF may be related, but this association is most likely confounded, especially by smoking. Our confidence in the estimate of association is low because it is exclusively from case-control studies.

TRIAL REGISTRY

PROSPERO; No.: CRD42016053728; URL: http://www.crd.york.ac.uk/PROSPERO.

Aspiration Pneumonia and Related Syndromes

Aspiration is a syndrome with variable respiratory manifestations that span acute, life-threatening illnesses, such as acute respiratory distress syndrome, to chronic, sometimes insidious, respiratory disorders such as aspiration bronchiolitis. Diagnostic testing is limited by the insensitivity of histologic testing, and although gastric biomarkers for aspiration are increasingly available, none have been clinically validated. The leading mechanism for microaspiration is thought to be gastroesophageal reflux disease, largely driven by the increased prevalence of gastroesophageal reflux across a variety of respiratory disorders, including chronic obstructive pulmonary disease, asthma, idiopathic pulmonary fibrosis, and chronic cough. Failure of therapies targeting gastric acidity in clinical trials, in addition to increasing concerns about both the overuse of and adverse events associated with proton pump inhibitors, raise questions about the precise mechanism and causal link between gastroesophageal reflux and respiratory disease. Our review summarizes key aspiration syndromes with a focus on reflux-mediated aspiration and highlights the need for additional mechanistic studies to find more effective therapies for aspiration syndromes.

Symptom prevalence of patients with fibrotic interstitial lung disease: a systematic literature review

Background

Those affected by advanced fibrotic interstitial lung diseases have limited treatment options and in the terminal stages, the focus of care is on symptom management. However, quantitatively, little is known about symptom prevalence. We aimed to determine the prevalence of symptoms in Progressive Idiopathic Fibrotic Interstitial Lung Disease (PIF-ILD).

Methods

Searches on eight electronic databases including MEDLINE for clinical studies between 1966 and 2015 where the target population was adults with PIF-ILD and for whom the prevalence of symptoms had been calculated.

Results

A total of 4086 titles were screened for eligibility criteria; 23 studies were included for analysis. The highest prevalence was that for breathlessness (54–98%) and cough (59–100%) followed by heartburn (25–65%) and depression (10–49%). The heterogeneity of studies limited their comparability, but many of the symptoms present in patients with other end-stage disease were also seen in PIF-ILD.

Conclusions

This is the first quantitative review of symptoms in people with Progressive Idiopathic Fibrotic Interstitial Lung Diseases. Symptoms are common, often multiple and have a comparable prevalence to those experienced in other advanced diseases. Quantification of these data provides valuable information to inform the allocation of resources.

Electronic supplementary material

The online version of this article (10.1186/s12890-018-0651-3) contains supplementary material, which is available to authorized users.

Gastroesophageal reflux symptoms are not sufficient to guide esophageal function testing in lung transplant candidates

Gastroesophageal reflux disease and esophageal dysmotility are prevalent in patients with advanced lung disease and are associated with graft dysfunction following lung transplantation. As a result, many transplant centers perform esophageal function testing as part of the wait-listing process but guidelines for testing in this population are lacking. The aim of this study is to describe whether symptoms of gastroesophageal reflux correlate with abnormal results on pH-metry and high-resolution manometry and can be used to identify those who require testing. We performed a retrospective cohort study of 226 lung transplant candidates referred for high-resolution manometry and pH-metry over a 12-month period in 2015. Demographic data, results of a standard symptom questionnaire and details of esophageal function testing were obtained. Associations between the presence of symptoms and test results were analyzed using Fisher's exact tests and multivariable logistic regression. The most common lung disease diagnosis was interstitial lung disease (N = 131, 58%). Abnormal pH-metry was seen in 116 (51%) patients and the presence of symptoms was significantly associated with an abnormal study (p < 0.01). Dysmotility was found in 98 (43%) patients, with major peristaltic or esophageal outflow disorders in 45 (20%) patients. Symptoms were not correlated with findings on esophageal high-resolution manometry. Fifteen of 25 (60%) asymptomatic patients had an abnormal manometry or pH-metry. These results demonstrate that in patients with advanced lung disease, symptoms of gastroesophageal reflux increase the likelihood of elevated acid exposure on pH-metry but were not associated with dysmotility. Given the proportion of asymptomatic patients with abnormal studies and associated post-transplant risks, a practice of universal high-resolution manometry and pH-metry testing in this population is justifiable.

Comparison of short-term outcomes for connective tissue disease-related interstitial lung disease and idiopathic pulmonary fibrosis after lung transplantation

Background

Pulmonary involvement is common in connective tissue disease (CTD), and respiratory failure is a major cause of morbidity and mortality in CTD-related interstitial lung disease (CTD-ILD). Lung transplantation is thus important for these patients. However, survival, outcomes, and management of these patients after transplantation have been debated. The aim of this study was to evaluate the outcomes for CTD-ILD compared to those for idiopathic pulmonary fibrosis (IPF) after lung transplantation.

Methods

We performed a single-centre retrospective study of 62 patients with CTD-ILD or IPF who underwent lung transplantation at a tertiary hospital in South Korea between October 2012 and October 2016.

Results

Patients with CTD-ILD (n=15) were younger (46 vs. 60 years, P=0.001) and were less likely to be male (33.3% vs. 76.6%, P=0.004) than were patients with IPF (n=47). The 1-year cumulative survival rate was 80.0% for CTD-ILD and 59.6% for IPF (log-rank P=0.394). There was no difference in the cumulative survival rate (log-rank P=0.613) of age- and sex-matched patients with CTD-ILD (n=15) and IPF (n=15). The incidence of primary graft dysfunction was similar (P=0.154), and 2 (18.2%) patients developed possible CTD flare.

Conclusions

Patients with CTD-ILD and those with IPF who underwent lung transplantation had similar survival rates.

Gastroesophageal Reflux and Idiopathic Pulmonary Fibrosis

BACKGROUND

Idiopathic pulmonary fibrosis (IPF) is a progressive interstitial lung disease of unknown origin that affects about 40,000 new patients every year in the USA. Albeit the disease is labelled as idiopathic, it is thought that pathologic reflux, often silent, plays a role in its pathogenesis through a process of microaspiration of gastric contents.

AIMS

The aim of this study was to review the available evidence linking reflux to IPF, and to study the effect of medical and surgical therapy on the natural history of this disease.

RESULTS

Medical therapy with acid-reducing medications controls the production of acid and has some benefit. However, reflux and aspiraion of weakly acidic or alkaline gastric contents can still occur. Better results have been reported after laparoscopic anti-reflux surgery, as this form of therapy re-establishes the competence of the lower esophageal sphincter, therefore stopping any type of reflux.

CONCLUSIONS

A phase II NIH study in currently in progress in the USA to determine the role of antireflux surgery in patients with GERD and IPF. The hope is that this simple operations might alter the natural history of IPF, avoiding progression and the need for lung transplantation.