Gastroesophageal reflux as a reversible cause of allograft dysfunction after lung transplantation

Neurogastroenterology and Motility Disorders of the Gastrointestinal Tract in Cystic Fibrosis

PURPOSE OF REVIEW

To discuss all the various motility disorders impacting people with Cystic Fibrosis (PwCF) and provide diagnostic and management approaches from a group of pediatric and adult CF and motility experts and physiologists with experience in the management of this disease.

RECENT FINDINGS

Gastrointestinal (GI) symptoms coexist with pulmonary symptoms in PwCF regardless of age and sex. The GI manifestations include gastroesophageal reflux disease, esophageal dysmotility gastroparesis, small bowel dysmotility, small intestinal bacterial overgrowth syndrome, distal idiopathic obstruction syndrome, constipation, and pelvic floor disorders. They are quite debilitating, limiting the patients' quality of life and affecting their nutrition and ability to socialize. This genetic disorder affects many organ systems and is chronic, potentially impacting fertility and future family planning, requiring a multidisciplinary approach. Our review discusses the treatments of motility disorders in CF, their prevalence and pathophysiology. We have provided a framework for clinicians who care for these patients that can help to guide their clinical management.

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.

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.

Utility of bile acids in large airway bronchial wash versus bronchoalveolar lavage as biomarkers of microaspiration in lung transplant recipients: a retrospective cohort study

Background

Bronchoalveolar lavage (BAL) is a key tool in respiratory medicine for sampling the distal airways. BAL bile acids are putative biomarkers of pulmonary microaspiration, which is associated with poor outcomes after lung transplantation. Compared to BAL, large airway bronchial wash (LABW) samples the tracheobronchial space where bile acids may be measurable at more clinically relevant levels. We assessed whether LABW bile acids, compared to BAL bile acids, are more strongly associated with poor clinical outcomes in lung transplant recipients.

Methods

Concurrently obtained BAL and LABW at 3 months post-transplant from a retrospective cohort of 61 lung transplant recipients were analyzed for taurocholic acid (TCA), glycocholic acid (GCA), and cholic acid by mass spectrometry and 10 inflammatory proteins by multiplex immunoassay. Associations between bile acids with inflammatory proteins and acute lung allograft dysfunction were assessed using Spearman correlation and logistic regression, respectively. Time to chronic lung allograft dysfunction and death were evaluated using multivariable Cox proportional hazards and Kaplan–Meier methods.

Results

Most bile acids and inflammatory proteins were higher in LABW than in BAL. LABW bile acids correlated with inflammatory proteins within and between sample type. LABW TCA and GCA were associated with acute lung allograft dysfunction (OR = 1.368; 95%CI = 1.036–1.806; P = 0.027, OR = 1.064; 95%CI = 1.009–1.122; P = 0.022, respectively). No bile acids were associated with chronic lung allograft dysfunction. Adjusted for risk factors, LABW TCA and GCA predicted death (HR = 1.513; 95%CI = 1.014–2.256; P = 0.042, HR = 1.597; 95%CI = 1.078–2.366; P = 0.020, respectively). Patients with LABW TCA in the highest tertile had worse survival compared to all others.

Conclusions

LABW bile acids are more strongly associated than BAL bile acids with inflammation, acute lung allograft dysfunction, and death in lung transplant recipients. Collection of LABW may be useful in the evaluation of microaspiration in lung transplantation and other respiratory diseases.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12931-022-02131-5.

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.

Early postoperative complications in lung transplant recipients

Lung transplantation has become an established therapy for end-stage lung diseases. Early postoperative complications can impact immediate, mid-term, and long-term outcomes. Appropriate management, prevention, and early detection of these early postoperative complications can improve the overall transplant course. In this review, we highlight the incidence, detection, and management of these early postoperative complications in lung transplant recipients.

Safety and efficacy of an implantable device for management of gastroesophageal reflux in lung transplant recipients

Background

Magnetic sphincter augmentation (MSA) is a promising minimally invasive surgical technique for management of gastroesophageal reflux disease (GERD); however, device implantation after transplantation has not been studied and may be concerning in these immunosuppressed patients. We explored the safety of the LINX Reflux Management System (MSA device) for management of GERD following lung transplantation (LTx).

Methods

Lung transplant recipients who underwent LINX implantation at our institution between 2017 and 2019 were followed prospectively in the Reflux Following Lung Transplantation and Associated Treatment Registry. Ambulatory pH testing and acid-suppressing medication use were compared before and after LINX implantation. One-year outcomes and change in pulmonary function were compared between matched LINX and fundoplication groups.

Results

Of 17 patients who underwent post-lung transplant LINX implantation, 8 (47.1%) agreed to undergo post-LINX pH testing. Three/eight (37.5%) patients achieved normal esophageal acid exposure time; 14 (82.4%) remained on acid-suppressing medication at one-year under the direction of their transplant teams. One-year patient survival and change in pulmonary function were similar between groups. LINX patients experienced more early side effects.

Conclusions

Use of the LINX MSA device in a cohort of lung transplant recipients at our institution was associated with similar short-term safety compared to traditional fundoplication, however assessment of efficacy was limited. Further investigation is needed to characterize the long-term efficacy of LINX implantation after LTx.

Focus on gastroesophageal reflux disease in patients with cystic fibrosis

Gastroesophageal reflux disease (GERD) is a common gastrointestinal disorder in cystic fibrosis (CF), and based on various studies, its prevalence is elevated since childhood. There are several pathogenetic mechanisms on the basis of association between CF and GERD. However, there are no specific guidelines for GERD in CF patients, so diagnosis is based on guidelines performed on patients not affected by CF. The aim of this review is to provide the pathophysiology, diagnostic and therapeutic options, complications, and future directions in the management of GERD patients with CF.

Esophageal pH-impedance monitoring in children: position paper on indications, methodology and interpretation by the SIGENP working group

Multichannel intraluminal impedance pH (MII-pH) monitoring currently represents the gold standard diagnostic technique for the detection of gastro-esophageal reflux (GER), since it allows to quantify and characterize all reflux events and their possible relation with symptoms. Over the last ten years, thanks to its strengths and along with the publication of several clinical studies, its worldwide use has gradually increased, particularly in infants and children. Nevertheless, factors such as the limited pediatric reference values and limited therapeutic options still weaken its current clinical impact. Through an up-to-date review of the available scientific evidence, our aim was to produce a position paper on behalf of the working group on neurogastroenterology and acid-related disorders of the Italian Society of Pediatric Gastroenterology, Hepatology and Nutrition (SIGENP) on MII-pH monitoring technique, indications and interpretation in pediatric age, in order to standardise its use and to help clinicians in the diagnostic approach to children with GER symptoms.

Parenteral administration of oral medications in lung transplant recipients: An underrecognized problem

Microcrystalline cellulose (MCC) is an insoluble material commonly used as a binder and filler in oral medications. Identification of pulmonary intravascular deposition of MCC in transbronchial biopsies from lung transplant (LT) recipients following parenteral injection of oral medications has only been reported once. A search of our surgical pathology electronic database was performed from January 1, 2000 to November 1, 2017 using the text "transplant transbronchial." The diagnosis field for all cases retrieved was then searched for the text "cellulose." These cases were queried for patient demographics and outcomes. Between January 1, 2000 and November 1, 2017, 1558 lung transplants were performed in 1476 individual patients at our institution; 12 were identified to have MCC in their lung tissue. Patients with MCC identified on biopsies were more likely to be transplanted for cystic fibrosis versus other indications and younger versus older. MCC identified in 2 of our cases was favored to be donor derived. Of the 12 patients, 6 (50%) are deceased. MCC within the pulmonary vasculature may be an indicator of increased complications, mortality, or shortened survival in LT recipients. Detecting intravascular MCC and distinguishing it from aspirated foreign material can be challenging. Awareness of the differential diagnosis for pulmonary foreign material is of paramount importance for the pathologist.

Donor-derived cell-free DNA predicts allograft failure and mortality after lung transplantation

Background

Allograft failure is common in lung-transplant recipients and leads to poor outcomes including early death. No reliable clinical tools exist to identify patients at high risk for allograft failure. This study tested the use of donor-derived cell-free DNA (%ddcfDNA) as a sensitive marker of early graft injury to predict impending allograft failure.

Methods

This multicenter, prospective cohort study enrolled 106 subjects who underwent lung transplantation and monitored them after transplantation for the development of allograft failure (defined as severe chronic lung allograft dysfunction [CLAD], retransplantation, and/or death from respiratory failure). Plasma samples were collected serially in the first three months following transplantation and assayed for %ddcfDNA by shotgun sequencing. We computed the average levels of ddcfDNA over three months for each patient (avddDNA) and determined its relationship to allograft failure using Cox-regression analysis.

Findings

avddDNA was highly variable among subjects: median values were 3·6%, 1·6% and 0·7% for the upper, middle, and low tertiles, respectively (range 0·1%–9·9%). Compared to subjects in the low and middle tertiles, those with avddDNA in the upper tertile had a 6·6-fold higher risk of developing allograft failure (95% confidence interval 1·6–19·9, p = 0·007), lower peak FEV1 values, and more frequent %ddcfDNA elevations that were not clinically detectable.

Interpretation

Lung transplant patients with early unresolving allograft injury measured via %ddcfDNA are at risk of subsequent allograft injury, which is often clinically silent, and progresses to allograft failure.

Fund

National Institutes of Health.

Cystic Fibrosis and gastroesophageal reflux disease

Gastroesophageal reflux is common in children and adults with cystic fibrosis (CF). Pathological gastroesophageal reflux disease (GERD) is also frequent in patients of all ages with CF. This article reviews the pathophysiology, diagnostic work-up, management options, complications, and future directions in the evaluation and management of GERD - unique to and pertinent for - patients with CF in particular.

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

BACKGROUND

Acid reflux has been associated with poor outcomes following lung transplantation. Unlike surgical fundoplication, the role of noninvasive, pharmacologic acid suppression remains uncertain.

AIMS

To assess the relationship between post-transplant acid suppression with proton pump inhibitors (PPI) or histamine-2 receptor antagonists (H2RA) and onset of early allograft injury or chronic rejection following lung transplantation.

METHODS

This was a retrospective cohort study of lung transplant recipients at a tertiary center in 2007-2014. Patients with pre-transplant antireflux surgery were excluded. Time-to-event analysis using the Cox proportional hazards model was applied to assess acid suppression therapy and onset of acute or chronic rejection, defined histologically and clinically. Subgroup analyses were performed to assess PPI versus H2RA use.

RESULTS

A total of 188 subjects (60% men, mean age 54, follow-up 554 person-years) met inclusion criteria. During follow-up, 115 subjects (61.5%) developed rejection, with all-cause mortality of 27.6%. On univariate analyses, acid suppression and BMI, but not other patient demographics, were associated with rejection. The Kaplan-Meier curve demonstrated decreased rejection with use of acid suppression therapy (log-rank p = 0.03). On multivariate analyses, acid suppression (HR 0.39, p = 0.04) and lower BMI (HR 0.67, p = 0.04) were independently predicted against rejection. Subgroup analyses demonstrated that persistent PPI use was more protective than H2RA or no antireflux medications.

CONCLUSIONS

Post-lung transplant exposure to persistent PPI therapy results in the greatest protection against rejection in lung transplant recipients, independent of other clinical predictors including BMI, suggesting that PPI may have antireflux or anti-inflammatory effects in enhancing allograft protection.

Prevention of chronic rejection after lung transplantation

Long-term survival after lung transplantation (LTx) is limited by chronic rejection (CR). Therapeutic strategies for CR have been largely unsuccessful, making prevention of CR an important and challenging therapeutic approach. In the current review, we will discuss current clinical evidence regarding prevention of CR after LTx.

Recipient selection process and listing for lung transplantation

Lung transplantation remains the ultimate treatment option for selected patients with end-stage (cardio) pulmonary disease. Given the current organ shortage, it is without any doubt that careful selection of potential transplant candidates is essential as this may greatly influence survival after the procedure. In this paper, we will review the current guidelines for referral and listing of lung transplant candidates in general, and in more depth for the specific underlying diseases. Needless to state that these are not absolute guidelines, and that decisions depend upon center's activity, waiting list, etc. Therefore, every patient should be discussed with the transplant center before any definite decision is made to accept or decline a patient for lung transplantation.

Current Nutrition Practices in Adult Lung Transplantation

Nutrition therapy is vital to the overall management of lung transplant recipients. The objective of this review is to outline the current applications of pre- and posttransplant nutrition management of the adult lung transplant recipient. Pretransplant nutrition therapy decisions are based on cause of end-stage lung disease, transplant indications, and pretransplant nutritional status. Maintaining adequate nutrient stores is the major goal of nutrition therapy for patients awaiting transplantation. In the posttransplant course, several gastrointestinal (GI) complications such as gastroesophageal reflux, gastroparesis, and distal intestinal obstruction syndrome complicate nutritional recovery. Long-term nutrition therapy for lung transplant recipients is aimed at management of common comorbid conditions such as obesity, diabetes mellitus, hypertension, osteoporosis, and hyperlipidemia. Lung transplantation outcomes are steadily improving; however, much has yet to be explored to improve the nutrition management of these patients in both the pre- and posttransplantation course.

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

BACKGROUND

Antireflux surgery (ARS) has been associated with improved lung transplant outcomes. Pre-transplant ARS has been shown in small studies to improve pulmonary function among transplant candidates with gastroesophageal reflux disease (GERD). Although early post-transplant ARS has been shown to be effective in reducing chronic rejection, the optimal timing of ARS in transplant recipients remains unclear. The aim of this study is to evaluate the time to early allograft injury among lung transplant recipients by timing of ARS.

METHODS

This was a retrospective cohort study of lung transplant recipients undergoing ARS before or after transplantation at a tertiary care center since 2007, with at least 1-year follow-up. Early allograft injury was defined clinically and histologically as acute rejection or lymphocytic bronchiolitis, occurring within the first year after transplantation. In accordance with prior studies, the cutoff between early and late post-transplant ARS was set at 6 months. Time-to-event analysis using the Cox proportional hazards model was applied to assess the relationship between timing of surgery and early allograft injury. Subjects not meeting this outcome were censored at 1 year in the time-to-event analysis. Fisher’s exact test for binary variables and Student’s t test for continuous variables were performed to assess for differences among the three groups: ARS pre-transplant, ARS early post-transplant, and ARS late post-transplant.

RESULTS

Forty-eight subjects (60% men, mean age 55) met the inclusion criteria for the study. Patient demographics, pre-transplant cardiopulmonary function, BMI, CMV status, and PPI exposure were similar between groups. Kaplan-Meier analysis demonstrated significantly increased early allograft injury in late post-transplant ARS patients compared with both pre-transplant (log-rank p = 0.007) and early post-transplant (log-rank p = 0.05) patients, as well as a significant trend across groups (log-rank p = 0.005). No significant difference between pre- and early post-transplant groups was noted. Three ARS failures were noted in the pre- and late post-transplant groups. Complications included one death due to aspiration pneumonia in a late post-transplant ARS recipient. No early post-transplant ARS patients experienced ARS failure or complications.

CONCLUSION

Late post-lung transplant ARS resulted in increased risk of early allograft injury compared to pre-transplant and early post-transplant ARS. Both pre- and early post-transplant ARS appear equally safe and effective in improving lung transplant outcomes. These findings support consideration of aggressive reflux testing and application of antireflux measures before or soon after transplantation to minimize the impact of reflux on allograft injury.

Lung transplantation in IIP: A review

The idiopathic interstitial pneumonias (IIP) encompass a large and diverse subtype of interstitial lung disease (ILD) with idiopathic pulmonary fibrosis (IPF) and non-specific interstitial pneumonia (NSIP) being the most common types. Although pharmacologic treatments are available for most types of IIP, many patients progress to advanced lung disease and require lung transplantation. Close monitoring with serial functional and radiographic tests for disease progression coupled with early referral for lung transplantation are of great importance in the management of patients with IIP. Both single and bilateral lung transplantation are acceptable procedures for IIP. Procedure selection is a complex decision influenced by multiple factors related to patient, donor and transplant centre. While single lung transplant may reduce waitlist time and mortality, the long-term outcomes after bilateral lung transplantation may be slightly superior. There are numerous complications following lung transplantation including primary graft dysfunction, chronic lung allograft dysfunction (CLAD), infections, gastroesophageal reflux disease (GERD) and airway disease that limit post-transplant longevity. The median survival after lung transplantation is 4.7 years in patients with ILD, which is less than in patients with other underlying lung diseases. Although long-term survival is limited, this intervention still conveys a survival benefit and improved quality of life in suitable IIP patients with advanced lung disease and chronic hypoxemic respiratory failure.

Weight loss prior to lung transplantation is associated with improved survival

BACKGROUND

Obesity is associated with increased mortality after lung transplantation and is a relative contraindication to transplant. It is unknown whether weight reduction prior to transplantation ameliorates this risk. Our objective was to determine whether weight loss prior to lung transplantation improves survival.

METHODS

Our investigation was a two-center, retrospective cohort study of lung transplant recipients between January 1, 2000 and November 5, 2010. Change in weight, demographics, transplant details, lung allocation score, length of intensive care and mechanical ventilator days and graft and patient survival were abstracted. Wilcoxon's signed-rank test and the Cox proportional hazard model were used for analysis where appropriate.

RESULTS

Three hundred fifty-five patients (55% male, median age 59 years) satisfied inclusion and exclusion criteria. After adjusting for standard demographic and clinical measures, a 1-unit reduction in BMI pre-transplant was associated with a reduced risk of death with a hazard ratio 0.89 (95% confidence interval 0.82 to 0.96; p = 0.004). This survival benefit persisted in the group with baseline BMI ≥ 25 kg/m(2) (overweight and obese) and hazard ratio 0.85 (95% CI 0.77 to 0.95; p = 0.003), but not in those with a BMI ≤ 24.9 kg/m(2). The 1-unit reduction in BMI was also associated with a 6.1% decrease in median mechanical ventilator days (p = 0.02) and a trend toward decreased intensive care unit length of stay (p = 0.06).

CONCLUSIONS

A reduction in BMI prior to lung transplantation was associated with a reduction in the risk of death and mechanical ventilator days. A greater reduction in BMI was associated with a greater survival benefit.

Current views on chronic rejection after lung transplantation

Chronic lung allograft dysfunction (CLAD) was recently introduced as an overarching term mainly to classify patients with chronic rejection after lung transplantation, although other conditions may also qualify for CLAD. Initially, only the development of a persistent and obstructive pulmonary function defect, clinically identified as bronchiolitis obliterans syndrome (BOS), was considered as chronic rejection, if no other cause could be identified. It became clear in recent years that some patients do not qualify for this definition, although they developed a chronic and persistent decrease in FEV1 , without another identifiable cause. As the pulmonary function decline in these patients was rather restrictive, this was called restrictive allograft syndrome (RAS). In the present review, we will further elaborate on these two CLAD phenotypes, with specific attention to the diagnostic criteria, the role of pathology and imaging, the risk factors, outcome, and the possible treatment options.

Prevalence of gastroesophageal reflux in cystic fibrosis and implications for lung disease

Gastroesophageal reflux (GER) is common in patients with cystic fibrosis (CF) and is often regarded as playing a role in the pathogenesis of CF lung disease. Individuals with CF have many predisposing factors to the development of GER, with a reported prevalence ranging from 35 to 81%. Several studies have suggested that patients with CF who have coexisting GER have more severe lung disease with lower pulmonary function and increased numbers of respiratory exacerbations. Furthermore, GER may alter the respiratory microbiology in CF. Both the acid and nonacid components of GER may have an effect on lung disease. More than 50% of U.S. patients with CF were being treated with proton pump inhibitors in 2012; however, data regarding safety and efficacy of these agents in CF are lacking. Pharmacologic and surgical treatment of GER may improve respiratory morbidity, although prospective controlled studies have not been performed. Given the lack of evidence-based guidelines for evaluation, diagnosis, and treatment of GER in CF, initiation of treatment for symptomatic GER should be based on standard guidelines for the general population. Because there is no clear evidence that GER leads to worse respiratory outcomes in CF or that treatment of GER improves pulmonary outcomes, invasive testing for GER in patients without reflux symptoms is not warranted. Further studies to determine the role of GER in CF lung disease and the risks and benefits of surgical and pharmacologic therapy for GER are warranted.

Update on Bronchiolitis Obliterans Syndrome in Lung Transplantation

Lung transplantation has become an important therapeutic option for patients with end-stage organ dysfunction; however, its clinical usefulness has been limited by the relatively early onset of chronic allograft dysfunction and progressive clinical decline. Obliterative bronchiolitis is characterized histologically by luminal fibrosis of the respiratory bronchioles and clinically by bronchiolitis obliterans syndrome (BOS) which is defined by a measured decline in lung function based on forced expiratory volume (FEV₁). Since its earliest description, a number of risk factors have been associated with the development of BOS, including acute rejection, lymphocytic bronchiolitis, primary graft dysfunction, infection, donor specific antibodies, and gastroesophageal reflux disease. However, despite this broadened understanding, the pathogenesis underlying BOS remains poorly understood and once begun, there are relatively few treatment options to battle the progressive deterioration in lung function.

Three-year results of an investigator-driven multicenter, international, randomized open-label de novo trial to prevent BOS after lung transplantation

BACKGROUND

Chronic lung allograft dysfunction (CLAD), predominantly manifest as bronchiolitis obliterans syndrome (BOS), is the primary cause of morbidity and death after lung transplantation. We assessed the efficacy and safety of 2 de novo immunosuppression protocols to prevent BOS.

METHODS

This was a multicenter, prospective, international, randomized (1:1) open-label superiority study of de novo enteric-coated mycophenolate sodium (MPS) vs delayed-onset everolimus (RAD), both arms in combination with cyclosporine (CsA) monitored by 2-hour post-dose (C2) levels, and corticosteroids. Target C2 levels were lower in the RAD group because RAD is known to potentiate CsA nephrotoxicity. Cytolytic induction therapy was not used. Patients were stratified at entry for cystic fibrosis. Confirmation of anastomotic healing was required for randomization. Primary efficacy was freedom from BOS Grade 1 on intention-to-treat (ITT) analysis. Secondary efficacy parameters were patient and graft survival and severity of rejection. Treatment failure was defined by graft loss, patient death, drug cessation, or need for other therapy.

RESULTS

The 3-year freedom from BOS Grade 1 was 70% for MPS (n = 80) vs 71% for RAD (n = 84; p = 0.95 by log-rank) in ITT but was lower in the RAD arm of the per-protocol population (p = 0.03). The 3-year survival was 84% (MPS) vs 76% (RAD; p = 0.19 by log-rank). Thirteen patients switched from MPS vs 31 from RAD (p < 0.01). Days on MPS were greater than days on RAD (p < 0.01). Rejection events proven by biopsy specimen were more common on MPS (p = 0.02), as were leucopenia (p < 0.01), diarrhea (p < 0.01), and cytomegalovirus infection (p = 0.04). Venous thromboembolism was more frequent on RAD (p = 0.02). Creatinine at 3 years was 160 ± 112 μmol/1iter in MPS patients vs 152 ± 98 μmol/1iter in RAD patients (p = 0.67).

CONCLUSIONS

This 3-year ITT analysis found no significant difference between arms but was underpowered to accept the null hypothesis that RAD and MPS have equivalent efficacy in preventing BOS or death after lung transplantation.

Domperidone for delayed gastric emptying in lung transplant recipients with and without gastroesophageal reflux

Evidence demonstrates a link between gastroesophageal reflux disease and chronic allograft dysfunction in lung transplant recipients. Delayed gastric emptying plays an important role in the occurrence of gastroesophageal reflux disease, with limited therapeutic options available for treatment. This retrospective observational study reports the use of domperidone in the management of delayed gastric emptying in lung transplant recipients. All patients who underwent lung transplant at our institution from 2007 to 2011 were reviewed and patients who were treated with domperidone were identified. Clinical symptoms and results of gastric emptying studies before and after initiation of domperidone were documented. QTc intervals were compared from before to after domperidone treatment at 3 months and at 1 year. Weight and dose-normalized calcineurin inhibitor troughs were evaluated before and 2 weeks after domperidone treatment was started. Of 82 patients, 24% (n = 20) had documented delayed gastric emptying and 35% (n = 29) had documented gastroesophageal reflux disease. Twelve of the 20 patients with delayed gastric emptying started treatment with domperidone. All patients responded symptomatically and 6 patients with gastric emptying studies before and after domperidone had documented improvement. No adverse effects were observed in any patients treated with domperidone. Results indicate that domperidone can be used safely and may improve symptoms related to delayed gastric emptying in lung transplant recipients.

Gastroesophageal reflux disease-induced aspiration injury following lung transplantation

PURPOSE OF REVIEW

Chronic allograft failure remains the leading cause of late mortality following lung transplantation. Considerable evidence demonstrates a relationship between gastroesophageal reflux disease (GERD) induced allograft injury and bronchiolitis obliterans syndrome; however, the mechanism of injury, identification of at-risk patients, and treatment options remain to be elucidated.

RECENT FINDINGS

The recent findings in this area help delineate the inflammatory pathways associated with GERD-induced lung injury. They also demonstrate that clinically useful markers of aspiration-induced injury may be available via studying bronchoalveolar fluid or even induced sputum. Simple acid neutralization is not adequate to protect these patients from aspiration injury. In fact, there are no convincing data to indicate that medical therapies provide adequate treatment. In contradistinction, surgical fundoplication is associated with decreased levels of inflammatory cytokines and markers of aspiration in bronchoalveolar fluid, as well as improvements in pulmonary function in these patients.

SUMMARY

Recent findings support ubiquitous testing for GERD or aspiration in patients with end-stage lung disease both pretransplant and posttransplant and demonstrate that fundoplication can safely and effectively protect these patients from the on-going injury of GERD-induced pulmonary injury.

Lung transplantation for interstitial lung disease

For selected parenchymal lung disease patients who fail to respond to medical therapy and demonstrate declines in function that place them at increased risk for mortality, lung transplantation should be considered. Lung transplantation remains a complex medical intervention that requires a dedicated recipient and medical team. Despite the challenges, lung transplantation affords appropriate patients a reasonable chance at increased survival and improved quality of life. Lung transplantation remains an appropriate therapeutic option for selected patients with parenchymal lung disease.

A prospective interventional study on the use of extracorporeal photopheresis in patients with bronchiolitis obliterans syndrome after lung transplantation

BACKGROUND

The aim of this prospective study was to evaluate the efficacy and safety of extracorporeal photopheresis (ECP) in patients with bronchiolitis obliterans syndrome (BOS) after lung transplantation and to identify factors predicting treatment response.

METHODS

The study was performed at a single center and consisted of a cohort of 1,012 lung transplant recipients (November 1989-June 2010). A total of 194 patients developed BOS after a mean of 1,293 ± 1,008 days (range, 99-4,949 days) and received established treatment, and 51 patients received additional ECP.

RESULTS

Thirty-one (61%) of the ECP-treated patients responded to the therapy and showed sustained stabilization (forced expiratory volume in 1 second range, -5% to 5% vs baseline at start of ECP) of lung function over 6 months. Responders to ECP showed significantly greater survival and less need for retransplantation (p = 0.001) than non-responders. Factors associated with an inferior treatment response were cystic fibrosis as underlying lung disease and a longer time between transplantation and development of BOS. No side effects were observed after ECP. Compared with BOS patients not treated with ECP, the ECP responders showed an improved graft survival (p = 0.05).

CONCLUSIONS

These results confirm and suggest that early use of ECP could be an effective adjunct treatment for patients who develop BOS after lung transplantation.

Bronchiolitis Obliterans Syndrome and Chronic Lung Allograft Dysfunction: Evolving Concepts and Nomenclature

Bronchiolitis obliterans syndrome (BOS) eventually occurs in the majority of lung transplant recipients who survive beyond 1 year, can greatly impair quality of life, and is, directly or indirectly, the major cause of delayed allograft dysfunction and recipient death. A number of associated events or conditions are strongly associated with the risk for developing BOS; these include acute rejection, gastroesophageal reflux, infections, and autoimmune reactions that can occur in the setting of alloimmune responses to the lung allograft as recipients are given intense immunosuppression to prevent allograft rejection. The term chronic lung allograft dysfunction (CLAD) is being increasingly used to refer to recipients with late allograft dysfunction that meets the spirometric criteria for the diagnosis of BOS, but clinicians should recognize that such dysfunction can occur for a variety of reasons other than BOS. The recently identified entity of restrictive allograft syndrome, which is now recognized as a relatively distinct phenotype of CLAD, has features that differentiate it from classic obstructive BOS. A number of other entities that can also significantly affect allograft function must also be considered when significant allograft dysfunction is encountered following lung transplantation.

In the face of chronic aspiration, prolonged ischemic time exacerbates obliterative bronchiolitis in rat pulmonary allografts

Aspiration of gastric fluid into the lung mediates the development of obliterative bronchiolitis (OB) in orthotopic WKY-to-F344 rat pulmonary transplants that have been subjected to immunosuppression with cyclosporine. However, the contribution of ischemic time to this process remains unknown. In this study, the effect of long (n = 16) and short (n = 12) ischemic times (average of 6 h and of 73 min, respectively) on rat lung transplants receiving aspiration of gastric fluid was assessed. Long ischemic times (LIT) led to significantly (p < 0.05) greater development of OB (ratio of OB lesions/total airways = 0.45 ± 0.07, mean ± standard error) compared to short ischemic times (ratio = 0.19 ± 0.05). However, the development of OB was dependent on aspiration, as controls receiving aspiration with normal saline showed little development of OB, regardless of ischemic time (p < 0.05). These data suggest that LIT, while insufficient by itself to lead to OB, works synergistically with aspiration of gastric fluid to exacerbate the development of OB.

Gastroesophageal reflux disease in lung transplant patients with cystic fibrosis

BACKGROUND

Gastroesophageal reflux disease (GERD) in lung transplant patients is being increasingly investigated because of its reported association with chronic rejection. However, information concerning the characteristics of GERD in cystic fibrosis (CF) patients is scarce.

METHODS

We compared esophageal pH monitoring, manometry, gastric emptying studies, and barium swallow of 10 lung transplant patients with CF with those of 78 lung transplant patients with other end-stage pulmonary diseases.

RESULTS

In lung transplant patients with CF, the prevalence of GERD was 90% (vs 54% controls, P = .04), of whom 70% had proximal reflux (vs 29% controls, P = .02).

CONCLUSIONS

Lung transplant patients with CF have a significantly higher prevalence and proximal extent of GERD than do other lung transplant recipients. These data suggest that CF patients in particular should be routinely screened for GERD after transplantation to identify those who may benefit from antireflux surgery, especially given the risks of GERD-related aspiration and chronic allograft injury.

Aspiration of gastric fluid in pulmonary allografts: effect of pH

BACKGROUND

Chronic aspiration of gastric fluid potentially plays a central role in the pathogenesis of obliterative bronchiolitis, which is often associated with chronic pulmonary allograft failure. It remains unknown whether pharmaceutical-induced increases in gastric pH might effectively prevent any putative pulmonary injury associated with chronic aspiration.

MATERIALS AND METHODS

To test the hypothesis that neutralization of gastric fluid would affect the development of aspiration-associated obliterative bronchiolitis, an established rat lung transplant model (WKY-to-F344) was utilized. Pulmonary allograft recipients were subjected to eight weekly aspirations of gastric fluid at pH 2.5 (low-pH), gastric fluid at pH 7.4 (neutralized-pH), or saline as a control.

RESULTS

Histologic analysis revealed that the fraction of airways affected with lesions consistent with obliterative bronchiolitis was 0.55 ± 0.08 (mean ± SEM) in rats receiving aspiration with low-pH gastric fluid, 0.49 ± 0.07 in animals receiving neutralized-pH gastric fluid, and 0.07 ± 0.05 in rats receiving normal saline only. The difference between groups receiving gastric fluid, regardless of pH, was significantly different from the saline control (P < 0.0001), whereas the difference between the groups receiving low-pH gastric fluid and neutralized-pH gastric fluid was not significant (P = 0.75).

CONCLUSIONS

Effective management of gastroesophageal reflux disease in lung transplant recipients should probably include more than neutralization of gastric fluid.

Gastroesophageal reflux in cystic fibrosis: current understandings of mechanisms and management

Cystic fibrosis (CF) is an inherited disease that affects both the lungs and the digestive system in children and adults. Thick mucus fills the gut and blocks lumens of the pancreas and hepatobiliary systems, creating insufficient pancreas function and liver disease. Chronic gastrointestinal (GI) complications, including intestinal obstruction, occur in neonates, and poor digestion and gastroesophageal reflux disease (GERD) in children. Although GI symptoms tend to improve with age, CF and associated GERD eventually create respiratory insufficiency; the only available treatment option at this stage is a bilateral lung transplant, which carries considerable morbidity and mortality. While GERD may reoccur as a complication of lung transplantation, GERD symptoms are often reduced following a fundoplication.

The prevalence and extent of gastroesophageal reflux disease correlates to the type of lung transplantation

BACKGROUND

Evidence is increasingly convincing that lung transplantation is a risk factor of gastroesophageal reflux disease (GERD). However, it is still not known if the type of lung transplant (unilateral, bilateral, or retransplant) plays a role in the pathogenesis of GERD.

STUDY DESIGN

The records of 61 lung transplant patients who underwent esophageal function tests between September 2008 and May 2010, were retrospectively reviewed. These patients were divided into 3 groups based on the type of lung transplant they received: unilateral (n=25); bilateral (n=30), and retransplant (n=6). Among these groups we compared: (1) the demographic characteristics (eg, sex, age, race, and body mass index); (2) the presence of Barrett esophagus, delayed gastric emptying, and hiatal hernia; and (3) the esophageal manometric and pH-metric profile.

RESULTS

Distal and proximal reflux were more prevalent in patients with bilateral transplant or retransplant and less prevalent in patients after unilateral transplant, regardless of the cause of their lung disease. The prevalence of hiatal hernia, Barrett esophagus, and the manometric profile were similar in all groups of patients.

CONCLUSIONS

Although our data show a discrepancy in prevalence of GERD in patients with different types of lung transplantation, we cannot determine the exact cause for these findings from this study. We speculate that the extent of dissection during the transplant places the patients at risk for GERD. On the basis of the results of this study, a higher level of suspicion of GERD should be held in patients after bilateral or retransplantation.

Cough reflex in lung transplant recipients

Lung transplantation has become the standard of care for particular individuals with advanced lung disease. However, this surgical procedure involves interruption of the lower vagal nerve fibers which leads to loss of the protective cough reflex. Injury of the neural pathways involved with the sensory limb of the cough reflex is associated with an increased risk of complications involving the allograft. While loss of the cough reflex was once considered permanent, recent evidence indicates functional and structural restoration is a time-dependent process that occurs 6-12 months after lung transplantation. The implication that the cough reflex may be reestablished in lung transplant recipients provides insight into the dynamic response to airway neural injury that may lead to improvements in allograft tissue repair.

The protective role of laparoscopic antireflux surgery against aspiration of pepsin after lung transplantation

BACKGROUND

The goal of this study was to determine, in lung transplant patients, if laparoscopic antireflux surgery (LARS) is an effective means to prevent aspiration as defined by the presence of pepsin in the bronchoalveolar lavage fluid (BALF).

METHODS

Between September 2009 and November 2010, we collected BALF from 64 lung transplant patients at multiple routine surveillance assessments for acute cellular rejection, or when clinically indicated for diagnostic purposes. The BALF was tested for pepsin by enzyme-linked immunosorbent assay (ELISA). We then compared pepsin concentrations in the BALF of healthy controls (n = 11) and lung transplant patients with and without gastroesophageal reflux disease (GERD) on pH-monitoring (n = 8 and n = 12, respectively), and after treatment of GERD by LARS (n = 19). Time to the development of bronchiolitis obliterans syndrome was contrasted between groups based on GERD status or the presence of pepsin in the BALF.

RESULTS

We found that lung transplant patients with GERD had more pepsin in their BALF than lung transplant patients who underwent LARS (P = .029), and that pepsin was undetectable in the BALF of controls. Moreover, those with more pepsin had quicker progression to BOS and more acute rejection episodes.

CONCLUSION

This study compared pepsin in the BALF from lung transplant patients with and without LARS. Our data show that: (1) the detection of pepsin in the BALF proves aspiration because it is not present in healthy volunteers, and (2) LARS appears effective as a measure to prevent the aspiration of gastroesophageal refluxate in the lung transplant population. We believe that these findings provide a mechanism for those studies suggesting that LARS may prevent nonallogenic injury to the transplanted lungs from aspiration of gastroesophageal contents.

Fundoplication after lung transplantation prevents the allograft dysfunction associated with reflux

BACKGROUND

Gastroesophageal reflux disease (GERD) in lung recipients is associated with decreased survival and attenuated allograft function. This study evaluates fundoplication in preventing GERD-related allograft dysfunction.

METHODS

Prospectively collected data on patients who underwent transplantation between January 2001 and August 2009 were included. Lung transplant candidates underwent esophageal pH probe testing before transplantation and surveillance spirometry evaluation after transplantation. Bilateral lung transplant recipients who had pretransplant pH probe testing and posttransplant 1-year forced expiratory volume in the first second of expiration (FEV1) data were included for analysis.

RESULTS

Of 297 patients who met study criteria, 222 (75%) had an abnormal pH probe study before or early after transplantation and 157 (53%) had a fundoplication performed within the first year after transplantation. Patients with total proximal acid contact times greater than 1.2% or total distal acid contact times greater than 7.0% demonstrated an absolute decrease of 9.4% (±4.6) or 12.0% (±5.4) in their respective mean 1-year FEV1 values. Patients with abnormal acid contact times who did not undergo fundoplication had considerably worse predicted peak and 1-year FEV1 results compared with recipients receiving fundoplication (peak percent predicted=75% vs. 84%; p=0.004 and 1-year percent predicted=68% vs. 77%; p=0.003, respectively).

CONCLUSIONS

Lung transplant recipients with abnormal esophageal pH studies attain a lower peak allograft function as well as a diminished 1-year FEV1 after transplantation. However a strategy of early fundoplication in these recipients appears to preserve lung allograft function.

Histological examination of the relationship between respiratory disorders and repetitive microaspiration using a rat gastro-duodenal contents reflux model

Microaspiration due to gastroesophageal reflux (GER) has been suggested as a factor contributing to the development and exacerbation of several respiratory disorders. To explore the relationship between GER and respiratory disorders, we histologically examined the bilateral lungs of a rat gastroduodenal contents reflux model, which was previously used to investigate the histogenesis of Barrett's esophagus and esophageal carcinoma. GER was surgically induced in male Wistar rats. The bilateral lungs of the reflux rats were examined with hematoxylin and eosin (HE), PAS-Alcian blue, and Azan staining at 10 and 20 weeks after surgery. Immunohistochemical staining of CD68 and α-SMA was also performed. Aspiration pneumonia with severe peribronchiolar neutrophilic and lymphocytic infiltrates, goblet cell hyperplasia, prominence of blood vessels, and increased thickness of the smooth muscle layer were detected. Bronchiolitis obliterans (BO)-like lesions comprising granulation tissue with macrophages, spindle cells, and multinucleated giant cells in the lumen of respiratory bronchioles were observed in the bilateral lungs of the reflux animals. These findings suggest that the severe inflammation and the BO-like lesions may play a role in exacerbation of the forced expiratory volume in 1 second (FEV 1) in human cases. In conclusion, we speculate that repetitive microaspiration due to GER may contribute to the exacerbation of various respiratory diseases, particularly asthma and chronic obstructive pulmonary disease (COPD), and the development of BO syndrome following lung transplantation. The reflux model is a good tool for examining the causal relationships between GER and respiratory disorders.

Diagnosis of supra-esophageal gastric reflux: correlation of oropharyngeal pH with esophageal impedance monitoring for gastro-esophageal reflux

BACKGROUND

Oropharyngeal (OP) pH monitoring has been developed as a new way to diagnose supra-esophageal gastric reflux (SEGR), but has not been well validated. Our aim was to determine the correlation between OP pH and gastro-esophageal reflux (GER) events detected by multichannel intraluminal impedance-pH (MII-pH).

METHODS

Fifteen patients (11 males, median age 10.8 years) with suspected GER were prospectively evaluated with ambulatory 24-h OP pH monitoring (positioned at the level of the uvula) and concomitant esophageal MII-pH monitoring. Potential OP events were identified by the conventional pH threshold of <4 and by the following alternative criteria: (i) relative pH drop >10% from 15-min baseline and (ii) absolute pH drop below thresholds of <5.5, 5.0, and 4.5. The 2-min window preceding each OP event was analyzed for correlation with an episode of GER detected by MII-pH.

KEY RESULTS

A total of 926 GER events were detected by MII-pH. Application of alternative pH criteria increased the identification of potential OP pH events; however, a higher proportion of OP events had no temporal correlation with GER (45-81%), compared with the conventional definition of pH < 4 (40%). A total of 306 full-column acid reflux episodes were detected by MII-pH, of which 10 (3.3%) were also identified by OP pH monitoring.

CONCLUSIONS & INFERENCES

Use of extended pH criteria increased the detection of potential SEGR events, but the majority of decreases in OP pH were not temporally correlated with GER. Oropharyngeal pH monitoring without concurrent esophageal measurements may overestimate the presence of SEGR in children.

Laparoscopic antireflux surgery for gastroesophageal reflux disease after lung transplantation

BACKGROUND

Although gastroesophageal reflux disease (GERD) is highly prevalent in lung transplantation, the pathophysiology of GERD in these patients is unknown. We hypothesize that the pathophysiology of GERD after lung transplantation differs from that of a control population, and that the 30-d morbidity and mortality of laparoscopic antireflux surgery (LARS) are equivalent in both populations.

METHODS

We retrospectively compared the pathophysiology of GERD and the 30-d morbidity and mortality of 29 consecutive lung transplant patients with 23 consecutive patients without lung transplantation (control group), all of whom had LARS for GERD between November 2008 and May 2010.

RESULTS

Both groups had a similar prevalence of endoscopic esophagitis and Barrett's esophagus , comparable manometric profiles, and similar prevalence of abnormal peristalsis. However, hiatal hernia was more common in controls than in lung transplant patients (57% versus 24%; P = 0.04). Lung transplant patients had a higher prevalence and severity of proximal GERD (65% versus 33%; P = 0.04). The 30-d morbidity and mortality following LARS were similar in both groups regardless of the higher surgical risk of lung transplants (median ASA class: 3 versus 2 for controls, P < 0.001).

CONCLUSIONS

These results show that despite similar manometric profiles, lung transplant patients are more prone to proximal reflux than the general population with GERD; the prevalence of endoscopic esophagitis and Barrett's esophagus is the same in both groups of patients; a hiatal hernia is uncommon after lung transplantation; and the morbidity and mortality of LARS are the same for lung transplant patients as the general population with GERD.

Lung transplantation in autoimmune diseases

In the last 45 years, lung transplantation has evolved from its status as a rare extreme form of surgical therapy for the treatment of advanced lung diseases to an accepted therapeutic option for select patients. Although pulmonary fibrosis and pulmonary vascular diseases are important indications for lung transplantation, only a small percentage of transplants are performed in patients with collagen vascular diseases. The reasons for this low number are multifactorial. This article reviews issues relevant to all lung transplant candidates and recipients as well as those specific to patients with autoimmune diseases.

Effect of different pH criteria on dual-sensor pH monitoring in the evaluation of supraesophageal gastric reflux in children

BACKGROUND AND AIM

Existing tests for supraesophageal gastric reflux (SEGR) that focus on pH drops <4 in the proximal esophagus have had limited sensitivity and specificity. The aim of the present study was to evaluate the effect of newly proposed pH criteria on SEGR detection.

PATIENTS AND METHODS

Twenty-four-hour dual-sensor pH tracings of 32 patients were reviewed. Proximal esophageal pH data were evaluated according to the conventional definition of pH drop <4 and 2 proposed definitions: pH drop <5.5 while upright and <5.0 while supine and pH drop of >10% from a running baseline. For each potential SEGR event, the preceding 1-minute window was examined for corresponding distal acid reflux.

RESULTS

Of the 542 distal acid reflux events detected, 200 were associated with a proximal pH drop <4; this number increased to 295 using the definition of proximal pH drop <5.5 (upright)/<5.0 (supine) and 301 using the definition of proximal pH drop >10%. A proportion of proximal events, however, was not associated with distal acid reflux: 21 of 200 (10.5%) proximal pH <4 events, 119 of 414 (29%) proximal pH <5.5 (upright)/<5.0 (supine) events, and 272 of 573 (47%) proximal pH drop >10% events lacked a preceding or simultaneous drop in distal pH <4.

CONCLUSIONS

Although the use of more liberal pH criteria increased the diagnostic yield for SEGR events with dual-sensor monitoring, a significant proportion of proximal pH events did not correlate with distal acid reflux. These events could represent either false-positive measurements or association with weakly acid reflux.

Bile acids aspiration reduces survival in lung transplant recipients with BOS despite azithromycin

Azithromycin (AZM) improved bronchiolitis obliterans syndrome (BOS) and reduced aspiration in lung transplant (LTx) recipients. We hypothesize that AZM could improve graft and overall survival more efficiently in LTx patients with BOS who have bile acid (BA) aspiration by protecting against the aspiration-induced progression of BOS. The goal was to compare FEV(1) (% baseline), BOS progression and overall survival in LTx recipients treated with AZM for BOS, both with versus without BA aspiration. Therefore, LTx recipients treated with AZM for BOS were recruited and broncho-alveolar lavage (BAL) samples were analyzed for the presence of BA and neutrophilia before the start of AZM treatment. Short-term effect of AZM on FEV(1) and BAL neutrophilia was assessed, progression of BOS and survival were followed-up for 3 years and results were compared between patients with/without BA aspiration. 19/37 LTx patients had BA in BAL. BA aspiration predisposed to a significantly worse outcome, in terms of decline in FEV(1) , progression of BOS ≥ 1 and survival. AZM does not seem to protect against the long-term allograft dysfunction caused by gastroesophageal reflux (GER) and aspiration and an additional treatment targeting aspiration may be indicated in those LTx patients.