Diagnosis and Management of GERD Before and After Lung Transplantation

Proximal reflux: biochemical mediators, markers, therapeutic targets, and clinical correlations

Airway reflux is implicated in the pathophysiology of a wide range of adult and pediatric upper and lower airway diseases. However, the diagnosis of proximal reflux-associated disease remains challenging due to evolving clinical criteria and institutional and regional variances in diagnostic practices. Evidence suggests that nonacidic contents of reflux may serve as both pathologic mediators of and biomarkers for reflux in the upper airway. Furthermore, they offer potential pharmaceutical and surgical intervention targets and are the focus of novel clinical diagnostic tools currently under investigation.

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.

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.

Comorbidities impacting on prognosis after lung transplant

The aim of this review is to give an overview of the clinical circumstances presenting before lung transplant that may have negative repercussions on the long and short-term prognosis of the transplant. Methods for screening and diagnosis of common comorbidities with negative impact on the prognosis of the transplant are proposed, both for pulmonary and extrapulmonary diseases, and measures aimed at correcting these factors are discussed. Coordination and information exchange between referral centers and transplant centers would allow these comorbidities to be detected and corrected, with the aim of minimizing the risks and improving the life expectancy of transplant receivers.