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A3099 - Gastroesophageal Reflux and Associated Microaspiration in Lung Transplant Recipients
Author Block: J. Gualdoni1, J. Ritzenthaler2, J. Burlen1, T. Abell1, J. Roman1, D. R. Nunley3; 1University of Louisville School of Medicine, Louisville, KY, United States, 2Medicine, University of Louisville, Louisville, KY, United States, 3Pulmonary Medicine, University of Louisville, Louisville, KY, United States.
Rationale: Gastroesophageal reflux (GER) in recipients of lung transplant (LTX) has been associated with chronic allograft rejection presumably via the microaspiration of injurious particles and chemicals that consequently damage airway epithelium. As such, most LTX programs perform a single post-transplant esophageal test to determine the presence or absence of GER. The efficacy of this single esophageal test for identifying subsequent microaspiration is unclear.
Methods: Reviewed were five LTX recipients who had post-transplant esophageal manometry and pH probe monitoring (EmPhm) and subjected to follow-up for at least one year. Bronchoalveolar lavage (BAL) samples obtained from the lung allografts during sequential bronchoscopic surveillance were retrieved from a biorepository and assayed for the presence of bile salts. Assays were performed utilizing a competitive-ELISA detection method with a bile salt concentration > 0.312 nmol/ml being indicative of aspiration of gastric contents. The EmPhm studies were performed at approximately 3 months post-LTX utilizing high-resolution esophageal manometry to assess esophageal sphincter and peristaltic function. Multichannel intraluminal impedance-pH was used for the detection of bolus reflux and classified as ‘normal,’ ‘acid,’ ’alkaline,’ or a ‘combination.’ The data from the EmPhm studies were reviewed by an experienced gastroenterologist (blinded to the results of the BAL assays) who interpreted each test as either ‘positive’ or ‘negative’ for the presence of GER.
Results: Each recipient had between five and nine BAL samples assayed for bile salts, and the EmPhm study was performed on median post-transplant day 112 (range 68-146). Two of the five EmPhm studies were ‘positive’ for GER, but only one of the corresponding recipients revealed a ‘positive’ assay for bile salts. Of the three EmPhm studies that were ‘negative’ for GER, BAL analysis revealed that one recipient experienced aspiration of gastric contents. The two recipients who had confirmed gastric aspiration had a total of fifteen BAL samples assayed between them, only three of which were ‘positive’ for bile salts thus suggesting intermittent aspiration episodes.
Conclusion: It would appear that over the course of the first post-transplant year, microaspiration in LTX recipients is an intermittent phenomenon, and a single EmPhm study screening for GER appears to poorly correlate with BAL evidence of aspiration of gastric contents. As the detection of aspiration in this population is crucial, further analysis is warranted to ascertain whether a single EmPhm study alone is adequate to make this determination.