ABSTRACT
Gastro-esophageal reflux has been suggested to be associated with several pulmonary complications such as asthma, and post-transplant bronchiolitis obliterans [BO]. Pepsin or bile salts in the sputum is shown to be an optimal molecular marker of gastric contents macro/micro aspiration. In this study, we investigated sputum pepsin as a marker of micro-aspiration in sulfur mustard [SM] exposed cases compared to healthy controls. In a case controlled study, 26 cases with BO and 12 matched healthy controls were recruited and all cases were symptomatic and their exposure to SM was previously documented during Iran-Iraq conflict. Pepsin levels in sputum and total bile acids were measured using enzymatic assay. The severity of respiratory disorder was categorized based upon the spirometric values. The average concentration of pepsin in sputum was higher in the case group [0.29 +/- 0.23] compared with healthy subjects [0.13 +/- 0.07; P +/- 0.003]. Moreover, the average concentration of bile acids in the sputum cases was not significantly different in comparison to the controls [P = 0.5]. Higher pepsin concentrations in sputum of SM exposed patients compared with healthy control subjects indicate the occurrence of significantly more gastric micro-aspiration in SM exposed patients