Bronchoalveolar lavage findings in patients with chronic nonproductive cough

Mast cells and eosinophils may play a role in the pathophysiology of chroni c cough in nonasthmatics. It is unknown, how;ever, whether degranulation of these cells occurs in the airways of such patients. Thirty-five nonsmoking patients referred with a chronic nonproductive cough (mean cough duration 76.2 months) were evaluated using a comprehensive dia gnostic protocol. Bronchoalveolar lavage (BAL) cell differentials and BAL h istamine, tryptase and eosinophilic cationic protein (ECP) concentrations w ere determined. Ten nonsmoking healthy volunteers served as controls. Diagnostic subgroups were identified: eight postnasal drip syndrome (PNDS), seven cough variant asthma (CVA), seven gastro-oeseophageal reflux (GOR), seven dual aetiology and sis idiopathic, Nonasthmatic coughers (NAC) were c haracterized as those patients without bronchial hyperresponsiveness on his tamine challenge and whose cough had either responded to therapy for PNDS o r GOR or failed to improve with antiasthma therapy. There was a significant increase in both eosinophil and mast cell numbers (p<0.05) and in histamin e levels (p= 0.027) when NAC patients were compared with controls, Tryptase and ECP levels were elevated in 7 of 23 and 6 of 23 NAC patients, respecti vely. In conclusion, airway inflammatory cell numbers are not only increased but also activated, suggesting an important role for airways inflammation in th e pathophysiology of chronic nonproductive cough.