title: Exhaled breath condensate pH and cysteinyl leukotriens in patients with chronic cough secondary to acid gastroesophageal reflux.
abstract: Chronic cough is one of the most common clinical problems and it may be secondary to different stimuli and diseases, including low-level physical and chemical stimulation of the esophageal-bronchial reflex, suggestive of cough-reflex hyperresponsiveness, in patients with gastroesophageal reflux; however, it is still debated whether gastroesophageal reflux could induce airway inflammation and acidification. The aim of this study was to investigate airway pH and cysteynil-leukotrienes (Cys-LTs) concentration (a marker of airway inflammation) in exhaled breath condensate (EBC). Patients with chronic cough and for which all known causes, excluding gastroesophageal reflux, had been investigated and ruled out, were enrolled in the study. All patients underwent 24 h pH monitoring, and EBC was collected to assess pH and Cys-LTs concentration. Forty-five patients were included in the study and those with gastroesophageal reflux had significantly lower EBC-pH and higher concentration of EBC-Cys-LTs. There was a linear inverse correlation between EBC-pH values and EBC-Cys-LTs logarithmically transformed, and a multivariate analysis confirmed that the only significant determinat variable of EBC-Cys-LTs was the presence of gastroesophageal reflux. This study adds knowledge on possible mechanisms related to chronic cough associated with gastroesophageal reflux, which seems to be strictly dependent on airway acidification and the production of Cys-LTs, therefore suggesting an underlying neurogenic inflammation with tachykinins involvement.
authors.affiliation: Respiratory Medicine and Allergology, Department of Clinical and Experimental Medicine, AOU 'Policlinico-Vittorio Emanuele', University of Catania, Catania, Italy. Author to whom any correspondence should be addressed, at Pneumologia Riabilitativa e Allergologia, AOU 'Policlinico-Vittorio Emanuele', Università degli Studi di Catania, Via Santa Sofia 78 (Edificio 4, Piano 2), 95123 Catania, Italy.
authors.forename: Enrico
authors.initials: E
authors.lastname: Heffler
authors.forename: Claudia
authors.initials: C
authors.lastname: Crimi
authors.forename: Luisa
authors.initials: L
authors.lastname: Brussino
authors.forename: Stefania
authors.initials: S
authors.lastname: Nicola
authors.forename: Stefania
authors.initials: S
authors.lastname: Sichili
authors.forename: Luca
authors.initials: L
authors.lastname: Dughera
authors.forename: Giovanni
authors.initials: G
authors.lastname: Rolla
authors.forename: Nunzio
authors.initials: N
authors.lastname: Crimi
mesh_terms: D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000378:metabolism; D001944:Breath Tests; D016022:Case-Control Studies; D002908:Chronic Disease; D003371:Cough / Q000150:complications / Q000378:metabolism*; D003545:Cysteine / Q000378:metabolism*; D005260:Female; D005764:Gastroesophageal Reflux / Q000150:complications / Q000378:metabolism*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007249:Inflammation / Q000150:complications / Q000378:metabolism; D015289:Leukotrienes / Q000378:metabolism*; D008297:Male; D008875:Middle Aged
chemical_list: D015415:Biomarkers; D015289:Leukotrienes; C112381:cysteinyl-leukotriene; D003545:Cysteine