Documents Savoirs Exhaled breath condensate pH as a biomarker of COPD severity in ex-smokers Papaioannou, Loukides Stelios, Minas Markos, Kontogianni Konstantina, Bakakos Petros, Gourgoulianis, Alchanatis Manos, Papiris Spyros, Kostikas, Kostikas Konstantinos