Malondialdehyde in Exhaled Breath Condensate as a Marker of Oxidative Stress in Different Pulmonary Diseases

Background . Oxidative stress plays a role in the pathogenesis of many chronic inflammatory lung diseases. Exhaled breath condensate (EBC) collection is a noninvasive method to investigate pulmonary oxidative stress biomarkers such as malondialdehyde (MDA). Subjects and Methods . We measured MDA levels in EBC in a large number of patients ( N = 194) with respiratory diseases: asthma ( N = 64), bronchiectasis (BE, N = 19), chronic obstructive pulmonary disease (COPD, N = 73), idiopathic pulmonary fibrosis (IPF, N = 38). Fourteen healthy nonsmoking subjects were included as controls. Results . Excluding IPF subjects, MDA levels were significantly higher in all disease groups than in control group. MDA was significantly higher in COPD than asthmatic and BE subjects. Among asthmatics, corticosteroids-treated subjects had lower MDA levels than untreated subjects. COPD subjects showed an inverse correlation between MDA concentrations and FEV 1 % (rho:  −0.24, P < .05). Conclusions . EBC-MDA is increased in subjects with chronic airway disorders, particularly in COPD, and it is related to FEV 1 reduction.