Measurement of 8-isoprostane in exhaled breath condensate of patients with chronic obstructive pulmonary disease

Abstract

Background 8-Isoprostane is an accurate biomarker of oxidative stress. Despite 8-isoprostane concentrations in exhaled breath condensate (EBC) had showed higher values in chronic obstructive pulmonary disease (COPD), the association between EBC 8-isoprostane and different clinical and functional parameters of COPD remains debatable. For this reason, the aim of this study was to evaluate the relation between EBC 8-isoprostane and the clinical and functional parameters of COPD. Participants and methods A cohort had been conducted including 100 participants classified into two groups matched for age and sex. Group A (COPD group) included 80 COPDs with different Global Initiative for Chronic Obstructive Lung Disease (GOLD) stages; group B included 20 healthy controls. All COPD patients were assessed by high-resolution computed tomography of chest. Both groups had undergone spirometry, 6-min walk test, and SpO2 assessment. EBC collection and 8-isoprostane had been measured for all participants in the study. Results Moderate and severe stages constituted the majority of recruited COPD patients. 8-Isoprostane concentration was significantly higher in COPD patients compared with controls. Forced expiratory volume in first second (FEV1), 6-min walk test, and SpO2 showed inverse significant correlation with 8-isoprostane. 8-Isoprostane also had higher levels in COPD patients with very severe GOLD stage. Smoking and sex were not predictive factors of higher 8-isoprostane. Conclusion 8-Isoprostane is considered a sensitive and valuable biomarker measured in EBC, reflecting the intensity of the inflammatory process in COPD. 8-Isoprostane showed a significant positive correlation with COPD GOLD stage and negative correlation with lung function.

Keywords

• 8-isoprostane
• chronic obstructive pulmonary disease
• forced expiratory volume in first second