Introduction: Chronic obstructive pulmonary disease (COPD) is characterised by the airflow limitation as a consequence of progressive inflammatory response to inhaled noxious particles and gases, particularly cigarette smoke. Three factors play a main role in pathogenesis of the disease: inflammatory process, oxidative stress and imbalance between proteases and antiproteases. Recently there are some evidences that also extrapulmonary changes like cachexia, osteoporosis or depression are associated with COPD. The aim of the study was to access local and systemic inflammation in patients with COPD. Material and methods: The study group consisted of 23 patients with COPD during stable and exacerbation phase of the disease. As a control served 16 asymptomatic smokers. We investigated: 1) concentration of hydrogen peroxide (H2O2) and proinflammatory cytokines like TNF-a and IL-6 in expired breath condensate (EBC); 2) serum levels of TNF-a and IL-6. Results: It was showed that the level of H2O2 in EBC of patients with stable COPD was significantly higher as compared with healthy smokers. Additional significant enhanced in H2O2 exhalation was demonstrated during exacerbation of COPD. There was no difference in IL-6 concentration between the study groups (p>0,05). Discernible level of TNF-a in exhaled air was measured only in those with COPD exacerbation. Exhaled H2O2 correlated with FEV1% predicted value in patients with stable as well as with exacerbation phase of COPD. Also serum levels of TNF-a and IL-6 of patients with stable disease were higher compared to the values of healthy smokers. The serum concentrations of studied cytokines did not change significantly during exacerbation of COPD. Conclusions:Our results demonstrated the occurrence of local oxidative stress in patients with stable COPD. This process significantly increased during exacerbation of the disease. Besides of local reaction in respiratory compartment of patients with stable COPD we revealed systemic inflammatory process measured by serum levels of TNF-a and IL-6. Exhaled H2O2 correlated with lung function (FEV1% pred).
Keywords: COPD, expired breath condensate, hydrogen peroxide, TNF -a, IL -6