The Measure And Clinical Significance Of IL-6 And 8-isoprostane In Expired Breath Condensate Of Patients With COPD

Study objectives: To evaluate the levels of IL-6 and 8-isoprostane in the expired breath condensate (EBC) of patients with COPD, and to assess the relationship between the above markers of oxidative stress and airway inflammation and disease severity. Exhaled breath condensate could provide noninvasive, real-time assessment of oxidative stress and airway inflammation of patients with COPD ,It is simple to perform and highly reproducible.Menthods: We studied 20 serious COPD, 10 mild COPD(all smokers) and 12 healthy nonsmokers ,10 healthy smokers, as control group, breath condensate samples were collected using a specially design condensing chamber (Ecoscreen; Jaeger, Hoechberg, Germany). 8-isoprostane and Interleukine-6 were measured in their breath condensate through a specific enzyme immunoassay kit. analyse data by statistic measure.Results: Significantly higher concentrations of exhaled 8-isoprostane were found in severity COPD patients(23±3.5pg/ml)compared to mild COPD(13±3.3 pg/ml) and healthy nonsmoker (4.7±1.8 pg/ml) and health smoker ( 3.1±0.4 pg/ml) (p＜0.0001). furthermore, health smoker is higher with healthy nonsmoker(P＜0.05), concentrations of exhaled IL-6 is increased in severity COPD patients(7.1±1.2pg/ml)compared to mild COPD(4.8±0.9 pg/ml) and healthy nonsmoker (3.2±0.6pg/ml) and health smoker (2.8±0.4 pg/ml) (P＜0.001), healthy nonsmoker and health smoker were similar(P＜0.05). There was a negative correlation between concentrations of exhaled 8-isoprostane in severity COPD patients and FEV1 (r=-0.541; p＜0.05),MMEF(r=-0.732; p＜0.05)and FEV1/FVC (r=-0.620; p＜0.05), concentrations of exhaled 8-isoprostane in mild COPD was not correlation with FEV1,FEV1/FVC and MMEF; concentrations of exhaled IL-6 in severity COPD was negative correlation with FEV1 (r=-0.564; p＜0.05) and MMEF (r=-0.631; p＜0.05) , There was also a negative correlation between IL-6 and FEV1/FVC (r=-0.68; p＜0.05) ,in severity COPD, concentrations of exhaled IL-6 in mild COPD patients was not correlation with FEV1,FEV1/FVC and MMEF;There was also a positive correlation between IL-6 and 8-isoprostane levels (r= 0.410; p＜0.05).Condusions: We conclude that levels of IL-6 and 8-isoprostane are elevated in the EBC of patients with COPD, These findings suggest that there is an increase of 8-isoprostane and Interleukine-6 concentrations in the breath condensate of COPD patients compared to healthy controls especially during serious COPD. concentrations of exhaled 8-isoprostane in health smoker is higher with healthy nonsmoker. concentrations of exhaled IL-6 were similar both health smoker and healthy nonsmoker. The measurement of IL-6 and 8-isoprostane levels may prove to be useful in screening and monitoring airway inflammation and oxidative stress of patient with COPD. There was a negative correlation between concentrations of exhaled 8-isoprostane and IL-6 in severity COPD patients and FEV1,FEV1/FVC and MMEF, which was suggest that change of concentrations of exhaled 8-isoprostane and IL-6 in severity COPD patients may reflect change of lung function in a certain extent, furthermore both 8-isoprostane and IL-6 were concerned with the process of the air way stricture.