Exhaled breath condensate levels of 8-isoprostane, growth related oncogene α and monocyte chemoattractant protein-1 in patients with chronic obstructive pulmonary disease

SummaryChronic obstructive pulmonary disease (COPD) patients have increased neutrophils and macrophages in their lungs, and inflammation of the airway is related to oxidative stress. This study assessed the levels of 8-isoprostane (an oxidative stress marker) and chemokines related to neutrophil and monocyte inflammation (growth-related oncogene α [GROα] and monocyte chemoattractant protein-1 [MCP-1]) in the airway of ex-smoking COPD patients by exhaled breath condensate (EBC) collection.Thirty-two (28 males) stable COPD patients (14 with FEV1 ⩾50% [Group 1], 18 with FEV1 <50% predicted [Group 2]) and 18 non-smoking age and sex-matched controls were studied in this cross-sectional study. EBC was collected using the EcoScreen (Jaeger, Germany) during 10 min of tidal breathing with the nose clipped. Concentrations of 8-isoprostane, GROα and MCP-1 were measured by enzyme immunoassays.COPD patients had a higher concentration of 8-isoprostane than controls (COPD versus control, P<0.001P<0.001; Group 1 versus Group 2, P=0.045P=0.045). 8-isoprostane increased across the groups from normal, Group 1 to Group 2 (r=0.64r=0.64, P<0.001P<0.001). The median intraquartile range (IQR) levels in pg/ml for GROα were 45.3(44.5–46.5), 45.4(44.5–46.0), 46.0(45.6–47.3), whereas MCP-1 levels were 5.3(5.2–5.9), 6.2(5.4–6.9) and 5.7(5.5–6.4) in Group 1, Group 2 COPD and control subjects, respectively. GROα level was lower in COPD patients when compared to controls (P=0.01P=0.01). MCP-1 level did not differ between COPD and the control group.8-isoprostane level, but not GROα and MCP-1, in EBC was increased in COPD patients with poorer lung function. This suggests an increased oxidative stress in the airway in patients with more severe COPD.