Systemic and Lung Inflammation in 2 Phenotypes of Chronic Obstructive Pulmonary Disease

To study whether patients with chronic obstructive pulmonary disease (COPD) at the same level of flow limitation but with different clinical phenotypes present different degrees of systemic and/or pulmonary inflammation.We studied 15 male smokers without COPD (control group) and 39 males with COPD in stable clinical condition. The COPD patients were assigned to 2 groups based on the ratio of carbon monoxide diffusing capacity (DLCO) to alveolar volume (DLCO/VA) expressed as a percentage as follows: a) mainly emphysema (n = 15) and b) mainly chronic bronchitis (n = 24). Classification was determined by comparing both clinical features and diagnostic images.Mean (SD) concentrations of interleukin 8 (IL-8) and 8-isoprostane in exhaled breath condensate (EBC) were significantly lower in patients with mainly emphysema (IL-8, 0.34 [0.70] pg/mL; 8-isoprostane, 0.07 [0.26] pg/mL) than in patients with chronic bronchitis (IL-8, 2.32 [3.10] pg/mL; 8-isoprostane, 1.77 [2.98] pg/mL) or in the controls (IL-8, 3.14 [4.59] pg/mL; 8-isoprostane, 1.92 [2.84] pg/mL); P.05 for IL-8 comparisons and P.01 for 8-isoprostane. IL-8, leukotriene B4, and 8-isoprostano in EBC correlated significantly with DLCO/VA (% of predicted) (r = 0.30, P.05; r = 0.29, Por = .05; and r = 0.46, P.01, respectively) but not with forced expiratory volume in 1 second. There was a negative correlation between EBC and serum levels of both IL-8 (r = -0.31; P.05) and 8-isoprostane (r = -0.51; P.001). The correlation between leukotriene B4 concentrations in EBC and serum was not significant, however. No significant differences were found between smokers' and ex-smokers' serum levels of IL-8, leukotriene B4, 8-isoprostane in serum or EBC.The results indicate that COPD patients with an emphysematous phenotype have a less intense inflammatory response and less oxidative stress in the lung.