Exhaled eicosanoids and biomarkers of oxidative stress in exacerbation of chronic obstructive pulmonary disease

Abstract

IntroductionEicosanoids and oxidants play an important role in inflammation, but their role in chronic obstructive pulmonary disease (COPD) is uncertain. In this study we hypothesized that levels of exhaled leukotrienes, prostaglandins and biomarkers of oxidative stress are increased in infectious exacerbations of COPD and that they decrease after antibiotic therapy.Material and methodsCysteinyl-leukotrienes (LTs), leukotriene B4 (LTB4), prostaglandin E4, hydrogen peroxide (H2O2) and 8-isoprostane were measured in exhaled breath condensate (EBC) in 16 COPD patients with infectious exacerbations (mean age 64 ±12 years, 13 male) on day 1, during antibiotic therapy (days 2-4), 2-4 days after therapy and at a follow-up visit when stable (21-28 days after therapy).ResultsThere was a significant fall in concentration of cys-LTs, LTB4 and 8-isoprostane at visit 3 compared to day 1 (cys-LTs: 196.5 ±38.4 pg/ml vs. 50.1 ±8.2 pg/ml, p < 0.002; LTB4: 153.6 ±25.5 pg/ml vs. 71.9 ±11.3 pg/ml, p < 0.05; 8-isoprostane: 121.4 ±14.6 pg/ml vs. 56.1 ±5.2 pg/ml, p < 0.03, respectively). Exhaled H2O2 was higher on day 1 compared to that at visits 2 and 3 (0.74 ±0.046 µM vs. 0.52 ±0.028 µM and 0.35 ±0.029 µM, p < 0.01 and p < 0.01, respectively). Exhaled PGE2 levels did not change during exacerbations of COPD. Exhaled eicosanoids and H2O2 in EBC measured at the follow-up visit (stable COPD) were significantly higher compared to those from healthy subjects.ConclusionsWe conclude that eicosanoids and oxidants are increased in infectious exacerbations of COPD. They are also elevated in the airways of stable COPD patients compared to healthy subjects.