Lipoxygenase-Derived Arachidonic Acid Metabolites in Chronic Obstructive Pulmonary Disease

Abstract

Chronic obstructive pulmonary disease (COPD) is characterized by a persistence of inflammation in large and small airways. We hypothesized that this could be caused by the inability of an inflammatory process to resolve. In the resolution of inflammation, a switching of arachidonic acid metabolism from the production of proinflammatory leukotriene B(4) (LtB(4)) to the synthesis of anti-inflammatory lipoxins plays an important role. The aim of our study was to determine the content of lipoxin A(4) (LXA(4)) and LtB(4) in induced sputum of patients with exacerbated COPD and to compare it to healthy controls, as well as to analyze the relationship between proinflammatory and anti-inflammatory mediators and an inflammatory cell spectrum in induced sputum. Induced sputum from 17 COPD patients and 7 healthy controls were analyzed for LXA(4) and LtB(4) content and inflammatory cell spectrum. COPD patients had a significantly lower sputum LXA(4) concentration and LtB(4)/LXA(4) ratio compared with healthy controls. A significant negative correlation was found between the LXA(4) concentration and the relative neutrophil count and between the LtB(4)/LXA(4) ratio and the relative macrophage count. COPD patients during the late phase of exacerbation had a suppressed production of LXA(4) and an elevated LtB(4)/LXA(4) ratio in induced sputum demonstrating a proinflammatory imbalance. The correction of a balance between proinflammatory and anti-inflammatory eicosanoids by the administration of stable analogues of lipoxins could improve the treatment of chronic obstructive pulmonary disease in the future.