The Impact of Airway Oxidative Stress on Macrophage Polarization in Stable Asthma and COPD : Association With Clinical Features in a Prospective Observational Study

The polarization status of pulmonary macrophages is dependent on cytokines and mediators present locally in the airways. This study aimed to evaluate whether oxidative stress present in the airways of asthma or COPD patients promotes M1 or M2 macrophage polarization. M1 macrophages predominated in COPD, whereas no increase in M2 macrophages was observed in any of the investigated groups. The elevated number of M1 in COPD was related to a higher level of increased oxidative stress marker mRNA expression, CYP1B1 , and enhanced IL‐6 and IL‐8 levels. The M2 macrophage polarization was not disease‐related and correlated with higher FEV 1 /VC. Airway oxidative stress is related to M1 macrophage polarization in COPD, associated with increased inflammation and CYP1B1 mRNA expression. M1 macrophages were not related to clinical features in stable asthma or COPD, whereas higher levels of M2 macrophages were associated with better spirometry results.