Reduction in sputum neutrophil and eosinophil numbers by the PDE4 inhibitor roflumilast in patients with COPD

PDE4 inhibition by roflumilast treatment for 4 weeks reduced the number of neutrophils and eosinophils, as well as soluble markers of neutrophilic and eosinophilic inflammatory activity in induced sputum samples of patients with COPD. This anti-inflammatory effect may in part explain the concomitant improvement in post-bronchodilator FEV(1).