RT Journal Article SR Electronic T1 Reduction in sputum neutrophil and eosinophil numbers by the PDE4 inhibitor roflumilast in patients with COPD JF Thorax JO Thorax FD BMJ Publishing Group Ltd and British Thoracic Society SP 1081 OP 1087 DO 10.1136/thx.2006.075937 VO 62 IS 12 A1 Diana C Grootendorst A1 Stefanie A Gauw A1 Renate M Verhoosel A1 Peter J Sterk A1 Jeannette J Hospers A1 Dirk Bredenbröker A1 Thomas D Bethke A1 Pieter S Hiemstra A1 Klaus F Rabe YR 2007 UL http://thorax.bmj.com/content/62/12/1081.abstract AB Background: Roflumilast is a targeted oral once-daily administered phosphodiesterase 4 (PDE4) inhibitor with clinical efficacy in chronic obstructive pulmonary disease (COPD). Results from in vitro studies with roflumilast indicate that it has anti-inflammatory properties that may be applicable for the treatment of COPD.Methods: In a crossover study, 38 patients with COPD (mean (SD) age 63.1 (7.0) years, post-bronchodilator forced expiratory volume in 1 s (FEV1) 61.0 (12.6)% predicted) received 500 μg roflumilast or placebo once daily for 4 weeks. Induced sputum samples were collected before and after 2 and 4 weeks of treatment. Differential and absolute cell counts were determined in whole sputum samples. Markers of inflammation were determined in sputum supernatants and blood. Spirometry was performed weekly.Results: Roflumilast significantly reduced the absolute number of neutrophils and eosinophils/g sputum compared with placebo by 35.5% (95% CI 15.6% to 50.7%; p = 0.002) and 50.0% (95% CI 26.8% to 65.8%; p<0.001), respectively. The relative proportion of sputum neutrophils and eosinophils was not affected by treatment (p>0.05). Levels of soluble interleukin-8, neutrophil elastase, eosinophil cationic protein and α2-macroglobulin in sputum and the release of tumour necrosis factor α from blood cells were significantly reduced by roflumilast compared with placebo treatment (p<0.05 for all). Post-bronchodilator FEV1 improved significantly during roflumilast compared with placebo treatment with a mean difference between treatments of 68.7 ml (95% CI 12.9 to 124.5; p = 0.018).Conclusion: 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 FEV1.