Figure 4

Concentrations of IL-8 and MPO in sputum supernatants. Individual data and mean values of log transformed values are displayed. BL: baseline, LPS 1: first LPS challenge, LPS: second LPS challenge at least 4 weeks after LPS 1, LPS Tx: third LPS challenge at least 4 weeks after LPS 2 and after 5 days of treatment with roflumilast (500 μg /day). For statistical details please refer to Table 2. *** p < 0.001 compared with baseline.