CXCL8 and chronic obstructive pulmonary disease: Compared with the pre-therapy values, the induced sputum IL-8 level and the PaCO2 were reduced, while the induced sputum IL-10 level, the FEV1%pred, the FEV1/FVC and the PaO2 were increased significantly (all P<0.01) in the three COPD groups.