CSF2 and chronic obstructive pulmonary disease: The sputum GM-CSF concentration was correlated with the sputum eosinophilia in subjects with disease as a whole group (rs = 0.28; p = 0.007), all those with asthma (rs = 0.3; p = 0.04) and moderate and severe disease (rs = 0.41; p = 0.018), but not COPD.