IL6 and chronic obstructive pulmonary disease: Whereas in our study, the levels of IL-1β, IL-6 and CXCL8 were higher in unstimulated cells from COPD patients, we report for the first time that PBMC from COPD patients exhibit a defective pro-inflammatory cytokine (including IL-1β, IL-6, IL-12 and IL-23) secretion in response to bacteria compared to controls or to smokers.