TNF and chronic obstructive pulmonary disease: Notably, while no differences were observed in platelet-free leucocyte-endothelium interactions between groups (EDTA, Figure 1B), circulating leucocyte-platelet aggregates from patients with GOLD 1 showed greater adhesiveness to TNFα-stimulated HPMECs when compared with those of normal LF smokers (45.6% increase) and non-smokers (63.7% increase) (heparin, Figure 1A), indicating that platelets likely play a key role in leucocyte-endothelium interactions in early-stage COPD.