CF plasma causes activation of normal and CF platelets. (A) Monocyte- and neutrophil-platelet aggregates in CF whole blood after incubation in ABO/RhD-matched CF or normal control plasma. (B) Monocyte- and neutrophil-platelet aggregates in normal whole blood after incubation in ABO/RhD-matched CF or normal control plasma. (C) Comparison of the solid bars of panel A (CF plasma + CF whole blood) with the open bars of panel B (CF plasma + normal whole blood). Panel C demonstrates that when whole blood from CF and healthy subjects was incubated in CF plasma, platelet activation (as determined by monocyte-platelet and neutrophil-platelet aggregates) was greater in CF blood than in normal blood. Data are mean ± SEM; n = 6. ^*P < .05 versus normal plasma or whole blood.