Effect of EDTA on platelet count and other platelet parameters in blood and blood components collected with CPDA-1.

We have shown in this study that addition of dried K2EDTA (1.5 mg/ml) to blood samples anticoagulated with CPDA-1 increases significantly the platelet count and mean platelet volume (MPV) of whole blood, red cell concentrate (RCC) and platelet concentrate (PC), but not of platelet-rich plasma (PRP) or of platelet-poor plasma (PPP). Transmission and scanning electron microscopy illustrated that platelet aggregates which are present in some components are dispersed on mixing of the sample with EDTA and that this is accompanied by a change in platelet morphology. Determination of the platelet distribution width (PDW) indicated that the platelet populations in whole blood and RCC seem to be more uniform in size than the populations in PRP, PPP and PC. The determination of MPV and PDW changes after addition of EDTA may provide a new approach to quality control of PC.