Figure 3

Decreasing haematocrit significantly reduces platelet interactions with VWF but has no effect on platelet translocation speeds. RBCs isolated from whole blood of 5 donors were diluted in platelet-poor plasma to mimic a 2-fold or 3-fold reduction in HCT, then reconstituted back into platelet-rich plasma. The blood was then perfused over VWF at arterial shear rates and measured using the dynamic platelet function assay. HCT correlated strongly with the extent of platelet interactions with VWF but not with the speed of platelet motion across the VWF surface. A simple linear regression model was used to test the slopes between the HCT and measured platelet interactions with VWF. The best-fit lines with a 95% confidence band are shown in the graph.