Thrombus generation on a collagen surface in a healthy control and type 2A and 2B VWD patients at a typical low or high shear rate.
Whole blood containing mepacrine-labeled platelets was perfused through a collagen-coated glass surface at a low (50 s−1) or high (1500 s−1) shear rate condition. Images, displayed as accumulated mepacrine fluorescence, were obtained at 7 minutes after the beginning of platelet-surface interaction during perfusion. Two patients were selected as representative of each VWD subtype (Tables 1and 2), and control images (control-2 in Table 2) are representative of 5 independent perfusions using blood from 5 individual donors (original magnifications × 400). At a low shear rate, platelet thrombi in all VWD patients were generated to an extent comparable to that in healthy controls. In contrast, thrombus generation in type 2A patients was apparently reduced compared with a healthy control at a high shear rate. The extent of thrombus generation in type 2B patients under high shear was heterogeneous, ranging from normal to significantly reduced (Table 2).
