VWF self-association at various HDL and LDL levels. Bio-VWF (5 μg/mL) in 10 mM N-2-hydroxyethylpiperazine-N′-2-ethanesulfonic acid, pH 7.4 was vortexed for 90 minutes at room temperature in the presence of increasing concentrations of HDL (A) or in the presence of either 1.2 or 2.4 mg/mL of HDL and increasing concentrations of LDL (B). The Bio-VWF remaining in solution was measured using ELISA. Bio-VWF in tubes not vortexed served as control (100%) (n = 3 in [A], n = 4 in [B]). (C) Citrated pooled human plasma (50%) in 10 mM EDTA was sheared by vortexing for 3 hours. VWF remaining in solution was measured using ELISA and expressed as a percentage of the VWF in parallel samples not exposed to shear stress (n = 3). The ratios of LDL to HDL are shown in both cholesterol ratios (LDL-C to HDL-C) and total particle weight ratios (LDL to HDL).