The rate of hemolysis in sickle cell disease correlates with the quantity of active von Willebrand factor in the plasma

Supplemental materials for: Chen et al

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• Figure S1. Ristocetin-induced platelet agglutination with sickle cell plasma (JPG, 64.6 KB) -
  In these experiments, formalin-fixed platelets (Helena Laboratories, TX) were agglutinated by normal or sickle plasma in the presence of 0.5 mg/ml ristocetin. (A) Plasma from patient 4 was diluted to the same concentration of VWF as pooled normal plasma and mixed with platelets (2 × 10⁵/µl). Ristocetin was added at time zero. Note both the enhanced agglutination and the reduced lag time to initiation of agglutination using sickle plasma. (B) Comparison of agglutination at different VWF concentrations using pooled normal plasma and plasma from patient 4 taken during two episodes of red cell exchange. The activation factors were 3.5 and 1.8 for samples 1 and 2, respectively.