Biological effects of a S/D-treated, very high purity, von Willebrand factor concentrate in five patients with severe von Willebrand disease.

A highly purified von Willebrand factor (vWf) concentrate with low factor VIII (FVIII) content was tested to evaluate its biological effects in five patients with severe von Willebrand disease (vWd). The patients were infused with a single dose of this product corresponding to approximately 65 IU vWf:RCo and approximately 11 IU FVIII:C/kg and were followed up for 48 h. The plasma levels of FVIII and vWf and the multimeric pattern of vWf were determined before and 1, 3, 6, 12, 24 and 48 h after infusion.