Chromatographic Preparation of a Therapeutic Highly Purified von Willebrand Factor Concentrate from Human Cryoprecipitate

Abstract

A therapeutic highly purified von Willebrand factor (vWF) concentrate has been prepared from cryoprecipitate by a three-step chromatographic procedure. After solvent/detergent treatment to inactivate viruses, the cryoprecipitate solution was chromatographed on DEAE-fractogel TSK 650 M to separate vWF from most cryoprecipitate proteins, including factor Vili (FVIII) and fibrinogen. A second DEAE-fractogel TSK 650 M was then performed to further purify vWF and to allow concentrating it to over 100 U ristocetin cofactor activity/ml. The last step on immobilized gelatin removed fibronectin and increased the purity of vWF. vWF was recovered with about 18 and 40% yield in antigen and collagen-binding (CB) activity, respectively, from cryoprecipitate. vWF was obtained in an essentially pure state corresponding to a purification factor of over 10,000-fold from plasma. Immunonephelometric and SDS-PAGE analyses of the concentrate did not reveal any detectable cryoprotein contaminants, especially fibrinogen, fibronectin, immunoglobulins and albumin. The content in intermediate- and high-molecular-weight multimers in the concentrate was similar or higher than that of plasma, as the ion-exchanger selectively favored the binding and concentration of the larger multimeric forms while reducing the amount of the smaller forms with abnormal structure and low activity. Other characteristics of the concentrate included a CB activity to antigen ratio of 1.69 and a high capacity (86%) to correct platelet adhesion in a perfusion system. Clinical use of this standardized vWF concentrate has been shown to be efficacious in the treatment of vWF patients.

Pharmacokinetics of von Willebrand factor and factor VIIIC in patients with severe von Willebrand disease (type 3 VWD): estimation of the rate of factor VIIIC synthesis

“…Correspondence Previous studies of the pharmacokinetics of factor VIII in patients with VWD were complicated by the infusion of large amounts of exogenous factor VIII. The availability of a von Willebrand factor preparation containing very low quantities of factor VIII (Burnouf-Radosevich & Burnouf, 1992;Mazurier et al, 1991) enables more precise definition and modelling of FVIIIC and VWF pharmacokinetics in patients with severe VWD.…”