Chromatography of the VIII/vWF complex on dextran sulphate sepharose

Application of bioaffinity technology in therapeutic extracorporeal plasmapheresis and large-scale fractionation of human plasma

This paper describes the increasingly unique and powerful role that affinity chromatography is occupying both as a tool for the treatment of extracorporeal plasma exchange (to discard biological compounds with noxious metabolic or immunologic effects in patients) and as a purification tool in the production of therapeutic plasma protein derivatives. Management of both applications requires careful monitoring of the parameters applied to the plasma material, to avoid immunological stimulation or activation of the coagulation cascade. Examples of direct current applications of affinity ligands in therapeutic removal and industrial production of plasma compounds are presented.

Direct capture of plasma factor VIII:C by ion exchange chromatography

An ion exchange medium, DEAE-Fractogel 650M, can be used to capture factor VIII (FVIII) directly from plasma. Previous reports have focussed on the use of this medium to capture FVIII from cryoprecipitate. In this report, citrate phosphate dextrose plasma was batch-stirred with DEAE-Sephadex A50, filtered, diluted, loaded onto a column packed with DEAE-Fractogel TSK 650M, and chromatographed. Most of the unwanted proteins flowed through the gel unadsorbed. Bound FVIII was eluted by increasing the ionic strength of the buffer. A citrate-based buffer gave an overall FVIII:C yield of 670 IU/kg plasma with a specific activity of 0.68 IU FVIII:C/mg protein. This process gave a higher yield of FVIII:C but significantly more prothrombin complex factors than cryoprecipitation. This method is a promising alternative to cryoprecipitation of FVIII.

Chromatographic preparation of a therapeutic highly purified von Willebrand factor concentrate from human cryoprecipitate

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 VIII (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.