A highly purified factor VIII:c concentrate prepared from cryoprecipitate by ion-exchange chromatography

Abstract

A new ion-exchange chromatographic procedure has been developed to produce a highly purified factor VIII (FVIII) concentrate from plasma cryoprecipitate. Solubilized cryoprecipitate, after adsorption on aluminium hydroxide and cold precipitation, was treated with 0.3% tri(n-butyl)phosphate and 1% Tween 80 at 25 degrees C for at least 8 h to inactivate lipid-enveloped viruses. The fraction was then loaded onto a column packed with DEAE-Fractogel TSK 650 M and chromatographed. Most proteins and TnBP-Tween 80 flowed through the gel unretarded. FVIII:c, which bound to the gel, was eluted by increasing the ionic strength, then was directly filter-sterilized without ultrafiltration or addition of a protein stabilizer. Chromatographic recovery of FVIII:c was 80-90%. After freeze-drying, FVIII:c was at a concentration of 42.5 +/- 9.5 IU/ml and had a specific activity of 175.4 +/- 37.8 IU/mg (n = 40), corresponding to a purification factor of over 12,000 from plasma. The typical yield of the freeze-dried FVIII:c from cryoprecipitate was 55-65%. FVIII:c was stable for over 24 h at room temperature in the liquid state. The mean content of fibrinogen and immunoglobulin G was only 65 and 100 mg/l, respectively, corresponding to 1.4 and 2.3 mg/1,000 IU FVIII:c. This concentrate, which is much purer than traditional FVIII concentrates, has been found to be well tolerated and effective in clinical treatment of hemophilia A patients.