Studies on the procurement of coagulation factor VIII: selective precipitation of factor VIII with hydrophilic...

Early work on the purification of factor VIII using polyethylene glycol (PEG) indicated that other polymers might also be used to precipitate factor VIII leaving fibrinogen in solution. Recently polyvinylpyrrolidone (PVP) has also been advocated for this purpose. In this study, different concentrations and molecular weights of hydroxyethyl starch, dextran, PEG, PVP, Ficoll, Percoll and albumin were examined for their ability to precipitate the factor VIII complex from cooled (not frozen) fresh CPD plasma. At optimal concentrations near quantitative recovery of VIIIR:Ag and VIII:CAg was achieved in 2 hr with minimal precipitation of fibrinogen or total protein. The best separations were observed with hydroxyethyl starch, albumin or Ficoll. PVP and PEG gave inferior purifications. Results for cryoprecipitate and intermediate-purity factor VIII concentrate were inferior to those obtained with plasma. Simple pre-concentration of plasma prior to chilling is an attractive alternative for large scale continuous production.