Use of Frozen Cryoprecipitate for the Preparation of Clinical Factor VIII Concentrate

Two years of experience is described in the preparation of factor VIII concentrate for clinical use, prepared from frozen cryoprecipitate by a modified polyethylene glycol procedure. The yield of factor VIII was fire plasma equivalents per gram of starting material with a 100‐fold purification over plasma. Anti‐A and B isoagglutinin levels were consistently higher in factor VIII concentrates derived from paid donors than from volunteer donors. The incidence and levels of hepatitis B antigen in the factor VIII concentrates from paid unscreened donors were significantly higher than that derived from volunteer donors. Factor VIII concentrates derived from screened paid or volunteer donors contained little or no detectable hepatitis B antigen. These highly soluble concentrates met all the Bureau of Biologics requirements and have been clinically effective.