A method for preparing plasma factor 8 (antihemophilic globulin) concentrate.

Abstract

Treatment of patients with hemophilia A is based on the administration of exogenous Factor VIII (antihemophilic globulin). Usually this is accomplished by infusing fresh, fresh-frozen, or reconstituted freeze-dried normal human plasma. The large volume of plasma needed to achieve and maintain hemostasis may be sufficient to cause circulatory overload, and thereby represents a critical limiting factor in therapy. During recent years, several therapeutically effective concentrated Factor VIII preparations have become available. These products are similar to Cohn Fraction I, which is prepared from whole plasma by ethanol extraction. Unfortunately, the difficulties encountered in procuring large volumes of fresh plasma to use as raw material, and other problems related to the lability of Factor VIII, the complexity of necessary equipment and methods, and the need for rigid bacteriologic control, have limited production and raised the cost of these products. Attempts to produce an inexpensive concentrate have recently met with success. Two developments have permitted formulation of a method for preparation of Factor VIII concentrate that may be used in any blood bank. The first important observation was that of Pool and Robinson, who found that Factor VIII precipitates with fibrinogen in the cold, just as it does in salting-out and ethanol precipitation procedures. The second contributing factor was the definition of plasmapheresis as an alternate form of blood donation which permits collection of large