Antihaemophilic globulin: preparation by an improved cryoprecipitation method and clinical use.

Abstract

The control of bleeding episodes in haemophilia and the pre vention of excessive haemorrhage after surgical procedures depend chiefly on raising the patient's plasma factor VIII concentration to an appropriate haemostatic level, and maintain ing this so long as the likelihood of bleeding continues. With whole plasma it is impossible to achieve levels much above 25%, or to maintain values constantly above about 10% for more than two or three days, without overloading the patient's circulation. In order to overcome this problem antihaemophilic globulin concentrates have been prepared for clinical use by a variety of methods. Most of these require much time and technical skill, and involve considerable loss of activity during the process. The cryoprecipitate method of Pool and her associates, however (Pool et al., 1964 ; Pool and Shannon, 1965), based on their observation (Pool and Robinson, 1959) that when frozen plasma is thawed in the cold most of the factor VIII remains in the cold-insoluble precipitate, provides a simple means of preparation of potent antihaemophilic globulin con centrates, suitable for introduction as a routine blood-banking procedure.