Determinants of factor VIII recovery in cryoprecipitate.

Many aspects of the production of cryoprecipitate were studied to determine which methods resulted in the greatest recovery of Factor VIII. The following recommendations resulted: 1) blood should be mixed with anticoagulant throughout phlebotomy; 2) blood should be centrifuged within a few hours of collection; 3) larger satellite bags should be used to contain the usual volume of plasma, for example, 200 ml of plasma should be frozen in a 600-ml capacity bag; 4) plasma should be centrifuged as soon as thawing is complete; 5) cryoprecipitate should be refrozen on dry ice; 6) cryoprecipitate should be stored at or below -30 C.; and 7) prolonged storage of frozen plasma or cryoprecipitate should be avoided. Variations in Factor VIII content from one bag of cryoprecipitate to another, under uniform production conditions, depends largely on two donor-specific attributes which tend to remain constant from time to time, namely, the donor's plasma Factor VIII level and the cryoprecipitability of his Factor VIII.