Factor VIII:C activity in cryoprecipitate prepared at the Blood Bank, University Hospital of the West Indies, Jamaica - abstract

ABSTRACT

Cryoprecipitate is the blood product rich in factor VIII C activity used in the treatment of haemophhlia A. The University Hospital Blood Bank makes most of this product used in Jamaica. Commercially prepared factor VIII concentrates are expensive. We examined the effect of donor variables and techniques of preparation on the potency of cryoprecipitates in order to determine the most efficient production method. Factor VIII C activity of cryoprecipitate was measured using the activated partial thromboplastin time with a normal plasma pool being used as reference plasma. Donor age and method of freezing the plasma had no effect on potency. Blood group B had a higher yield of factor VIII C than groups A and O. Potency was decreased by prolonged storage of blood prior to processing (p = 0.015) but was increased by increasing volumes of cryprecipitate (p<0.01). The mean potency of the factor VIII C was 184 i.u., surprisingly higher than the usually assumed 70 i.u. used for calculating the requirements of our haemophiliacs. We recommend that plasma from fresh tested blood, frozen in - 40§C be used for preparing cryoprecipitate and that a higher value than 70 i.u. of factor VIII C be used for each bag of cryoprecipitate (AU)