Effect of plasma freezing temperature, anticoagulant and time of storage on factor VIII:C activity in cryoprecipitate.

The influence of ACD and CPDA-1 anticoagulants, and storage time for 3 and 6 months on F VIII:C activity were compared in cryoprecipitate obtained at -70 degrees C, and -30 degrees C plasma freezing temperature. To eliminate variations in F VIII:C activity between donor plasma, the cryoprecipitation at -70 degrees C and -30 degrees C was made in paired plasma volumes (approximately 100 ml) from each blood unit. Employing ACD plasmas (n = 50), there was no significant difference in F VIII:C activity between cryoprecipitate prepared at -70 degrees C (mean = 31.1 IU/bag) and -30 degrees C (X = 30.5 IU/bag), and the storage did not modify F VIII:C activity. In contrast, in cryoprecipitate prepared from CPDA-1 plasmas (n = 31), the F VIII:C levels obtained at -30 degrees C (mean = 43.8 IU/bg) were significantly higher than those at -70 degrees C (mean = 37.3 IU/bag), but a deterioration of F VIII:C activity (about 50%) was observed after 6 months of cryoprecipitate storage. Therefore, if cryoprecipitate is stored it would be more convenient to use ACD instead of CPDA-1 and make cryoprecipitation either at -70 degrees C or -30 degrees C.