Factors influencing factor VIII activity in frozen plasma

Abstract

For an optimal yield of FVIII, freezing should start within 4 h after plasma donation. We propose the use of the term 'ice front velocity' instead of 'freezing speed', taking into consideration that the volume and shape of plasma containers may differ. We found only a marginal loss of FVIII:C when the ice front velocity was 26 mm/h or faster, but a significant loss when it was 9 mm/h or slower. We recommend freezing times of 60 min or shorter. We were not able to demonstrate any eutectic point in human plasma. We therefore recommend that the term eutectic point should not be used as a reference temperature in guidelines on plasma handling.

The impact of whole blood processing and freezing conditions on the quality of therapeutic plasma prepared from whole blood

“…Source plasma units frozen completely within 1 hour to a core temperature below −30°C contained significantly greater levels of FV and FVIII than plasma units frozen more slowly at −30°C in large walk‐in freezers, which takes several hours to reach a core temperature of −30°C . FVIII recovery in 100‐mL plasma aliquots decreased by 7% when the freezing time was prolonged from 1 to 4 hours and by 27% when freezing time was prolonged up to 24 hours . The difference between FVIII levels in source plasma units frozen at −30 and at −20°C in industrial‐size chambers was 12.6% .…”

“…13 In two studies PC was reduced by 5 and 6%, respectively, when PF24 and PF24RT were compared with FFP. 9,12 Cardigan and colleagues 7 has been the only study group that found considerably lower fibrinogen, FV, and FXI levels in PF24 than in FFP (12,15, and 7%, respectively). Others have failed to observe such differences when PF24 or PF24RT was compared with FFP.…”

“…Studies dealing with the composition of non–pathogen‐reduced, WB‐derived plasma preparations for transfusion have neglected the influence on quality of the conditions under which the plasma was frozen. Three studies have shown that the amount of FVIII recovered in plasma depends on the velocity and the temperature of plasma freezing . Source plasma units frozen completely within 1 hour to a core temperature below −30°C contained significantly greater levels of FV and FVIII than plasma units frozen more slowly at −30°C in large walk‐in freezers, which takes several hours to reach a core temperature of −30°C .…”

Plasma and cryoprecipitate manufactured from whole blood held overnight at room temperature meet quality standards

“…It has been shown previously that the time taken to freeze plasma can affect the resulting FVIII activity; a small difference was recorded between freezing times of 1 and 4 hours. 13 Taken together these minor differences may have contributed to the improved FVIII activity seen in the QC data compared to the validation data. Of note, it is the QC data that are reflective of the products used in Canadian hospitals.…”

Quality Assessment of Established and Emerging Blood Components for Transfusion

“…FVIII activity in plasma was found to be stable to prefreezing room temperature holds of up to 4 hours. Rapid freezing to a core temperature of −30°C within 60 minutes, as compared to slow freezing over 24 hours, resulted in mean FVIII recoveries of 93.6 versus 68.2% [69]. Runkel et al pooled and split whole blood donations, generating plasma within 8 hours of phlebotomy that was frozen at the 8-hour time point or held at either ambient or refrigerated temperatures for an additional 16 hours prior to freezing [70].…”