Coagulation factor levels in plasma frozen within 24 hours of phlebotomy over 5 days of storage at 1 to 6 degrees C.

Background: The use of plasma frozen within 24 hours after phlebotomy (FP24) is likely to increase as male donors become the predominant source of plasma products. This study was performed to investigate the levels of clotting factors in thawed plasma (TP) prepared from FP24 during 5 days of storage at 1 to 6 degrees C.

Study Design And Methods: Five units of A, B, and O and 3 units of AB FP24 were obtained from the local blood provider. They were thawed and maintained at 1 to 6 degrees C for a total of 5 days. Within 6 hours of thawing and every 24 hours thereafter for 5 days, each unit was assayed for the following clotting factors: Factor (F)II, FV, FVII, FVIII, F IX, FXI, FXII, antithrombin (AT), protein C (PC), and protein S (PS). ADAMTS-13 was assayed on Days 2, 4, and 5. Time is expressed as mean hours or days (standard deviation).

Results: On average the units were frozen 21.3 (3.8) hours after phlebotomy and had been frozen for a mean of 30.1 (32.3) days before thawing. The activities of all procoagulant factors including FVIII, along with AT, PC, and ADAMTS-13, were well maintained in their normal range during the 5-day storage. The activity of PS was slightly below the normal range by Day 5.

Conclusions: The activity of all factors assayed, except for PS, were within their normal range during the 5-day storage period. These results show comparable factor assay levels in TP prepared from fresh-frozen plasma and FP24.