Thawing procedures and the time course of clotting factor activity in fresh-frozen plasma: A controlled laboratory investigation

BACKGROUND: In this study, we evaluated the effects of the thawing process of 2 commercially available devices on the activity of clotting factors, inhibitors and activation markers of the hemostatic system in fresh-frozen plasma (FFP). In an experimental procedure, FFP was thawed under running warm water at 42 degrees C. METHODS: Plasma of 20 healthy donors was sampled, separated, and distributed in 3 plasma bags. Within 2 h after sampling plasma bags was frozen at a temperature of -30 degrees C to -40 degrees C and stored for at least 8 wk. After sampling (baseline) as well as immediately and 1, 2, 4, and 6 h after thawing, the activity of FV, FVII, FVIII, fibrinogen, fibrin monomers (FM), D-dimers (DD), alpha 2-antiplasmin (alpha 2-AP), and protein S (PS) was determined from each plasma bag. RESULTS: From I h to 6 h after thawing, no significant differences in the activity of the investigated coagulation markers dependent on the thawing procedure were found. However, immediately after thawing and independent of the thawing procedure, the activity of FVII was significantly decreased (P < 0.01), whereas FM were significantly increased (P = 0.001). CONCLUSION: The thawing procedures studied exhibited no significant influence on activity and stability of the investigated markers of coagulation over the study period. The decreased activity of FVII and the clinical significance of the increase in FM require further research.