A Preliminary Study on Coagulation Parameters and Sterility of Thawed Refrozen Fresh Frozen Plasma

Abstract

Thawed fresh frozen plasma (FFP) if not used within 6 h, may have to be discarded due to the risk of contamination and uncertainty about its quality. The main objective of this study was to evaluate the levels of coagulation Factor II (FII), Factor VIII (FVIII), fibrinogen and bacterial growth in thawed refrozen FFP. Thirty FFP samples were collected from healthy donors. FFP were thawed in water bath at 37 °C for 20-25 min. Approximately 10 mL of plasma from each FFP unit was tested for FII, FVIII, fibrinogen and sterility. The thawed FFP units were then kept at 4 °C for 6 h before being refrozen and stored at -20 °C. Two weeks later, the refrozen FFP were thawed again and representative samples were analysed as before. There was a significant decline in the mean FVIII level, from 155.77% to 85.6% at second thaw. The mean FII level increased significantly from 74.9% to 82%, whereas the mean fibrinogen level fell from 3.34g/L to 3.28 g/L, but the decline was not statistically significant. There was no bacterial contamination in all samples at both time points. Refrozen plasma may be considered as an alternative to the storage of thawed unused FFP provided they are kept in a controlled environment to reduce wastage. These thawed refrozen FFP can be used later in bleeding cases like other FFP as the levels of FVIII are still within the standard haematology range (0.5-2 IU/mL) and above the minimal level of 30% coagulation factors required for adequate haemostasis.

Experiences in the use of multiple doses of convalescent plasma in critically ill patients with COVID‐19: An early phase 1 descriptive study

“…All the CCP units used for this study were thawed following the same sterile procedure and transfused within 60 min, a practice demonstrated to be safe for preserving sterility. 28 Although this study was not designed to demonstrate efficacy, the difference in the proportion of extubated versus intubated patients depending on the time of transfusion after symptom onset suggests a trend towards better outcomes when transfusions were initiated earlier in the disease course. This is congruent with other reports that also observed that after Day 9 of symptoms onset, most patients already had potent neutralizing antibodies against SARS-CoV-2 before CCP transfusion, with titers comparable to that of donors, 10,12,24 and that these titers increased or stayed stable during the first month of follow up.…”

“…Moreover, the standard practice of our blood bank involves weekly quality control checks to monitor bacterial growth in every blood product. All the CCP units used for this study were thawed following the same sterile procedure and transfused within 60 min, a practice demonstrated to be safe for preserving sterility 28 …”