Ben-Tal Ofira, Zwang Ety, Eichel Roza, Badalbev Tanya, Hareuveni Mara
Blood Bank and Hematology, Tel Aviv, Sourasky, Medical, Center, Tel Aviv, Israel.
Transfusion. 2003 Jul;43(7):873-7. doi: 10.1046/j.1537-2995.2003.00444.x.
FFP is considered adequate for transfusion up to 24 hours after thawing and is currently used most often to replace deficient clotting factors, such as in warfarin overdose. We set to examine the levels of vitamin K-dependent factors (i.e., prothrombin, FVII, F IX, FX), as well as fibrinogen, upon twice freezing and thawing of FFP. If factor levels in refrozen FFP remain within normal limits, this component can possibly be transfused, thus avoiding wastage of precious blood components.
Twenty units of FFP, five units of each blood group A, B, AB, and O, were thawed, and aliquots were taken for measurement of coagulation factors. The plasma units were then kept for 24 hours at 4 degrees C, at which point a second aliquot was taken, The remaining FFP units were refrozen and kept at -80 degrees C for 1 week. The above procedure was then repeated. Coagulation-factor activity and fibrinogen level were measured by the coagulation analyzer.
The mean levels of prothrombin, FVII, F IX, FX, and fibrinogen of each blood group (A, B, AB, and O) were calculated for each of four time points and found not statistically different (p > 0.05). Therefore, the rest of the analysis was done for all 20 FFP units as one group. The mean +/- SD levels of each coagulation factor at each time point demonstrated that all levels were within normal limits of all factors measured and that for none of the factors was there a significant decay of activity.
The levels of prothrombin, FVII, F IX, FX, and fibrinogen remain stable and adequate for transfusion in twice-thawed-and-refrozen FFP. This component can be safely used for transfusion as a source of vitamin K-dependent clotting factors and fibrinogen.
新鲜冰冻血浆（FFP）在解冻后24小时内被认为适合输注，目前最常用于补充缺乏的凝血因子，如华法林过量时。我们着手研究FFP两次冻融后维生素K依赖因子（即凝血酶原、FVII、FIX、FX）以及纤维蛋白原的水平。如果再冻融FFP中的因子水平仍在正常范围内，该成分可能可以输注，从而避免宝贵血液成分的浪费。
解冻20单位FFP，每个血型（A、B、AB和O型）各5单位，取等分试样测定凝血因子。然后将血浆单位在4℃保存24小时，此时再取一份等分试样，其余FFP单位重新冻存并在-80℃保存1周。然后重复上述过程。通过凝血分析仪测量凝血因子活性和纤维蛋白原水平。
计算每个血型（A、B、AB和O型）在四个时间点的凝血酶原、FVII、FIX、FX和纤维蛋白原的平均水平，发现无统计学差异（p>0.05）。因此，将所有20个FFP单位作为一组进行其余分析。每个时间点各凝血因子的平均±标准差水平表明，所有水平均在所有测量因子的正常范围内，且没有一个因子的活性有显著下降。
凝血酶原、FVII、FIX、FX和纤维蛋白原的水平在两次冻融的FFP中保持稳定且适合输注。该成分可作为维生素K依赖凝血因子和纤维蛋白原的来源安全用于输血。
