Cold-Promoted Activation of Factor VII: Is It a Problem under Blood Bank Conditions?

Abstract

Transfusion of blood or plasma kept at 4 °C for 12–14 h could be hazardous since about 15% of plasmas from healthy donors undergo cold activation of factor VII under such conditions. In this study we were unable to demonstrate in plasma from 209 healthy donors a significant rise in mean factor VII level after storage of plasma in the blood bank bags at 4 °C for 24 h. The blood bank unfavorable conditions for cold activation of factor VII were manifested in the plasma from a known cold activator whose plasma underwent cold activation in a plastic test tube while in the blood bank bag it did not. The lack of cold activation observed in blood bank versus laboratory conditions did not stem from differences in anticoagulant, in speed of centrifugation, in proportion anticoagulant-blood or in the plastic ware; it appeared to stem from differences in the ratio between plasma volume and surface of the containers used in the blood bank versus the laboratory. Since plasma factor VII from 3 out of 16 women taking contraceptives became activated in the cold even at relatively small surface exposure it seems advisable to separate and freeze as fast as possible plasma components from blood donated by women on contraceptives.

Thrombin Generation During Collection of Blood from Donors Taking Oral Contraceptives

“…The PKK levels, however, differed significantly in the two groups. PKK participates in accel In accordance with Seligsohn et al [20,21], no coldpromoted activation of factor VII following storage could be observed in any of the groups. Even though the TT clotting times were less prolonged in the OC group, none of the donors demonstrated significantly shortened TT times consistent with activation of factor VII.…”

“…Even though the TT clotting times were less prolonged in the OC group, none of the donors demonstrated significantly shortened TT times consistent with activation of factor VII. Seligsohn et al [19,20] concluded that a high ratio between plasma and PVC surface of the bags, as opposed to test tubes, could explain the lack of cold-promoted activation under blood bank conditions.…”

Unexpected effects of donor gender on the storage of liquid plasma

“…A recommendation was previously made that plasma from female donors should be quickly frozen [14,15]. Considering the findings in the present study, a suitable preventive measure would be to exclude plasma from women for use in transfusion and to limit the storage period for liquid plasma to 7 days.…”

Vitamin K‐dependent coagulation factors and fibrinogen levels in FFP remain stable upon repeated freezing and thawing

“…FVII was known to become activated in plasma under refrigerator conditions. Seligsohn et al 11 looked at FVII activation in tubes versus blood‐bank bags and found that FVII activation was negligible in blood bank conditions, making storage of FFP for 24 hours in the cold safe for transfusion.…”