Background: Swedish regulations in effect since 2006 allow the storage of plasma for transfusion up to 14 days at 2-6 degrees C and for 3 years at < or = -30 degrees C. In this study, the quality of currently used plasma components was investigated.
Materials and methods: Plasma components, prepared from whole blood or by apheresis, either leucocyte depleted or not leucocyte depleted, were stored at 2-6 degrees C as liquid plasma or as thawed fresh-frozen plasma; 31% were from female donors. Concentration, function and activation markers of the plasma coagulation systems were investigated during storage for up to 42 days.
Results: Cold-induced contact activation was the dominant storage lesion, occurring earlier and at higher frequency in plasma from females. Increased kallikrein-like activity led to changes in activated partial thromboplastin time, prothrombin time, protein C and C1 inhibitor (C1INH). C1INH function dropped to 53% on Day 14 in cold-activated plasma components.
Conclusion: Contact activation may be triggered before Day 14, especially in plasma from females, and may progress as a result of the consumption of C1INH. The data suggest that lack of cold-induced contact activation may be an important quality criterion. To achieve this, plasma from male donors could be selected for transfusion and the storage time limited to 7 days.