Hemostatic function, immunomodulatory capacity, and effects of lipemia in cold-stored whole blood

Background: Whole blood (WB) is increasingly being used for resuscitation of trauma patients. Although platelet-, red blood cell (RBC)- and plasma-specific parameters in cold-stored WB are well characterized, there has been limited investigation of biological response modifiers (BRMs), which may induce adverse reactions in recipients. The aim of this study was to evaluate the quality and function of RBC, platelets, plasma proteins, and BRMs in cold-stored WB during storage.

Methods: WB (n = 24) was collected into collected into citrate-phosphate-dextrose (CPD) anticoagulant, held overnight, processed through a platelet-sparing filter, and stored at 2-6°C for 21 days. RBC, platelet, coagulation factor quality and function, and BRM concentrations were measured throughout the duration of storage.

Results: WB was effectively leukoreduced, with 99.98% reduction in leukocyte count and 81% platelet count recovery following filtration. Five WB units were significantly lipemic, with a visible lipid layer appearing after being cold storage overnight. These were more turbid with higher hemolysis compared to non-lipemic units (p = .023). Despite a decrease in platelet count during storage (p < .001), hemostatic function as measured by thromboelastography was maintained for at least 21 days (R time and maximum amplitude; both p < .001). There was a significant increase in PF4, CD62P, and RANTES during cold storage (all p < .001).

Discussion: WB retains hemostatic potential for at least 21 days of cold storage, and with further development, may be suitable for transfusion in Australia. Before implementation in Australia, quality control measures for lipemia and hemolysis would need to be defined as part of our manufacturing processes.