grouP O wholE blooD : storagE leSion impacT And infLammation

Hemorrhage is one of the main causes of preventable death among soldiers in combat. Currently, the majority of patients receive blood components (red blood cells, platelets, plasma) rather than whole blood. These factors lead doctors deployed on external operations (OPEX) to use plasma, RBCs and platelets. However, platelet concentrates may not be available on missions, as their storage conditions and shelf life are not always compatible with OPEX logistics. The only solutions to this problem is to use group O leucocyte-depleted whole blood without hemolysin (or Low Titer O Whole Blood, LTOWB), which provides the three elements in physiological proportions. However, while studies have shown this product to be effective in stopping bleeding, its inflammatory potential, linked to the presence of platelets, has not yet been investigated. Indeed, in addition to their hemostatic role, platelets are also involved in inflammation. The main objective of our research project is to deploy in vitro and in vivo tools to compare LTOWB, focusing on its inflammatory component with conventional and well-mastered transfusion products for (1) platelet-related inflammation (LTOWB vs. Buffy coat pooled platelet concentrate or single donor apheresis platelet concentrates), (2) RBC-related inflammation (LTOWB vs. RBC concentrates) and (3) other circulating inflammatory molecules (LTOWB vs. fresh frozen plasma). The definition of biomarkers is essential to optimize the use of these products, depending on the therapeutic indication. Linking these biomarkers with the effectiveness of transfusions will help to determine the risk/benefit ratio of transfusions that may be required in rural and austere environments, such as OPEX in comparison to civilian transfusion medicine.