Red blood cell microvesicles: a storage lesion or a possible salvage mechanism

Erythrocyte concentrates are the major labile blood products used for transfusion worldwide. Erythrocyte concentrates are stored at 4°C for up to 42–49 days in additive solutions. This storage induces cellular lesions, which include alterations in red blood cell (RBC) metabolism, protein content and rheological properties. The impact of these storage lesions is intensely debated, because transfusion-related clinical adverse outcomes have been associated with the age of erythrocyte concentrates. Although altered red blood cell metabolism and early rheological changes are reversible with one transfused, oxidized proteins cannot be repaired. Thus, some irreversible damage might affect the quality of the blood product and the efficiency of the transfusion. In vivo, red blood cells are constantly exposed to oxygen fluxes but are well equipped to deal with oxidative challenges. Moreover, erythrocytes can eliminate oxidized proteins by capturing them in microvesicles, which are subsequently shed into the medium. This review discusses some biochemical aspects of RBC storage and microvesiculation.