Red cell storage lesion: The potential impact of storage-induced CD47 decline on immunomodulation and the survival of leucofiltered red cells

Red blood cells undergo major biochemical and biomechanical changes during storage that could effect their post transfusion performance [Hogman CF, Meryman T. Storage parameters affecting red blood cell survival and function after transfusion. Transfus Med Rev 1999;13:275-96; Tinmouth A, Chin-Yee I. The clinical consequences of the red cell storage lesion. Transfus Med Rev 2001;15:91-107]. Biochemical effects include changes in 2,3-diphosphoglycerate (2,3-DPG), ATP, and calcium levels, as well as metabolic modulation and release of Annexin V, a cytosolic component of blood cells, as a global marker of cellular injury and fragmentation [Krailadsiri P, Seghatchian J, Amiral J, Vissac AM, Contreras M. Annexin V, a new marker of platelet storage lesion: correlation with dMPV. Transfus Sci 1997;18:223-26; Seghatchian J, Krailadsiri P. Red cell storage lesion assessed by the levels of potassium, haemoglobin and Annexin V in supernatants. Transfus Apher Sci 2002;26:139-43]. Biomechanical changes include alterations in cellular membrane, shape changes, phospholipid content, phospholipid asymmetry, and antigenic markers. Although the extent of these changes under various storage conditions has been well documented, their clinical effects remain unclear [McLellan S, Walsh TS, McClelland DBL. Should we demand fresh red blood cells for perioperative and critically ill patients? Br J Anaesth 2002;89:537-39; Mclellan S, Walsh TS, McClelland DBL. Anaemia and red blood cell transfusion in the critically ill patient. Blood Rev 2003;17(4):195-208]. In the current era of universal leucodepletion, the immunomodulatory effects of some essential markers such as CD47 and phosphatidyl serine become the focus of interest as highlighted in this manuscript.