Leukoreduced red blood cell: storage-related complement regulatory proteins and CD47

Background Despite progress in red blood cell (RBC) storage, storage lesions still occur, which lead to complement activation and removal of RBCs from circulation. The aim of this study was to assess the surface concentration of complement regulatory proteins, as well as CD47, on leukoreduced RBCs collected on the atreus device and stored in sodium–adenine–glucose–mannitol medium for 42 days. Materials and methods We studied the surface expression of leukoreduced RBC C3d, CD35, CD55, CD59, and CD47 using flow cytometry on weekly intervals from day 1 to day 42 of storage. Results We observed a nonsignificant increase of surface C3d levels (P=0.146) and a decrease in CD47 overall storage time (P=0.196). There was a significant decrease demonstrated in CD35 (P=0.025), and a strong significant decrease in CD55 in their expression over storage time (P=0.000). Last, a nonsignificant alteration of CD59 was observed (P=0.353). Conclusion The study of atreus-processed leukoreduced RBC units stored in sodium–adenine–glucose–mannitol medium for surface expression of complement regulatory proteins showed its inhibition until toward the end of storage time, and also showed a good preservation of CD47, which was thought to be important in transfused RBC survival. However, more research is potentially needed in areas of complement evaluation during component processing.