QUALITY OF IRRADIATED RED BLOOD CELL COMPONENTS DURING 42 DAYS OF STORAGE AFTER COLLECTION

: The shelf-life of red blood cell (RBC) components in mannitol-adenine-phosphate additive solution was previously set at 42 days, but this was shortened to 21 days in 1995 due to the risk of bacterial contamination. Apart from this risk of bacterial contamination, however, the quality of current non-irradiated RBC components is assumed to be accept-able for usage up to 42 days after collection. If the quality of current irradiated RBCs beyond storage for 21 days is comparable to that of non-irradiated RBCs on Day 42, the shelf life of irradiated RBC components may be extended. Here, we compared the quality of irradiated and non-irradiated RBCs on storage for 42 days. The increase in hemolysis and decreases in ATP concentration and deformability during storage were greater in irradiated than non-irradiated RBCs. Nevertheless, levels in irradiated RBCs up to 35 days were superior or equal to those in non-irradiated RBCs on Day 42. Irradiation did not effect CD47 or phosphatidylserine expression on RBCs, nor RBC mi-croparticle production. In contrast, it enhanced the increase in supernatant potassium concentration by storage. These results suggest that the shelf life of irradiated RBC components may be extended up to 35 days, with atten-tion to increases in supernatant potassium concentration.