Gamma-irradiation of deglycerolized red cells does not significantly affect in vitro quality.

Red cells frozen with glycerol may require gamma-irradiation after thawing and deglycerolization for transfusion to at-risk patients. Both freezing and irradiation are known to cause red cell damage. However, the effect of irradiation on the quality of deglycerolized red cells and the optimal shelf life of such a component is currently unknown. Red cells (<7 days) were pooled, split and glycerolized using an ACP-215 automated cell washer (n = 12 pairs) and frozen at -80°C. Red cells were thawed, deglycerolized and resuspended in SAG-M. One of each pair was gamma-irradiated, while the other served as a control. Products were stored at 2-6°C and sampled for in vitro testing immediately after irradiation, and at 24 and 48 h postirradiation. Irradiation of deglycerolized red cells led to a >1·5-fold increase in extracellular potassium, compared to control units at 24 and 48 h postirradiation. Other parameters, including haemolysis, were not significantly affected by irradiation postdeglycerolization. Deglycerolized, irradiated red cells had increased supernatant potassium, but remained of acceptable quality for 24 h postirradiation.