Gamma irradiation (GI) can prevent transfusion-associated graft-vs.-host disease, result in a small decrement in 24-h in vivo red blood cell (RBC) recovery and in a minor loss of maintenance of several in vitro parameters during routine storage. Results from studies by Davey et al. (Transfusion 1995, 35, 55S) demonstrated that the decrement in 24-h recovery was not observed if units were first leucoreduced (LR), suggesting that RBC damage on leucocytes from GI was secondary to the effects of irradiation. In this study, we further investigated how leucoreduction affected eight in vitro storage parameters of gamma-irradiated units by using a matched sample study design.
Leucoreduction significantly reduced (P < 0·05) the deleterious effect of GI on adenosine triphosphate glucose levels, haemolysis and mean corpuscular volume (MCV) for AS-3 units and significantly decreased (P < 0·05) the deleterious effect of GI on glucose levels, haemolysis and MCV for AS-1 units. Leucoreduction did not influence (P >> 0·5) the enhanced potassium release associated with GI. Some, but not all, the observed RBC damage caused by GI appears to be secondary to the effect of irradiation on leucocytes. Based on the in vivo survival studies of Davey et al. and the results of this study, there is justification to consider performing additional survival studies to support extended storage of LR gamma-irradiated RBC.