Impact of G6PD status on red cell storage and transfusion outcomes

There are inter-individual differences in the quality of refrigerator-stored red blood cells (RBCs). Possible sources of these variations include nutritional and genetic factors. Glucose-6-phosphate dehydrogenase (G6PD) deficiency, the most common enzyme deficiency worldwide that affects the ability of RBCs to respond to oxidative stress, has been implicated as a genetic factor that affects the quality of stored RBCs. This review considers the literature concerning G6PD-deficient RBCs. It discusses RBC unit variables such as in vitro storage, 24-hour post-transfusion recovery (PTR), post-transfusion survival, and post-transfusion clinical outcomes.There are several differences in the in vitro storage characteristics between G6PD-deficient and G6PD-normal RBCs. Recent studies identified differences in the pathways related to glycolysis, purine metabolism, glutathione homeostasis, and fatty acid metabolism. In vitro experiments modelling the transfusion of G6PD-deficient RBCs, as well as autologous PTR studies in vivo, demonstrate increased haemolysis and decreased PTR, respectively, both indicators of a decrease in quality as compared to G6PD-normal RBCs. Finally, studies transfusing G6PD-deficient and G6PD-normal RBCs show that, in certain clinical settings, G6PD-deficient RBCs are associated with increased haemolysis.In summary, G6PD deficiency is associated with a decrease in the quality of RBCs after storage and its impact is often under-estimated. Understanding the underlying mechanisms by which G6PD deficiency affects RBC storage and transfusion outcomes may provide important clues to help optimise the future efficacy and safety of transfusions.