Influence of early irradiation on in vitro red blood cell (RBC) storage variables of leucoreduced RBCs in additive solution SAG-M.

Background: The only accepted way to avoid transfusion-associated graft-versus-host disease is irradiation of blood components. With respect to irradiation and associated storage time, different recommendations exist. We examined early irradiated (day +3) leucoreduced red blood cell units for irradiation-associated damages during storage.
Study Design and Methods: We studied 80 leucoreduced units from two manufacturers. All RBCs were stored in the additive solution saline-adenine-glucose-mannitol (SAG-M) and leucoreduced on collection day. Forty components were irradiated on day +3 with 30 Gy, 40 served as non-irradiated controls. Samples were drawn and analysed from these 80 units on days +3, +7, +14, +21, +28, +35 and +42.
Results: From day +14, there was a significant difference in the in vitro haemolysis rate between the non-irradiated and the irradiated components. Two of the irradiated units showed a haemolysis rate over the recommended limit of 0·8% on day +42. Potassium and lactate dehydrogenase activity increased faster in irradiated groups during storage.
Conclusions: Our findings show that leucoreduced RBCs which are irradiated early after collection show an obvious radiation damage over storage period. Interestingly, on days +28, +35 and +42 the quality of RBCs which were irradiated on day +3 was nearly identical to the quality of RBCs which were irradiated on day +14 in a former series. Early irradiation does not cause more damage of RBCs during subsequent storage than irradiation on day +14. The maximum storage period of irradiated RBCs should remain restricted to 28 days from collection, however independently from the day of irradiation within this period.
(© 2015 International Society of Blood Transfusion.)