Serial assessment of biochemical changes in irradiated red blood cells.

BACKGROUND: Transfusion associated graft vs host disease (TA-GVHD) is delayed effect of blood component therapy with a very high mortality rate. The use of irradiated blood components is the only proven method to prevent TA-GVHD in susceptible patients.

AIM: Our study was designed to analyze the quality of irradiated PRBCs in terms of their biochemical parameters during a storage period up to 28 days post irradiation.

METHODS: A total of 80 PRBC units were analyzed, 40 units each stored in CPDA-1 and additive solution-SAGM. The units were evaluated serially for the following biochemical parameters, plasma/ supernatant potassium, sodium, pH, glucose, lactate, plasma/supernatant hemoglobin and red cell ATP. We further evaluated the differences in these parameters between units irradiated on day 1 and day 7 of storage and stored these units up to 28 days and 35 days respectively. Ten units in each group were used as control. The assessment was done at weekly intervals from the day of irradiation.

RESULTS: Within each group of red cells, there was a rise in mean concentration of plasma potassium (K(+)) from day 1 to last day of storage. There was a highly significant difference (P<0.01) between irradiated and control units after first week of storage in both types of PRBCs. Irradiated CPDA-1 PRBC had significantly higher (K(+)) than irradiated SAGM PRBC. Intergroup comparison revealed significantly higher (P<0.05) mean hemoglobin in irradiated CPDA-1 PRBC as compared to SAGM PRBC. The mean pH was significantly higher (P<0.05) in irradiated CPDA-1 PRBC as compared to irradiated SAGM PRBC only on day 7 of storage. ATP levels significantly decreased in irradiated units as compared to control units. SAGM PRBCs had significantly higher (P<0.05) mean ATP concentration than CPDA-1PRBCs.

CONCLUSION: Our study demonstrates that SAGM-PRBCs show better stability after irradiation compared to CPDA-1 PRBCs. The limits of safety for CPDA-1 PRBCs appear to be two weeks after irradiation. SAGM-PRBCs on the other hand show acceptable limits of safety up to three weeks of irradiation. The shelf life of irradiated PRBCs may vary depending upon the storage solution and day of irradiation.