Effects of gamma irradiation on red cells from donors with sickle cell trait

BACKGROUND: Transfusion-associated graft-versus-host disease can be prevented by gamma irradiation of blood components. Red cells (RBCs) from sickle cell disease patients may exhibit oxidative changes of RBC membranes due to the instability of hemoglobin (Hb) S. Persons with sickle cell trait are eligible to donate blood, and 35 to 45 percent of their total Hb is Hb S. The effect of gamma irradiation on RBCs from such persons is of interest. STUDY DESIGN AND METHODS: RBCs from 12 donors with sickle cell trait (Hb AS) and from 12 with normal Hb (Hb AA) were studied. Each of the 24 RBC units was divided equally into two transfer bags via a sterile connecting device. One bag from each RBC unit received a 2500-cGy dose of gamma irradiation at its mid-plane and was stored at 4 degrees C; the second set of bags was stored without irradiation. For RBCs from 6 donors with Hb AS and 6 donors with Hb AA, units were irradiated on Day 7 and studied on Day 35 of storage (Group 1). For the RBCs from the other 6 donors with Hb AS and the other 6 donors with Hb AA, units were irradiated on Day 28 and studied on Day 42 of storage (Group 2). RESULTS: For Group 1 and Group 2, plasma potassium and plasma Hb concentrations were significantly higher and RBC ATP concentrations were slightly lower in the irradiated units than in the nonirradiated units. In Group 1 and Group 2, there were no significant differences in the plasma potassium or RBC ATP concentrations in either the irradiated or the nonirradiated units of RBCs from donors with Hb AS and donors with Hb AA. Plasma Hb concentrations were consistently lower in the units from donors with Hb AS, whether or not they were irradiated. However, in both groups, proportionally similar changes in plasma Hb concentration were detected when the irradiated Hb AS and Hb AA units were compared to nonirradiated Hb AS and Hb AA units. CONCLUSION: Gamma irradiation of RBCs from donors with Hb AS or with Hb AA resulted in comparable changes in plasma potassium, RBC ATP, and plasma Hb concentrations, although donors with Hb AS had lower plasma Hb. RBCs from donors with Hb AS subjected to 2500 cGy of gamma irradiation did not evidence a storage lesion greater than that seen in RBCs from donors with Hb AA.