Abstract
γ-ray or X-ray irradiation of blood products is a common method to decrease the risk of posttransf usion graft versus host disease. To verify the effects of γ irradiation on the immunoavailability of stored peripheral blood, subsets of mononuclear cells were examined after
γ irradiation. Peripheral blood cells were suspendend in mannitol-adenine-phosphate solution, then immediately irradiated with 15 Gy of γ-rays. Cells were counted and flow cytometric analysis was performed immediately after irradiation (day 0) and after 4 days of storage at 4°C (day 4) . By day 4 γ irradiation had decreased the number of white blood cells by 22.2±6.7 %, lymphocytes by 21.3±5.0%, CD3-positive cells by 29.6±7.2%, CD19-positive cells by 31.4±5.8%, CD4-positive cells by 30.3±4.1%, CD8-positive cells by 20.7±4.6%, and CD16-positive cell by 27.5±8.6%. The ratio of CD4-positive cells to CD8-positive cells was decreased by 11.7±3.6% after γ irradiation. In nonirradiated blood, the decrease was 2.7±7.3%. The present study shows that γ irradiation suppresses the immunoavailability of blood products. p<0.05
