Transfusion of γ-irradiated blood components to individuals does not compromise the cytogenetic dose assessment

Most blood components for transfusions are irradiated ex vivo to prevent transfusion-associated graft-versus-host disease (TA-GvHD); this irradiation can potentially affect the cytogenetic dose assessment of patients showing acute radiation syndrome (ARS) with bone marrow suppression or acute anaemia. Whole blood samples from five donors were irradiated with 0, 10 or 25 Gy γ-rays. The mitotic activity of each cultured blood sample was measured by calculating the mitotic index. A dicentric chromosome assay was used to evaluate the chromosomal aberrations and absorbed dose of blood lymphocytes. Mitogenic activity and scorable metaphase spreads were significantly decreased in the blood samples irradiated with 10 and 25 Gy (p < 0.001). Moreover, a significant increase in the mean scores of all types of chromosomal aberrations in the 10 Gy γ-irradiated samples was observed, with the estimated dose being 11.3 Gy (95% CI: 10.67-11.95 Gy); however, we were unable to estimate the exposure dose in the 25 Gy γ-irradiated samples due to a limited number of scorable metaphase spreads. The mitotic index of the 25 Gy γ-irradiated whole blood samples was significantly suppressed by more than 4-log fold. Thus, in the present study, we evaluated the effects of recommended radiation doses in γ-irradiated transplantation blood components using cytogenetic dosimetry. These results suggest that the partial transfusion of blood components to patients with ARS or acute anaemia did not compromise the estimation of the exposure dose using cytogenetic dosimetry.