Preliminary study of alterations in human red blood cells by irradiation with high energy photons

Introduction: Transfusion-associated graft-versus-host disease can be prevented by treating cellular blood products with gamma irradiation. A wide range of gamma irradiation dose levels are used in routine practice, but gamma irradiation dose of 25 Gy may be required to completely inactivate T cells in Red Blood Cells (RBC) units (Pelszynski, M. et al., 1994). This process decreases the survival of the RBC transfused, so it is crucial to understand the alterations caused by gamma irradiation to the erythrocyte membrane. In previous works, the biochemical and hematological effects of gamma irradiation at different storage periods were studied. It was observed that irradiation of the erythrocytes increases red cells hemolysis and leakage of intracellular potassium (Adams, F. et al., 2015; Yousuf, R. et al., 2018). The mechanisms through which irradiation causes the loss of RBC viability could be related to the primary effects of radiation. Gamma and X-ray Ionizing radiation cause indirect damage through the reactive oxygen species generated by water radiolysis (Anand, A.J. et al., 1997). The reduced deformability of RBC after irradiation could be related to the interaction of the oxygen-derived radicals with the membranes, affecting their mechanical properties and leading to deformability impairment (Kim, Y.-K. et al., 2008). In a recent work (AlZahrani K. et al., 2017), nanoestructural changes in the RBC membrane at different doses of gamma irradiation were observed using atomic force microscopy. The images shown that the roughness of the cell membrane increased dramatically with increasing doses, affecting their biophysical properties. However, more research is needed to understand the effects of gamma irradiation on the mechanical and adhesion properties of RBC. For this reason, in the present work we set out to measure the mechanical and aggregation parameters of human red blood cells exposed to gamma photons in different doses in order to determine the possible alterations due to radiation.