Use of X-rays to prevent transfusion-induced graft-versus-host disease

Abstract

Transfusion associated graft versus host disease (TA-GvHD) is a rare complication of transfusion treatment with blood products containing viable lymphocytes. The risk of developing TA-GvHD depends on number and sustainability of lymphocytes in blood product, host’s immune system reactivity and the difference in human leukocyte antigen (HLA) system between donor and recipient. Standard method of TA-GvHD prevention is irradiation of blood products with ionizing radiation and absorbed dose of 25-50 Gy. The aim of irradiation is inactivation of viable lymphocytes in blood product containing cells (red blood cells, platelets, granulocytes) and lymphocyte proliferation inhibition in blood product recipient. In the last two decades, gamma irradiation has been extensively abandoned and replaced with specially designed cabinet machines using X-ray irradiation which are suitable for hospital and blood bank use. This reduces the risk of accidental or deliberate misuse of radioactive source, solves radioactive waste disposal issues and reduces ionizing irradiation exposure of employees in blood establishments. In Blood Bank of Croatian Institute of Transfusion Medicine, X-ray irradiation of blood products has been carried out since 2014 with a year rate of 20,000 irradiated cell blood products used in treatment of patients at risk of developing TA-GvHD.