Chapter 42 - Irradiation of Blood Products

Abstract

Irradiation (or pathogen inactivation) of blood products, by γ-irradiation or X-ray, is performed to prevent transfusion-associated graft-versus-host disease (TA-GVHD). TA-GVHD is a rare and almost universally fatal complication of blood transfusion that has no consistently successful treatment options. It is caused by the infusion of viable lymphocytes that engraft in the recipient and mount an immune response against the host. Irradiation results in the generation of electrons that damage lymphocyte DNA, rendering the lymphocytes unable to proliferate. Because the identification of all individuals at risk of TA-GVHD may not always be successful, some institutions and countries irradiate all cellular blood products (universal irradiation); however, policies for irradiating cellular blood products only for those patients at increased risk for developing TA-GVHD are more common. For irradiation of cellular blood products to be successful in preventing TA-GVHD, the irradiation dose must be sufficient to inhibit lymphocyte proliferation.