Irradiated blood components are used to prevent Transfusion-associated graft-versus host disease (TA-GVHD) the primary cause of which is proliferation and engraftment of transfused donor T-lymphocytes in the bone marrow of susceptible recipients.
The minimum expected dose of irradiation is 25 Gy and no part of the component should receive more than 50 Gy.
Red cells may be irradiated at any time up to 14 days after collection, and thereafter stored for a further 14 days from the date of irradiation.
Platelets can be irradiated at any stage in their shelf-life and thereafter stored up to their normal 7 day expiry.
Granulocytes should be irradiated as soon as possible after manufacture, and thereafter transfused with minimal delay.
Side effects and hazards
Ionising irradiation of red cells causes an increase in the level of extracellular potassium. The clinical significance of the potassium load depends on the speed and volume of the transfusion, as well as the age of the blood.
Blood for intrauterine and exchange transfusion should be used within 24 hours of irradiation.
When should I use irradiated components?
The following tool provides health professionals with guidance on the use of irradiated cellular components. This guidance, which is based on current national guidelines, may not be appropriate in all patient situations, and individual circumstances or evolving best clinical practice may dictate an alternative approach.