Blood components that contain viable lymphocytes may be irradiated to prevent the proliferation of T-lymphocytes, which is the immediate cause of Transfusion-associated graft-versus-host disease (TA-GVHD).
The minimum dose achieved in the irradiation field should be 25 Gy with no part receiving greater 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 irradiation.
Platelets can be irradiated at any stage in their 5 day storage and thereafter can be stored up to their normal shelf life of five days after collection.
Granulocytes for all recipients should be irradiated as soon as possible after production, and thereafter transfused with minimal delay.
Side effects and hazards
Gamma irradiation of red cells increases level of extracellular potassium. The clinical significance of this potassium load depends on both the speed and volume of the transfusion, as well as the age of the blood.
Blood should be used within 24 hours of irradiation for intrauterine and exchange transfusion.
When should I use this modification?
The following tool provides health professionals with guidance on situations when the use of irradiated cellular components is appropriate. This guidance may not be appropriate in all patient situations, and individual circumstances may dictate an alternative approach.