Irradiated components
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.
When should I use this modification?
Irradiate blood components for the prevention of TA-GVHD. The following groups of patients should get irradiated components:
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recipients of intrauterine transfusion
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neonates who have previously received intrauterine transfusions
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patients with congenital immune deficiencies, Hodgkin’s disease or receiving purine analogue drugs
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recipients of stem cell or bone marrow transplants
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patients with aplastic anaemia receiving immunosuppressive therapy
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recipients of directed donations from family members
- recipients of HLA-compatible single donor platelets and granulocyte transfusions
Side effects and hazards
Gamma irradiation of red cells increases the rate of efflux of extracellular potassium. Take into account 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 and within 48 hours of irradiation for paediatric transfusion.
For further details, consult the Guidelines for Gamma Irradiation of Blood Components (2003).
