Transfusion medicine handbook

4. Blood Components

4.6 Irradiation

Transfusion-associated graft-versus-host-disease (TA-GvHD) is a rare but usually fatal complication of transfusion. The risk associated with an individual transfusion depends on the number and viability of contaminating lymphocytes, the susceptibility of the patient's immune system to donor lymphocyte engraftment (primarily related to the degree of T-cell immunosuppression) and the degree of immunological incompatibility between donor and patient.

Cellular components, with the exception of thawed haematopoietic progenitor cells (HPC) intended for transplantation, must be irradiated to prevent TA-GvHD in at-risk patients.  It should be noted that all platelet units in New Zealand are irradiated routinely. Frozen plasma components and fractionated products do not require irradiation.

The following tables 4.2 to 4.5 summarise the clinical indications for blood component irradiation according to the Australian and New Zealand Society for Blood Transfusion, and the British Society for Haematology [1] [2]. ANZSBT have flowcharts which can be helpful in decisions about irradiation [1].

It should be noted that these are tables are based on guidelines and individual cases may warrant their own assessment of risk and benefit.

Table 4.2: Definite Clinical Indications for Use of Irradiated Blood Components [2]

Table 4.3: Possible Clinical Indications for Use of Irradiated Blood Components

Table 4.4: No Clinical Indication for Use of Irradiated Blood Components

Table 4.5: Recommendations on Duration of Use of Irradiated Blood Components [2]