Some red cell and platelet donations (from donors previously testing Cytomegalovirus (CMV) negative and new donors) are screened by the Blood Service for the presence of CMV antibodies to provide a CMV seronegative inventory of cellular components.
As transmission of CMV disease is associated with cellular components, donations manufactured into fresh frozen plasma, cryoprecipitate and other plasma-derived blood components do not require CMV screening.
All cellular products in Australia are leucodepleted. Neither leucodepletion nor seronegativity for CMV completely eliminates risk of CMV transmission. Some data suggest CMV seronegative components and leucodepleted components have equivalent risk of CMV transmission. Whether using a combination of leucocyte depletion and CMV-seronegative components provides any additional safety benefits is unknown. For at-risk patients early detection of CMV infection by polymerase chain reaction (PCR) monitoring should be considered.
When should I use this modification?
CMV seronegative products should be used for the following clinical indications:
Pregnant women regardless of CMV status who require regular elective transfusions during pregnancy (but not during delivery);
Recipients of intrauterine transfusions IUT;
Neonates (up to 28 days post expected date of delivery) and
- Granulocyte transfusions for CMV negative patients.
For other groups, the use of CMV negative or leucodepleted blood products (i.e. CMV safe), will be dictated by local clinical policies:
Solid organ transplants;
Haemopoietic stem cell transplants (HSCT);
Haematology and oncology patients and
Immunodeficient patients, including those with HIV.
For further details, consult the ANZSBT Guidelines for Transfusion and Immunohaematology and Laboratory Practice (2016).
Guidance on the use of CMV seronegative components and in particular clinical indications for prioritising CMV seronegative blood components in times of supply shortage can be found in the platelet annex of the National Blood Supply Contingency Plan.