CMV seronegative components

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, but despite leucodepletion reducing both the white cell content and any CMV present, it does not eliminate the risk of CMV transmission.

When should I use this modification?

National guidelines for the use of CMV seronegative components are being developed. The position statement and report prepared by the UK Department of Health’s Advisory Committee on the Safety of Blood, Tissues and Organs (SaBTO) is also a useful reference.

CMV seronegative components are provided to hospitals on request for specific CMV seronegative patients who are at risk for severe CMV disease including:

  • recipients of allogeneic or autologous stem cell, bone marrow or solid organ transplants

  • recipients of highly immunosuppressive chemotherapy (eg, leukaemia or lymphoma)

  • recipients of intrauterine red cell transfusions

  • premature (<1500 g) or immunocompromised neonates

  • pregnant women who require transfusion regardless of CMV status

When CMV seronegative blood components are required, the following recommendations should be followed:

  • Select CMV seronegative components whenever possible

  • If not available, leucocyte depleted components are considered to offer a high level of safety in preventing CMV transmission but are not universally believed to be equivalent to CMV seronegative components

  • Carefully monitor for CMV infection and disease in high risk patients. The additional benefit of leucocyte depletion in preventing transfusion transmitted CMV infection, in the context of the sole use of CMV seronegative components, is unknown.

For further details, consult the Guidelines for Pretransfusion Laboratory Practice (2007).