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CMV Negative Blood Components

Transfusion acquired CMV is of little concern in immunocompetent individuals, but can be a serious problem in immunocompromised patients. In the latter group of patients, CMV transmission can result in pneumonitis, chronic hepatitis, gastroenteritis, chorioretinitis, or disseminated disease. CMV negative blood components are indicated for patients in the first two groups in the table below. Indications for CMV negative units have not yet been well established for the third group of patients.

Indications for the Transfusion CMV Negative Products

Established Indications

1. All fetal and intrauterine transfusions
2. Low birth weight premature infants born to CMV seronegative mothers
3. CMV negative recipients of organ, peripheral blood stem cell or bone marrow transplants from CMV negative donors.
4. Antepartum transfusions for CMV negative women.

Less Well Established Indications

1. CMV negative patients with HIV
2. CMV negative patients who are potential candidates for autologous or allogeneic bone marrow transplant.
3. CMV negative patients undergoing splenectomy
4. Potential seronegative donors for bone marrow transplant.

Unestablished Indications

1. CMV negative BMT recipients from CMV positive donors
2. CMV positive BMT recipients
3. CMV negative solid organ transplants from CMV positive donors
4. CMV positive recipients of solid organ transplants

Depending on need, a blood center screens a certain percentage of donated units for CMV IgG and IgM antibody. ISBT labelling of products uses the term "CMV Antibody Status" to distinguish whether units have been tested and/or have been found positive or negative for anti-CMV antibodies. Labelling a unit as seronegative indicates that the unit does not contain antibodies against CMV. CMV seronegative donors are presumed to be free of CMV infection. The use of CMV negative blood does not entirely eliminate the risk of transfusion transmitted CMV infection because a donor with a recent infection could harbor virus in their plasma or white blood cells even though they test negative for antibodies. The window period for CMV infection is estimated to be 6 to 8 weeks in duration.

Seronegative donors serve as a continuous supply of CMV negative products. The CMV status of these donors is reconfirmed with each donation. Administration of CMV negative units is the same as regular units of red blood cells and platelets.