Dosing and uses of CMV negative blood and components
CMV-Reduced-Risk
Please see specific component monograph (i.e., RBCs, Platelets, Whole Blood, or Granulocytes) for dosing
Other Indications & Uses
“CMV-reduced-risk” such as CMV seronegative or leukocyte reduced cellular blood products decrease risk of transfusion transmitted symptomatic CMV infection in recipients that are CMV naïve and profoundly immunocompromised. Please check with your blood bank to discuss your institutions standard protocols for the use of CMV seronegative blood products. The indications for choosing CMV seronegative products versus leukocyte reduced CMV unknown products are controversial and vary among institutions.
At-risk recipients include
- Pregnant women and their fetuses (to prevent congenital CMV)
- Low birthweight infants
- Hematopoietic progenitor cell transplant recipients
- Solid-organ transplant recipients
- Severely immunosuppressed patients
- Congenital immunodeficiency patients
- HIV-infected patients
Pediatric dosage forms and strengths
CMV-Reduced-Risk
Please see specific component monograph (i.e., RBCs, Platelets, Whole Blood, or Granulocytes) for dosing
CMV negative blood and components adverse (side) effects
Frequency not defined
Hemolytic Transfusion Reactions
Febrile Non-Hemolytic Reactions
Allergic Reactions ranging from urticaria to anaphylaxis
Septic Reactions
Transfusion Related Acute Lung Injury (TRALI)
Circulatory Overload
Transfusion Associated Graft Versus Host Disease
Postransfusion Purpura
Warnings
Contraindications
Please see component specific contraindications.
Cautions
CMV seronegative blood products do NOT prevent all cases of symptomatic CMV infection. The studies comparing the effectiveness of using CMV seronegative versus leukocyte reduced cellular products to reduce symptomatic CMV infection from transfusion have been an area of great debate over the last decade. Overall both methods effectively decrease the risk of CMV transmission (>90% risk reduction). Although it would seem that providing products that are both leukocyte reduced and CMV seronegative would decrease the risk even more, there are no documented data that supports this approach and there are limited reports that would argue against this.
By adulthood, most individuals have been exposed to CMV and are thus CMV seropositive. Up to 85% of the population is CMV seropositive by the age of 40 depending on geographic region. Therefore CMV seronegative units are often not available in large quantities and may not even be kept in stock at your institution. Waiting for CMV seronegative components can cause significant delays in transfusion and leukocyte reduced components may need to be considered if transfusion is urgent and CMV seronegative components are not readily available.
All transfusions must be given via blood administration sets containing 170- to 260-micron filters or 20- to 40-micron microaggregate filters even if the unit was previously leukocyte reduced via filtration. Additional filtration is not needed when transfusion is given via a bedside leukocyte reduction filter. No other medications or fluids other than normal saline should be simultaneously given through the same line without prior consultation with the medical director of the blood bank.
Patient’s should be monitored for signs of a transfusion reaction including vitals pre, during, and post transfusion.
Please see specific component monograph for full safety information.
Consult with blood bank medical director or hematologist if you have questions regarding special transfusion requirements.
Pregnancy and lactation
CMV-negative or CMV reduced risk (leukocyte reduced) RBCs should be used in pregnant women who are CMV-negative or whose CMV status is unknown. Consult with your blood bank medical director regarding your institutions policy for reducing CMV transmission in this population.
Pregnancy categories
A: Generally acceptable. Controlled studies in pregnant women show no evidence of fetal risk.
B: May be acceptable. Either animal studies show no risk but human studies not available or animal studies showed minor risks and human studies done and showed no risk.
C: Use with caution if benefits outweigh risks. Animal studies show risk and human studies not available or neither animal nor human studies done.
D: Use in LIFE-THREATENING emergencies when no safer drug available. Positive evidence of human fetal risk.
X: Do not use in pregnancy. Risks involved outweigh potential benefits. Safer alternatives exist.
NA: Information not available.
Pharmacology of CMV negative blood and components
Please see specific component monograph.
Mechanism of action
Donors are tested for antibodies directed against CMV and if absent are labeled as CMV seronegative. Not all donors are tested for CMV status because it is cost prohibitive and blood donor centers have various approaches for CMV testing strategies depending on their donor and recipient populations. The blood components without “CMV seronegative” label are generally considered to be “CMV untested”.
Please see specific component monograph for full mechanism of action.
