Which patients receive leucoreduced (white blood cell reduced) blood?

Patients Who Should Receive Leukoreduced Blood

Leukoreduced blood products should be provided to patients with acute myeloid leukemia (AML) from the time of diagnosis, and are likely beneficial for patients with other types of leukemia and cancer patients receiving chemotherapy who require multiple transfusions. 1

Primary Indications for Leukoreduction

Leukoreduction is strongly recommended for:

• Patients with acute myeloid leukemia (AML) receiving induction chemotherapy - high-quality evidence shows reduced alloimmunization and platelet refractoriness 1
• Patients with other types of leukemia receiving chemotherapy - likely beneficial based on expert consensus 1
• Cancer patients receiving chemotherapy who will require multiple transfusions - recommended to prevent alloimmunization 1
• Patients with aplastic anemia or myelodysplasia - consensus recommendation despite fewer direct studies 1

Benefits of Leukoreduction

Leukoreduction provides several important clinical benefits:

• Reduces alloantibody-mediated refractoriness to platelet transfusion 1
• Decreases incidence of febrile non-hemolytic transfusion reactions 1
• Reduces transmission of cytomegalovirus (CMV) infection 1
• May reduce short-term mortality in cardiac surgery patients 2

Patient Selection Considerations

The decision to use leukoreduced blood should consider:

• Expected duration of transfusion support - most beneficial for patients requiring multiple transfusions 1
• Underlying disease - highest benefit in hematologic malignancies 1
• Treatment intensity - patients receiving intensive chemotherapy benefit most 1
• Age and gender - particularly important for younger patients who may need future transfusions 1

Current Practice

In the United States and many other countries, universal leukoreduction has become standard practice:

• Most blood products are now leukoreduced at the time of collection (prestorage leukoreduction) 1
• This eliminates the need for bedside filtration in most cases 1
• Target level is typically <5 × 10^6 leukocytes per unit (99.9% or log 3 reduction) 3

Special Considerations

For patients requiring platelet transfusions:

• RhD-negative children (particularly girls) and women of childbearing age should receive either RhD-negative platelets or anti-D immunoprophylaxis when receiving platelets from RhD-positive donors 1
• This prevents potential RhD alloimmunization from contaminating red blood cells in platelet products 1

Clinical Evidence and Limitations

• The Trial to Reduce Alloimmunization to Platelets (TRAP) demonstrated significant reduction in HLA antibody formation (17-21% vs 45%) and immune-mediated platelet refractoriness (3-5% vs 13%) with leukoreduction 1
• Despite these benefits, only 10-15% of newly diagnosed AML patients might actually benefit clinically from leukoreduction during their treatment course 1
• The quality of evidence for mortality benefit is very low to low in most patient populations 4
• Leukoreduction adds cost to transfusion therapy, which is why it was historically reserved for specific patient populations 1

Implementation Considerations

Modern leukoreduction methods include:

• Prestorage filtration (most common in current practice) 1
• Bedside filtration (less common now) 1
• Apheresis collection techniques 3

These methods can achieve greater than 4 log reduction of white blood cells, effectively preventing the complications associated with leukocyte contamination 3.