Should Platelet Transfusion Be Based on Blood Group?
Yes, platelet transfusion should prioritize ABO compatibility whenever possible, as ABO-compatible products optimize platelet increments and minimize hemolysis risk, though strict ABO-identical matching is not absolutely required in all clinical situations. 1
Primary Recommendation
The American Society of Clinical Oncology recommends that ABO-compatible products should be provided whenever possible to optimize platelet increments and minimize hemolysis risk. 1 Transfusing ABO-identical or ABO-compatible platelets is preferred whenever inventory allows. 1
Impact of ABO Incompatibility on Clinical Outcomes
Effects on Platelet Increments
- ABO incompatibility can compromise post-transfusion increments, particularly when group A platelets are given to group O recipients. 2, 1
- ABO-major incompatible transfusions are associated with lower platelet count increments compared to either ABO-identical or minor incompatible transfusions. 3
- Despite reduced increments, ABO-incompatible platelets are still equally effective in preventing clinical bleeding. 4
Hemolysis Risk
- Incompatible plasma from platelet transfusions can cause hemolysis, particularly in children. 1, 5
- ABO-minor incompatible transfusions may rarely result in acute hemolytic reactions that are not predicted by isohemagglutinin titers. 3, 6
- Group O single-donor platelets transfused to non-group O recipients carry particular risk, even with low isohemagglutinin titers. 6
Critical Clinical Scenarios Requiring ABO Compatibility
Assessing Platelet Refractoriness
ABO compatibility is essential when evaluating refractoriness to platelet transfusion. 1 Refractoriness should only be diagnosed after at least two ABO-compatible transfusions stored less than 72 hours result in poor increments (corrected count increment <5,000 or absolute increment <2,000/unit). 2, 1 Do not diagnose platelet refractoriness based on ABO-incompatible transfusions. 1
Massive Transfusion in Trauma
The platelet concentrate transfused must be ABO-identical or at least ABO-compatible to provide good yield in trauma patients requiring massive transfusion. 1
Pediatric Patients
Exercise greater caution with ABO-incompatible platelets in children due to higher hemolysis risk from incompatible plasma. 1, 6
Rh(D) Compatibility Considerations
- Red cell cross-matching is not required for platelet products due to minimal red cell content. 1
- Transfusion of platelets from RhD-positive donors to RhD-negative patients is considered effective and safe, though associated with low rates of anti-D alloimmunization. 4
- Women who are RhD-negative and of childbearing age who are resuscitated with RhD-positive blood or platelets can develop immune anti-D, which can cause hemolytic disease in future pregnancies. 2
- Prevention of D alloimmunization is recommended only for women of childbearing age. 4
Practical Implementation
When ABO-Identical Is Not Available
- Group O RhD-negative is the blood group of choice for emergency transfusion where clinical need is immediate. 2
- It is acceptable to give O RhD-positive red cells to male patients to preserve O RhD-negative stock. 2
- Clinical staff should endeavor to provide immediate blood samples for grouping to allow use of group-specific blood. 2
Inventory Management Challenges
- Adherence to a strict policy of transfusing exclusively ABO-identical platelets may lead to increased product wastage and challenges in maintaining adequate platelet availability. 3
- Available inventory and selection practices often result in the majority of group O patients receiving cellular-incompatible platelet transfusions due to supply-demand mismatch. 7
Evidence Quality and Limitations
No high-quality randomized trials have definitively proven that strict ABO matching improves clinical outcomes such as bleeding or mortality. 1 Published evidence to date does not clearly demonstrate improvements in clinical outcomes for patients receiving ABO-identical versus ABO-compatible platelets. 3 The strongest evidence base comes from American Society of Clinical Oncology guidelines (2001,2018). 1
Key Pitfalls to Avoid
- Do not use ABO-incompatible transfusions when assessing for platelet refractoriness, as this will confound the diagnosis. 2, 1
- Be particularly vigilant when transfusing group O platelets to non-group O recipients due to hemolysis risk. 6
- Do not assume low isohemagglutinin titers eliminate risk in immunosuppressed or transfusion-dependent patients. 6