Platelet transfusion plays an important role in the treatment of hematologic cancers. Transfusion services do not always consider ABO donor-recipient plasma compatibility prior to transfusion. Although most patients do not experience any complications due to this plasma incompatibility, some transfusion recipients experience hemolytic transfusion reactions.
Patients being considered for platelet transfusion are usually very ill and anemic so the typical signs of hemolysis may not be recognized. Furthermore, patients who undergo platelet transfusion in an outpatient setting rarely have their blood counts, bilirubin or other markers of hemolysis tracked post-transfusion. Thus, platelet-mediated hemolytic transfusion reactions may be under reported.
In a recent editorial in the journal Transfusion, Dr. Karen Quillen, a physician at Boston University Medical Center, discussed the risks of hemolytic transfusion reactions and the role of ABO compatibility in the safety and efficacy of platelet transfusions
While transfusion services in the United Kingdom and Germany routinely utilize mitigation strategies such as screening for high-titer ABO antibodies and using ABO-identical platelets as much as possible, no universal strategies have been implemented in the United States.
It is estimated that at a single institution using only apheresis platelets, hemolytic transfusion reactions may occur as often as once in every 2500 platelet transfusions. In the United States, one out of three reported fatal hemolytic transfusion reactions in fiscal year 2011 was due to ABO-incompatible plasma in apheresis platelets. It should also be noted that the total number of transfusion-related fatalities has declined over the last decade.
It is somewhat unclear which factors are predictive of platelet-mediated hemolytic transfusion reactions, but antibody type and titer are likely to play a role. Some transfusion services use threshold values of ABO antibody titers to screen platelet products, but there is no universally accepted threshold.
Two studies published in the journal Transfusion further examined the risk for hemolytic transfusion reactions and potential strategies for mitigation.
Dr. Karafin and colleagues from the Johns Hopkins University found that anti-A and anti-B titers were not predictive of hemolytic transfusion reactions. They also found that the change in hemoglobin level after transfusion was not significantly different between patients receiving plasma-incompatible platelets and those receiving plasma-compatible platelets. However, the study sample and potential underreporting of reactions limited the ability to generalize these results.
Dr. Fontaine and colleagues from Stanford University reviewed their institution’s new policies on reducing the plasma volume of apheresis platelets. Their policies included volume reducing plasma-incompatible group O units for all patients and volume reducing plasma-incompatible units of all blood groups for hematopoietic stem cell transplant recipients. They determined that these new policies increased the total number of plasma reduction procedures fourfold. This substantially increased employee workload, but did not impact the number of platelet products outdated.
Dr. Quillen noted:
“I believe sufficient data exist to justify a call to action to mitigate platelet-mediated hemolytic reactions. There is no single evidence-based intervention since we cannot currently predict with certainty which patients or donors are at high risk. Transfusion services should respect ABO for platelets as much as possible, proactively look for this reaction – and work with their blood suppliers to minimize its occurrence.”
We’ll be back on October 30th with another edition of Transfusion News. In the meantime, you can always keep up to date with the latest information by visiting transfusionnews.com. Thanks for joining us.
References
1. Fontaine MJ, Mills AM, Weiss S, Hong WJ, Viele M, Goodnough LT: How we treat: Risk mitigation for abo-incompatible plasma in plateletpheresis products. Transfusion 2012;52:2081-2085.
2. Karafin MS, Blagg L, Tobian AA, King KE, Ness PM, Savage WJ: Abo antibody titers are not predictive of hemolytic reactions due to plasma-incompatible platelet transfusions. Transfusion 2012;52:2087-2093.
3. Quillen K: Hemolysis from platelet transfusion: Call to action for an underreported reaction. Transfusion 2012;52:2072-2074.
4. FDA Center for Biologics Evaluation and Research. Fatalities Reported to the FDA Following Blood Collection and Transfusion: Annual Summary for Fiscal Year 2011. Accessed at http://www.fda.gov/BiologicsBloodVaccines/SafetyAvailability/ReportaProblem/TransfusionDonationFatalities/ucm302847.htm on September 17, 2012.
