ABO-incompatible platelets are associated with increased transfusion reaction rates

BACKGROUND ABO compatibility can affect platelet transfusion safety and efficacy, and ABO-incompatible (ABOi) platelets likely increases the risks of transfusion reactions though the magnitude of this risk is unclear. STUDY DESIGN AND METHODS Data collected on all platelet transfusions administered over 36+ months were classified based on patient and product ABO blood group type and merged with a data set that included all transfusion reactions reported during that period. The transfusion reaction rates among various subsets was calculated. RESULTS In patients greater than 1 year of age, the transfusion reaction rate in the ABO-compatible (ABO-identical) platelet group was 1.0%, while the ABOi platelet group had an elevated reaction rate of 1.7%. The increased reaction rate for ABOi platelets held true even if the analysis were limited to Centers for Disease Control and Prevention/National Healthcare Safety Network qualifying reactions or just allergic or febrile nonhemolytic reactions. The increased reaction rate with ABOi platelets was independent of unit age. Surprisingly, major-incompatible transfusions (A/B antigen incompatible) had the highest rate of reactions, at 2.0%. During the study period, three acute hemolytic reactions were reported out of 2522 plasma-incompatible platelet transfusions (0.12%). CONCLUSIONS Our results find that compatible platelet transfusions have the lowest rate of transfusion reactions. While hemolytic reactions were observed with plasma-incompatible transfusions, the rate was low. Transfusion of ABO antigen-incompatible platelets had the highest rate of transfusion reactions and resulted in a transfusion reaction rate 1.5 to 2 times that of ABO compatible transfusions.