The safety of ABO minor incompatible platelets transfusions using a rapid infuser

Abstract Background Administering platelets through a rapid infuser is proven to be safe. However, the clinical significance of infusing ABO‐incompatible platelets with red blood cells (RBCs) in a rapid infuser remains unclear. There is a theoretical risk that isoagglutinin in the plasma of a platelet unit can interact with RBCs and induce hemolysis. Materials and Methods Seven in vitro studies were performed including five cases (type A RBCs and type O platelets) and two controls (type A RBCs and platelets). Anti‐A titers were measured in platelet units. An RBC unit and a platelet unit were mixed in the rapid infuser reservoir and incubated for 30 min. The primary outcome was the presence of hemolysis based on the following parameters: free hemoglobin concentration, hemolysis check, direct antiglobulin test (DAT), and direct agglutination. Results The post‐mix DAT was positive for IgG in all test samples (5/5), and weakly positive for complement in 3/5. The changes in free Hb in test cases between measured and calculated post‐mix spanned −2.2 to +3.4 mg/dL. Post‐mix hemolysis check was negative in 3/5 and slightly positive in 2/5 cases, with no significant differences compared to the control case. Anti‐A titers ranged from 16 to 512 and were not associated with hemolysis. All samples were negative for direct agglutination. Conclusion Our study suggested that mixing ABO‐incompatible platelets with RBCs in a rapid infuser does not induce in vitro hemolysis. These findings support the use of rapid infusers regardless of platelet compatibility in support of hemostatic resuscitation.