Abstract: Objectives To study the clinical efficacy and safety of ABO incompatible platelet transfusion in emergency situations. Methods 271 cases of ABO incompatible platelet transfusion in our hospital from January 2020 to January 2024 were collected, and 128 cases were enrolled which were divided into bidirectional mismatch group (10 cases), major mismatch group (56 cases), and minor mismatch group (62 cases). All 128 patients had ABO homologous platelet transfusion history before and within 10 days after ABO incompatible platelet transfusion. The incompatible transfusion was set as the ABO blood group incompatible experimental group (subgroup B), the previous ABO homozygous platelet transfusion was set as the ABO homozygous control group (subgroup A), and the subsequent ABO homozygous platelet transfusion was set as the ABO homozygous experimental group (subgroup C). Platelet count change after platelet transfusion (△PLT) and 24 h platelet corrected count Increment (CCI) were used to evaluate the clinical effect of platelet transfusion, and the safety of platelet transfusion was assessed by the presence or absence of hemolytic transfusion reactions. Results In the bidirectional mismatch group, there was no significant difference in △PLT and CCI among subgroups A, B and C (P>0.05). In the major mismatch group, the △PLT and CCI of subgroup B were significantly lower than those of subgroups A and C (P<0.05), but there was no significant difference between subgroup A and C (P>0.05). In the minor mismatch group, there was no significant difference in △PLT and CCI among subgroups A, B and C (P>0.05). There was no acute hemolytic transfusion reactions in any of the ABO incompatibility infusion. Conclusion The clinical effect of ABO major mismatch platelet transfusion is obviously weaker than that of ABO compatible platelet transfusion, but did not affect the outcome of subsequent ABO homozygous platelet transfusion. The clinical effect of ABO minor mismatch platelet transfusion is similar to that of ABO compatible platelet transfusion, but could potentially affect the outcome of subsequent ABO homozygous platelet transfusions. No significant hemolytic transfusion reaction was found by ABO incompatible platelet transfusion.

Key words: ABO incompatible, Platelet transfusion, Clinical efficacy, Safety