Abstract: Objective Analyze the effectiveness and safety of minor ABO incompatible platelet transfusions and ABO compatible platelet transfusions in emergency special cases, and promote a scientific basis for the clinical application of minor ABO incompatible platelet transfusions. Methods ① 24 cases of minor ABO incompatible platelet transfusions were collected as minor ABO incompatible group in emergency special cases from Guangzhou First People's Hospital, Shenzhen Hospital of Integrated Traditional Chinese and Western Medicine, The Second Affiliated Hospital of Guangdong Medical University from January 2013 to June 2023;610 cases of ABO compatible platelet transfusions were collected during the same period, and 24 cases of them with similar characteristics were selected as ABO compatible group using propensity score matching method. The differences were compared in the effectiveness of platelet transfusions, hospitalization days, Liver and kidney function etc between two groups. Analyzed the acute hemolytic transfusion reaction rate of minor ABO incompatible platelet transfusions. ②The minor ABO incompatible platelet transfusions were simulated in blood recipients,the strength of red blood cell agglutination were detected by Saline Medium. Results ①There were no differences in the effectiveness of platelet transfusions between the minor ABO incompatible group and the ABO compatible group, ∆PLT were (18.0±20.2)×10⁹/L, (20.6±15.4)×10⁹/L respectively, t value was 0.51, P=0.61; PPR were (55.4±54.5)%, (61.9±48.9)% respectively, t value was 0.46, P=0.65. ②The hospitalization days, ALT, Cr, IgG, IgM, CD4, CD8 and B lymphocytes of the minor ABO incompatible group were (30.4±17.8) d, (33.0±16.3) U/L, (104.9±64.7) μmol/L, (9.1±2.6) g/L, (1.24±0.83) g/L, (299.3±341.5) cells/μL, (475.7±283.9) cells/μL, (142.8±218.6) cells/μL;the ABO compatible group were (29.5±17.5) d, (31.1±40.5) U/L, (95.6±55.6) μmol/L, (11.8±3.0) g/L, (0.96±0.42) g/L, (397.3±250.9) cells/μL, (622.7±406.6) cells/μL, (190.7±216.6) cells/μL respectively, there were no differences between the two groups, t values were 0.15, 0.01, 0.39, 1.90, 1.03, 0.72, 0.65, 0.21, all P>0.05. ③No acute hemolytic transfusion reactions were reported on 24 cases of minor ABO incompatible platelet transfusions. ④The results of erythrocyte agglutination reaction were negative in simulated type B (or type AB) adults transfused with 1 U A platelet; the results of erythrocyte agglutination reaction were negative in simulated type A (or type AB) adults transfused with 1U B platelet; the results of erythrocyte agglutination reaction were negative in simulated type A (or type B or type AB) adults transfused with 1 U O platelet. Conclusion ①There were no differences in the effectiveness of platelet transfusions between the minor ABO incompatible group and the ABO compatible group. ②In emergency or special cases, no more than 1 U minor ABO incompatible platelet transfusion did not cause acute hemolytic transfusion reaction.

Key words: Platelet, ABO blood group, Minor ABO incompatible, Blood transfusion, Hemolysis, Effectiveness