[Abstract] [Objective] To analyze the production of platelet antibodies in children with congenital heart disease, identify the types of antibodies, and explore their effects on platelet count, coagulation function and platelet function. [Methods] A retrospective analysis was conducted on 3 504 congenital heart disease patients without a history of blood transfusion who were treated at Beijing Children's Hospital between January 2019 and June 2024 to study the positive rate of platelet antibodies. Platelet antibody types were detected using the solid-phase agglutination method, and the platelet count and coagulation function of the children were analyzed. The impact of platelet antibodies on platelet function was evaluated using a coagulation and platelet function analyzer. [Results] The positive rate of platelet antibody in children with congenital heart disease with no history of blood transfusion was 9.7% (341/3 504), higher than the overall positive rate of 6.6% (2 657/40 311) in the general pediatric population. The platelet antibodies in congenital heart disease cases with positive platelet antibodies were mainly autoantibodies. There was no significant difference in platelet count between antibody-positive children and antibody-negative children. However, the prothrombin time (s) of antibody-positive children was significantly longer than that of antibody-negative children[(12.19±1.07) vs (11.32±0.77)]. Platelets sensitized by antibodies showed a significant reduction in function compared to non-sensitized platelets. [Conclusion] Children with congenital heart disease have a high rate of positivity for autoantibodies, which are associated with abnormalities in coagulation function and can lead to reduced platelet function.

【Objective】 To investigate the transfusion effect of 0.5-dose of apheresis platelet in pediatric patients. 【Methods】 A total of 195 children who underwent 0.5-dose platelet transfusion from August 2021 to June 2022 were enrolled, and the platelet count within 24 hours before and after platelet transfusion were recorded. They were grouped by gender, disease type, blood product transfusion history, platelet antibody results, platelet storage time and weight to analyze the effect of platelet transfusion. 【Results】 Among 195 cases, 77.4% (151/195) were effective and 22.6% (44/195) were ineffective after 0.5-dose of platelet transfusion. Platelet transfusion more than three times has significant impact on the effectiveness of platelet transfusion, with platelet transfusion efficiency decreased from 80.8% to 65.9% (P<0.05), and CCI decreased from 11.56±8.94 to 8.52±8.42 (P<0.05). The transfusion effect of the HLA and HPA antibodies positive group was significantly lower than the negative group, with CCI decreased from 11.39±8.87 to 7.82±8.59 (P=0.05). Linear regression analysis showed that the effect of platelet transfusion decreased with the increasing of platelet storage time (P<0.05), and the effect of platelet transfusion decreased in children weighing less than 20 kg compared with those weighing more than 20 kg, with the effective rate decreased from 84.1% to 63.5% (P<0.05). Different gender, disease type and the number of red blood cell transfusions had no significant effect on platelet transfusion. 【Conclusion】 The 0.5-dose platelet transfusion has good therapeutic effect in children below 20 kg. The results of HLA and HPA antibodies and the number of platelet transfusions greatly influence the effect of platelet transfusion in children, and the transfusion effect decreases with the increase of platelet storage time.