Abstract: ObjectiveTo analyze the positive rate distribution of platelet antibodies in different types of patients and different diseases by screening platelet antibodies in 27, 239 emergent and hospitalized patients, aiming to explore the influencing factors of platelet production. Methods 27, 239 emergent and hospitalized patients who were scheduled for blood reservation or transfusion in Department of Blood Transfusion of the Third Affiliated Hospital of Sun Yat-sen University from June 2020 to June 2024 were selected. Platelet antibody screening was performed using the solid-phase agglutination method. According to the results of platelet antibody detection, the patients were divided into the positive and negative platelet antibody groups. Clinical data between two groups were analyzed. Binary Logistic multivariate regression analysis was used to screen for relevant risk factors for platelet antibody production in patients. ResultsThe overall positive rate of platelet antibodies in 27, 239 patients was 3.91%. The positive rate of platelet antibodies in female patients was significantly higher than that in male counterparts （5.01% vs. 2.41%, P < 0.001）. The positive rate of platelet antibodies in patients in different age groups showed significant differences （χ ²=123.83, all P < 0.001）, with the highest positive rate of 9.19% in children aged ≤10, followed by 5.46% in patients aged 20-40 years. The positive rate of platelet antibodies in patients with a history of blood transfusion was significantly higher than that in patients without a history of blood transfusion （9.07% vs. 3.45%, P <0.001）. In addition, the departments with the highest positive rate of platelet antibodies were the Emergency Department, followed by Department of Hematology, Department of Obstetrics, ICU, and Department of Infectious Diseases. Binary Logistic multivariate regression analysis showed that female, history of blood transfusion, pregnancy, thalassemia, thyroid disease, liver failure, severe pneumonia and thrombocytopenia were risk factors for positive platelet antibody （all P < 0.05）. ConclusionFor female patients, those with a history of blood transfusion, pregnancy, and those diagnosed with thrombocytopenia, liver failure, pneumonia, thalassemia, or thyroid disease, platelet antibody screening should be highly valued before platelet or red blood cell transfusion, aiming to prevent ineffective platelet transfusion and reduce adverse transfusion reactions.