Associations of Blood Donor and Product Characteristics with Platelet Transfusion Outcomes

To understand the impact of blood donor and product characteristics on platelet transfusion outcomes, we linked these variables with recipients of single-unit apheresis derived platelet products between 6/1/2020 and 3/31/2022. We used multivariable logistic regression to examine associations between donor and product characteristics on post-transfusion platelet counts and 24-hour red blood cell (RBC) transfusion events in 2,808 transfusion recipients who received one or more platelet transfusions (n=8,207 units). Post-transfusion platelet increments greater than 20 x 109/L and RBC transfusion within 24 hours occurred following 24.9% and 37.7% of platelet transfusion events, respectively. After multivariable adjustment, donor variables, including increasing body mass index (BMI), platelet unit concentration, and elevated SARS-CoV-2 nucleocapsid antibody levels, were associated with increased odds of recipient platelet increments greater than 20 x 109/L; while pathogen reduction, storage in platelet additive solution (PAS), platelet splits, and platelet storage between 5 and 7 days were associated with reduced odds. In parallel, increasing donor BMI and elevated SARS-CoV-2 nucleocapsid antibody levels were associated with lower odds of 24-hour RBC transfusion events. In contrast, pathogen reduction and irradiation were associated with increased odds of RBC transfusion, whereas longer storage, storage in PAS, and platelet unit concentration and splits were not associated with changes in RBC transfusion events. In conclusion, blood donor and product characteristics are predictors of changes in platelet counts and RBC requirements following platelet transfusion. Future studies examining the impact of blood donor and product characteristics on platelet function could be used to optimize platelet transfusion practice.