Transfusion‐related adverse events in the P latelet D ose study

Background How platelet ( PLT ) product characteristics such as dose, source (whole blood derived [ WBD ] vs. apheresis), storage duration, and ABO matching status affect the risks of transfusion‐related adverse events ( TRAE s) is unclear. Similarly, more information is needed to define how recipient characteristics affect the frequency of TRAEs after PLT transfusion. Study Design and Methods In the multicenter P latelet D ose (“ PLADO ”) study, pediatric and adult hematology‐oncology patients with hypoproliferative thrombocytopenia were randomized to receive low‐dose ( LD ), medium‐dose ( MD ), or high‐dose ( HD ) PLT prophylaxis for a pretransfusion PLT count of not more than 10 × 10 9 / L . All PLT units (apheresis or WBD ) were leukoreduced. Post hoc analyses of PLADO data were performed using multipredictor models. Results A total of 5034 PLT transfusions to 1102 patients were analyzed. A TRAE occurred with 501 PLT transfusions (10.0%). The most common TRAE s were fever (6.6% of transfusions), allergic or hypersensitivity reactions (1.9%), and sinus tachycardia (1.8%). Patients assigned HD PLTs were more likely than LD or MD patients to experience any TRAE (odds ratio for HD vs. MD , 1.50; 95% confidence interval, 1.10‐2.05; three‐group comparison p = 0.02). PLT source and ABO matching status were not significantly related to overall TRAE risk. Compared to a patient's first PLT transfusion, subsequent PLT transfusions were less likely to have a TRAE reported, primarily due to a lower risk of allergic or hypersensitivity reactions. Conclusion The most important PLT unit characteristic associated with TRAE s was PLT dose per transfusion. HD PLT s may increase the risk of TRAE s, and LD PLT s may reduce the risk.