Effects of Donor-recipient Sex-matched Blood Transfusion on Patient Outcomes

Red blood cell (RBC) transfusions are selected based upon matching donor and recipient blood group: donor and recipient sex are not considered when selecting blood for transfusion. Hence, transfused patients can currently receive sex-matched and/or unmatched RBCs when transfusions are given. Sex-matched stem cell transplants, and some solid organ transplants, have shown that sex-matching donor to recipient improves patient outcomes. Recent exploratory studies have also suggested that patient outcomes could be improved by sex-matching for RBC transfusion. There is emerging evidence of underlying biologic mechanism(s) to support these observations. This study is designed as a randomized controlled trial and will explore the impact on patients who receive RBC transfusions from donors of the same sex ("sex-matched") compared with donors of the opposite sex ("sex-mismatched"). The trial will study adult patients admitted to the Intensive Care Unit who require an RBC transfusion. Patients will be assigned (through a process called randomization) to receive sex-matched RBCs or sex-mismatched RBCs to determine if there is a difference in mortality between those receiving matched versus mismatched RBCs. The results of this trial could have direct implications on resources, blood inventory, and RBC transfusion ordering practices.