BACKGROUND: Cardiopulmonary adverse events after transfusion include transfusion-related acute lung injury (TRALI) and transfusion-associated circulatory overload (TACO), which are potentially lethal and incompletely understood.
STUDY DESIGN AND METHODS: To determine whether the incidence of TRALI and TACO was affected by leukoreduction we conducted a retrospective, before-and-after study of acute transfusion reactions for the 7 years before and after introduction of universal leukoreduction in 2000, involving 778,559 blood components.
RESULTS: Substantial decreases occurred in the rates of TRALI (−83%; from 2.8 cases per 100,000 components before to 0.48 after universal leukoreduction; p = 0.01), TACO (−49%; 7.4 to 3.8 cases per 100,000; p = 0.03), and febrile reactions (−35%; 11.4 to 7.4 cases per 10,000; p < 0.0001). The incidence of allergic reactions remained unchanged (7.0 per 100,000 before and after universal leukoreduction). These outcomes were primarily attributable to decreased TRALI and/or TACO associated with red blood cell (RBC) and platelet (PLT) transfusions (−64%) with notably smaller decreases associated with fresh-frozen plasma or cryoprecipitate transfusions (−29%). The incidence of TRALI and/or TACO after 28,120 washed RBC and 69,325 washed transfusions was zero.
CONCLUSION: These data suggest novel hypotheses for further testing in animal models, in prospective clinical trials, and via the new US hemovigilance system: 1) Is TACO or TRALI mitigated by leukoreduction? 2) Is the mechanism of TACO more complex than excessive blood volume? and 3) Does washing mitigate TRALI and TACO due to PLT and RBC transfusions?