There is currently a controversy about whether transfusion of stored RBCs results in more transfusion complications, including increased recipient morbidity and mortality, compared with fresh RBCs. The present study investigates the impact of microparticles from stored RBCs in a murine animal model. Mice transfused with microparticles showed substantially increased pulmonary neutrophil accumulation and altered lung histology compared with the control group without microparticles. The authors conclude that microparticles may contribute to neutrophil priming and activation. It remains to be demonstrated whether these experimental data may explain transfusion-associated side effects in humans, including lung injury.

– Rainer Moog