Abstract 14891: Removal of Phosphatidylserine Positive Microparticles From Stored Red Cell Units by Washing Ameliorates Inflammation in a Novel in vitro Model of Human TRALI
Background: Allogenic RBC transfusion is associated with an increase in pulmonary morbidity after cardiac surgery. Transfusion of RBC stored for longer periods increases the frequency of this injury. These associations are attributed to the ‘storage lesion’ - accumulation of toxic metabolites in the supernatant and depletion of cellular ATP and 2,3-DPG during storage. We have shown that removal of the storage supernatant and washing of stored RBC attenuates post transfusion acute lung injury (TRALI) in a swine model. The aims of this study were to identify which components of the storage lesion cause TRALI, and are subsequently altered by washing, in a novel in vitro model of lung injury.
Methods: The effects of storage and washing of leucodepleted human RBC (from NHSBT, UK) on inflammatory responses; platelet and monocyte adherence, rolling velocity, oxidative stress, were assessed in a live imaging microfluidics system seeded with human pulmonary endothelial cells and perfused with fresh whole blood.
Results: Administration of human RBC to the in vitro model reproduced our observations in pigs; older blood increased leucocyte and platelet recruitment compared to younger blood. This effect was attenuated by washing, which preserved RBC ATP and 2,3-DPG levels and significantly reduced toxic metabolites. It also significantly reduced amount of phosphatidylserine-positive (PS+ve) microparticles (MP). Since the physical properties of red cells (deformability, osmotic fragility) did not change, we fractionated the RBC supernatant by centrifugation to separate PS+ve MP from soluble toxic components and tested them in the in vitro model (fig.). Our data points towards PS and its receptors (further investigated here) as possible regulators of lung injury following transfusion.
Conclusion: PS+ve MP generated by RBC during storage contribute to inflammation in vitro by platelet and leucocyte activation, which may be attenuated by washing of RBC prior to transfusion.
- © 2013 by American Heart Association, Inc.