Pre-storage leucoreduction of platelet concentrates reduced biological response modifier concentrations and TRALI incidence in an in vivo sheep model.

Transfusion-related acute lung injury (TRALI) is a potentially fatal transfusion reaction. It can be caused by the transfusion of proteins, lipids, and extracellular vesicles that accumulate in blood components during routine storage and are collectively referred to as biological response modifiers (BRMs). It has been suggested that leucoreduction might reduce TRALI risk by limiting the accumulation of leucocyte-derived BRMs; however, there are conflicting data from haemovigilance reports and animal models regarding this. We harvested supernatant (SN) from leucoreduced buffy coat pooled platelet concentrates (PCs) at days 2, 5, or 7 (n = 25 each). The SNs from each time-point were pooled, aliquoted, and frozen. Similar SN pools collected from non-leucoreduced PCs in a previous study were also used. The PC SN pools underwent analyses for protein, extracellular vesicle and lipid BRMs. The leucoreduced PC SN pools were also transfused to lipopolysaccharide-treated sheep for TRALI assessment (n = 7 per group), with a further four sheep receiving saline infusion as a control. Leucoreduction limited storage-related accumulation of several potential BRMs. This was associated with a lower incidence of TRALI compared to our previous study using non-leucoreduced PC SN. Sheep who developed TRALI had lower plasma levels of interleukin-10, providing further evidence that it may play a protective role against TRALI development.