Experimental prestorage filtration removes antibodies and decreases lipids in RBC supernatants mitigating TRALI in vivo.

Transfusion-related acute lung injury (TRALI) remains a significant cause of transfusion-related mortality with red cell transfusion. We hypothesize that prestorage filtration may reduce proinflammatory activity in the red blood cell (RBC) supernatant and prevent TRALI. Filters were manufactured for both small volumes and RBC units. Plasma containing antibodies to human lymphocyte antigen (HLA)-A2 or human neutrophil antigen (HNA)-3a was filtered, and immunoglobulins and specific HNA-3a and HLA-2a neutrophil (PMN) priming activity were measured. Antibodies to OX27 were added to plasma, and filtration was evaluated in a 2-event animal model of TRALI. RBC units from 31 donors known to have antibodies against HLA antigens and from 16 antibody-negative controls were filtered. Furthermore, 4 RBC units were drawn and underwent standard leukoreduction. Immunoglobulins, HLA antibodies, PMN priming activity, and the ability to induce TRALI in an animal model were measured. Small-volume filtration of plasma removed >96% of IgG, antibodies to HLA-A2 and HNA-3a, and their respective priming activity, as well as mitigating antibody-mediated in vivo TRALI. In RBC units, experimental filtration removed antibodies to HLA antigens and inhibited the accumulation of lipid priming activity and lipid-mediated TRALI. We conclude that filtration removes proinflammatory activity and the ability to induce TRALI from RBCs and may represent a TRALI mitigation step.