Delayed Leukoreduction of whole blood with a platelet‐sparing filter to increase low‐titer group O whole blood production in the United States.

Background: Demand for low‐titer Group O whole blood (LTOWB) is increasing for trauma. The whole blood (WB) platelet‐sparing (WB‐SP) filter enables leukoreduction (LR) while retaining platelet quantity and function; however, in the United States WB must be filtered and placed in the cold within 8 h of collection. A longer processing window would facilitate improved logistics and supply of LR‐WB to meet the growing medical need. This study evaluated the impact of increasing filtration timing from <8 h to <12 h on the quality of LR‐WB. Study Design and Methods: Thirty WB units were collected from healthy donors. Control units were filtered within 8 h and test units within 12 h of collection. WB was tested throughout 21 days of storage. Hemolysis, WBC content, component recovery, and 25 additional markers of WB quality were tested including hematologic and metabolic markers, RBC morphology, aggregometry, thromboelastography, and p‐selectin. Results: There were 0 failures for residual WBC content, hemolysis, or pH, and no differences in component recovery between arms. Few differences in metabolic parameters were observed, but the small effect size suggests these are not clinically significant. Trends throughout storage were similar and filtration timing did not impact hematological parameters, platelet activation and aggregation, or hemostatic capacity. Conclusion: Our studies showed that extending filtration timing from 8 to 12 h from the collection does not significantly impact the quality of LR‐WB. Characterization of the platelets demonstrated that storage lesions were not exacerbated. Extending the time from collection to filtration will improve LTOWB inventory in the United States. [ABSTRACT FROM AUTHOR]