Evaluation of a whole-blood WBC-reduction filter that saves platelets: in vitro studies

BACKGROUND: in this study, a new WBC-reduction inline filter that removes W BCs but not platelets was evaluated. Three WBC-reduced blood components wer e prepared: RBCs, plasma, and platelet concentrates (PCs). STUDY DESIGN AND METHODS: Whole-blood components (n = 30) were filtered wit hin 2 to 4 hours after collection and then were centrifuged and separated i nto RBCs, plasma, and WBC-reduced buffy coat. Saline-adenine-glucose-mannit ol solution was added to the RBCs. The WBC-reduced huffy coats were stored overnight; on the following day, PCs were prepared from pooled WBC-reduced huffy coats and stored in a medium composed of approximately 35 percent CPD plasma and 65 percent platelet additive solution (T-Sol, Baxter). The WBC- reduction capacity of the filter, the recovery of cells after filtration, a nd the in vitro storage of RBCs (n = 10) and platelets (n = 6) were evaluat ed. RESULTS: Mean and maximum WBC counts after filtration were 0.08 x 10(6) and 0.3 x 10(6), respectively, per filtered whole-blood unit. Recovery of RBCs (mean values) after filtration was 90 percent in whole-blood components an d 73 percent in RBCs. Recovery of platelets (mean values) was 81 percent af ter filtration and 66 percent in PCs. The in vitro storage study of RBCs sh owed results comparable with previously published data, except for a lower degree of hemolysis. In the in vitro platelet storage study, results were c ompared with those of standard preparations. In all essentials, similar res ults were found. CONCLUSION: The results of the present study suggest that effective WBC red uction meets current standards and satisfactory recovery after filtration. The storage characteristics for RBCs and PCs are similar to those of standa rd preparations. Use of a whole-blood in-line filter to save platelets is a new option for whole-blood processing, which may simplify WBC reduction an d blood component preparation, as well as reduce costs in the future.