Evaluation of a New Whole-Blood Filter that Allows Preparation of Platelet Concentrates by Platelet-Rich Plasma Methods

BACKGROUND: A novel WBC-reduction in-line whole-blood (WB) filter that does not retain platelets was evaluated to assess the filtration performance and, after processing WB by the platelet-rich plasma (PRP) method, to analyze the storage quality of filtered platelet concentrate (PC) units.

STUDY DESIGN AND METHODS: To analyze the filter retention, blood was collected from random donors into quadruple blood packs with an integral in-line filter (Imuflex WB-SP, Terumo; n = 25) or in standard triple bag systems (n = 30). To assess the in vitro storage characteristics of platelets, 26 WB units were pooled in pairs and redistributed into 13 units that underwent WBC reduction and 13 units that were not WBC reduced. In all cases, WB was separated into RBCs, PCs, and plasma by the PRP method and platelet function was compared.

RESULTS: The filtration procedure led to RBC and PC WBC-reduced products that met the AABB and European requirements. The average filtration time was 30 minutes, the filter retained about 45 mL of WB, and there was no further loss of RBCs during the fractionation procedure. In vitro PC storage characteristics of the filtered units were similar to those of the nonfiltered units.

CONCLUSION: A 4- and 3-log WBC reduction was observed in RBC and PC units that were produced by the PRP method, with a mean residual WBC content of 0.24 +/- 0.38 x 106 and 0.02 +/- 0.03 x 106 per unit, respectively. The procedure, performed under relatively simple logistics, results in good-quality, standard components that may reduce costs and ease the process of WBC reduction in transfusion services.