Research and development in the blood bank: Efforts of a hospital donor center to improve efficiency of in‐line leukocyte reduction filters for automated plateletpheresis

Abstract

In-line leukocyte reduction filters (LRF) are available for use with an automated plateletpheresis (PPH) system. Initially, 62% of PPH units produced with such a filter (LRF6, N = 29) had postfiltration (POF) white blood cell (WBC) counts < 5 x 10(6), with a mean POF WBC of 42 x 10(6). In an attempt to decrease POF WBCs, PPH were rested 30 to 60 minutes before filtration with LRF6. A new, larger-volume LRF (LRF10) was also assessed for its efficiency of leukodepletion. A total of 625 PPH, 490 filtered with LRF6 and 135 with LRF10, were evaluated using prefiltration (PRF) and POF samples. Mean prefiltration WBC loads averaged 80 x 10(6) (range, 60-88 x 10(6)) using seven combinations of filters, collection software, and PRF rest periods. Ninety-three percent of PPH units rested prior to filtration with LRF6 (N = 237) had < 5 x 10(6) WBC POF, with a mean of 5 x 10(6) WBC POF. All PPH units filtered with LRF10 (N = 135), whether rested or not, had < 5 x 10(6) WBC POF, with a mean WBC count of 0.2 x 10(6) POF. Mean platelet (PLT) yields POF ranged from 3.1 to 3.4 x 10(11). A PRF rest decreased mean POF WBC counts in products filtered with LRF6. The LRF10 consistently produced PPH with < 5 x 10(6) WBC POF. Blood centers must thoroughly validate equipment utilized in the production of blood components.

Improved removal of white cells with minimal platelet loss by filtration of apheresis platelets during collection

“…This is similar to the levels reported previously by Murphy et al 26 : 87 percent had WBC counts <5 × 10 6 and 62 percent had counts <1 × 10 6 . Similar results have also been reported by Drew et al, 29 and slightly better WBC‐retention results by Sweeney et al 35 and Twait et al 27 On the other hand, far better retention of WBCs in the LRF6 with MCS+ PCs has been found by Schooneman and Claise 32 (100% had counts <1 × 10 6 and 96% <1 × 10 5 ), by Burgstaler and Pineda, 28 (100% <1 × 10 6 ), and Fitzpatrick et al 36 (100% <1 × 10 6 and 76% <1 × 10 5 ). The reason for these discrepancies may be related partly to differences in WBC‐counting methods, 37 but it is more likely related to differences in filtration flow rates.…”

“…The platelet loss observed with the LRF6 (8% at a platelet yield of 4.0 × 10 11 platelets) is similar to or less than that reported in other studies using the MCS+ and the LRF6 26–29 . Higher platelet losses by postcollection filtration have been reported from PCs collected with other apheresis systems 11–20,30,31 .…”