In vitro and in vivo evaluation of cotton wool filtration of platelet concentrates obtained by automated and manual apheresis

Abstract

The effect of cotton wool filtration of apheresis platelet concentrates (PCs) on platelet viability and complement activation was evaluated by two laboratories. PCs were prepared by automated (Lab A, n = 5) or manual (Lab B, n = 5) apheresis. After storage for 1 day, the PC was filtered through cotton wool before transfusion on one occasion and, on the other occasion, filtered through a standard screen filter before transfusion to the same donor. Five paired studies were performed by each laboratory. Except for a small, but significant reduction in mean platelet size, from 7.3 +/- 1.1 to 6.6 +/- 0.9 microns 3, after cotton wool filtration, no effect of filtration on various tests of in vitro platelet function and morphologic integrity was found. As demonstrated by autologous radiolabeled studies, no effect of cotton wool filtration on platelet viability was found by Laboratory B, while Laboratory A found a slight increase in the percentage of recovery from 59 +/- 4 to 68 +/- 13 percent, and a small reduction in survival, from 8.2 +/- 0.9 to 7.7 +/- 0.5 days after cotton wool filtration (p less than 0.05). Cotton wool filtration was associated with a slight increase in C3a levels found in manual apheresis PCs. Neither laboratory found any effect of cotton wool filtration per se on the recipients' white cell (WBC) counts or C3a and C5a levels after transfusion.(ABSTRACT TRUNCATED AT 250 WORDS)

Benefit of Prestorage Leukocyte Depletion of Single–Donor Platelet Concentrates

“…Complement has been shown to be activated during storage of PC and it has been postulated that indirect effects of C3a could be responsible for platelet activation [18, 34, 35]. In this study no correlation was observed between increased C3a levels and platelet activation as determined by CD62 expression.…”

“…The reason why there was no increase in IL–1β levels as found in other studies is not clear [8, 9, 10]. It may be because increased levels of IL–1β have so far been only demonstrated in pooled donor PC [8, 9, 10, 16, 18]. The mean number of WBCs at day 0 per apheresis in this study [0.74×10 9 (0.38–1.08)] or per liter [3.7×10 9 (1.4–5.4)] is not very different from that found in other studies with PC [8, 9, 10, 29], but is higher than that obtained with new plateletpheresis systems (such as the Cobe Spectra LRS and the Fenwal Amicus) [30].…”

“…In addition, anaphylatoxins such as C3a or C5a can be generated during storage of PC and their increased levels may be due to filtration through polyester leukocyte reduction filters. Depending on the type of filter, C3a and C5a may also be adsorbed during passage through the filter [18, 19]. …”

Adsorption of Anaphylatoxins and Platelet-Specific Proteins by Filtration of Platelet Concentrates with a Polyester Leukocyte Reduction Filter

“…Leaving collected blood at room temperature accelerates com plement activation [2]. The single donor apheresis pro cedure elicited much higher C3a levels in PC products than those of random donor PCs [3]. Holme et al [3] found a small, temporary reduction of leukocyte counts in volunteers after a 30-min infusion of stored autolo gous apheresis PCs.…”

“…The single donor apheresis pro cedure elicited much higher C3a levels in PC products than those of random donor PCs [3]. Holme et al [3] found a small, temporary reduction of leukocyte counts in volunteers after a 30-min infusion of stored autolo gous apheresis PCs. Although we do not have much knowledge of these side effects on the transfusion of blood products, including high concentrations of anaphylatoxins, it may well be beneficial to reduce deleterious reac tions following transfusion of PCs with high anaphylatoxin levels.…”