Leukocyte reduction in platelet concentrates with gas plasma treated polyethylene terephthalate nonwoven filters

Non-woven polyethylene terephthalate (PET) filter fabric, usually used for leukocyte reduction of red cell concentrates, is not compatible with platelets. To increase the compatibility for platelets the surface of non-woven PET fabric was modified by gas plasma treatment. After modification and eventual subsequent γ-sterilization and storage under different conditions, biological evaluation was performed using different kinds of platelet concentrates (PCs). From 500ml blood, stored overnight at 20°C, different types of PC were prepared. PCs prepared from platelet-rich-plasma (PRP-PC) and overnight stored and fresh buffy-coat (BC) derived PCs were tested, either from single BCs or from pooled BCs. Filterps were tested with PC in a miniaturized set-up. The product recovery (P), platelet recovery (T), the percentage of leukocyte reduction and the platelet morphology were determined. There was no significant difference in overall platelet recovery (PxT) between either freshly prepared (0.77±0.049, mean±SD) or overnight stored single EC-PC (0.78±0.031) or overnight stored PRP-PC (0.75±0.082). The pooled BC-PC, either freshly prepared or after overnight storage, showed a significant higher platelet recovery (0.84±0.030) compared to the other types of PC. The leukocyte depletion (92-97%) did not differ significantly between the different types of PC. For non of the tested PCs, changes in morphology were induced by filtration. Compared to untreated PET material the gas plasma treatment gave a major improvement of PxT from 0.57 to about 0.80. γ-sterilization and subsequent storage for 3, 12 and 24 weeks at 20°C or 37°C had no significant influence on the filtration results