In Vitro Evaluation of Platelet Concentrates from Buffy Coat Treated with Two Pathogen Reduction Technology (PRT)

Abstract

Background/Case Studies: In the past decade, technology for inactivation of potential pathogens and leukocytes in labile blood components has been introduced into Blood Centres to reduce the risk of transfusion-associated adverse effects. Intercept® treatment of platelet concentrates (PC) has been used in our Center since 2008. Last year, PRT with Mirasol® was evaluated. We have assessed platelet activation and other parameters for extended periods post-treatment with both PRTs. Study Design/Methods: Intercept® PC was obtained by pooling 5 buffy coat (BC), suspended in InterSol addi-tive solution (AS, 280 ml) with a ratio plasma: AS (37:63) and amotosalen plus illumination UV was applied after. Mirasol® treated PC was obtained the same way, but SSP plus (AS, 250 ml) was used. Then, ribofl avin 500 μM plus light UV were applied to PC. In both strategies, pool-BCs were pro-cessed in an OrbiSac System. All products were stored at 22°C until day 7th.The parameters tested were: pH, glucose, lactate and LDH, as markers of platelet metabolism; CD62p, as an indicator of platelet activation, and annexin V binding, as a measure of phosphatidylserine exposure, were determined by fl ow cytometry. Soluble CD62p, TGF-β1 and RANTES were analyzed by specifi c ELISA assays. Results/Findings: The fi nal cell con-centration in Intercept PC was 850 ± 90 × 106/ml (2nd day); in Mirasol® PC was 1073 ± 70 × 106/ml (2nd day). Swirling scores were good throughout 7 days of storage. Cell loss during processing was 8% and 1% for the Inter-cept® and Mirasol® system, respectively. Other results are shown with more detail in the attached table. On day 7th, 40% of the units in Mirasol contained low glucose levels, but the platelet concentration was higher in Mirasol PCs. Conclusion: In vitro results showed that in both treatments PRTs applied to PCs in the presence of AS generates units that can be stored for seven days with acceptable cell quality. Clinical studies have shown “in vivo” effi -cacy, currently large scale studies are in progress with Mirasol® platelet in AS. The treatment with PRT provided some advantages logistics, elimination gamma irradiation and protection from emerging pathogens.