YS05 In Vitro Evaluation of Platelet Concentrates Prepared Using the Automated Gambro OrbiSac System

Abstract

Introduction The Gambro OrbiSac device is designed to automate the preparation of platelet concentrates (PC) from buffy coats (BC). The aim of this study was to evaluate the in vitro function of PC produced using the OrbiSac system and stored in plasma.Study design Ten PC were produced by automated pooling of four ABO matched BC and a single unit of plasma. The ring‐shaped pooling bag was centrifuged and the platelet rich supernatant automatically expressed, through a leucodepletion filter, into a Gambro ELP storage bag. All PC were stored at 22°C with agitation and sampled on days 1, 5, 7 and 9. Samples were evaluated for platelet count and standard markers of platelet quality. Parameter OrbiSac PC Specification (Manual PC) Volume (mL) 366 (327–396) 150–350 mL (Local) Platelet Content (×109 U−1) 297 (251–419) >240 (UK) Median (range) n = 10. The assay results were compared to platelets produced by manual methods and stored in a Pall ELX bag in a previous study. Parameter OrbiSac PC Manual PC Day 1 Day 5 Day 7 Day 9 Day 1 Day 5 Day 7 Day 9 pH (22 °C) 7.23 7.45 7.38 7.29 7.13 7.36 7.32 7.24 pO2 (kPa) 9.1 7.1 7.2 8.6 6.3 5.4 5.8 6.2 pCO2 (kPa) 4.5 1.8 1.7 1.7 5.9 2.6 2.5 2.4 HSR (%) 61.8† 54.3† 55.6 58.1 76.3 71.4 64.5 70.6 % +ve CD62P 25.5 21.9 28.9 36.2 22.1 16.6 31.3 43.1 % +ve CD63 12.9 18.5 15.9 16.9 9.4 11.3 14.2 17.2 Median n = 10. † P < 0.001 versus manual (T‐test). Results Hypotonic shock response (HSR) values were found to be significantly lower in this study when compared to manually produced PC. This was due to increased red cell contamination in these units. HSR was further investigated during a larger scale trial and all units (n = 25) showed improved day 1 values (78%, range: 61–93%). Values from these additional PC were comparable with those from manually produced PC.Conclusion PC produced with the OrbiSac system achieved the local specification for platelet count. However, these units were higher in volume than those produced by manual methods, with 70% of units exceeding the locally specified maximum volume of 350 mL. This problem could be addressed during later trials. OrbiSac PC have acceptable pH, blood gases, HSR levels and platelet activation markers and results are broadly comparable to data generated in a previous study of manually produced PC. These results suggest that platelets produced with the Gambro OrbiSac system are comparable to those produced using the current manual methods.