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Preparations of platelet concentrates (PCs) that are stored under blood bank conditions and used for transfusion purposes, appear to be enriched in platelet derived-microparticles (PMPs) with high coagulant activity that may change platelet efficacy and safety issues. High shear stress could cause shedding of PMPs from the platelet plasma membrane, platelet aggregation, and activation of the coagulation cascade by increasing the catalytic phospholipid surface. These stresses may be prompted by processing and storage of blood and platelet rich plasma through various variables that has been fully described in this review. Depending on different rates of shear stress during processing and storage of PC, different quantities of MPs might be shed from platelets. On the other hand, the therapeutic effect of high levels of PMPs in PC has been reported for some patients. By using more sensitive and standardized methods for PMP measurement and change of platelet preparation process, further studies are required to monitor PMP generation during blood collection, processing and storage of PC to improve quality of PC and also in recipient’s reactions to transfusion. Keywords: Platelet-derived microparticle, Platelet concentrate, Blood collection, Platelet storage

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Background: Platelets rapidly lose their qualities usually after 5 day of storage. Different standard methods have been recommended to check the quality of platelets during storage which some of them show better correlation with other quality markers during storage. The purpose of this study was to demonstrate if platelet factor 3 (PF3) assay could be an indicator of storage lesion and provide a significant correlation with other quality markers during long-term storage of platelet concentrates (PC) up to 11 days.
Methods: Twelve random units of PC were placed in a standard platelet incubator under continuous agitation at 22-24°C for eleven days. Samples were taken on days 1, 3, 5, 8 and 11. Parameters such as pH, glucose, lactate dehydrogenase (LDH), platelet count of the bags, mean platelet volume (MPV) and platelet distribution width (PDW) and PF3 were measured. The correlation coefficient of PF3 and pH with the abovementioned parameters was evaluated.
Results: The mean percentage of changes for PF3, pH, glucose, LDH, platelet count, MPV and PDW on day 11 compared to the first day were found to be 61, 15, 52, 440, 19, 18 and 39%, respectively. After LDH, PF3 had the highest change relative to the other markers. PF3 demonstrated better correlation with glucose, platelet count, MPV and PDW compared with pH during long-term PC storage.
Conclusion: Platelet factor 3 based-clotting time assay could be a potential candidate for monitoring the quality of PC due to apparent trend of its changes during storage with better correlation between the quality markers.