Platelet Factor 3 Based-clotting Time Assay as a Quality Marker for Long-term Storage of Platelet Concentrates

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.