Levels of red blood cells derived microparticles in stored erythrocyte concentrate

There is increasing evidence of the clinical importance of microparticles (MPs) and their role in blood transfusion-related side effects and the transmission of pathogens. The study aims to examine the red blood cell-derived MPs in blood bags during storage under standardized blood bank conditions. The samples were tested at various times to demonstrate the presence of RBC-derived MPs by flow cytometry. The quantitative assay was carried out in stored erythrocyte concentrate on days 0, 25 and 35 and their number from day 0 to 25 and 35 and the number of day 25 to day 35 were compared. The MPs were counted after being concentrated in a supernatant (labeled with the respective antibodies CD47, CD235a and Annexin V) obtained by a specific centrifugation procedure. The analysis showed that the number of Annexin V positive MPs increased between day 0 and day 35 (~ 0.001) and CD47 expression on MPs at day 25 and day 35 decreased compared to day 0 (~ 0.001). In addition, CD235a expression had shown minimal insignificant changes with an upward trend (> 0.05) during the storage period. It is concluded that monitoring the release of MPs from RBC units during storage is a sensitive approach to identifying MPs for transfusion drugs and, more broadly, for cell-based therapies.   Key words: Red blood cells, phosphatidylserine, cell-derived microparticle.