Procoagulant activity of red blood cell microparticles in stored packed red blood cell units and its relation to ABO blood grouping

Background Throughout the storage of blood, the red cells undergo alterations known as "storage lesions," which involve shape changes and the formation of microparticles (MPs). Studies of the formation of red cell microparticles (RMPs) emphasize the prospective application of RMPs as a quality control measure in the preparation and storage of blood components in the future. In the present study, twenty packed RBC units in citrate phosphate dextrose adenine-1 (CPDA1) were collected from volunteers and stored for 35 days. Over 35 days of storage, samples were collected at six distinct time points weekly and evaluated for the presence of RMPs. MPs were separated by the ultracentrifugation method. Electron microscopy was used to characterize the morphology and size of the isolated microparticles, and flow cytometry was performed to determine the percentage of RMPs that expressed glycophorin A (CD235a) and Annexin V antigens. RMPs' procoagulant activity (PCA) was assessed using a plasma recalcification test. RMP concentration in accordance with ABO blood grouping was assessed by using various types of donated blood groups.Results RMPs progressively increased over storage. The procoagulant activity (PCA) exhibited a significant increase during storage, as evidenced by a shorter plasma recalcification time (P value = 0.001). A significant negative correlation (P value = 0.001) between plasma recalcification time and Annexin V-positive microparticles, as well as a dual-positive Annexin V/CD235a population, was identified, indicating a strong correlation between the direct quantitative assay by flowcytometry and the functional assay through the PCA.Conclusion RMPs increase on storage with increased PCA. Finding ways to reduce these microparticles in packed RBC units is crucial for reducing the risk of transfusion-related coagulopathy.