Evaluation of Blood Storage Lesions in Leuko-depleted Red Blood Cell Units

Background: Red blood cells (RBCs) undergo biochemical and morphologic alterations during storage that are known as the storage lesions causing decreased RBC quality and are correlated with transfusion reactions in certain groups especially in infants and critically ill patients. Microvesicles (MVs) as one of storage lesions may be derived from various cell types and have key roles in several biological processes. The aim of the study was to evaluate various storage quality measures in RBC concentrates during storage under blood bank condition. Materials and Methods: In this descriptive study, twenty leuko-depleted packed RBCs bags from healthy donors were prepared and stored at 4°C for up to 42 days. Samples were withdrawn at seven different times and evaluated for various hematological, biochemical, and hemolysis measures. In addition, red blood cell microvesicles (RBC-MVs) were separated and characterized based on the expression of Glycophorin A (Gly.A) antigen. Results: The assessment of RBCs during cold storage showed significant increase in hemolysis rate, hematocrit (Hct), free hemoglobin, plasma potassium, and plasma lactate (p<0.0001), while a significant decrease in plasma sodium and glucose (p<0.0001) was observed. Significant increase was also identified in the RBC osmotic fragility (p<0.001). During the storage of RBCs in Saline- Adenine- Glucose- Mannitol (SAGM), the MVs count increased significantly. The majority of MVs had positive staining for Gly.A (74%) and it correlated with the changes in hemolysis rate (r= 0.77; p<0.001). Conclusion: Storage of RBC was associated with important changes which influence biochemical parameters, hemolysis, and microvesiculation process that generally affected the product quality and may contribute to the negative post-transfusion outcome.