Blood unit segments accurately represent the biophysical properties of red blood cells in blood bags but not hemolysis.

BACKGROUND: The biophysical properties of red blood cells (RBCs) provide potential biomarkers for the quality of donated blood. Blood unit segments provide a simple and nondestructive way to sample RBCs in clinical studies of transfusion efficacy, but it is not known whether RBCs sampled from segments accurately represent the biophysical properties of RBCs in blood bags. STUDY DESIGN AND METHODS: RBCs were sampled from blood bags and segments every two weeks during 8 weeks of storage at 4°C. RBC deformability was measured by deformability-based sorting using the microfluidic ratchet device in order to derive a rigidity score. Standard hematological parameters, including mean corpuscular volume (MCV), red cell distribution width (RDW), mean cell hemoglobin (MCH), mean corpuscular hemoglobin concentration (MCHC), and hemolysis were measured at the same time points. RESULTS: Deformability of RBCs stored in blood bags was retained over 4 weeks storage, but a progressive loss of deformability was observed at weeks 6 and 8. This trend was mirrored in blood unit segments with a strong correlation to the blood bag data. Strong correlations were also observed between blood bag and segment for MCV, MCHC, and MCH but not for hemolysis. CONCLUSION: RBCs sampled from blood unit segments accurately represent the biophysical properties of RBCs in blood bags but not hemolysis. Blood unit segments provide a simple and nondestructive sample for measuring RBC biophysical properties in clinical studies.