Blood storage alters mechanical stress responses of erythrocytes

BACKGROUND: Erythrocytes undergo irreversible morphological and biochemical changes during storage. Reduced levels of deformability have been reported for stored erythrocytes. Erythrocyte deformability is essential for healthy microcirculation. OBJECTIVE: The aim of this study is to evaluate shear stress (SS) induced improvements of erythrocyte deformability in stored blood. METHODS: Deformability changes were evaluated by applying physiological levels of SS (5 and 10 Pa) in metabolically depleted blood for 48 hours and stored blood for 35 days with citrate phosphate dextrose adenine-1 (CPDA-1). Laser diffractometry was used to measure erythrocyte deformability before and after application of SS. RESULTS: Erythrocyte deformability, as a response to continuous SS, was significantly improved in metabolically depleted blood, whereas it was significantly impaired in the blood stored for 35 days with CPDA-1 (p <= 0.05). The SS-induced improvements of deformability were deteriorated due to storage and relatively impaired according to the storage time. However, deformability of stored blood after exposure to mechanical stress tends to increase at low levels of shear while decreasing at high SS levels. CONCLUSION: Impairment of erythrocyte deformability after storage may contribute to impairments in the recipient's microcirculation after blood transfusion. The period of the storage should be considered to prevent microcirculatory problems and insufficient oxygen delivery to the tissues.