Studies on Oxidative Stress in Young and Old Erythrocytes of Stored Blood

Abstract

Storage lesions are formed that reduce the safety and efficacy of banked blood. Therefore, there newlineis a need to understand the changes that occur during storage. Most studies have focused on newlinestorage of a mixed population of erythrocytes, however very few studies have reported the newlinechanges in the subpopulation of erythrocytes over storage in different storage solutions with newlineantioxidant additives. This study aimed at investigating the continuous changes occurring in newlineaging erythrocytes in different storage solutions through oxidative stress markers. newlineBlood was collected from the blood bank at KIMS hospital, Bangalore and stored under blood newlinebank conditions in CPDA-1. Blood was stored for 35 days in CPDA-1 and every 5th day, newlineerythrocytes were isolated and separated into young and old erythrocytes through a PercollBSA density gradient in the control and rejuvenation groups, which were used for further newlineanalysis. Erythrocytes were isolated on day 0, separated into young and old through a PercollBSA density gradient, and stored in AS-7 with and without antioxidants for a period of 35 days. newlineEvery 5th day, an aliquot of these samples were used for further analysis. The OS markers: newlineHemoglobin (Hb), Hemolysis, Mechanical Fragility, antioxidant enzymes [Superoxide newlineDismutase (SOD) and Catalase (CAT)], Superoxides, Sialic Acid, Glutamic oxaloacetate newlinetransaminase (GOT), Glucose, Plasma Membrane Redox System (PMRS), TACCUPRAC, newlineLactate Dehydrogenase (LDH), lipid peroxidation products [Malondialdehyde (MDA) and newlineConjugate Dienes] and protein oxidation products [Advanced Oxidation Protein Products newline(AOPP) and Protein Sulfhydryls (P-SH)] were analysed. Reticulocytes could be isolated only newlineon day 0 and it was limited to a few microliters, which limited further storage studies. Young newlineerythrocytes disappeared day 20 onwards in controls and it was found that they could endure newlineOS more efficiently than old cells, as the OS levels are much higher in old cells than young newlineones. Rejuvenated erythrocytes increased its antioxidant capacity and reduced storage lesions newlinesignificantly. However, it was more effective in young Rej in terms of ROS, TACCUPRAC, PMRS, newlineand CAT than old Rej. Rejuvenation also yielded young erythrocytes beyond day 20, till the end newlineof the storage period. AS-7 was found to be more beneficial to young cells. The oxidative newlinechanges observed in young cells from day 25, were similar to old cells from day 5 itself. The newlinevariations between young and old erythrocytes in AS-7 + LC 10mM and AS-7 + VE 2mM newlinewere minimal. Though the antioxidants had a beneficial effect on both young and old newlineerythrocytes, it was found to be more favourable to young than old ones, similar to the results newlineof controls, rejuvenation and AS-7. newlineIn conclusion, storing higher young:old erythrocyte ratio would be beneficial, as young cells newlinehave a higher post transfusion survival rate, thereby improving the efficacy of stored blood. newlineThis study highlights the prospects of storing young erythrocytes for prolonged shelf life of newlineblood and lays the foundation for future young and old erythrocyte storage studies