The effect of storage on the accumulation of oxidative biomarkers in donated packed red blood cells

Background: Transfusion-related acute lung injury (TRALI) is a life-threatening condition characterized by oxidative stress. Longer storage times of packed red blood cells (PRBC) and other blood products have been implicated with an increased risk in developing TRALI in transfused patients. Methods: A total of 10 units of blood containing PRBC stored in citratephosphate-dextrose buffer at 4°C were included in the study. At Bonfils Blood Center (Denver, CO), samples were collected on storage day 1 and day 42. Samples were immediately centrifuged, and the supernatants were collected and stored at 80°C until further analysis. Oxidationreduction potential and protein oxidation were measured in both the day 1 and day 42 samples. Results: Oxidation-reduction potential significantly increased (p < 0.05) in the day 42 sample (98.1 mV 21.9 SD) versus the day 1 sample (62.6 mV 21.5 SD). The oxidation of human serum albumin increased by 63.6% during the storage time. Other serum proteins such as apolipoprotein A1 and transthyretin demonstrated similar increases in oxidation. Also, proteins with a cleaved C-terminal amino acid were observed indicating the presence of carboxypeptidase activity, a marker of inflammation. Conclusions: The presence of an oxidative environment in transfused PRBC increases with storage time. This could partially explain the increased risk of developing TRALI related to the transfusion of older blood products.