Effects of red cell storage and lysis on in vitro cytokine release

Cytokine release in whole blood assays is inhibited by addition of supernat ants from stored blood components in a storage time dependent manner. This is also observed after prestorage leucofiltration of the blood. The role of erythrocyte changes during storage is unknown. In this study, we have ther efore used prestorage leucofiltered buffy coat-depleted red blood cells sto red for 35 days. Assays of whole blood with addition of either complete sus pension or only supernatant from the stored blood units were stimulated wit h lipopolysaccharide (LPS) and incubated. Additionally, samples from the st ored blood units were partly haemolysed and added to similar whole blood as says. After incubation, tumour necrosis factor-alpha (TNF-alpha) and interl eukin-10 (IL-10) concentrations were determined. Results showed that the TN F-alpha release was not changed by addition of supernatants from prestorage leucofiltered blood, but significantly decreased with addition of red cell suspension in a storage time dependent manner. The IL-10 release increased with storage time with addition of both red cell suspension and supernatan t. The TNF-alpha /IL-10 ratio decreased with storage time, but significantl y more, 25% vs. 10%, during the 35 days, with addition of suspension compar ed with addition of supernatant. TNF-alpha and IL-10 release was not change d by addition of supernatant from lysed erythrocytes of various storage tim es. Therefore, storage time dependent inhibition of immune response by red cell suspension may in part be dependent on red cell presentation, and may cause some of the side effects by transfusion of red cells. (C) 2001 Elsevi er Science Ltd. All rights reserved.