CYTOKINES IN STORED RED-BLOOD-CELL CONCENTRATES - PROMOTERS OF SYSTEMIC INFLAMMATION AND SIMULATORS OF ACUTE TRANSFUSION REACTIONS

Background: The cytokine network has important implications for the sy stemic inflammatory and metabolic response in trauma and infection. Cy tokines exogenously administered to traumatized and infected patients may have implications for the trauma response in these patients. The m ain objective of this study was to characterize red blood cell concent rates (RBCs) with regard to cytokine content. Methods: We investigated the concentrations of tumor necrosis factor alpha (TNF), interleukin- l beta (IL-1), interleukin-6 (IL-6) and interleukin-8 (IL-8) in sixtee n units of RBCs stored at +4 degrees C during 40 days. Samples from RB Cs were taken every tenth day. Healthy volunteers were used as control s. Results: IL-1 and IL-8 in RBCs were increased compared to controls, P < 0.01 - P < 0.001 and TNF in RBCs were increased on days 1 and 40 compared to controls, P < 0.05. During storage TNF was highest on day 1, 69 (< 3 - 1060) pg/ml, median (range). IL-1 concentrations increase d during the period of storage from 5 (< 2 - 205) pg/ml to 174 (< 2 - 2180) pg/ml, P < 0.01. IL-6 was 6 (< 2 - 210) pg/ml on day 1 and did n ot change over the period of storage. IL-8 was highest on day 40, 164 (15 - 790) pg/ml and compared to day 1 the concentrations were increas ed on day 10 and day 40, P < 0.05 for both comparisons. Conclusions: T he results indicate the presence of TNF, IL-1, IL-6 and IL-8 in stored RBCs, though there was a great variability over the period of storage and between units of RBCs. In some samples of RBCs the content sf: cy tokines reached levels that may be anticipated to contribute to system ic inflammation and the symptomatology of acute transfusion reactions.