Impact of cell washing on cytokines and leucocytes in salvaged blood from patients with total knee arthroplasty

Background. The use of mechanical autotransfusion devices has been sporadic ally associated with adverse effects including pulmonary dysfunction and sy stemic inflammatory response. Stimulated immune cells and proinflammatory c ytokines are suspected mediators of these complications. This study was des igned to evaluate whether mechanical autotransfusion stimulates immune cell s in wound blood thus leading to an increase in cytokines. Methods. The wound blood of 100 patients undergoing total knee arthroplasty was collected and processed using four different devices in a randomized o rder. Leucocyte and cytokine concentrations (TNF-alpha, IL-6, IL-10) were d etermined in the collected wound blood and in the washed erythrocyte concen trate. Results. IL-6 concentrations in the collected wound blood were markedly hig her. TNF-alpha and IL-10 could also be detected at lower concentrations. Ce ll washing reduced IL-6 and IL-10 levels efficiently, while TNF-alpha conce ntrations were significantly increased. Leucocyte concentrations were decre ased only slightly. A content of 1.0x10(9) leucocytes remained in the proce ssed blood. Conclusion. High concentrations of IL-6 in the collected wound blood are re duced extensively by all mechanical autotransfusion devices investigated. H owever, a large amount of leucocytes remains in the processed blood. Consid ering the increase in TNF-alpha concentration after the washing, an elevate d activity of mononuclear cells in the blood product must be assumed.