ABSTRACT
BACKGROUND: The use of mechanical autotransfusion devices has been sporadically associated with adverse effects including pulmonary dysfunction and systemic inflammatory response. Stimulated immune cells and proinflammatory cytokines are suspected mediators of these complications. This study was designed to evaluate whether mechanical autotransfusion stimulates immune cells 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 order. Leucocyte and cytokine concentrations (TNF-alpha, IL-6, IL-10) were determined in the collected wound blood and in the washed erythrocyte concentrate. RESULTS: IL-6 concentrations in the collected wound blood were markedly higher. TNF-alpha and IL-10 could also be detected at lower concentrations. Cell washing reduced IL-6 and IL-10 levels efficiently, while TNF-alpha concentrations were significantly increased. Leucocyte concentrations were decreased only slightly. A content of 1.0 x 10(9) leucocytes remained in the processed blood. CONCLUSION: High concentrations of IL-6 in the collected wound blood are reduced extensively by all mechanical autotransfusion devices investigated. However, a large amount of leucocytes remains in the processed blood. Considering the increase in TNF-alpha concentration after the washing, an elevated activity of mononuclear cells in the blood product must be assumed.
