Inflammatory mediators in autotransfusion drain blood after knee arthroplasty, with and without leucocyte reduction

Background and Objectives The aim of this study was to evaluate whether leucocyte‐reducing filters influenced complement activation and the formation of pro‐inflammatory cytokines in autotransfusion drain blood after knee arthroplasty. Materials and Methods Twenty‐three patients undergoing knee arthroplasty were divided into two groups. All patients were given salvage blood postoperatively. In Group A, a leucocyte filter was connected between the wound and the drain blood container. In Group B the drain blood was not leucocyte filtered. Complement split products and cytokines were analysed in circulating blood and in drain blood, together with blood‐cellular differential counts. Results Drain blood showed activation vs. venous blood, with elevated concentrations of C3a, SC5b‐9, interleukin (IL)‐6, IL‐8, polymophonuclear (PMN) elastase and tumour necrosis factor‐α (TNF‐α) (P