Effect of autologous blood transfusion on cerebral cytokine expression.

Background: Autologous blood transfusion (ABT), for example, by means of cell saver equipment, is used to reduce the need for allogenic blood transfusion in patients with high perioperative blood loss. This study investigated the effect of blood/extracorporal surface interaction during withdrawal and retransfusion of shed autologous blood on cerebral inflammation in rats. Rats subjected to hypotension with cerebral ischemia served as positive controls. Methods: Eighty-eight male Sprague-Dawley rats were anesthetized with sevoflurane, instrumented, and randomly assigned to the following groups: sham-operation (SHAM), autologous blood withdrawal/transfusion only (ABT), or bilateral carotid artery occlusion and autologous blood withdrawal/transfusion (BCAO/ABT). Inflammatory gene expression was investigated with real-time RT-polymerase chain reaction at 6, 12, and 24 hours after SHAM, ABT, or BCAO/ABT in brain hippocampal tissue. Naive rats were investigated as reference. Results: ABT alone had no impact on hippocampal inflammatory gene expression, whereas after BCAO/ABT tumor necrosis factor-alpha (10.7 fold at 24 h), interleukin-1 beta (2.1 fold at 6 h), interleukin-6 (35.7 fold at 24 h), COX-2 (9.3 fold at 6 h), and inducible nitric oxide synthase (3.4 fold at 24 h) increased compared with SHAM. Conclusions: ABT by itself did not provoke an inflammatory reaction in the healthy brain. However, in combination with cerebral ischemia the induction of a broad spectrum of inflammatory parameters indicates an inflammatory reaction of the hippocampus beginning after 6 hours and being most pronounced after 24 hours. Therefore, this study shows that cerebral inflammation is not induced by ABT after contact with extracorporal surfaces in rats.