Are leukocytes in salvaged washed autologous blood harmful for the recipient? The results of a pilot study

To explore whether polymorphonuclear leukocytes (PMNL) are activated to the priming threshold through intraoperative blood salvage, and are thus able to induce endothelial damage, we investigated chemotactic response (n = 20) and respiratory burst (RB; n = 20) of PMNL without (basal respiratory burs t, bPMNL-RB) and after in vitro stimulation with formyl-Met-Leu-Phe (fMLP-R B) and phorbol myristate acetate (PMA-RB). Blood was processed with a conti nuous autotransfusion device (CATS). Heparin (Heparin group) and sodium cit rate (Citrate group) were used alternately as an anticoagulant for each hal f of the chemotaxis and RB studies. Comparison of measurements from the pro cessed autologous erythrocyte concentrates (paEC) to pre- and intraoperativ e arterial blood samples showed no statistically significant difference for any test of PMNL functional responses in an orthopedic patient population. Analysis of intraindividual changes demonstrated a significantly increased bPMNL-RB (both groups, P = 0.0032; Heparin group, P = 0.0098), fMLP-RB (bo th groups, P = 0.0484; Citrate group, P 0.0371), and PMA-RB (Citrate group, P = 0.002) in the paEC compared with intraoperative arterial samples, wher eas the chemotactic response did not change. Nevertheless, median values of all RB measurements in the paEC were within the range of pre- and intraope rative values, indicating that PMNLs contained in the paEC are neither impa ired nor activated to the priming threshold. The results confirm the clinic al experience that intraoperative blood salvage is safe to use during major orthopedic surgery and questions the beneficial effect of special leukocyt e-removing filters.