Endotoxemia and acute-phase proteins in major abdominal surgery.

Abstract Background: Translocation of endotoxin is a controversial issue. The ability of plasma to inactivate endotoxin is an indirect measure of endotoxemia. Endotoxin is a potent stimulator of the inflammatory response and affects the innate immune system. Objective: To elucidate the kinetics of endotoxemia and the ability of plasma to inactivate endotoxin in patients with major abdominal operations. To demonstrate the early time course of the acute-phase proteins C-reactive protein (CRP), serum amyloid A (SAA), α 1 -antitrypsin, α 2 -macroglobulin, transferrin, and interleukin 6 (IL-6), and to correlate them with the amount of endotoxemia. Methods: Twenty patients with elective major abdominal operation and 10 healthy controls were investigated. Blood was collected preoperatively, during the operation and regularly up to 12 days after surgery. Endotoxin was measured by Limulus amebocyte lysate test (LAL), the ability of plasma to inactivate endotoxin by modified LAL, the acute-phase proteins nephelometrically, and IL-6 by enzyme-linked immunosorbent assay (ELISA). Results: Preoperative endotoxin plasma level (0.026 ± 0.004 EU/mL) did not differ from healthy volunteers but increased during operation (0.09 ± 0.02 EU/mL, P = 0.02). Endotoxemia peaked 1 hour after the surgical procedure (0.16 ± 0.03 EU/mL; P P 1 -Antitrypsin, although a positive acute-phase protein, decreased initially to 1.38 ± 0.1 g/L (preoperative, 2.33 ± 0.18 g/L; P P = 0.11 versus preoperative). The same was true for α 2 -macroglobulin (preoperative, 2.2 ± 0.16 g/L; intraoperative, 1.36 ± 0.13 g/L; day 5, 2.8 ± 0.4 g/L). Transferrin decreased already during surgery (1.6 ± 0.1 g/L versus preoperative 2.8 ± 0.17 g/L, P r = 0.67, P 2 -macroglobulin (−0.53 > r > −0.6, P 1 -antitrypsin (0.64 > r >0.55, P Conclusion: Major abdominal surgery is associated with transient endotoxemia and a transient reduced endotoxin inactivation capacity of the plasma. Endotoxemia correlates with the endotoxin inactivation capacity. The surgical procedure causes substantial changes in plasma concentrations of acute-phase proteins. α 2 -Macroglobulin and α 1 -antitrypsin correlate moderately with endotoxemia.