Abstract

Introduction: Complement activation occurs secondary to a variety of external stimuli. Lactic acidosis has been previously shown to activate the complement factors C3a and C5a. In the present investigation we examined the differential effect of lactic acidosis on anaphylatoxin levels in cord and adult blood. Furthermore we aimed to determine if the entire complement cascade could be activated by lactic acidosis.Methods: Cord and adult blood samples (n = 20 each) were collected and incubated for one hour in either untreated condition or with the addition of lactate in two concentrations (5.5 mmol/l vs 22 mmol/l). Following incubation, levels of C3a, C5a and sC5b-9, and blood gas parameters were determined.Results: Anaphylatoxin (C3a and C5a) and sC5b-9 levels increased with the addition of lactate in a dosedependent manner in cord and adult blood (C3a: 1 h, 5.5 mmol/l, 22 mmol/l: 418/498/622 μg/l in cord blood; 1010/1056/1381 μg/l in adult blood, p<0.05 similar results were found for C5a and sC5b-9).Conclusion: Lactic acidosis leads to an activation of the entire complement system in neonates and in adults. This activation is dose-dependent and more pronounced in adults as compared to neonates.