The Roles of Complement Factor C5a and CINC-1 in Glucose Transport, Ultrafiltration, and Neutrophil Recruitment during Peritoneal Dialysis

Background In a recent experimental study, we showed that low molecular weight heparin improved ultrafiltration and blocked complement activation and coagulation in a single peritoneal dialysis (PD) dwell.Objective The aim of the present study was to evaluate the possible contribution of the complement factor C5a and the potential interactions between C5a, the coagulation system, and cytokines of the interleukin (IL)-8 family (cytokine-induced neutrophil chemoattractant; CINC-1).Methods Nonuremic rats were exposed through an indwelling catheter to a single dose of 20 mL glucose- (2.5%) based filter-sterilized PD fluid, with or without the addition of anti-rat C5 antibody. The dwell fluid was analyzed 2 and 4 hours later concerning activation of the coagulation cascades, neutrophil recruitment, ultrafiltration volume; CINC-1, glucose, urea, and histamine concentrations; and ex vivo intraperitoneal chemotactic activity.Results The numbers of neutrophils and levels of thrombin–antithrombin complex (TAT) and CINC-1 increased significantly during the PD dwell. C5 blockade significantly reduced the levels of TAT and increased the ultrafiltration volumes at 2 hours. Glucose concentrations were significantly positively correlated to ultrafiltration volumes.Conclusions Blockade of C5 leads to an increase in ultra-filtration, probably by a mechanism that involves a reduction in glucose transport. This effect may form a basis for improving PD efficiency in situations where high glucose transport limits ultrafiltration. Mechanisms connected to complement activation during PD may involve coagulation. Further studies of the intraperitoneal cascade systems under conditions of PD are indicated.