Peritoneal dialysis fluid induces change of mononuclear phagocyte proportions.

Peritoneal macrophages from uninfected continuous ambulatory peritoneal dialysis (CAPD) patients in general show two different, endogenous peroxidase activity (PA) patterns: exudate and negative. This suggests, in accordance with the animal model, that these macrophages are changed proportionately in CAPD patients. This chronic change may be caused by mechanical stimulation alone (massage) or the composition of the dialysis fluid used. Therefore in the rat model both physiological saline and commercial dialysis fluid were intraperitoneally (i.p.) administrated. Our results on the PA-pattern of peritoneal macrophages do indicate that a single i.p. administration of commercial dialysis fluid induced an acute exudate, especially when compared with the minor saline effect. These results are confirmed by the percentage of macrophages positive for a differentiation antigen recognized by the monoclonal antibody ED2. In addition the percentage of Fc-receptor positive peritoneal cells is more enhanced after i.p. injection of dialysis fluid when compared with the saline effect. These findings strongly suggest that the dialysis fluid used in peritoneal dialysis patients is the inducer of exudate peritoneal macrophages in these patients.