In vivo exposure to the currently available peritoneal dialysis fluids decreases the function of peritoneal...

Previous in vitro studies have revealed that the currently available peritoneal dialysis fluids (PDF) inhibit several functions of phagocytic cells. To investigate the clinical relevance of those in vitro findings, we compared the in vivo effect of PDF pH on peritoneal macrophage (PMO) function in chronic peritoneal dialysis patients. In a randomized crossover setting, each of eight patients used exclusively PDF at pH five (D5) or pH seven (D7) on day one. The next day the patients who used D5 were switched to D7 and vice versa. Likewise the effect of glucose-mediated hypertonicity was studied in eight other patients, using PDF with 1.36% glucose (D136) or 3.86% glucose (D386). PMO were isolated from the effluents and studied for their phagocytic and killing capacity, and their ability to mount a respiratory burst (chemiluminescence response). PMO obtained after the intraperitoneal instillation of D7 were significantly better able to phagocytize both S. epidermidis (65 +/- 9 vs 37 +/- 8% uptake, p < 0.005) and E. coli (43 +/- 8 vs 25 +/- 4% uptake, p < 0.005). In addition, PMO harvested from D7 effluents revealed a significantly higher killing capacity than PMO derived from D5 effluents for S. epidermidis (60 +/- 5 vs 38 +/- 6%, p < 0.005) as well as for E. coli (51 +/- 10 vs 25 +/- 9%, p < 0.025). Moreover, PMO derived from D7 effluents mounted a significantly higher respiratory burst as compared to PMO in vivo exposed to D5 for the same time.(ABSTRACT TRUNCATED AT 250 WORDS)