The effect of glycerol-containing peritoneal dialysis fluid on peritoneal macrophage function in vivo

Though glucose is universally applied as osmotic agent in CAPD, there is great interest in the use of alternative osmotic agents. Glycerol-containing peritoneal dialysis fluids (G-PDF) have been used in an attempt to minimize the metabolic effects of long-term exposure to glucose, especially in patients with diabetes. Since data were lacking, we studied the effect of G-PDF on peritoneal macrophage (PMO) function. In a randomized cross-over setting eight stable diabetic CAPD patients performed the third and fourth exchange of the day with either G-PDF or with glucose-containing PDF (D-PDF) of comparable osmolality. The next day the patients who had used G-PDF were switched to D-PDF and vice versa. PMO were isolated from the effluents and tested for their phagocytic capacity and chemiluminescence response. No differences were encountered in total and differential white cell counts between G-PDF and D-PDF effluents. PMO phagocytic capacity for both S. epidermidis (SE) and E. coli (EC) was significantly depressed after the instillation of G-PDF as compared to D-PDF (SE: 52 +/- 2.7 vs 69 +/- 5.0%, p less than 0.02, and EC: 44 +/- 5.7 vs 63 +/- 6.7%, p less than 0.02). The same held true for peak chemiluminescence response (5.3 +/- 1.36 vs 7.2 +/- 1.43% of control cells, p less than 0.005). Thus, G-PDF may compromise PMO function in vivo more than D-PDF despite its more favourable metabolic profile as compared to D-PDF for diabetic patients.