Effect of N-acetylglucosamine on function of peritoneal leukocytes

Objective: To compare effects of N-acetylglucosamine (NAG)-based and glucose-based dialysis fluids on the function of peritoneal leukocytes in conditions of peritoneal dialysis. Design: In vitro experiments on ex vivo isolated rat peritoneal leukocytes. Materials: Peritoneal leukocytes were isolated from rats on chronic peritoneal dialysis. On alternate days, fluid exchanges were performed with NAG-based or glucose-based dialysis solutions. After a 4-hour dwell, dialysate was drained and peritoneal leukocytes were incubated in vitro ± lipopolysaccharide (LPS). Production of nitrites (index of NO synthesis), tumor necrosis factor α (TNFα), interleukin-1β (IL-1β), and interferon gamma (IFN-γ) by unstimulated or stimulated peritoneal leukocytes originating from NAG-based or glucose-based fluid was measured. Results: Dialysate cell count was lower during exchanges with NAG-based fluid (2113 ± 615 cells/μL) as compared to glucose-based fluid (3643 ± 1108 cells/μL; p < 0.01). Differential cell count was similar in both studied groups. Unstimulated peritoneal leukocytes from NAG-based dialysate produced more NO (nitrites) (0.65 ± 0.07 μmol per 10⁶ cells) than did cells from glucose-based dialysate (0.26 ± 0.09 μmol per 10⁶ cells, p < 0.01). Stimulated peritoneal leukocytes from NAG-based dialysate produced more cytokines than did cells from glucose-based dialysate: TNFα, 135.2 ± 37.0 pg versus 70.2 ± 21.8 pg per 10⁶ cells respectively, p < 0.01; IL-1β, 143.2 ± 60.9 pg versus 99.1 ± 22.4 pg per 10⁶ cells respectively, p < 0.05; IFN-γ, 16.2 ± 12.5 pg versus 6.0 ± 1.8 pg per 10⁶ cells respectively, p < 0.01. Conclusions: We demonstrated that rat peritoneal leukocytes exposed in vivo to NAG-based dialysis fluid have better ability to produce inflammatory mediators than do peritoneal leukocytes from the same donor, but exposed in vivo to glucose-based dialysis solution.