EFFECT OF GLUCOSE-CONCENTRATION, OSMOLALITY, AND STERILIZATION PROCESS OF PERITONEAL-DIALYSIS FLUIDS ON CYTOKINE PRODUCTION BY PERIPHERAL-BLOOD MONONUCLEAR-CELLS AND POLYMORPHONUCLEAR CELL FUNCTIONS IN-VITRO

We sought to investigate the effects of high glucose concentration, os molality, and heat sterilization of peritoneal dialysis fluids on tumo r necrosis factor-alpha (TNF-alpha) production by peripheral blood mon onuclear cells (PBMC) and polymorphonuclear cell (PMN) functions. Bloo d samples were obtained from eight healthy volunteers. PBMCs and PMNs were harvested by centrifugation with Ficoll-Hypaque (Sigma, St Louis, MO). PBMC were incubated with an equal volume of test fluids and RPMI for 4 hours (pH equilibrated), followed by incubation for 20 hours in RPMI with or without endotoxin (10 ng/mL). Total TNF-alpha production was measured by radioimmunoassay. PMNs were incubated with pH-adjuste d test fluids for 30 minutes. After incubation, phagocytosis was deter mined by the uptake of C-14-labeled Staphylococcus aureus, oxidative b urst by reduction of ferricytochrome C to ferrouscytochrome C on stimu lation with phorbol myristate acetate, and enzyme release by measureme nt of endotoxin-stimulated bactericidal/permeability increasing factor . To study the effects of increasing glucose concentration and osmolal ity an PBMC and PMN functions, we compared conventional 1.5% Dianeal ( 1.5%D), (Baxter Healthcare Corp, Deerfield, IL) 2.5% Dianeal (2.5%D), 4.25% Dianeal (4.25%D), and control (RPMI for PBMCs and Hank's balance d salt solution for PMNs), PMNs exposed to 4.25%D exhibited an inhibit ion of phagocytosis, phorbol myristate acetate (PMA)stimulated oxidati ve burst, and bactericidal/permeability increasing factor release comp ared with control, 1.5%D, or 2.5%D. To study the effects of increased osmolality when controlled for glucose concentration, we compared 1.5% D with 1.5%D in which osmolality was increased to that of 4.25%D with the addition of either sodium chloride (1.5%D+NaCl) or mannitol (1.5%D +M). High osmolality induced higher TNF-alpha production by unstimulat ed PBMCs and decreased TNF-alpha production by endotoxin-stimulated PB MCs. PMN functions were also inhibited by high osmolality. To study th e effects of increased glucose concentration when controlled for osmol ality, we compared 4.25%D with 1.5%D+NaCl and 1.5%D+M. High glucose co ncentration induced an increase in TNF-ol production by unstimulated P BMCs, a decrease in TNF-alpha production by endotoxin-stimulated PBMCs , and an inhibition of PMN functions. Finally, to investigate the effe cts of heat sterilization, we compared 4.25%D (heat sterilized) to a f ilter-sterilized 4.25%D (4.25%D-F). The filter-sterilized fluid induce d less changes in PBMC and PMN functions compared with the heat-steril ized fluid. These data suggest that the high glucose concentration, hi gh osmolality, and heat sterilization of peritoneal dialysis fluids ad versely affect PBMC and PMN functions. These effects could predispose continuous ambulatory peritoneal dialysis patients to peritonitis, com promise host defense during infection, and jeopardize long-term surviv al of the peritoneal membrane. (C) 1998 by the National Kidney Foundat ion, Inc.