In vivo exposure to bicarbonate/lactate- and bicarbonate-buffered peritoneal dialysis fluids improves ex vivo peritoneal macrophage function

The impact on peritoneal macrophage (PMO) function of acidic lactate-buffer ed (Lac-PDF [PD4]; 40 mmol/L of lactate; pH 5.2) and neutral-pH, bicarbonat e-buffered (TB; 38 mmol/L of bicarbonate; pH 7.3) and bicarbonate/lactate-b uffered (TBL; 25 mmol/L of bicarbonate/15 mmol/L of lactate; pH 7.3) perito neal dialysis fluids (PDFs) was compared during a study of continuous thera py with PD4, TB, or TBL, During a run-in phase of 6 weeks when all patients (n = 15) were treated with their regular dialysis regimen with Lac-PDF, me dian PMO tumor necrosis factor or (TNF alpha) release values were 203.6, 89 .9, and 115.5 pg TNF alpha/10(6) PMO in the patients subsequently randomize d to the PD4, TB, and TBL treatment groups, respectively. Median stimulated TNF alpha values (serum-treated zymosan [STZ], 10 mu g/mL) were 1,894.6, 5 67.3, and 554.5 pg TNF alpha/10(6) PMO in the same groups, respectively. Du ring the trial phase of 12 weeks, when the three groups of patients (n = 5 per group) were randomized to continuous treatment with PD4, TB, or TBL, me dian constitutive TNF alpha release values were 204.7, 131.4, and 155.4 pg TNF alpha/10(6) PMO, respectively. Stimulated TNF alpha values (STZ, 10 mu g/mL) were 1,911, 1,832, and 1,378 pg TNF alpha/10(6) PMO in the same group s, respectively. Repeated-measures analysis of variance comparing the run-i n phase with the trial phase showed that PMO TNF alpha release was signific antly elevated in patients treated with both TB (P = 0.040) and TBL(P = 0.0 14) but not in patients treated with Lac-PDF (P = 0.795). These data sugges t that patients continuously exposed to bicarbonate-and bicarbonate/lactate -buffered PDFs might have better preserved PMO function and thus improved h ost defense status. (C) 2000 by the National Kidney Foundation, Inc.