Dialysate interleukin-6 predicts increasing peritoneal solute transport rate in incident peritoneal dialysis patients

Yeoungjee Cho,Margaret Clarke,David W Johnson,Nicholas Topley,David A Vesey,Elaine M Pascoe,Carmel M Hawley

doi:10.1186/1471-2369-15-8

Abstract

BackgroundRepeated exposure to peritoneal dialysis (PD) solutions contributes to cumulative intraperitoneal inflammation and peritoneal injury. The present study aimed to explore the capacity of dialysate interleukin-6(IL-6) to a) predict peritoneal membrane function and peritonitis in incident PD patients, and b) to evaluate the influence of neutral pH, low glucose degradation product (GDP) PD solution on dialysate IL-6 levels.MethodsThe study included 88 incident participants from the balANZ trial who had completed 24-months of follow-up. Change in peritoneal solute transport rate (PSTR) and peritonitis were primary outcome measures, and the utility of IL-6 and IL-6 appearance rate (IL-6 AR) in predicting these outcomes was analyzed using multilevel linear regression and Cox proportional hazards models, respectively. Sensitivity analyses were performed by analyzing outcomes in a peritonitis-free cohort (n = 56).ResultsDialysate IL-6 concentration significantly increased from baseline to 24 months (mean difference 19.07 pg/mL; P < 0.001) but was not affected by the type of PD solution received (P = 0.68). An increase in PSTR from baseline was associated with higher levels of IL-6 (P = 0.004), the use of standard solutions (P = 0.005) and longer PD duration (P < 0.001). Baseline IL-6 level was not associated with a shorter time to first peritonitis (adjusted hazard ratio 1.00, 95% CI 0.99-1.00, P = 0.74). Analysis of IL-6 AR as well as sensitivity analyses in a peritonitis-free cohort yielded comparable results.ConclusionDialysate IL-6 concentration increased with longer PD duration and was a significant, independent predictor of PSTR. The use of biocompatible PD solutions exerted no significant effect on dialysate IL-6 levels but did abrogate the increase in PSTR associated with standard PD solutions. This is the first study to examine the impact of biocompatible solutions on the utility of IL-6 in predicting PSTR and peritonitis.

Highlights

Repeated exposure to peritoneal dialysis (PD) solutions contributes to cumulative intraperitoneal inflammation and peritoneal injury
Interest in IL-6 and its role in intraperitoneal inflammation in PD patients is increasing as a result of the link from single centre studies to changes in peritoneal solute transport rate (PSTR), data that has been corroborated by recent analysis from the large multicenter GLOBAL study [8,9,10]
Similar results were obtained when analyses were repeated in the peritonitis-free cohort (Table 2) as well as when IL-6 Interleukin-6 appearance rate (AR) (Additional file 1: Table S1) was analysed as the outcome

Summary

Introduction

Repeated exposure to peritoneal dialysis (PD) solutions contributes to cumulative intraperitoneal inflammation and peritoneal injury. Continuous exposure to conventional peritoneal dialysis (PD) solutions contributes to progressive peritoneal injury, is an important source of local inflammation that can result in Interleukin-6 (IL-6) is an immuno-modulatory cytokine that plays a critical role in many innate and acquired inflammatory processes [6]. It is secreted in large quantities by peritoneal mesothelial cells in response to inflammatory stimuli and modulated by exposure to PD solutions [7]. The utility of dialysate IL-6 as a potential predictor of adverse peritoneal membrane function has not been studied within an RCT setting

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