title: Dialysate interleukin-6 predicts increasing peritoneal solute transport rate in incident peritoneal dialysis patients.
abstract: BACKGROUND
  Repeated 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.
  
  
  METHODS
  The 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).
  
  
  RESULTS
  Dialysate 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.
  
  
  CONCLUSIONS
  Dialysate 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.
authors.forename: Yeoungjee
authors.initials: Y
authors.lastname: Cho
authors.affiliation: Department of Renal Medicine, Princess Alexandra Hospital, Brisbane, Australia. david.johnson2@health.qld.gov.au.
authors.forename: David W
authors.initials: DW
authors.lastname: Johnson
authors.forename: David A
authors.initials: DA
authors.lastname: Vesey
authors.forename: Carmel M
authors.initials: CM
authors.lastname: Hawley
authors.forename: Elaine M
authors.initials: EM
authors.lastname: Pascoe
authors.forename: Margaret
authors.initials: M
authors.lastname: Clarke
authors.forename: Nicholas
authors.initials: N
authors.lastname: Topley
mesh_terms: D015415:Biomarkers / Q000032:analysis; D015314:Dialysis Solutions / Q000378:metabolism*; D005260:Female; D015312:Hemodialysis Solutions / Q000378:metabolism*; D006801:Humans; D015850:Interleukin-6 / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D010530:Peritoneal Dialysis / Q000009:adverse effects*; D010538:Peritonitis / Q000175:diagnosis* / Q000209:etiology* / Q000378:metabolism; D015203:Reproducibility of Results; D012308:Risk Management; D012680:Sensitivity and Specificity; D016896:Treatment Outcome
chemical_list: D015415:Biomarkers; D015314:Dialysis Solutions; D015312:Hemodialysis Solutions; D015850:Interleukin-6