title: Biocompatibility and tolerability of a purely bicarbonate-buffered peritoneal dialysis solution.
abstract: BACKGROUND
  Novel peritoneal dialysis solutions are characterized by a minimal content of glucose degradation products and a neutral pH. Many studies have shown the biocompatibility of neutral lactate-buffered solutions; however, until now, the effect of purely bicarbonate-buffered solutions has not been intensively studied in vivo.
  
  
  METHODS
  This study was an open label, prospective, crossover multicenter trial to investigate the biocompatibility of a purely bicarbonate-buffered solution (bicPDF) by measuring biocompatibility parameters such as cancer antigen 125 (CA125) in peritoneal effluent. 55 patients were enrolled in the study. After a 2-week run-in phase, 53 patients could be randomized into 2 groups, starting with either standard lactate-buffered peritoneal dialysis fluid (SPDF) for 12 weeks (phase 1) and then switching to bicPDF for 12 weeks (phase 2), or vice versa. Overnight peritoneal effluents were collected at baseline and at the end of phases 1 and 2 and were tested for CA125, hyaluronic acid, vascular endothelial growth factor (VEGF), tumor necrosis factor-alpha (TNF-alpha), interleukin 6 (IL-6), interferon gamma (IFNgamma), and transforming growth factor-beta(1) (TGF-beta1). Total ultrafiltration and residual renal function were also assessed. At the end of the study, pain during fluid exchange and dwell was evaluated using special questionnaires.
  
  
  RESULTS
  34 patients completed the study; 27 of them provided data for analysis of the biocompatibility parameters. CA125 levels in overnight effluent were significantly higher with bicPDF (61.9 +/- 33.2 U/L) than with SPDF (18.6 +/- 18.2 U/L, p < 0.001). Hyaluronic acid levels were significantly lower after the use of bicPDF (185.0 +/- 119.6 ng/mL) than after SPDF (257.4 +/- 174.0 ng/mL, p = 0.013). Both TNF-alpha and TGF-beta1 showed higher levels with the use of bicPDF than with SPDF. No differences were observed for IL-6, VEGF, or IFNgamma levels. We observed an improvement in the glomerular filtration rate with the use of bicPDF but no differences were observed for total fluid loss. Pain scores could be analyzed in 23 patients: there was no difference between the solutions.
  
  
  CONCLUSIONS
  The use of a purely bicarbonate-buffered low-glucose degradation product solution significantly changes most of the peritoneal effluent markers measured, suggesting an improvement in peritoneal membrane integrity. Additionally, it seems to have a positive effect on residual renal function.
authors.affiliation: Department/Division of Nephrology, Centralsjukhuset, Karlstad, Germany.
authors.forename: Lars
authors.initials: L
authors.lastname: Weiss
authors.forename: Bernd
authors.initials: B
authors.lastname: Stegmayr
authors.forename: Gudrun
authors.initials: G
authors.lastname: Malmsten
authors.forename: Mattias
authors.initials: M
authors.lastname: Tejde
authors.forename: Henrik
authors.initials: H
authors.lastname: Hadimeri
authors.forename: Carl E
authors.initials: CE
authors.lastname: Siegert
authors.forename: Jarl
authors.initials: J
authors.lastname: Ahlmén
authors.forename: Rutger
authors.initials: R
authors.lastname: Larsson
authors.forename: Bo
authors.initials: B
authors.lastname: Ingman
authors.forename: Ole
authors.initials: O
authors.lastname: Simonsen
authors.forename: Henk W
authors.initials: HW
authors.lastname: van Hamersvelt
authors.forename: Ann C
authors.initials: AC
authors.lastname: Johansson
authors.forename: Britta
authors.initials: B
authors.lastname: Hylander
authors.forename: Michael
authors.initials: M
authors.lastname: Mayr
authors.forename: Per-Henrik
authors.initials: PH
authors.lastname: Nilsson
authors.forename: Per O
authors.initials: PO
authors.lastname: Andersson
authors.forename: Tatiana
authors.initials: T
authors.lastname: De los Ríos
mesh_terms: D001639:Bicarbonates; D002021:Buffers; D018592:Cross-Over Studies; D005260:Female; D015312:Hemodialysis Solutions; D006801:Humans; D007668:Kidney / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D010147:Pain Measurement; D010530:Peritoneal Dialysis; D010537:Peritoneum / Q000502:physiology; D011446:Prospective Studies; D016037:Single-Blind Method
chemical_list: D001639:Bicarbonates; D002021:Buffers; D015312:Hemodialysis Solutions