title: Peritoneal effluent MMP-2 and PAI-1 in encapsulating peritoneal sclerosis.
abstract: BACKGROUND
  Recently, the use of effluent matrix metalloproteinase 2 (MMP-2) and plasminogen activator inhibitor 1 (PAI-1) as potential biomarkers of peritoneal fibrosis has been demonstrated during longitudinal follow-up of incident peritoneal dialysis (PD) patients. This study focuses on effluent MMP-2 and PAI-1 as early diagnostic markers in the preceding years of patients who develop encapsulating peritoneal sclerosis (EPS).
  
  
  METHODS
  Diagnostic test study.
  
  
  METHODS
  PD patients who developed EPS were compared with controls using a 1:3 case-control design with a minimum PD duration of 57 months.
  
  
  METHODS
  Dialysate appearance rates of MMP-2 and PAI-1.
  
  
  METHODS
  EPS cases identified by 2 experienced nephrologists and a radiologist based on predefined criteria.
  
  
  RESULTS
  11 patients developed EPS within our center. The time course of MMP-2 appearance rates, studied by means of a linear repeated-measures model 4 years prior to the diagnosis of EPS, showed no difference between long-term controls and patients with EPS. In contrast, higher PAI-1 appearance rates were found in patients with EPS compared with controls (P=0.01). At a lag time of 1 year prior to EPS diagnosis, time-specific receiver operating characteristic curve analyses indicated a discriminative ability for PAI-1 appearance rate of 0.77 (95% CI, 0.63-0.91). A discriminative capacity was absent for those of MMP-2.
  
  
  CONCLUSIONS
  Low event rate of EPS prevented independent validation in this single-center study.
  
  
  CONCLUSIONS
  Elevated levels of PAI-1 appearance rates are present in patients who develop EPS, pointing to progressive peritoneal fibrosis and sclerosis. The PAI-1 appearance rate has fair discriminative capacity from 3 years prior to EPS diagnosis. Therefore, effluent PAI-1 may aid in monitoring peritoneal fibrosis and serve as a biomarker for EPS.
authors.affiliation: Division of Nephrology, Department of Internal Medicine, Academic Medical Center, University of Amsterdam, Amsterdam. Electronic address: d.lopesbarreto@amc.uva.nl.
authors.forename: Deirisa
authors.initials: D
authors.lastname: Lopes Barreto
authors.affiliation: Division of Nephrology, Department of Internal Medicine, Academic Medical Center, University of Amsterdam, Amsterdam; Dianet Foundation, Amsterdam-Utrecht, the Netherlands.
authors.forename: Dirk G
authors.initials: DG
authors.lastname: Struijk
authors.affiliation: Division of Nephrology, Department of Internal Medicine, Academic Medical Center, University of Amsterdam, Amsterdam.
authors.forename: Raymond T
authors.initials: RT
authors.lastname: Krediet
mesh_terms: D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000032:analysis*; D015314:Dialysis Solutions / Q000737:chemistry*; D005260:Female; D006801:Humans; D008297:Male; D020778:Matrix Metalloproteinase 2 / Q000032:analysis*; D008875:Middle Aged; D010530:Peritoneal Dialysis / Q000009:adverse effects; D056627:Peritoneal Fibrosis / Q000175:diagnosis* / Q000209:etiology; D017395:Plasminogen Activator Inhibitor 1 / Q000032:analysis*; D055815:Young Adult
chemical_list: D015415:Biomarkers; D015314:Dialysis Solutions; D017395:Plasminogen Activator Inhibitor 1; D020778:Matrix Metalloproteinase 2
keywords: Biomarkers; diagnostic accuracy; early detection; encapsulating peritoneal sclerosis (EPS); end-stage renal disease (ESRD); matrix metalloproteinase 2 (MMP-2); peritoneal dialysis (PD); peritoneal effluent; plasminogen activator inhibitor 1 (PAI-1)