title: Timing of renal replacement therapy does not influence survival and growth in children with congenital nephrotic syndrome caused by mutations in NPHS1: data from the ESPN/ERA-EDTA Registry.
abstract: Congenital nephrotic syndrome (CNS) of the Finnish type, NPHS1, is the most severe form of CNS. Outcomes of renal replacement therapy (RRT) in NPHS1 patients in Europe were analysed using data from the ESPN/ERA-EDTA Registry. As NPHS1 is most prevalent in Finland and the therapeutic approach differs from that in many other countries, we compared outcomes in Finnish and other European patients.
  
  
  
  NPHS1 mutations were confirmed in 170 children with CNS who initiated RRT (dialysis or renal transplantation) between 1991 and 2012. Finnish (n = 66) and non-Finnish NPHS1 patients (n = 104) were compared with respect to treatment policy, age at first RRT and renal transplantation (RTX), patient and graft survival, estimated glomerular filtration rate (eGFR) and growth. Age-matched patients with congenital anomalies of the kidney and urinary tract (CAKUT) served as controls.
  
  
  
  Finnish NPHS1 patients were significantly younger than non-Finnish patients, both at the start of RRT and at the time of RTX. We found similar overall 5-year patient survival on RRT (91 %) and graft survival (89 %) in both NPHS1 groups and CAKUT controls. At the start of RRT, height standard deviation score (SDS) was higher in Finnish patients than in non-Finnish patients (mean [95 % CI]: -1.31 [-2.13 to -0.49] and -3.0 [-4.22 to -1.91], p < 0.01 respectively), but not at 5 years of age. At 5 years of age height and body mass index (BMI) SDS were similar to those of CAKUT controls.
  
  
  
  Overall, 5-year patient and graft survival of both Finnish and non-Finnish NPHS1 patients on RRT were excellent and comparable with CAKUT patients with equally early RRT onset and was independent of the timing of RRT initiation and RTX.
authors.affiliation: Department of Pediatric Nephrology, Children's Hospital, University of Helsinki and Helsinki University Hospital, Helsinki, Finland.
authors.forename: Tuula
authors.identifier: 0000-0002-5355-4862
authors.initials: T
authors.lastname: Hölttä
authors.affiliation: ESPN/ERA-EDTA Registry, Department of Medical Informatics, Academic Medical Center, University of Amsterdam, PO Box 22700, 1100 DE, Amsterdam, The Netherlands. m.bonthuis@amc.uva.nl.
authors.forename: Marjolein
authors.initials: M
authors.lastname: Bonthuis
authors.affiliation: ESPN/ERA-EDTA Registry, Department of Medical Informatics, Academic Medical Center, University of Amsterdam, PO Box 22700, 1100 DE, Amsterdam, The Netherlands.
authors.forename: Karlijn J
authors.initials: KJ
authors.lastname: Van Stralen
authors.affiliation: Department of Pediatrics, Rikshospitalet, Oslo University Hospital, Oslo, Norway.
authors.forename: Anna
authors.initials: A
authors.lastname: Bjerre
authors.affiliation: Department of Nephrology, Hacettepe University Faculty of Medicine, Ankara, Turkey.
authors.forename: Rezan
authors.initials: R
authors.lastname: Topaloglu
authors.affiliation: Nephrogenetics Laboratory, Department of Pediatric Nephrology, Hacettepe University Faculty of Medicine, Ankara, Turkey.
authors.forename: Fatih
authors.initials: F
authors.lastname: Ozaltin
authors.affiliation: Department of Pediatric Nephrology, Children's Hospital, University of Helsinki and Helsinki University Hospital, Helsinki, Finland.
authors.forename: Christer
authors.initials: C
authors.lastname: Holmberg
authors.affiliation: Department of Pediatrics, Bordeaux University Hospital, Bordeaux, France.
authors.forename: Jerome
authors.initials: J
authors.lastname: Harambat
authors.affiliation: ESPN/ERA-EDTA Registry, Department of Medical Informatics, Academic Medical Center, University of Amsterdam, PO Box 22700, 1100 DE, Amsterdam, The Netherlands.
authors.forename: Kitty J
authors.initials: KJ
authors.lastname: Jager
authors.affiliation: Department of Pediatric Nephrology, Center for Pediatrics and Adolescent Medicine, University of Heidelberg, Heidelberg, Germany.
authors.forename: Franz
authors.initials: F
authors.lastname: Schaefer
authors.affiliation: Department of Pediatric Nephrology, Emma Children's Hospital AMC, University of Amsterdam, Amsterdam, The Netherlands.
authors.forename: Jaap W
authors.initials: JW
authors.lastname: Groothoff
mesh_terms: D000367:Age Factors; D015992:Body Mass Index; D005387:Finland; D005919:Glomerular Filtration Rate; D006085:Graft Survival; D006128:Growth; D016030:Kidney Transplantation; D008565:Membrane Proteins / Q000235:genetics*; D009154:Mutation; D009404:Nephrotic Syndrome / Q000151:congenital / Q000235:genetics / Q000628:therapy*; D012042:Registries; D017582:Renal Replacement Therapy / Q000379:methods*; D016019:Survival Analysis; D061665:Time-to-Treatment; D016896:Treatment Outcome
chemical_list: D008565:Membrane Proteins; C113267:nephrin
keywords: Congenital nephrotic syndrome; Dialysis; Graft survival; Kidney transplantation; NPHS1; Pediatrics