title: Urinary biomarkers in obstructive nephropathy.
abstract: OBJECTIVE
  Obstructive nephropathy is a leading cause of CKD in children. The assessment of severity of renal impairment and the prediction of which children will progress to renal failure are, however, challenging.
  
  
  METHODS
  This case-control study measured the urinary excretion of candidate biomarkers in 27 prevalent case-patients with posterior urethral valves (PUVs) and 20 age-matched controls, correlated their urinary concentration with GFR, and analyzed receiver-operating characteristic (ROC) curve and regression analyses to assess their performance as tests for low GFR.
  
  
  RESULTS
  The median urinary protein-to-creatinine ratio was higher in children with PUV (45 g/mol; range, 5-361 g/mol) than in controls (7 g/mol; range, 3-43 g/mol) (P<0.01) and correlated inversely with renal function (r = -0.44; P<0.05). In whole urine, excretion of aquaporin-2 was significantly decreased, whereas that of TGFβ and L1 cell adhesion molecule (L1CAM) was significantly increased. Whole-urine TGFβ excretion correlated inversely with GFR (r = -0.53; P<0.05). As tests for low GFR, whole-urine TGFβ, L1CAM, and urinary protein-to-creatinine ratio performed best, with areas under the ROC curves of 0.788, 0.795, and 0.814, respectively. By linear regression analysis, whole-urine TGFβ, L1CAM, and urinary protein-to-creatinine ratio were associated with low GFR in the case-patients.
  
  
  CONCLUSIONS
  Candidate biomarkers of obstructive nephropathy can be readily measured in whole urine and in urine exosomes. In boys with PUV, these biomarkers correlate with GFR.
authors.affiliation: Department of Paediatrics and Child Health, University of Queensland, Brisbane, Australia.
authors.forename: Peter
authors.initials: P
authors.lastname: Trnka
authors.forename: Larissa
authors.initials: L
authors.lastname: Ivanova
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Hiatt
authors.forename: Douglas G
authors.initials: DG
authors.lastname: Matsell
mesh_terms: D000293:Adolescent; D015703:Antigens, CD / Q000652:urine; D051399:Aquaporin 2 / Q000652:urine; D019540:Area Under Curve; D015415:Biomarkers / Q000652:urine; D015820:Cadherins / Q000652:urine; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D003404:Creatinine / Q000652:urine; D018450:Disease Progression; D055354:Exosomes / Q000378:metabolism; D005240:Feasibility Studies; D005919:Glomerular Filtration Rate; D006801:Humans; D007223:Infant; D007668:Kidney / Q000503:physiopathology*; D007674:Kidney Diseases / Q000175:diagnosis / Q000209:etiology / Q000503:physiopathology / Q000652:urine*; D007676:Kidney Failure, Chronic / Q000209:etiology / Q000652:urine; D016014:Linear Models; D016015:Logistic Models; D008297:Male; D039842:Neural Cell Adhesion Molecule L1 / Q000652:urine*; D011237:Predictive Value of Tests; D011507:Proteinuria / Q000209:etiology / Q000652:urine; D040901:Proteomics / Q000379:methods; D012372:ROC Curve; D050916:TRPV Cation Channels / Q000652:urine; D016212:Transforming Growth Factor beta / Q000652:urine*; D014524:Urethral Obstruction / Q000150:complications* / Q000503:physiopathology / Q000652:urine; D016482:Urinalysis; D025262:Vacuolar Proton-Translocating ATPases / Q000652:urine; D051176:beta Catenin / Q000652:urine
chemical_list: C496023:AQP2 protein, human; D015703:Antigens, CD; D051399:Aquaporin 2; D015415:Biomarkers; C513384:CDH1 protein, human; C050361:CDH2 protein, human; C495270:CTNNB1 protein, human; D015820:Cadherins; D039842:Neural Cell Adhesion Molecule L1; D050916:TRPV Cation Channels; C416986:TRPV4 protein, human; D016212:Transforming Growth Factor beta; D051176:beta Catenin; D003404:Creatinine; D025262:Vacuolar Proton-Translocating ATPases