title: Urinary NGAL levels correlate with differential renal function in patients with ureteropelvic junction obstruction undergoing pyeloplasty.
abstract: OBJECTIVE
  Recent investigations described the use of NGAL, a sensitive biomarker for kidney injury, in the setting of ureteropelvic junction obstruction. We prospectively evaluated urinary NGAL levels in the affected renal pelvis and bladder of children with ureteropelvic junction obstruction undergoing unilateral dismembered pyeloplasty. Our hypothesis was that higher NGAL in the kidney and bladder would correlate with decreased ipsilateral differential function.
  
  
  METHODS
  We performed a prospective cohort study in patients treated with unilateral dismembered pyeloplasty from 2010 to 2012. Urine was obtained intraoperatively from the bladder and obstructed renal pelvis. A control population of unaffected children was recruited to provide a voided bladder specimen. Bladder NGAL levels were compared between the study and control populations. We tested our study hypothesis by correlating bladder and renal pelvic NGAL levels with the differential renal function of the affected kidney.
  
  
  RESULTS
  A total of 61 patients with a median age at surgery of 1.62 years (range 0.12 to 18.7) were enrolled in the study. Median bladder NGAL was 18.6 ng/mg (range 1.4-1,650.8) and median renal pelvic NGAL was 26.2 ng/mg (range 1.2-18,034.5, p = 0.004). Median bladder NGAL was significantly higher than in controls (p = 0.004). The correlation of bladder and renal pelvic NGAL with differential renal function was r = -0.359 (p = 0.004) and r = -0.383 (p = 0.002), respectively.
  
  
  CONCLUSIONS
  Bladder NGAL is increased in children with ureteropelvic junction obstruction. Renal pelvic and bladder normalized urinary NGAL levels correlate inversely with the relative function of the affected kidney in cases of unilateral ureteropelvic junction obstruction.
authors.affiliation: Divisions of Urology and Nephrology (PD, MB, CH), Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio. Electronic address: nicholas.cost@cchmc.org.
authors.forename: Nicholas G
authors.initials: NG
authors.lastname: Cost
authors.forename: Paul H
authors.initials: PH
authors.lastname: Noh
authors.forename: Prasad
authors.initials: P
authors.lastname: Devarajan
authors.forename: Vesna
authors.initials: V
authors.lastname: Ivancic
authors.forename: Pramod P
authors.initials: PP
authors.lastname: Reddy
authors.forename: Eugene
authors.initials: E
authors.lastname: Minevich
authors.forename: Michael
authors.initials: M
authors.lastname: Bennett
authors.forename: Christopher
authors.initials: C
authors.lastname: Haffner
authors.forename: Marion
authors.initials: M
authors.lastname: Schulte
authors.forename: W Robert
authors.initials: WR
authors.lastname: DeFoor
mesh_terms: D000209:Acute-Phase Proteins / Q000652:urine*; D000293:Adolescent; D015415:Biomarkers / Q000652:urine; D002648:Child; D002675:Child, Preschool; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D006869:Hydronephrosis / Q000209:etiology / Q000503:physiopathology / Q000601:surgery*; D007223:Infant; D007682:Kidney Pelvis / Q000503:physiopathology / Q000601:surgery*; D000071068:Lipocalin-2; D054834:Lipocalins / Q000652:urine*; D008297:Male; D011446:Prospective Studies; D011518:Proto-Oncogene Proteins / Q000652:urine*; D020127:Recovery of Function; D016896:Treatment Outcome; D014517:Ureteral Obstruction / Q000150:complications / Q000601:surgery / Q000652:urine*; D014563:Urodynamics / Q000502:physiology*; D013520:Urologic Surgical Procedures / Q000379:methods*
chemical_list: D000209:Acute-Phase Proteins; D015415:Biomarkers; C489506:LCN2 protein, human; D000071068:Lipocalin-2; D054834:Lipocalins; D011518:Proto-Oncogene Proteins
keywords: LCN2 protein; NGAL; T(1/2); UPJO; biological markers; half-time; human; kidney; neutrophil gelatinase-associated lipocalin; normalized urinary NGAL; uNGAL; ureteral obstruction; ureteropelvic junction obstruction; urinary bladder