Urinary NGAL, cystatin C, β2-microglobulin, and osteopontin significance in hydronephrotic children.
BACKGROUND
Ureteropelvic junction obstruction (UPJO) accounts for 35 % of all congenital hydronephrosis cases. The challenge in managing childhood hydronephrosis is to distinguish obstructive from nonobstructive cases and, thereby, identify patients requiring surgical intervention. This study aimed to examine four urinary proteins as potential biomarkers of obstruction in hydronephrosis.


METHODS
Urine samples from 24 children with UPJO were collected pre-, peri-, and postoperatively, together with urine samples from healthy children. Neutrophil gelatinase-associated lipocalin (NGAL), cystatin C (CyC), β2-microglobulin (β2-M), and osteopontin (OPN) in the samples were measured simultaneously using multiplex sandwich immunoassay technology.


RESULTS
Compared with controls, NGAL and β2-M were significantly increased in urine from patients with obstructed kidneys at the time of surgery. This increase was followed by a decrease and stabilization to the same level as that of the controls. Furthermore, age was negatively correlated with preoperative urinary concentrations of CyC, β2-M, and OPN.


CONCLUSIONS
This study confirms increased concentrations of NGAL and β2-M in urine from obstructed kidneys and should be tested in larger studies to ascertain their ability to identify obstruction and to determine the importance of age-adjusted reference values.
Department of Urology, Pediatric Section, Aarhus University Hospital, Brendstrupgaardsvej 100, 8200, Aarhus N, Denmark. miagebauermadsen@ki.au.dk.|The Water and Salt Research Center, Institute of Clinical Medicine, Aarhus University Hospital, Brendstrupgaardsvej 100, 8200, Aarhus N, Denmark. miagebauermadsen@ki.au.dk.
Mia Gebauer
MG
Madsen
The Water and Salt Research Center, Institute of Clinical Medicine, Aarhus University Hospital, Brendstrupgaardsvej 100, 8200, Aarhus N, Denmark.
Rikke
R
Nørregaard
Research Unit for Molecular Medicine, Aarhus University Hospital, Brendstrupgaardsvej 21, 8200, Aarhus N, Denmark.
Johan
J
Palmfeldt
Department of Urology, Pediatric Section, Aarhus University Hospital, Brendstrupgaardsvej 100, 8200, Aarhus N, Denmark.
Lars Henning
LH
Olsen
The Water and Salt Research Center, Institute of Clinical Medicine, Aarhus University Hospital, Brendstrupgaardsvej 100, 8200, Aarhus N, Denmark.
Jørgen
J
Frøkiær
Department of Urology, Pediatric Section, Aarhus University Hospital, Brendstrupgaardsvej 100, 8200, Aarhus N, Denmark.
Troels Munch
TM
Jørgensen
D000209:Acute-Phase Proteins / Q000652:urine*; D000293:Adolescent; D000367:Age Factors; D015415:Biomarkers / Q000652:urine; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D055316:Cystatin C / Q000652:urine*; D003952:Diagnostic Imaging; D005260:Female; D006801:Humans; D006869:Hydronephrosis / Q000175:diagnosis / Q000209:etiology / Q000601:surgery / Q000652:urine*; D007118:Immunoassay; D007223:Infant; D007231:Infant, Newborn; D000071068:Lipocalin-2; D054834:Lipocalins / Q000652:urine*; D008297:Male; D053495:Osteopontin / Q000652:urine*; D011237:Predictive Value of Tests; D011446:Prospective Studies; D011518:Proto-Oncogene Proteins / Q000652:urine*; D012372:ROC Curve; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D015607:Stents; D013997:Time Factors; D016896:Treatment Outcome; D015854:Up-Regulation; D014517:Ureteral Obstruction / Q000150:complications* / Q000175:diagnosis / Q000601:surgery; D013520:Urologic Surgical Procedures / Q000295:instrumentation; D001613:beta 2-Microglobulin / Q000652:urine*
D000209:Acute-Phase Proteins; D015415:Biomarkers; C525030:CST3 protein, human; D055316:Cystatin C; C489506:LCN2 protein, human; D000071068:Lipocalin-2; D054834:Lipocalins; D011518:Proto-Oncogene Proteins; C506895:SPP1 protein, human; D001613:beta 2-Microglobulin; D053495:Osteopontin