Urinary nerve growth factor in children with overactive bladder: A promising, noninvasive and objective biomarker

Objective: This prospective study was designed to determine urinary nerve growth factor (NGF) levels in children with overactive bladder (OAB), and to evaluate whether this factor can be used as a biomarker for diagnosis and monitoring treatment outcome. Patients and methods: Urinary NGF levels were determined in 40 children with OAB and in a control group of 20 children with no urinary symptoms. Urine samples were collected from the patients prior to and at 3 and 6 months after the beginning of treatment. The total NGF levels (pg/mL) were further normalized to the concentration of urinary creatinine (NGF/Cr level). Results: Overall, both NGF and NGF/Cr levels were significantly higher at the beginning of the study. Mean NGF levels were 30.75 +/- 8.35 and 9.75 +/- 2.11 pg/ml (p=0.023) and mean NGF/Cr levels were 0.53 +/- 0.14 and 0.16 +/- 0.04 (p = 0.022) in patients and controls, respectively. After 6 months of therapy, the NGF/Cr level was significantly reduced to almost control levels (0.16 +/- 0.02, p = 0.047). Conclusion: NGF and NGF/Cr levels were significantly higher in children with OAB than controls at initial evaluation. Furthermore, the NGF/Cr level was significantly reduced following 6 months of therapy. NGF and NGF/Cr levels show promise as reliable biomarkers for OAB diagnosis and to monitor therapy in the pediatric age group. (C) 2012 Journal of Pediatric Urology Company. Published by Elsevier Ltd. All rights reserved.