Increased nerve growth factor in neurogenic overactive bladder and interstitial cystitis patients.

Abstract

OBJECTIVES: Studies have suggested that pathology of the lower urinary tract can be detected by following changes in urinary proteins. We evaluated urine nerve growth factor (NGF) levels from patients with a variety of urologic conditions to examine NGF's role as a future biomarker. MATERIALS AND METHODS: Urine samples were obtained from 72 patients with normal non-diseased urinary tracts (n = 13), neurogenic overactive bladder (NOAB) (n = 13), idiopathic overactive bladder (OAB) (n = 17), interstitial cystitis/painful bladder syndrome (IC/PBS) (n = 8), prostate cancer (n = 7), history of prostate cancer status post robot-assisted laparoscopic prostatectomy (RALP) (n = 6), active bladder cancer (n = 4), and nephrolithiasis (n = 4). Urinary NGF levels were measured by enzyme linked immunosorbent assay (ELISA) using the Emax ImmunoAssay System (Promega, Madison, WI, USA); each NGF level was normalized to the patient's urine creatinine (Cr) level. The Bonferroni correction was used to adjust for multiple comparisons. RESULTS: Urinary NGF/Cr levels were significantly elevated in patients with NOAB (23.02 pg/mg (0-293), p = 0.004) and IC/PBS (31.24 pg/mg (0-291), p = 0.006); and approached significance in patients with nephrolithiasis (19.46 pg/mg (0-85), p = 0.06) compared to controls (0.00 pg/mg (0-12). CONCLUSIONS: Urinary NGF levels were significantly elevated in patients with NOAB and IC/PBS. Future studies are needed to further examine the significance of urinary NGF levels in the pathogenesis of a variety of urologic diseases and whether NGF could be used as a diagnostic or prognostic marker for specific urologic diseases.