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

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.