Urinary proteins as OAB biomarker, therapeutic efficacy predictor in paediatric patients
Urinary nerve growth factor (NGF)/creatinine (Cr) levels, aside from being a potential biomarker for paediatric overactive bladder (OAB), may also predict therapeutic efficacy in children with OAB, a study suggests.
The study included 35 children with OAB (77.1 percent male) and 11 healthy controls (54.5 percent male). Enzyme-linked immunosorbent assay was used to measure urinary NGF levels, and the resulting values were corrected for the concentration of urinary Cr (NGF/Cr level). Urinary NGF/Cr was measured and compared between paediatric OAB patients and controls. The association between urinary NGF/Cr and treatment outcomes was also examined.
Children with OAB had significantly higher urinary NGF/Cr compared with controls (0.65±0.82 vs 0.11±0.09; p=0.0007). Among OAB patients, 74 percent demonstrated symptom improvement, while the remaining 26 percent had refractory symptoms (defined as little improvement in OAB symptoms despite at least 3 months of urotherapy and anticholinergic agent treatment). Urinary NGF/Cr was also significantly higher in the subgroup of patients with refractory symptoms than in the subgroup of those with improved symptoms (1.28±1.34 vs 0.44±0.39; p=0.027).
The current data highlight the potential of urinary NGF/Cr levels as an OAB biomarker and a predictor of therapeutic efficacy in paediatric patients.
OAB is characterized by urinary urgency with or without urge incontinence and is typically accompanied by frequency and nocturia. Evidence indicates that OAB patients have increased urinary proteins including NGF and prostaglandin E2, bladder outlet obstruction and detrusor overactivity. The increased urinary NGF levels are physiological in healthy individuals at urge to void and pathological in OAB patients at a small bladder volume and with a sensation of urgency. [Rev Urol 2010;12:e69–e77]