Re: Sheng W, Zhang H, Kirschner‐Hermanns R. Could urinary nerve growth factor be a biomarker for overactive bladder? A meta‐analysis. Neurourol Urodyn. 2017;9999:1–8. doi: 10.1002/nau.23210

Abstract

Sheng et al (Neurourology and Urodynamics 2017; DOI: 10.1002/nau.23210) presented a meta-analysis based on 17 publications to show that urinary nerve growth factor (NGF) may be a useful biomarker for overactive bladder syndrome (OAB). Unfortunately, 13 of the 17 studies used an unspecifc enzyme-linked immunosorbent assay (ELISA), the Promega NGF Emax Immunoassay, to quantify NGF in urine. This assay did not detect NGF in urine, but other urinary components, such as immunoglobulin G, and in 2014, it was withdrawn from the market. With other NGF-ELISAs, urinary NGF concentrations were found to be below detection level for both, OAB and healthy controls. Currently, ELISA techniques are not sensitive enough to detect NGF in urine, and urinary NGF cannot be used as a biomarker for OAB.

Urinary brain-derived neurotrophic factor and nerve growth factor as noninvasive biomarkers of overactive bladder in children

“…One of the most important is the limited sensitivity of current ELISA technology for determining urinary BDNF and NGF concentrations. In their letter to the editor on a meta-analysis on the usefulness of NGF as a biomarker in urine OBA, Gamper and Viereck emphasise that many studies used ELISA kits from Promega (Promega, Madison, USA) that were later shown to quantify urine components other than NGF and were therefore withdrawn from the market (25). They also refer to two of the above-mentioned studies in which NGF concentrations were below the limit of detection, which is consistent with our study (20,21).…”