Urinary Nerve Growth Factor Can Predict Therapeutic Efficacy in Children With Overactive Bladder

Urinary biomarkers in children with neurogenic and non-neurogenic lower urinary tract dysfunction: A systematic review and meta-analysis

AIM

The aim of this systematic review is to assess urinary biomarkers studied in children with neurogenic and non-neurogenic lower urinary tract dysfunction (LUTD).

MATERIALS AND METHODS

The systematic review was conducted in accordance with the PRISMA guidelines. The screening was performed on PUBMED without any publication date limitation. Only original articles were included. Parameters related to the following topics were obtained: study design, characteristics of participants, number of participants, age, control group, types of biomarkers, measurement technique in urine, subgroup analysis, urodynamic findings, and outcome. Dutch Cochrane Checklist (DCC) and level of evidence by EBRO platform were used for quality assessment. Meta-analysis was performed with the Comprehensive Meta-Analysis Version 4 program.

RESULTS

A total of 494 studies were screened and 16 studies were included. 11 (68.75%) were conducted in children with non-neurogenic LUTD and 5 (31.25%) neurogenic LUTD. Nerve growth factor (NGF) was evaluated in 12 studies, brain-derived neurotrophic factor (BDNF) in 5, Tissue Inhibitor of Metalloproteinase-2 (TIMP-2) in 2, transforming growth factor beta-1 (TGF Beta-1) in 2, neutrophil gelatinase-associated lipocalin (NGAL) in 1, and Aquaporin-2 in 1. According to DCC, 10 (62.5%) articles were evaluated on 4 (37.5%) items and 4 articles on 5 items. The average score was 3.91+/-0.56. The level of evidence was found as B for 13 (81.25%) articles and C for 3 (18.75%). In meta-analysis, urinary NGF levels in children with non-neurogenic LUTS were significantly higher than in the healthy control group (Hedges's g = 1.867, standard error = 0.344, variance = 0.119, p = 0.0001).

CONCLUSION

Urinary biomarkers are promising for the future with their noninvasive features. However, prospective studies with larger sample sizes are needed to better understand the potential of urinary biomarkers to reflect urodynamic and clinical findings in children with LUTD.

Could urinary nerve growth factor and bladder wall thickness predict the treatment outcome of children with overactive bladder?

Objective:

Bladder wall thickness (BWTh) measurements and Nerve Growth Factor (NGF) /creatinine (Cr) values, as noninvasive tools, were found to predict daytime voiding problems in children with overactive bladder (OAB). The goal of this research was to examine if bladder wall thickness together with urine NGF/Cr could be a clinical utility in treatment outcome of OAB in children.

Patients and Methods:

A total of 60 children with OAB, (Group 1; n=40) and healthy normal controls (Group 2; n=20), aged 6-14 years old were involved in this prospective study. Children were evaluated with detailed history and physical examination, including neurologic examination, and were asked to complete a self-reported questionnaire and a 3-day bladder diary with the aid of their parents. Uroflowmetry was performed in all cases. Urinary nerve growth factor levels were measured by the ELISA and BWTh was measured trans-abdominally by one uro-radiologist specialized in pediatric ultrasonography. Urinary NGF levels were normalized by urinary creatinine levels and compared among all subgroups. Children with OAB received urotherapy as first line treatment at least for three months. 18 children refractory to urotherapy received anticholinergic therapy defined as group 3.

Results:

The median age of the study group was 10 (range 6 to 16). After urotherapy, 22 children had similar BWTh and NGF/Cr values compared to controls. (2.75 ± 1.15; 2.40 ± 1.00 mm; p=0.86 and 1.02 ± 0.10; 0.78 ± 0.15; p=0.12, respectively). After anticholinergic treatment, BWTh levels (2.25 ± 0.90; 2.40 ± 1.00 mm; p=0.94) and NGF/Cr values (0.95 ± 0.10; 0.78 ± 0.15; p=0.42, respectively) had no significantly difference compared to controls (Group 2).

In receiver operating characteristic analysis, bladder wall thickness was found to have sensitivity of 85% and specificity of 84.2% (3,20 AUC, 913; 95 %) and NGF/Cr had sensitivity of 90% and specificity of 92.1% (1,595; AUC, 947; 95 %) in predicting treatment outcome in children with OAB.

Conclusions:

Bladder wall thickness measurements and NGF/Cr values, as noninvasive tools, could guide outcomes in the treatment of children with overactive bladder.

Expression of Low Affinity Nerve Growth Factor Receptor p75 in Classic Bladder Exstrophy

Successful primary closure of classic bladder exstrophy (BE) is crucial for development of bladder capacity and voided continence. It is universally agreed that an intensive pain management including the use of caudal epidural anesthesia is an essential cornerstone for the outcome of this complex surgery. Whether and to what extent pain is caused by structural or functional changes is not yet known. The nerve growth factor (NGF) is regarded as a marker for pain in different bladder disorders. This prospective study investigated the role of histological alterations and NGF in patients with BE including 34 patients with BE and 6 patients with congenital vesicoureterorenal reflux (VUR) who served as controls. Between January 2015 and April 2020 transmural bladder biopsies were taken from the posterior bladder wall during delayed primary bladder closure. The samples were stained for histological evaluation and subjected to immunohistochemistry to analyze NGFR p75. Differences in histological alterations were examined with Fisher's exact test, and Mann-Whitney-U-test was used to compare the NGFR p75 staining intensity between patients with BE and controls. Patients with BE showed significantly more often acute inflammation (p < 0.001), squamous metaplasia (p = 0.002), and cystitis glandularis (p = 0.005) as well as NGFR p75 in the urothelium (p = 0.003) than patients with VUR. A limitation of this study is the small number of participants due to the rare disease entity. Similar to other painful bladder disorders, pain transmission in BE after intitial closure may in part be facilitated by elevated NGF signaling through its receptor.

Urinary nerve growth factor: a biomarker for detrusor overactivity in children? A meta-analysis and trail sequential analysis

PURPOSE

Based on, previously, a systematic review, urinary nerve growth factor (NGF) has emerged as one potentially noninvasive biomarker for detrusor overactivity (DO) in adults. We performed this systematic review to explore if NGF is a biomarker for DO in children.

METHODS

A literature search was conducted in PubMed, Embase, Web of science, and Cochrane Library. Copies of all relevant articles were retrieved for quality assessment and data abstraction by two reviewers. Primary outcome was pooled standardized mean difference (SMD) for NGF/Cr (NGF normalized to urine creatinine) level between DO group and controls.

RESULTS

Three case-control studies published from 2012 to 2016 were included with 74 patients and 70 controls. Children with DO had a significant higher baseline urinary NGF/Cr level compared to controls (SMD = 2.48, 95%CI = 0.85-4.10, P < 0.01). After treatment, the level of NGF/Cr decreased significantly compared to baseline level at 6th month time points (SMD = 0.94, 95%CI = 0.03-1.86, P = 0.04). We calculated the required information size to 99 patients for comparison of urinary NGF/Cr level between DO and controls by trail sequential analysis (TSA).

CONCLUSION

Based on this systematic review, NGF/Cr may be a noninvasive biomarker for DO in children in the future. However, based on TSA, more original studies are needed to clarify the role of NGF/Cr in the biomarker effect.

Urinary nerve growth factor can predict therapeutic efficacy in children with monosymptomatic nocturnal enuresis

AIM

To determine the urinary levels of nerve growth factor (NGF) and brain-derived neurotrophic factor (BDNF) in children with monosymptomatic nocturnal enuresis (MNE) and evaluate whether these factors can be used as biomarkers for the treatment outcome.

METHODS

NGF and BDNF levels were measured and compared in 38 children (28 boys and 10 girls) with MNE and 25 children (18 boys and 7 girls) with no urinary symptoms were assessed. The mean ages in the patient and control groups were 9 and 10 years, respectively (P = .49). The patients were treated with either alarm or desmopressin therapy.

RESULTS

The urinary NGF/creatinine and BDNF/creatinine ratios were significantly higher in the patient group than in the control group (P = .0003 and P = .0095, respectively). NGF and BDNF levels showed a significant positive correlation (P = .0020, r = 0.40). With respect to the degree of response, 19 patients (50%) showed complete response (CR) or partial response (PR), and 19 patients (50%) showed nonresponse (NR). The urinary NGF/creatinine and BDNF/creatinine ratios were significantly higher in the NR group than in the CR and PR groups (P = .0003 and P = .0003, respectively).

CONCLUSIONS

Urinary NGF/creatinine and BDNF/creatinine ratios were significantly higher in children with MNE than in healthy controls. Urinary NGF/creatinine can be predictive factors of a poor treatment outcome in children with MNE.