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

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.

Brain-derived neurotrophic factor (BDNF): an effect biomarker of neurodevelopment in human biomonitoring programs

The present narrative review summarizes recent findings focusing on the role of brain-derived neurotrophic factor (BDNF) as a biomarker of effect for neurodevelopmental alterations during adolescence, based on health effects of exposure to environmental chemical pollutants. To this end, information was gathered from the PubMed database and the results obtained in the European project Human Biomonitoring for Europe (HBM4EU), in which BDNF was measured at two levels of biological organization: total BDNF protein (serum) and BDNF gene DNA methylation (whole blood) levels. The obtained information is organized as follows. First, human biomonitoring, biomarkers of effect and the current state of the art on neurodevelopmental alterations in the population are presented. Second, BDNF secretion and mechanisms of action are briefly explained. Third, previous studies using BDNF as an effect biomarker were consulted in PubMed database and summarized. Finally, the impact of bisphenol A (BPA), metals, and non-persistent pesticide metabolites on BDNF secretion patterns and its mediation role with behavioral outcomes are addressed and discussed. These findings were obtained from three pilot studies conducted in HBM4EU project. Published findings suggested that exposure to some chemical pollutants such as fine particle matter (PM), PFAS, heavy metals, bisphenols, and non-persistent pesticides may alter circulating BDNF levels in healthy population. Therefore, BDNF could be used as a valuable effect biomarker to investigate developmental neurotoxicity of some chemical pollutants.

Development and validation of brain-derived neurotrophic factor measurement in human urine samples as a non-invasive effect biomarker

Background

Brain-derived neurotrophic factor (BDNF), a neurotrophic growth factor mainly expressed in the brain, has been proposed as a potential effect biomarker; that is, as a measurable biomarker whose values could be associated with several diseases, including neurological impairments. The European Human Biomonitoring Initiative (HBM4EU) has also recognized effect biomarkers as a useful tool for establishing link between exposure to environmental pollutants and human health. Despite the well-establish protocol for measuring serum BDNF, there is a need to validate its assessment in urine, a non-invasive sample that can be easily repeated over time. The aim of this study was to develop, standardize and validate a methodology to quantify BDNF protein levels in urine samples before its implementation in biomonitoring studies.

Methods

Different experimental conditions and non-competitive commercial enzyme-linked immunosorbent assay (ELISA) kits were tested to determine the optimal analytical procedure, trying to minimize the shortcomings of ELISA kits. The fine-tune protocol was validated in a pilot study using both upon awakening (n = 150) and prior to sleeping (n = 106) urine samples from the same Spanish adolescent males in a well-characterized study population (the Spanish INMA-Granada cohort).

Results

The best results were obtained in 0.6 ml of urine after the acidification and extraction (pre-concentration) of samples. The highest reproducibility was obtained with the ELISA kit from Raybiotech. Urinary BDNF concentrations of adolescent males were within the previously reported range (morning = 0.047-6.801 ng/ml and night = 0.047-7.404 ng/ml). Urinary BDNF levels in the awakening and pre-sleep samples did not follow a normal distribution and were not correlated.

Conclusion

The developed methodology offers good sensitivity and reproducibility. Having reliable markers in urine may facilitate both diagnosis and monitoring possible diseases (and treatment). Further studies are needed to implement urinary BDNF in biomonitoring studies to further elucidate its usefulness and biological significance for neurological impairments.

Non-dipping phenomenon effects in monosymptomatic nocturnal enuresis treatment?

BACKGROUND

Monosymptomatic enuresis nocturna patients are shown to have disrupted blood-pressure regulation accompanying polyuria. In our study, we aimed to research the desmopressin response of enuresis patients with blood-pressure regulation problems.

METHODS

The study included 175 patients, aged from 6-15 years, with a diagnosis of monosymptomatic enuresis nocturna. Before treatment, 24 h ambulatory blood-pressure monitoring (ABPM) was used to identify 52 non-dipper patients and 73 patients with normal results. The responses to desmopressin treatment and clinical and demographic characteristics affecting response were compared.

RESULTS

The response to desmopressin treatment was found to be significantly low in the patients who were non-dippers on 24 h ABPM before treatment compared to those with normal ABPM results (P < 0.05). Similarly, the waking problems in the non-dipper group were found to be high by a significant degree (P < 0.05). In the non-dipper group, the systolic non-dipping rate was higher.

CONCLUSIONS

Before desmopressin use, assessment of patients with a 24 h ABPM may be beneficial to select the method to be used for treatment.

Evaluation of Functional Bladder Capacity in Children with Nocturnal Enuresis According to Type and Treatment Outcome

Purpose

This study aimed to identify whether functional bladder capacity (FBC) differs among subgroups of nocturnal enuresis (NE) patients and can be used to predict treatment response.

Methods

A total of 69 children with NE were included in this study between July 2017 and February 2019 according to medical chart review, retrospectively. All patients completed a questionnaire about voiding symptoms and 48-hour frequency/volume (48-h F/V) charts. FBC was obtained from the 48-h F/V charts and uroflowmetry (UFM) with post-void residual volume (PVR). All patients were primarily treated with standard urotherapy and pharmacological therapy. The response rate was analyzed at 3 months after treatment.

Results

The mean age of the 69 patients (42 male, 27 female) was 83.3 ± 22.4 months (range, 5–13 years) at the first visit. The percentages of children with monosymptomatic NE (MNE) and non-monosymptomatic NE (NMNE) on the questionnaire were 40.6% (28/69) and 59.4% (41/69), respectively. FBC of all patients was lower than the normal range of expected bladder capacity, and there were no significant differences between measurement methods, NE types (MNE vs NMNE), or response rates (p > 0.05).

Conclusion

Children with NE had diminished FBC in both 48-h F/V charts and UFM with PVR. We found no difference in FBC by NE type or treatment outcome. Therefore, FBC cannot be used to distinguish between NE types or predict treatment responses.