Urinary Nerve Growth Factor as a Potential Biomarker of Treatment Outcomes in Overactive Bladder Patients

Nerve Growth Factor and Brain-Derived Neurotrophic Factor as Potential Biomarkers of Mirabegron Efficacy in Patients with Overactive Bladder Syndrome

INTRODUCTION

Overactive Bladder Syndrome (OAB) significantly impacts quality of life, necessitating improved diagnostic tools and treatment monitoring. This study explores the potential of neurotrophins, nerve growth factor (NGF), and brain-derived neurotrophic factor (BDNF) as urinary biomarkers in patients with OAB undergoing mirabegron therapy, a β3-adrenergic agonist. This investigation is aimed at providing insights into the potential of neurotrophins to enhance OAB diagnosis and assess treatment efficacy.

MATERIALS AND METHODS

Urinary NGF and BDNF levels were measured in 15 healthy controls and 30 patients with OAB. Patients were treated with mirabegron 50 mg once daily. Urinary NGF and BDNF levels were measured by enzyme-linked immunosorbent assay method and normalized by urinary creatinine levels (NGF/Cre and BDNF/Cre). The urinary NGF/Cre and BDNF/Cre levels were compared between controls and patients with OAB and subsequently at baseline and 3 months after mirabegron treatment. Treatment efficacy was assessed with the Indevus Urgency Severity Scale (IUSS) questionnaire.

RESULTS

Urinary NGF/Cre and BDNF/Cre levels were significantly higher in patients with OAB than in the controls (p < 0.001 and p = 0.03 respectively). Moreover, NGF/Cre and BDNF/Cre levels significantly decreased post-mirabegron treatment (p < 0.001 and p = 0.005 respectively). Patients with improvement of OAB symptoms after treatment showed lower levels of NGF/Cre at the 3-month evaluation than those with no improvement (p = 0.05).

CONCLUSION

Although both NGF/Cre and BDNF/Cre levels were significantly decreased after mirabegron treatment, only NGF/Cre levels were associated with treatment response.

Role of urine glycosaminoglycan levels in the diagnosis and follow-up in men with lower urinary tract symptoms

OBJECTIVE

The aim of this study was to investigate whether urinary glycosaminoglycans (GAG) levels reflect clinical status in men with lower urinary tract symptoms and if they could be used as a marker in management of overactive bladder (OAB).

METHODS

A total of 34 patients were recruited who were admitted with LUTS and diagnosed as having clinically bladder outlet obstruction (BOO) due to prostate enlargement. These newly diagnosed, never treated patients underwent routine investigation, consisting of history, physical examination, PSA, ultrasound, uroflowmetry, assessment of symptoms scored by both International Prostate Symptom Score (IPSS) and Marmara- Overactive Bladder Questionnaire (M-OBQ). The patients were divided into two groups as those with an initial M-OBQ score < 12 (group 1) and ≥ 13 (group 2). Alfa blocker was initiated in eligible patients. Further evaluations included prostate volume measurement, pre- and post-treatment urinary GAG levels, IPSS and M-QAOB values and maximum urine flow rate (Qmax).

RESULTS

Before treatment, urinary GAG level was 21.5 mg/gCr (6.1-45.5) in Group 1, and 23.35 mg/gCr (15.6-32.6) in Group 2 (p =0.845). After the treatment, the GAG level in Group 1 and Group 2 were found to be 19.8 mg/gCr (7.4-70.5) and 18 (7.6- 41.7), respectively (p = 0.511). No difference in GAG levels was found in subgroup analysis for patients with or without OAB.

CONCLUSIONS

In recent years, there have been many studies investigating the relationship between LUTS and urinary markers. However, in our prospective study, no relationship was found between pre- and post- treatment urinary GAG levels in patients with LUTS with or without OAB.

Urinary beta 3-adrenoceptor as a diagnostic biomarker for overactive bladder in women

This study was to investigate urinary beta 3-adrenoceptor concentration as a biomarker for overactive bladder (OAB) and predictor of treatment outcomes in women receiving the beta 3-adrenoceptor agonist mirabegron. The study comprised 50 women identified with OAB and 35 women considered as healthy controls. All women with OAB received daily dosage of 50 mg of mirabegron for 12 weeks. Bladder diaries, OAB-related questionnaires, and global response assessment scale (GRAS) data were collected. Urinary beta 3-adrenoceptor concentration was measured through enzyme-linked immunosorbent assay. All OAB-related questionnaires and GRAS indicated improved posttreatment urinary health. After mirabegron treatment, the frequency of micturition and urgency episodes decreased, but the urinary beta 3-adrenoceptor/creatinine (Cr) ratio increased. The urinary beta 3-adrenoceptor/creatinine ratio was identified as a sensitive biomarker for OAB with a confidence interval of 0.656 to 0.856 (p < 0.001). A negative correlation (- 0.431, p = 0.040) between this biomarker and health-related quality of life (HRQL) scores. The Beta 3-adrenoceptor/Cr levels increased significantly in the treatment-responsive group, while they remained unchanged in the unsatisfactory outcome group. This study shows that 12 weeks of mirabegron treatment improves OAB symptoms and HRQL. Furthermore, urinary beta 3-adrenoceptor concentration may be a diagnostic biomarker for OAB.

Functional recovery of injured cavernous nerves achieved through endogenous nerve growth factor-containing bioactive fibrous membrane

Radical prostatectomy is a highly successful treatment for prostate cancer, among the most prevalent manifestations of the illness. Damage of the cavernous nerve (CN) during prostatectomy is the main cause of postoperative erectile dysfunction (ED). In this study, the capability of a personalized bioactive fibrous membrane to regenerate injured CN was investigated. The fibrous membrane bioactivity is conferred by the selectively bound nerve growth factor (NGF) present in the rat urine. In a rat model of bilateral CN crush, the implanted bioactive fibrous membrane induces CN regeneration and restoration of erectile function, showing a significantly increased number of smooth muscle cells and content of endothelial and neuronal nitric oxide synthases (eNOS; nNOS). In addition, the bioactive fibrous membrane promotes nerve regeneration by increasing the number of myelinated axons and nNOS-positive cells, therefore reversing the CN fibrosis found in untreated rats or rats treated with a bare fibrous membrane. Therefore, this personalized regenerative strategy could overcome the recognized drawbacks of currently available treatments for CN injuries. It may constitute an effective treatment for prostate cancer patients suffering from ED after being subject to radical prostatectomy. STATEMENT OF SIGNIFICANCE: The present work introduces a unique strategy to address post-surgical ED resulting from CN injury during pelvic surgery (e.g., radical prostatectomy, radical cystoprostatectomy, abdominoperineal resection). It comprises a bioactive and cell-free fibrous implant, customized to enhance CN recovery. Pre-clinical results in a rat model of bilateral CN crush demonstrated that the bioactive fibrous implant can effectively heal injured CN, and restore penile structure and function. This implant selectively binds NGF from patient fluids (i.e. urine) due to its functionalized surface and high surface area. Moreover, its local implantation reduces adverse side effects. This tailored regenerative approach has the potential to revolutionize the treatment of ED in prostate cancer patients following radical prostatectomy, overcoming current treatment limitations.

Discriminating Different Bladder and Bladder Outlet Dysfunctions by Urinary Biomarkers in Women with Frequency–Urgency Syndrome

Objectives: To investigate the role of urinary biomarkers in discriminating different bladder and bladder outlet dysfunctions in women with frequency–urgency syndrome. Materials and Methods: Urine samples collected from 146 women with frequency–urgency syndrome and 34 controls were investigated. All patients were included in previous clinical trials of functional urology studies and underwent a videourodynamic study. Patients with frequency–urgency syndrome were subdivided into idiopathic detrusor overactivity (IDO), neurogenic detrusor overactivity (NDO), dysfunctional voiding (DV), and hypersensitive bladder (HSB) subgroups. Urine samples were collected before any treatment, and urinary inflammatory proteins (interleukin- (IL-) 1β, IL-2, IL-6, IL-8, tumor necrosis factor-α (TNF-α), and vascular endothelial growth factor (VEGF)), neurogenic proteins (nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF), and prostaglandin E2 (PGE2)), and oxidative stress biomarkers (8-isoprostane, total antioxidant capacity (TAC), and 8-hydroxydeoxyguanosine (8-OHdG)) were measured and compared between the different OAB subgroups and controls. Results: Of the 146 patients, 31 had IDO, 41 had NDO, 45 had DV, and 29 had HSB. The control group included 34 women. The patients with HSB had lower urinary TAC and IL-2 levels than the controls. The patients with IDO, NDO, and DV had significantly higher urinary TNF-α levels than those with HSB. The patients with IDO and NDO showed an increase in the urinary 8-isoprostane levels, whereas the patients with IDO had higher urinary IL-2, NGF, and BDNF levels than those with NDO. The other urinary inflammatory biomarkers did not show enough significant differences to discriminate between the different bladder and bladder outlet dysfunctions. Conclusions: The urinary levels of inflammatory, neurogenic, and oxidative stress biomarkers varied widely among the patients with bladder and bladder outlet dysfunction. This study’s results provide evidence that women with frequency–urgency syndrome and different urodynamic subtypes have varying bladder inflammation and oxidative stress conditions, which might have an impact on treatment outcomes.

The Urobiome and Its Role in Overactive Bladder

Urine is no longer considered to be sterile. After the existence of the microbiome was revealed through metagenomic analysis using next-generation sequencing, the relationship between characteristics of the microbiome and diseases have been studied and published in various journals. A microbiome exists in the urinary tract and is associated with urinary tract infection, malignancy of the genitourinary tract, and lower urinary tract symptoms. Based on the urine sampling method, sampling site, culture method, and sex, the characteristics of the microbiome vary. Most of the Lactobacillus species are identified mainly in women, and various other species are identified in men. These microorganisms can cause or prevent various diseases. Variations in the microbiome are seen in those with and without disease, and an asymptomatic status does not indicate the absence of microbes. This microbiome has been implicated in a variety of lower urinary tract symptoms and diseases, in particular, overactive bladder. The microbiome differs between patients with urgency and urge urinary incontinence and healthy individuals. There are many aspects of the microbiome yet to be studied in relation to other lower urinary tract symptoms.

The use of urinary biomarkers in the diagnosis of overactive bladder in female patients. A systematic review and meta-analysis

INTRODUCTION AND HYPOTHESIS

Nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF), and other proteins are related to overactive bladder (OAB) syndrome, as their urinary concentrations are significantly different from those of the general non-OAB population. This review aims to systematically assess whether NGF, BDNF, and other urinary by-products can be used as potential biomarkers to manage women with OAB.

METHODS

This was a systematic review and metanalysis that was conducted according to PRISMA guidelines. Studies were identified by electronic search of Medline, Scopus, ScienceDirect, Embase, and Cochrane Register until October 2020. The included studies investigated the correlation of OAB with NGF, BDNF, and other potential biomarkers in symptomatic women and their controls.

RESULTS

Twelve studies (581 female OAB patients and 394 female controls) were included. Urinary NGF, NGF/Cr, BDNF/Cr, ATP/Cr, and PGE2/Cr ratios were identified as potential biomarkers in female OAB patients. Results of the meta-analysis indicated that uNGF [standard mean difference (SMD) 1.45, 95% CI 0.53-2.36], NGF/Cr ratio (SMD 1.23, 95% CI 0.67-1.78), BDNF/Cr ratio (SMD 0.78, 95% CI 0.006-1.50), and BDNF/Cr ratio (RR 0.78, 95% CI 0.006-1.50) were increased in female OAB patients compared to healthy controls, whereas no difference was found for the PGE2/Cr and ATP/Cr ratios. Current data are inadequate to assess any other potential biomarkers, such as urinary MDA, ATP, and cytokines, in the management of OAB in female patients.

CONCLUSIONS

uNGF, NGF/Cr, and BDNF/Cr ratio could be used in the assessment of female OAB patients. Further studies are needed to specify OAB urinary titer levels in OAB subgroups and healthy women and their potential as diagnostic and management tools in OAB women.

An Examination of the Relationship between Urinary Neurotrophin Concentrations and Transcutaneous Electrical Nerve Stimulation (TENS) Used in Pediatric Overactive Bladder Therapy

This article aims to explore changes in urinary concentrations of selected neurotrophins in the course of TENS therapy in children with overactive bladder (OAB). A two-group open-label prospective study was conducted. The intervention group comprised 30 children aged between 5 and 12 years old with OAB refractory to conservative therapy. They received 12 weeks of TENS therapy in a home setting. The urinary neurotrophins, NGF, BDNF, NT3, NT4, were measured by ELISA at baseline and at the end of the TENS therapy. Total urinary neurotrophins levels were standardized to mg of creatinine (Cr). We compared the results with the reference group of 30 participants with no symptoms of bladder overactivity. The results revealed that children with OAB both before and after TENS therapy had higher NGF, BDNF, and NT4 concentrations in total and after normalization to Cr than the reference group in contrast to NT3. The response to the therapy expressed as a decrease of urinary neurotrophins after TENS depended on the age and the presenting symptoms. In conclusion, children older than 8 years of age with complaints of daytime incontinence responded better to TENS.

Correlation between the NGF levels and questionnaire forms in patients receiving antimuscarinic treatment and those receiving onabotulinum toxin-A injection

OBJECTIVE

To compare nerve growth factor (NGF) levels in patients who received antimuscarinic, versus onabotulinum toxin-A (onaBoNT-A) injection, as well as to investigate whether there is a correlation between NGF levels, and 8-item overactive bladder questionnaire(OAB-V8), urogenital distress inventory (UDI)-6, and incontinence impact questionnaire (IIQ)-7 forms.

MATERIAL AND METHODS

Fourty adult patients with OAB were enrolled in this prospective study. An antimuscarinic was prescribed to 20 naive patients, and onaBoNT-A injection was administered to 20 patients, who were refractory to antimuscarinics. Urine samples were obtained before, and after 3^rd and 6^th months of treatment, and NGF levels were measured. Symptom scores of OAB-V8, UDI-6,and IIQ-7 were recorded.

RESULTS

There was no significant difference between groups in terms of the initial OAB-V8, IIQ-7, and UDI-6 scores, whereas NGF values showed no significant difference over time in onaBoNT-A group (p=0.069, p=0.069). NGF levels were significantly lower in 3^rd and 6^th months, in patients receiving antimuscarinic (p=0.003, p=0.007); a strong correlation was found in 3rd month between the NGF levels, OAB-V8 scores (r=0.704, p=0.001), and IIQ-7 scores (r=0.676, p=0.001), and a moderate correlation between NGF levels, and UDI-6 scores (r=0.583, p=0.007). In the 6^th months, a very strong correlation was found between NGF levels, and OAB-V8 scores (r=0.811, p=0.004), and a strong correlation was found between NGF levels, and IIQ-7 scores (r=0.671, p=0.001). In onaBoNT-A group, there was no significant correlation between NGF levels, and other variables.

CONCLUSION

NGF level might be a good marker to evaluate effectiveness of treatment in patients receiving antimuscarinics, owing to correlation of urinary NGF levels with symptom scores. Lack of correlation in patients receiving onaBoNT-A injection could be a result of differences in the mechanism of action.

Application of methylene blue as an improvement of the injection technique of botulinum toxin A in the treatment of refractory idiopathic overactive bladder: prospective, single-blind (patient-blind), randomized trial

Introduction

Refractory idiopathic overactive bladder (RIOAB) is a common condition with a significant negative impact on quality of life. Intravesical injection of botulinum toxin A (BTX-A) is widely used as an intervention for these cases. In the standard method the drug solution is colorless. The addition of dye such as methylene blue (MB) facilitates visualization during the procedure and may have a beneficial effect.

Aim

To evaluate the injection of BTX-A with the addition of methylene blue (MB) against a standard method in the treatment of RIOAB.

Material and methods

In this 1-center, single-blinded, randomized controlled trial, we recruited 80 patients with RIOAB. A total of 39 were assigned to injection into the bladder wall of 100 U BTX-A with MB (in 9.5 ml normal saline + 0.5 ml MB), and 41 were assigned to BTX-A 100 U alone (in 10 ml normal saline). Cystoscopy with a submucosal injection of the solution was performed systematically, including the bladder triangle. Participants were assessed 6 and 12 weeks after the treatment using a Likert scale and OABSS questionnaire.

Results

Significant improvement was similar (result of 1 or 2 on the Likert scale) and was achieved in 66.7% and 69.2% after 6 weeks and in 63.9% and 64.1% after 12 weeks in the BTX-A + MB group and only-BTX-A group, respectively. There was a significant difference between the two groups (p = 0.049) in the total number of patients with complications: 2 (5.6%) vs. 9 (23.1%).

Conclusions

The addition of MB to BTX for treatment of RIOAB patients does not influence treatment efficacy, while it limits the risk of complications.