Several studies indicate that the prevalence of overactive bladder (OAB) symptoms is higher in individuals with pelvic organ prolapse (POP) compared to those without POP. Bladder outlet obstruction resulting from POP is likely the primary mechanism behind the onset of OAB symptoms. Recent research suggests that certain biomarkers may qualify as potential diagnostic aids and could contribute to personalized patient profiles. Evaluating the diagnostic accuracy of these biomarkers would help clarify their usefulness in women with OAB. 
This is an original research project. The aim of this study was to investigate the changes in the levels of urine neurotrophic factors (NGF and BDNF) in women with POP and OAB in comparison to POP-only women, who were all treated with native tissue vaginal surgery.

This prospective case-control study was approved by the Institutional Ethics Committee. Written informed consent was obtained from all the women enrolled. Participants were recruited from January 2018 till January 2022, and divided to POP only (controls) or POP-OAB groups, using as criterion the score in question 3 from the ICIQ-FLUTS questionnaire (scores >1 identified those with OAB). 
Demographic data such as age and body mass index (BMI), parity, birth weight, instrumental birth, menopause status, smoking was collected. Participants were excluded if they had any previous pelvic surgery, radiotherapy, urinary tract infection, renal or hepatic disease, known cancer, neurologic or autoimmune disease, or any invasive OAB therapy. Prolapse assessment using POP-Q and multichannel urodynamics were performed both pre-operatively and 3 months post-operatively. All participants completed standardized questionnaires (ICIQ-UI SF, ICIQ-FLUTS, and ICIQ-VS). The Patient Global Impression of Improvement (PGI-I) and Severity (PGI-S) scores were used to evaluate the patients' satisfaction after surgery. Pre- and Post-operatively NGF and BDNF were collected and their concentrations were determined using the Human Beta Nerve Growth Factor ELISA Kit (NGFB) (Abcam,USA) and Total BDNF Quantikine ELISA Kit (Bio-Techne brands,R&D systems, Minneapolis, USA). Statistics were performed using Microsoft EXCEL.

A total of 112 women were enrolled: n = 58 in the POP-OAB group and n = 54 in the control POP only group. Patients’ demographic characteristics are displayed in Table 1. Upon entry into the study the two groups were not different in terms of age, BMI, parity, and years in menopause. Similarly, there were no differences in prolapse severity pre-operatively (Table 2). The mean NGF and NGF/Cr were 59.1±12.8vs20±5 (p<0.000) and 1.1±2.1vs 0.3±0.5 (p<0.001) in OAB and control group, respectively. The mean BDNF and BDNF/Cr were 13.7±3.8 vs 5.3±1.3(p<0.000) and 0.23±0.4 vs 0.1±0.1 (p<0.000) and in OAB and control group, respectively. 
All patients underwent native tissue vaginal surgery. All procedures were completed without any major complications and performed by two experienced Urogynaecologists. There was no statistically significant difference in POP-Q measurements between the two groups of three months post-surgery. The mean NGF and NGF/Cr 52.1±24.1 vs 17.8±6.1 (p<0.000) and 1.6±2.4 vs 0.4±0.4, (p<0.001) respectively. The mean BDNF and BDNF/Cr were 29±57.3 vs 6.6±2.4 (p<0.001) and 0.9±2.1 vs 0.2±2, no statistically significant. (Table 2)

NGF and BDNF are increased in women with POP and OAB compared to women with POP without OAB. These findings support the potential role of these agents as biomarkers in the diagnosis and treatment success of these types of patients. OAB symptoms in patients with POP appear to diminish after addressing pelvic prolapse through native-tissue surgery. Recent studies indicate that more than 50% of patients will experience satisfactory post-operative management of OAB symptoms. In our study, we did not find any significant reduction in the levels of biomarkers post-operatively. It is more probable that the 3-month follow-up period is insufficient for these agents to achieve a reduction. The bibliography lacks consistency in its assessment of the correlation between urinary biomarkers and OAB symptoms.

Our findings suggest that in a consecutive case control study, native tissue POP surgery seems to be efficacious for the control of OAB symptoms in patients with POP and OAB. Neurotrophic factors as NGF, BDNF seem to be clinically useful in the assessment of female OAB patients. Additional research is needed to gather more comprehensive data regarding the correlation of urinary biomarkers between POP management and OAB patients.

de Boer TA, Salvatore S, Cardozo L, Chapple C, Kelleher C, van Kerrebroeck P, Kirby MG, Koelbl H, Espuna-Pons M, Milsom I, Tubaro A, Wagg A, Vierhout ME. Pelvic organ prolapse and overactive bladder. Neurourol Urodyn. 2010;29(1):30-9. doi: 10.1002/nau.20858. PMID: 20025017.
Bhide AA, Cartwright R, Khullar V, Digesu GA. Biomarkers in overactive bladder. Int Urogynecol J. 2013;24(7):1065-1072.
Johnson, Justine R. MD*; High, Rachel A. DO†; Dziadek, Olivia MD‡; Ocon, Adriana BS§; Muir, Tristi W. MD?; Xu, Jiaqiong PhD¶; Antosh, Danielle D. MD?. Overactive Bladder Symptoms After Pelvic Organ Prolapse Repair. Female Pelvic Medicine & Reconstructive Surgery 26(12):p 742-745, December 2020. | DOI: 10.1097/SPV.0000000000000700

Continence 12S (2024) 101500
DOI: 10.1016/j.cont.2024.101500