Phenotyping of interstitial cystitis/bladder pain syndrome

Clustering of Urinary Biomarkers to Identify Interstitial Cystitis Subtypes and Different Clinical Characteristics and Treatment Outcomes

Purpose: Interstitial cystitis/bladder pain syndrome (IC/BPS) is mysterious and difficult to diagnose without cystoscopic hydrodistention. This study aimed to explore non-invasive and highly reliable urine biomarkers to identify Hunner's IC (HIC) and different non-Hunner's IC (NHIC) subtypes. Methods: In total, 422 women with and without clinically diagnosed IC/BPS (n = 376 and 46, respectively) were retrospectively enrolled. Patients were diagnosed with HIC or NHIC by cystoscopic hydrodistention under anesthesia. Then, the maximal bladder capacity (MBC) and glomerulation grade were determined. Thirteen urine inflammatory cytokines, chemokines, and oxidative stress biomarkers based on the previously reported predictors of IC/BPS were assayed using commercial microsphere kits. The dataset was randomly divided into training (70%) and test (30%) sets for model construction and validation using logistic regression and stepwise variable selection techniques. To construct the predictive models, univariate analysis was performed to evaluate the discriminative power of each urinary biomarker, measured by the area under the curve (AUC). Biomarkers with AUC values < 0.6 were excluded from further modeling. Multivariate logistic regression was then employed, with variables selected through stepwise forward selection based on log-likelihood criteria. For dichotomization, cutoff values were determined using quartile ranges from the control group. The final model's performance was assessed using AUC, accuracy, sensitivity, and specificity in both training and test sets. Results: By setting the screening criterion to AUC ≥ 0.60, the potential urinary biomarkers for identifying IC/BPS cases were eotaxin, monocyte chemoattractant protein-1, tumor necrosis factor-alpha (TNF-α), 8-hydroxy-2'-deoxyguanosine (8-OHdG), and 8-isoprostane. Those for identifying HIC from the IC/BPS cohort were interleukin (IL)-6, IL-8, interferon γ-inducible protein 10 (IP-10), and regulated on activation, normal T-cell expressed and secreted (RANTES). A diagnostic algorithm using a cluster of urinary biomarkers included TNF-α ≥ 0.95 pg/mL or 8-OHDG ≥ 22.34 pg/mL and 8-isoprastane ≥ 22.34 pg/mL for identifying IC/BPS from the overall cohort; for identifying HIC from the IC/BPS cohort, the urinary IP-10 ≥ 3.74 pg/mL or IP-10 ≥ 19.94 pg/mL was added. Conclusions: Using a cluster of urinary biomarkers such as TNF-α or 8-OHdG and 8-isoprostane can identify IC/BPS from a study cohort, and adding the urinary IP-10 can distinguish HIC from IC/BPS cases.

Latent bladder hypersensitivity induced by neonatal cystitis in rats unmasked by segmental but not hetero-segmental inflammation

Rats which experienced neonatal bladder inflammation (NBI) have been demonstrated to exhibit latent bladder hypersensitivity with a nociceptive component that becomes unmasked by a second inflammatory insult as an adult. Manifested as augmented reflex and neuronal responses to urinary bladder distension (UBD), these NBI-induced changes are revealed by using inflammation of nearby structures as an adult pretreatment. The effect of inflammation in distant structures is not known. These studies examined visceromotor reflex responses and lumbosacral spinal dorsal horn neuronal responses to UBD in rats and compared effects of segmental (hindpaw) versus hetero-segmental (forepaw or face) inflammatory pretreatments in 192 female Sprague-Dawley rats raised from birth. On postnatal days 14-16 these rats underwent either NBI or control procedures. As adults, these rats received control injections or 0.1 ml Complete Freund's Adjuvant (CFA) injections into one of four sites. Three days later they were studied in reflex or spinal single-cell neuronal experiments where responses were evoked by UBD. Visceromotor responses to UBD were more robust in rats which had injections in the hindpaw (either side) but were not significantly affected by forepaw or facial injections. Similar results were identified in L6/S1 neurons with more robust UBD-evoked responses observed in rats receiving hindpaw CFA injections but not forepaw injections. These results indicate that latent bladder hypersensitivity induced by NBI is made manifest by segmental, but not hetero-segmental inflammatory stimuli. This observation correlates with pain in patients with interstitial cystitis who often have flares in symptoms associated with inflammation of nearby structures.

Sentiments of Individuals with Interstitial Cystitis/Bladder Pain Syndrome Toward Pentosan Polysulfate Sodium: Infodemiology Study

Background

Interstitial cystitis/bladder pain syndrome (IC/BPS) is a multifactorial, chronic syndrome involving urinary frequency, urgency, and bladder discomfort. These IC/BPS symptoms can significantly impact individuals' quality of life, affecting their mental, physical, sexual, and financial well-being. Individuals sometimes rely on peer-to-peer support to understand the disease and find methods of alleviating symptoms. The only US Food and Drug Administration-approved medication to treat IC/BPS is pentosan polysulfate sodium (PPS). However, ocular pigmentary maculopathy has been described in some individuals, with greater severity associated with prolonged PPS exposure.

Objective

While prior research has separately assessed the benefits and side effects of PPS, this study sought to identify (1) sentiments of individuals with IC/BPS toward PPS and (2) topics discussed by individuals with IC/BPS in conjunction with PPS through use of an internet peer-to-peer forum.

Methods

Data were collected from Inspire-an anonymous web-based health community where individuals gather by condition to find support and information. Sentiment analysis and percentages of negative, positive, and neutral sentiment for PPS discussions encompassing each topic was conducted using VADER (Valence Aware Dictionary for Sentiment Reasoning). Topic modeling was conducted using latent Dirichlet allocation. Words with the highest probability were ranked to categorize each topic, and authors manually investigated and labeled discussions.

Results

There were 354 forum posts related to PPS. Topic modeling with latent Dirichlet allocation revealed 5 topic categories: "ineffectiveness or discontinued use," "alternative treatments," "personal treatment suggestions based on experience," "severe side effects," and "risk of long-term use." Topics related to "severe side effects" and "risk of long-term use" garnered less discussion, with the former also having the lowest positive sentiment (4.28, 14.29%). The topic "ineffectiveness or discontinued use" was most frequently discussed. This topic also had the highest percentage of negative posts (52/152, 34.21%). However, the average compound score was within the neutral compound score range (-0.094, SD 0.625). In addition, forum data highlighted individuals' acknowledgment of the efficacy of PPS in improving their quality of life, with statements such as "saved my sanity" being representative. The overall compound individuals' sentiment toward PPS was -0.083, split across 32.49% (115/354) negative, 22.03% (78/354) positive, and 45.48% (161/354) neutral sentiment categories.

Conclusions

The overall authentic sentiment toward PPS is broad but balances to neutral. This neutral sentiment suggests that while some individuals express concerns about the side effects and long-term risks associated with PPS, others appreciate its positive impact on their quality of life. This research confirms that individuals with IC/BPS actively engage with health forums like Inspire to seek information, share their experiences, and explore different treatment options. As IC/BPS remains a complex syndrome, this study highlights the value of patient-led discussions in informing treatment decisions. Furthermore, these findings suggest that health care providers might benefit from considering the insights shared on peer-to-peer forums to better understand individual preferences, concerns, and expectations.

APRIL/BAFF upregulation is associated with clonal B-cell expansion in Hunner-type interstitial cystitis

Hunner-type interstitial cystitis (HIC) is a chronic inflammatory disease of the urinary bladder with an unknown etiology. We conducted comprehensive immunogenomic profiling of bladder specimens obtained by biopsy and cystectomy from 37 patients with HIC. Next-generation RNA sequencing demonstrated abundant plasma cell infiltration with frequent light chain restriction in HIC-affected bladder tissue. Subsequent analysis of the B-cell receptor repertoire revealed spatial and temporal expansion of B-cell clones. The extent of B-cell clonal expansion was significantly correlated with the gene expression levels of TNFSF13 and TNFSF13B, which encode APRIL and BAFF, respectively. These findings indicate that APRIL and BAFF are the key regulators of clonal B-cell expansion in HIC and might serve as therapeutic targets in this debilitating disease. © 2024 The Author(s). The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.

[A glass of clean water - A guide to diagnosing and treating bladder pain syndrome]

A húgyhólyagfájdalom-szindróma (latin nevén cystitis interstitialis) kivizsgálásának és kezelésének számos elismert és tudományosan alátámasztott, ugyanakkor sok alternatív, kevesebb evidenciával rendelkező megoldása és módozata ismert. Munkánkban összegyűjtöttük a kórállapotra vonatkozó hazai és nemzetközi irányvonalakat és útmutatásokat, hogy tisztázzuk, melyek azok a nagy evidenciájú módszerek, amelyek a legnagyobb biztonsággal és bizonyossággal segítenek a helyes diagnózis megállapításában, és vezetnek a krónikus hólyagfájdalomtól szenvedő személyek panaszainak enyhítéséhez. Orv Hetil. 2024; 165(31): 1191–1196.

Stem cell therapy for interstitial cystitis/bladder pain syndrome

Interstitial cystitis/bladder pain syndrome (IC/BPS) is a chronic disease with limited treatment options. Current multidisciplinary approach targeting bladder inflammation and urothelial dysfunction has limited durable effect that major surgery is ultimately required for both Hunner and non-Hunner type IC. Various investigational attempts are underway to avoid such operations and preserve the urinary bladder. Stem cell therapy is a fascinating option for treating chronic illnesses. Stem cells can self-renew, restore damaged tissue, and have paracrine effects. The therapeutic efficacy and safety of stem cell therapy have been demonstrated in numerous preclinical models, primarily chemically induced cystitis rat models. Only one clinical trial (phase 1 study) has investigated the safety of human embryonic stem cell-derived mesenchymal stem cells in three Hunner-type IC patients. Under general anesthesia, participants underwent cystoscopic submucosal stem cell injection (2.0 × 107 stem cells/5 mL). No safety issues were reported up to 12 months of follow-up and long-term follow-up (up to 3 years). Although there were variations in therapeutic response, all patients reported significant improvement in pain at 1 month postoperatively. One patient underwent fulguration of the Hunner lesion after the trial, but others reported an overall improvement in pain. The analysis on phase 1/2a trial which had several modifications in protocol is currently ongoing. Despite several limitations that need to be overcome, stem cell therapy could be a potential therapeutic option for treating IC/BPS. Clinical outcome on phase 1/2a trial is important and might provide more insight into the clinical application of stem cell therapy for IC/BPS.

UPK3A+ umbrella cell damage mediated by TLR3-NR2F6 triggers programmed destruction of urothelium in Hunner-type interstitial cystitis/painful bladder syndrome

Urothelial damage and barrier dysfunction emerge as the foremost mechanisms in Hunner-type interstitial cystitis/bladder pain syndrome (HIC). Although treatments aimed at urothelial regeneration and repair have been employed, their therapeutic effectiveness remains limited due to the inadequate understanding of specific cell types involved in damage and the lack of specific molecular targets within these mechanisms. Therefore, we harnessed single-cell RNA sequencing to elucidate the heterogeneity and developmental trajectory of urothelial cells within HIC bladders. Through reclustering, we identified eight distinct clusters of urothelial cells. There was a significant reduction in UPK3A+ umbrella cells and a simultaneous increase in progenitor-like pluripotent cells (PPCs) within the HIC bladder. Pseudotime analysis of the urothelial cells in the HIC bladder revealed that cells faced challenges in differentiating into UPK3A+ umbrella cells, while PPCs exhibited substantial proliferation to compensate for the loss of UPK3A+ umbrella cells. The urothelium in HIC remains unrepaired, despite the substantial proliferation of PPCs. Thus, we propose that inhibiting the pivotal signaling pathways responsible for the injury to UPK3A+ umbrella cells is paramount for restoring the urothelial barrier and alleviating lower urinary tract symptoms in HIC patients. Subsequently, we identified key molecular pathways (TLR3 and NR2F6) associated with the injury of UPK3A+ umbrella cells in HIC urothelium. Finally, we conducted in vitro and in vivo experiments to confirm the potential of the TLR3-NR2F6 axis as a promising therapeutic target for HIC. These findings hold the potential to inhibit urothelial injury, providing promising clues for early diagnosis and functional bladder self-repair strategies for HIC patients. © 2024 The Pathological Society of Great Britain and Ireland.

Combination of urinary biomarkers and machine-learning models provided a higher predictive accuracy to predict long-term treatment outcomes of patients with interstitial cystitis/bladder pain syndrome

PURPOSE

To identify predictive factors for satisfactory treatment outcome of the patients with IC/BPS using urine biomarkers and machine-learning models.

METHODS

The IC/BPS patients were prospectively enrolled and provide urine samples. The targeted analytes included inflammatory cytokines, neurotrophins, and oxidative stress biomarkers. The patients with overall subjective symptom improvement of ≥ 50% were considered to have satisfactory results. Binary logistic regression, receiver-operating characteristic (ROC) curve, machine-learning decision tree, and random forest models were used to analyze urinary biomarkers to predict satisfactory results.

RESULTS

Altogether, 57.4% of the 291 IC/BPS patients obtained satisfactory results. The patients with satisfactory results had lower levels of baseline urinary inflammatory cytokines and oxidative biomarkers than patients without satisfying results, including interleukin-6, monocyte chemoattractant protein-1 (MCP-1), C-X-C motif chemokine 10 (CXCL10), oxidative stress biomarkers 8-hydroxy-2'-deoxyguanosine (8-OHDG), 8-isoprostane, and total antioxidant capacity (TAC). Logistic regression and multivariable analysis revealed that lower levels of urinary CXCL10, MCP-1, 8-OHDG, and 8-isoprostane were independent factors. The ROC curve revealed that MCP-1 level had best area under curve (AUC: 0.797). In machine-learning decision tree model, combination of urinary C-C motif chemokine 5, 8-isoprostane, TAC, MCP-1, and 8-OHDG could predict satisfactory results (accuracy: 0.81). The random forest model revealed that urinary 8-isoprostance, MCP-1, and 8-OHDG levels had the most important influence on accuracy.

CONCLUSION

Machine learning decision tree model provided a higher accuracy for predicting treatment outcome of patients with IC/BPS than logistic regression, and levels of 8-isoprostance, MCP-1, and 8-OHDG had the most important influence on accuracy.

Validation of Distinct Bladder Pain Phenotypes Utilizing the MAPP Research Network Cohort

INTRODUCTION AND HYPOTHESIS

As interstitial cystitis/bladder pain syndrome (IC/BPS) likely represents multiple pathophysiologies, we sought to validate three clinical phenotypes of IC/BPS patients in a large, multi-center cohort using unsupervised machine learning (ML) analysis.

METHODS

Using the female Genitourinary Pain Index and O'Leary-Sant Indices, k-means unsupervised clustering was utilized to define symptomatic phenotypes in 130 premenopausal IC/BPS participants recruited through the Multidisciplinary Approach to the Study of Chronic Pelvic Pain (MAPP) research network. Patient-reported symptoms were directly compared between MAPP ML-derived phenotypic clusters to previously defined phenotypes from a single center (SC) cohort.

RESULTS

Unsupervised ML categorized IC/BPS participants into three phenotypes with distinct pain and urinary symptom patterns: myofascial pain, non-urologic pelvic pain, and bladder-specific pain. Defining characteristics included presence of myofascial pain or trigger points on examination for myofascial pain patients (p = 0.003) and bladder pain/burning for bladder-specific pain patients (p < 0.001). The three phenotypes were derived using only 11 features (fGUPI subscales and ICSI/ICPI items), in contrast to 49 items required previously. Despite substantial reduction in classification features, unsupervised ML independently generated similar symptomatic clusters in the MAPP cohort with equivalent symptomatic patterns and physical examination findings as the SC cohort.

CONCLUSIONS

The reproducible identification of IC/BPS phenotypes, distinguishing bladder-specific pain from myofascial and genital pain, using independent ML analysis of a multicenter database suggests these phenotypes reflect true pathophysiologic differences in IC/BPS patients.

Progress and challenges in intravesical drug delivery

INTRODUCTION

Intravesical drug delivery (IDD) has gained recognition as a viable approach for treating bladder-related diseases over the years. However, it comes with its set of challenges, including voiding difficulties and limitations in mucosal and epithelial penetration. These challenges lead to drug dilution and clearance, resulting in poor efficacy. Various strategies for drug delivery have been devised to overcome these issues, all aimed at optimizing drug delivery. Nevertheless, there has been minimal translation to clinical settings.

AREAS COVERED

This review provides a detailed description of IDD, including its history, advantages, and challenges. It also explores the physical barriers encountered in IDD, such as voiding, mucosal penetration, and epithelial penetration, and discusses current strategies for overcoming these challenges. Additionally, it offers a comprehensive roadmap for advancing IDD into clinical trials.

EXPERT OPINION

Physical bladder barriers and limitations of conventional treatments result in unsatisfactory efficacy against bladder diseases. Nevertheless, substantial recent efforts in this field have led to significant progress in overcoming these challenges and have raised important attributes for an optimal IDD system. However, there is still a lack of well-defined steps in the workflow to optimize the IDD system for clinical settings, and further research is required to establish more comprehensive in vitro and in vivo models to expedite clinical translation.

A machine learning-based nomogram model for predicting the recurrence of cystitis glandularis

Background

Cystitis glandularis is a chronic inflammatory disease of the urinary system characterized by high recurrence rates, the reasons for which are still unknown.

Objectives

This study aims to identify potential factors contributing to recurrence and propose a simple and feasible prognostic model through nomogram construction.

Design

Patients with confirmed recurrence based on outpatient visits or readmissions were included in this study, which was subsequently divided into training and validation cohorts.

Methods

Machine learning techniques were utilized to screen for the most important predictors, and these were then employed to construct the nomogram. The reliability of the nomogram was assessed through receiver operating characteristic curve analysis, decision curve analysis, and calibration curves.

Results

A total of 252 patients met the screening criteria and were enrolled in this study. Over the 12-month follow-up period, the relapse rate was found to be 57.14% (n = 144). The five final predictors identified through machine learning were urinary infections, urinary calculi, eosinophil count, lymphocyte count, and serum magnesium. The area under curve values for all three time points assessing recurrence exceeded 0.75. Furthermore, both calibration curves and decision curve analyses indicated good performance of the nomogram.

Conclusion

We have developed a reliable machine learning-based nomogram for predicting recurrence in cystitis glandularis.

Cystoscopic characteristic findings of interstitial cystitis and clinical implications

Interstitial cystitis/bladder pain syndrome (IC/BPS) is a chronic inflammatory bladder disease of unknown etiology, characterized by bladder pain and frequency urgency symptoms. Based on the cystoscopic findings after hydrodistention under anesthesia, the phenotype of IC/BPS includes no glamerulation, characteristic glomerulation, and with Hunner's lesion. IC is specifically defined if there are characteristic Hunner's lesion appeared in cystoscopy or after hydrodistention. If there are glomerulations without Hunner's lesion, BPS should be considered. The definition of Hunner's lesion and glomerulations differs based on different definition and observations. Currently, there has been no clear description and grading of the glomerulations and Hunner's lesion. Because the classification of IC/BPS has an impact on the treatment strategy and associated with therapeutic outcome, it is unmet to have a clear definition and consensus on the characteristic cystoscopic findings of IC/BPS. This article reviews the literature and presents the figures of Hunner's lesions and description of different mucosal lesions after cystoscopic hydrodistention.

Impact of chronic pelvic pain and painful bladder syndrome on the Pittsburgh Sleep Quality Index on women with deep endometriosis: a cross-sectional study

INTRODUCTION AND HYPOTHESIS

Painful bladder syndrome (PBS) is frequently associated with deep endometriosis (DE), and both conditions cause chronic pelvic pain (CPP), which often impairs sleep quality. This study was aimed at analyzing the impact of CPP plus PBS in women with DE on the global sleep quality index using the Pittsburgh Sleep Quality Index (PSQI) and subsequently examine each sleep dimension.

METHODS

One hundred and forty women with DE were included and answered the PSQI and the O'Leary-Sant Interstitial Cystitis Symptoms and Problem Index questionnaires with or without CPP. Women were categorized into good or poor sleepers using the PSQI cutoff; subsequently, a linear regression model was used to analyze the PSQI score and a logistic regression model for each questionnaire's sleep component.

RESULTS

Only 13% of women with DE had a good sleep. Approximately 20% of those with DE but no/mild pain were good sleepers; 138 women with DE (88.5%), 94% with PBS, and 90.5% with moderate/severe pain were poor sleepers. For PSQI components, CPP worsened the subjective sleep quality by more than threefold (p = 0.019), increased sleep disturbances by nearly sixfold (p = 0.03), and decreased the sleep duration by practically sevenfold (p = 0.019). Furthermore, PBS increased sleep disturbances by nearly fivefold (p < 0.01).

CONCLUSIONS

The addition of PBS to CPP in women with DE is devastating for overall sleep quality, probably because it impacts some sleep dimensions unaffected by CPP and amplifies the problem in those already affected by pain.

4-PBA inhibits endoplasmic reticulum stress to improve autophagic flux in the treatment of protamine/lipopolysaccharide-induced interstitial cystitis in rats

Interstitial cystitis (IC) has severe clinical symptoms with unclear mechanism. The continuous inflammatory response of the bladder is the basis of its pathogenesis. Endoplasmic reticulum stress (ERS) is involved in the regulation and development of various inflammatory diseases. And autophagy plays an important role in IC. In this study, we mainly focus on the therapeutic effect of endoplasmic reticulum stress and autophagy on protamine/lipopolysaccharide-induced interstitial cystitis. Female Sprague-Dawley rats were randomized into three experimental groups as follows: sham controls(N), IC alone, and IC+4-PBA.Rats in group IC received 10 mg/ml PS in the urinary bladder, followed by 2 mg/ml LPS instillation after 30 min, IC+4-PBA group SD rats received 4-PBA solution administered intragastrically once a day for 5 days. ERS biomarker (GRP78), autophagy-related proteins (LC3I/II, and Beclin1), autophagic flux biomarker (P62), inflammatory biomarkers (IL-6, TNF-a, NF-κB), apoptotic biomarkers (Caspase 3, Bax) were highest in the IC group compared to IC+4-PBA group and N group and the biomarkers expression in IC+4-PBA group were lower than in the IC group, anti-apoptotic biomarker (Bcl-2) was highest in the N group compared to the IC group and IC+4-PBA group and lower in the IC group than in the IC+4-PBA group, oxidative stress biomarkers (HO-1, NQO-1) were remarkably lower in the control group than in the IC and IC+4-PBA groups and notably lower in the IC group than in the IC+4-PBA group. The histological score and mast cell count demonstrated most severe in the IC group than those in the IC+4-PBA group. TUNEL assay examined the level of apoptosis in IC group was higher than in the IC+4-PBA group. The bladder micturition function was significantly improved with 4-PBA treatment. 4-PBA inhibits ERS to recover autophagic flux, and then to suppress the bladder oxidative stress, the inflammatory reaction and apoptosis, finally improve the bladder urinary function in Protamine/Lipopolysaccharide (PS/LPS) induced IC.

Study protocol of a multicentre double-blind RCT, comparing a traditional RCT with an aggregated N-of-1 trial: GAG therapy Efficacy Trial Solution for Bladder pain syndrome/Interstitial cystitis (GETSBI study)

INTRODUCTION

Obtaining level 1 evidence on efficacy of glycosaminoglycan (GAG) therapy is difficult, due to low incidence of bladder pain syndrome/interstitial cystitis (BPS/IC) and heterogeneous symptoms experienced by patients with BPS/IC. Currently, because of a lack of high-grade evidence, the recommendation for applying GAG therapy in most guidelines is 'low grade'. An aggregated N-of-1 trial is a multicrossover design that yields similar level 1 evidence as a traditional randomised controlled trial (RCT), while requiring far less patients. The goal of this study is to investigate the efficacy of intravesical GAG therapy (Ialuril) for patients with BPS/IC with Hunner lesions using a dual RCT and aggregated N-of-1 trial design to obtain level 1 evidence.

METHODS AND ANALYSIS

The GETSBI study is a double-blind multidesign multicentre randomised placebo-controlled study to assess the short-term and long-term efficacy of hyaluronic acid (1.6%) + chondroitin sulfate (2%) therapy (Ialuril Prefill, IBSA, Goodlife) in patients with symptomatic BPS/IC with Hunner lesions. It starts as a standard RCT (n=80), but continues as an aggregated N-of-1 trial. There are three parallel arms, receiving blinded treatment for three periods (1 x/week for 6 weeks, ratio placebo to intervention in periods of 2:1). Followed by an open prospective part for the long-term efficacy. The primary study outcome is the maximum bladder pain experienced in the last 3 days measured using the visual analogue pain scale (0-10).This study is a collaboration with the Dutch government and will deliver evidence for the decision to reimburse the therapy. Furthermore, this multidesign study will allow us to compare the two main methods to evaluate applicability for future study designs for BPS/IC research.

ETHICS AND DISSEMINATION

Ethical approval was given by METC Oost-Nederland, file number: 2020-7265, NL-number: NL76290.091.20. Findings from this study will be disseminated via publication, reports and conference presentations.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov identifier (NCT number): NCT05518864.

Molecular Profiling of Inflammatory Processes in a Mouse Model of IC/BPS: From the Complete Transcriptome to Major Sex-Related Histological Features of the Urinary Bladder

Animal models are invaluable in the research of the pathophysiology of interstitial cystitis/bladder pain syndrome (IC/BPS), a chronic aseptic urinary bladder disease of unknown etiology that primarily affects women. Here, a mouse model of IC/BPS was induced with multiple low-dose cyclophosphamide (CYP) applications and thoroughly characterized by RNA sequencing, qPCR, Western blot, and immunolabeling to elucidate key inflammatory processes and sex-dependent differences in the bladder inflammatory response. CYP treatment resulted in the upregulation of inflammatory transcripts such as Ccl8, Eda2r, and Vegfd, which are predominantly involved in innate immunity pathways, recapitulating the crucial findings in the bladder transcriptome of IC/BPS patients. The JAK/STAT signaling pathway was analyzed in detail, and the JAK3/STAT3 interaction was found to be most activated in cells of the bladder urothelium and lamina propria. Sex-based data analysis revealed that cell proliferation was more pronounced in male bladders, while innate immunity and tissue remodeling processes were the most distinctive responses of female bladders to CYP treatment. These processes were also reflected in prominent histological changes in the bladder. The study provides an invaluable reference dataset for preclinical research on IC/BPS and an insight into the sex-specific mechanisms involved in the development of IC/BPS pathology, which may explain the more frequent occurrence of this disease in women.

Deep Learning Models for Cystoscopic Recognition of Hunner Lesion in Interstitial Cystitis

Background

Accurate cystoscopic recognition of Hunner lesions (HLs) is indispensable for better treatment prognosis in managing patients with Hunner-type interstitial cystitis (HIC), but frequently challenging due to its varying appearance.

Objective

To develop a deep learning (DL) system for cystoscopic recognition of a HL using artificial intelligence (AI).

Design setting and participants

A total of 626 cystoscopic images collected from January 8, 2019 to December 24, 2020, consisting of 360 images of HLs from 41 patients with HIC and 266 images of flat reddish mucosal lesions resembling HLs from 41 control patients including those with bladder cancer and other chronic cystitis, were used to create a dataset with an 8:2 ratio of training images and test images for transfer learning and external validation, respectively. AI-based five DL models were constructed, using a pretrained convolutional neural network model that was retrained to output 1 for a HL and 0 for control. A five-fold cross-validation method was applied for internal validation.

Outcome measurements and statistical analysis

True- and false-positive rates were plotted as a receiver operating curve when the threshold changed from 0 to 1. Accuracy, sensitivity, and specificity were evaluated at a threshold of 0.5. Diagnostic performance of the models was compared with that of urologists as a reader study.

Results and limitations

The mean area under the curve of the models reached 0.919, with mean sensitivity of 81.9% and specificity of 85.2% in the test dataset. In the reader study, the mean accuracy, sensitivity, and specificity were, respectively, 83.0%, 80.4%, and 85.6% for the models, and 62.4%, 79.6%, and 45.2% for expert urologists. Limitations include the diagnostic nature of a HL as warranted assertibility.

Conclusions

We constructed the first DL system that recognizes HLs with accuracy exceeding that of humans. This AI-driven system assists physicians with proper cystoscopic recognition of a HL.

Patient summary

In this diagnostic study, we developed a deep learning system for cystoscopic recognition of Hunner lesions in patients with interstitial cystitis. The mean area under the curve of the constructed system reached 0.919 with mean sensitivity of 81.9% and specificity of 85.2%, demonstrating diagnostic accuracy exceeding that of human expert urologists in detecting Hunner lesions. This deep learning system assists physicians with proper diagnosis of a Hunner lesion.

Diagnostic and therapeutic cystoscopy in bladder pain syndrome/interstitial cystitis: systematic review of literature and consensus on methodology

INTRODUCTION AND HYPOTHESIS

Cystoscopy has been routinely performed in patients suspected to be suffering from bladder pain syndrome/interstitial cystitis (BPS/IC) across the globe. The methodology reported by various guidelines appears to have differences in the techniques and hence there is a need for a review of all those techniques in order to arrive at a consensus. The aim was to review the literature describing the prevalent techniques of cystoscopy for patients of BPS/IC and try to evolve a consensus.

METHODS

The group the Global Interstitial Cystitis, Bladder Pain Society (GIBS) has worked collectively to systematically review the literature using the key words, "Cystoscopy in Hunner's lesions, bladder pain syndrome, painful bladder syndrome and interstitial cystitis" in the PubMed, COCHRANE, and SCOPUS databases. A total of 3,857 abstracts were studied and 96 articles referring to some part of technique of cystoscopy were short-listed for review as full-length articles. Finally, six articles with a description of a technique of cystoscopy were included for final tabulation and comparison. The group went on to arrive at a consensus for a stepwise technique of diagnostic and therapeutic cystoscopy in cases of BPS/IC. This technique has been compared with the previously described techniques and may serve to be a useful practical guide for treating physicians.

CONCLUSION

It is important to have a uniform standardized technique for performing a diagnostic and therapeutic cystoscopy in patients with BPS/IC. Consensus on one such a technique has been arrived at and described in the present article.

Broaden Horizons: The Advancement of Interstitial Cystitis/Bladder Pain Syndrome

Interstitial cystitis/bladder pain syndrome (IC/BPS) is a debilitating disease that induces mental stress, lower urinary symptoms, and pelvic pain, therefore resulting in a decline in quality of life. The present diagnoses and treatments still lead to unsatisfactory outcomes, and novel diagnostic and therapeutic modalities are needed. Although our understanding of the etiology and pathophysiology of IC/BPS is growing, the altered permeability of the impaired urothelium, the sensitized nerves on the bladder wall, and the chronic or intermittent sensory pain with inaccurate location, as well as pathologic angiogenesis, fibrosis, and Hunner lesions, all act as barriers to better diagnoses and treatments. This study aimed to summarize the comprehensive information on IC/BPS research, thereby promoting the progress of IC/BPS in the aspects of diagnosis, treatment, and prognosis. According to diverse international guidelines, the etiology of IC/BPS is associated with multiple factors, while the presence of Hunner lesions could largely distinguish the pathology, diagnosis, and treatment of non-Hunner lesions in IC/BPS patients. On the basis of the diagnosis of exclusion, the diverse present diagnostic and therapeutic procedures are undergoing a transition from a single approach to multimodal strategies targeting different potential phenotypes recommended by different guidelines. Investigations into the mechanisms involved in urinary symptoms, pain sensation, and bladder fibrosis indicate the pathophysiology of IC/BPS for further potential strategies, both in diagnosis and treatment. An overview of IC/BPS in terms of epidemiology, etiology, pathology, diagnosis, treatment, and fundamental research is provided with the latest evidence. On the basis of shared decision-making, a multimodal strategy of diagnosis and treatment targeting potential phenotypes for individual patients with IC/BPS would be of great benefit for the entire process of management. The complexity and emerging evidence on IC/BPS elicit more relevant studies and research and could optimize the management of IC/BPS patients.

The effects of alpha-lipoic acid (ALA) on the urinary bladder injury in rats exposed to chronic stress: A histochemical study

Objective: In the present study, we aimed to investigate the morphological and biochemical effects of alpha-lipoic acid (ALA) on bladder injury caused by water avoidance stress (WAS) and to show its effect on the number of degranulated mast cells, which increase after stress. Materials and Methods: Wistar albino rats were subjected to WAS and the animals in the treatment group were injected ALA. After the urinary bladder tissues were subjected to routine tissue processing, hematoxylin-eosin staining and periodic acid-Schiff reaction were applied to observe general morphology and acidic toluidine blue method to investigate mast cells. Biochemical assessments of malondialdehyde (MDA) and glutathione (GSH) were also obtained. Transmission electron microscope was used for the ultrastructural, and scanning electron microscope for the topographical analyses. Results: The experiments showed that chronic stress caused injury in the bladder, increased degranulated and total number of mast cells and decreased GSH and increased MDA levels. ALA treatment after WAS ameliorated bladder injury in most areas, decreased degranulated and total mast cell number and increased GSH and decreased MDA levels. Conclusion: It was concluded that ALA can be a useful agent in the treatment of interstitial cystitis.

Safety of Human Embryonic Stem Cell-derived Mesenchymal Stem Cells for Treating Interstitial Cystitis: A Phase I Study

There are still no definite treatment modalities for interstitial cystitis (IC). Meanwhile, stem cell therapy is rising as potential alternative for various chronic diseases. This study aimed to investigate the safety of the clinical-grade mesenchymal stem cells (MSCs) derived from human embryonic stem cells (hESCs), code name MR-MC-01 (SNU42-MMSCs), in IC patients. Three female IC patients with (1) symptom duration >6 months, (2) visual pain analog scale (VAS) ≥4, and (3) one or two Hunner lesions <2 cm in-office cystoscopy within 1 month were included. Under general anesthesia, participants received cystoscopic submucosal injection of SNU42-MMSCs (2.0 × 107/5 mL) at the center or margin of Hunner lesions and other parts of the bladder wall except trigone with each injection volume of 1 mL. Follow-up was 1, 3, 6, 9, and 12 months postoperatively. Patients underwent scheduled follow-ups, and symptoms were evaluated with validated questionnaires at each visit. No SNU42-MMSCs-related adverse events including immune reaction and abnormalities on laboratory tests and image examinations were reported up to 12-month follow-up. VAS pain was temporarily improved in all subjects. No de novo Hunner lesions were observed and one lesion of the first subject was not identifiable on 12-month cystoscopy. This study reports the first clinical application of transurethral hESC-derived MSC injection in three patients with IC. hESC-based therapeutics was safe and proved to have potential therapeutic efficacy in IC patients. Stem cell therapy could be a potential therapeutic option for treating IC.

A pilot study on oral cyclosporine A in association with fulguration for the treatment of interstitial cystitis with Hunner's lesions

AIMS

To evaluate the efficacy and safety of lesion fulguration in combination with cyclosporine A (CyA) as a maintenance therapy in patients with interstitial cystitis/bladder pain syndrome (IC/BPS) with Hunner's lesion (HL).

METHODS

Retrospective observational study of refractory patients with HL treated with daily 1.5 mg/kg or less of oral CyA following lesion fulguration. Pain severity, subjective improvement, urinary symptoms, and adverse events were used to assess long-term treatment efficiency and safety.

RESULTS

Among the 22 patients, median follow-up under CyA was 27 months. Patients reported sustained significant reduction compared to pretreatment in pain (0/10 vs. 8/10; p < 0.001), urinary frequency per 24 h (9.5 vs. 20.8; p < 0.001), and nocturia (2.3 vs. 7.6; p < 0.001). Subjective improvement rate (SIR) and patient global impression of improvement were of 90% and 1 ("very much better"), respectively, including four patients who considered themselves cured (SIR: 100%). Three patients needed an additional procedure due to pain relapse. Minor increase in creatinine was observed and three patients developed or worsened their arterial hypertension. CyA dosage was decreased to 1.2 mg/kg or less for long-term relief (n = 8), creatinine increase (n = 5), and neutropenia (n = 1) with subsequent improvement in renal function without symptom deterioration.

CONCLUSIONS

Oral CyA seems to allow a sustained long-term relief following HL fulguration by alleviating pain, decreasing urinary symptoms, and procuring great subjective improvement. The daily low dose of 1.5 mg/kg or less appears to have limited adverse events while preventing repeated procedures. Larger trials are warranted.

The Japanese Herbal Medicine Yokukansan Exerted Antioxidant and Analgesic Effects in an Experimental Rat Model of Hunner-Type Interstitial Cystitis

Background and Objectives: The Japanese herbal medicine Yokukansan (YKS) has analgesic properties and is used for various pain disorders. The purpose of the present study was to investigate the effects of YKS in Hunner-type interstitial cystitis (HIC) using an experimental rat model of HIC and to explore its antioxidant activity and role as the underlying mechanism of action. Materials and Methods: The antioxidant capacity of YKS was evaluated by determining its hydroxyl radical (·OH) scavenging capacity using electron spin resonance (ESR). Next, the effects of YKS administration were explored using a toll-like receptor-7 agonist-induced rat model of HIC. The von Frey test was performed to assess bladder pain. Three days after HIC induction, the bladder was removed, and the expression of oxidative stress parameters in the bladder wall was investigated (reactive oxygen metabolites (ROMs), ·OH, and 8-hydroxy-2′-deoxyguanosine (8-OhdG)). Results: YKS had a ·OH scavenging capacity according to the ESR study. In the von Frey test, a significant decrease in the withdrawal threshold was observed in the HIC group compared with the control group; however, the decrease was ameliorated by the administration of YKS. Oxidative stress parameters showed increasing tendencies (ROMs test and 8-OHdG) or a significant increase (·OH) in the HIC group compared with the control group; however, the increase was significantly suppressed by the administration of YKS. Conclusions: These findings suggest that YKS is effective against HIC and that its antioxidant activity is involved in the mechanism of action.

Pulsed Electromagnetic Field Therapy for Pain Management in Interstitial Cystitis/Bladder Pain Syndrome: A Proof-of-Concept Case Series

OBJECTIVE

To evaluate the efficacy of pulsed electromagnetic field (PEMF) therapy for symptom and pain management in women with non-bladder centric interstitial cystitis/bladder pain syndrome (IC/BPS).

METHODS

Women with non-bladder centric IC/BPS and a numeric rating scale score for pelvic pain ≥6 underwent twice-daily 8-minute full body PEMF therapy sessions for 4 weeks. The primary outcome metric was a reduction in pelvic pain score ≥2 points. A 7-day voiding diary (collected at baseline and conclusion), 3 validated symptom scores, and the Short Form-36 Quality of Life questionnaire (completed at baseline, conclusion of treatment, and 8-week follow-up), were used to assess secondary outcomes. Treatment effects were analyzed via Wilcoxon-signed rank test; P < .05 was considered significant.

RESULTS

The 4-week treatment protocol was completed by 8 of 10 enrolled patients, and 7:8 (87.5%) had a significant reduction in pelvic pain (-3.0 points, P = .011) after 4 weeks. There was also a significant decrease in scores on all validated IC/BPS questionnaires, daily number of voids, and nocturia symptom score (P < .05). Significant increases in several quality-of-life questionnaire sub-scores were also identified at 4 weeks (P < .05). At 8-week post-therapy, the positive effects were somewhat attenuated, yet 4:8 patients (50%) continued to have significant pain reduction (P = .047). No adverse events or side effects were reported.

CONCLUSION

Whole body pulsed electromagnetic field therapy is an alternative treatment option for women with chronic bladder pain syndrome that warrants investigation through comparative trials.

Use of Urinary Cytokine and Chemokine Levels for Identifying Bladder Conditions and Predicting Treatment Outcomes in Patients with Interstitial Cystitis/Bladder Pain Syndrome

BACKGROUND

Interstitial cystitis/bladder pain syndrome (IC/BPS) is a condition causing bladder inflammation. Urinary biomarkers have been assessed as suitable for the diagnosis and treatment. This study aimed at investigating the role of urinary biomarkers in identifying bladder conditions and predicting the treatment outcome of IC/BPS.

METHODS

A total of 309 patients with IC/BPS and 30 controls were enrolled in this study. All patients underwent a comprehensive urological workup of symptoms, pain severity, and cystoscopic hydrodistention findings including maximal bladder capacity (MBC) and glomerulation grade. Urine samples were collected to investigate the levels of urinary cytokines and chemokines. According to MBC and glomerulation grade, patients with IC/BPS were further classified into the Hunner's IC (HIC) and non-HIC groups. The urinary biomarkers between IC/BPS and control groups and HIC and non-HIC groups were compared. Moreover, the treatment response was graded according to global response assessment (GRA) scores, and urinary biomarker levels were analyzed based on different GRAs.

RESULTS

Patients with IC/BPS had significantly high urinary monocyte chemoattractant protein-1, eotaxin, tumor necrosis factor -alpha (TNF-α), and prostaglandin E2 levels. Significantly higher levels of urinary interleukin-8, C-X-C motif chemokine ligand 10 (CXCL 10), brain-derived neurotrophic factor, eotaxin, and regulated-on-activation, normal T-cell expressed and secreted (RANTES) were noted in HIC than those with non-HIC and controls. Among all biomarkers, TNF-α had the best sensitivity, specificity, positive predictive value, and negative predictive value. There was a significant correlation between biomarker levels and GRA.

CONCLUSIONS

Significantly higher urine cytokines and chemokine levels were found in patients with IC/BPS. Most urinary biomarkers were significantly associated with MBC, glomerulation grade, and treatment outcome.

Bladder Oxidative Stress and HMGB1 Release Contribute to PAR4-Mediated Bladder Pain in Mice

Activation of intravesical PAR4 receptors leads to bladder hyperalgesia (BHA) through release of urothelial macrophage migration inhibitory factor (MIF) and urothelial high mobility group box-1 (HMGB1). MIF deficiency and/or MIF antagonism at the bladder block BHA in mice yet the mechanisms are not clear. Since oxidative stress and ERK phosphorylation are involved in MIF signaling we hypothesized that oxidative stress and/or ERK signaling, activated by MIF release, promote intravesical HMGB1 release to induce BHA. We induced BHA by intravesical PAR4 infusion in female C57BL/6 mice. Mechanical sensitivity was evaluated by measuring abdominal von Frey (VF) 50% thresholds before (baseline) and 24 h post-infusion. Intravesical pre-treatment (10 min infusion prior to PAR4) with N-acetylcysteine amide (NACA; reactive-oxygen species scavenger; 3 mg in 50 μl), FR180204 (selective ERK1/2 inhibitor; 200 μg in 50 μl), ethyl pyruvate (EP; HMGB1 release inhibitor; 600 μg in 50 μl), or diluent controls (50 μl) tested the effects of pre-treatment on PAR4-induced BHA. Intravesical fluid was collected after each treatment and HMGB1 concentration was measured using ELISA. Awake micturition parameters (volume and frequency) were assessed at the end of the experiments. Bladders were collected and examined for histological signs of edema and inflammation. Pre-treatment with PBS followed by PAR4 induced BHA in mice but PBS followed by scrambled peptide did not. Pre-treatment with NACA or EP partially blocked PAR4-induced BHA while FR180204 had no effect. A significant correlation between intravesical HMGB1 levels and 50% VF thresholds was observed. All PAR4 treated groups had increased levels of HMGB1 in the intravesical fluid compared to PBS-Scrambled group although not statistically significant. No significant effects were noted on awake micturition volume, micturition frequency or histological evidence of bladder edema or inflammation. Our results show that intravesical antagonism of bladder reactive-oxygen species accumulation was effective in reducing PAR4-induced bladder pain. The correlation between intravesical levels of HMGB1 and bladder pain indicates that released HMGB1 is pivotal to bladder pain. Thus, modulating events in the MIF signaling cascade triggered by PAR4 activation (including bladder oxidative stress and HMGB1 release) warrant further investigation as possible therapeutic strategies.

Supratrigonal cystectomy and augmentation cystoplasty with ileum or ileocecum in the treatment of ulcerative interstitial cystitis/bladder pain syndrome: a 14-year follow-up

INTRODUCTION AND HYPOTHESIS

This study analyzes the long-term results of supratrigonal cystectomy and augmentation cystoplasty in patients with severe ulcerative interstitial cystitis/bladder pain syndrome (IC/BPS) and reduced bladder capacity.

METHODS

Outcome data were retrospectively and prospectively collected and analyzed in women who underwent supratrigonal cystectomy and augmentation cystoplasty for ulcerative IC/BPS at Muenster University Hospital between 1991 and 2006. We used cross-tabulation and Pearson's Chi-squared test to examine how outcome is influenced by age, preoperative functional bladder volume, and choice of augmentation material.

RESULTS

After a median 171-month follow-up, analysis could be done in 26 of 27 patients. Persistent pain necessitated early revision in 2 patients (7.7%). Mean postoperative O'Leary Sant IC Score was 12.7 in the prospectively questioned patients. Responses to Patient Global Impression of Improvement (PGI-I) were: "very much better" in 15 cases (65.2%) and "much better" in 7 (30.4%). Twelve patients (52.2%) emptied their augmented bladder voluntarily, whereas 7 (32%) needed intermittent self-catheterization (ISC). The rate of patients requiring ISC tended to be lower when detubularized ileocecal bowel was used. All 5 patients (19.2%) with late relapse of ulcerative IC/BPS needed ISC.

CONCLUSIONS

Severe ulcerative IC/BPS can be curatively treated in some patients by supratrigonal cystectomy and augmentation, which is associated with a high satisfaction rate and few long-term complications even over a very long follow-up. In our analysis, the need for ISC is a risk factor for late relapse, although ileocecal augmentation could increase the proportion of patients with sufficient voluntary micturition.

Can We Use Urinary Cytokine/Chemokine Analysis in Discriminating Ulcer-Type Interstitial Cystitis/Bladder Pain Syndrome?

Purpose: Interstitial cystitis/bladder pain syndrome (IC/BPS) has ulcer (HIC) and non-ulcer subtypes. Differentiation of these two subtypes could only be based by cystoscopy. This study analyzed the urinary cytokines and chemokines among IC/BPS subtypes and controls for discriminating HIC from non-HIC and controls. Materials and Methods: A total of 309 consecutive patients with clinically diagnosed IC/BPS were enrolled. All patients received cystoscopic hydrodistention under anesthesia and urine samples were collected prior to the procedure. Enrolled patients were classified into subtypes based on the glomerulation grade, maximal bladder capacity (MBC), and presence of Hunner’s lesion. Inflammation-related cytokines and chemokines in urine samples, including interleukin-8 (IL-8), C-X-C motif chemokine ligand 10 (CXCL10), monocyte chemoattractant protein-1 (MCP-1), brain-derived neurotrophic factor (BDNF), eotaxin-1 (eotaxin), IL-6, macrophage inflammatory protein-1 beta (MIP-1β), regulated upon activation, normally T-expressed, and presumably secreted (RANTES), tumor necrosis factor-alpha (TNF-α), and prostaglandin E2 (PGE2) were assayed using commercially available microspheres with the Milliplex® Human Cytokine/Chemokine Magnetic Bead-based Panel kit. The clinical data and urine levels of analytes between IC/BPS patients and controls, and among HIC, non-HIC, and controls were analyzed. Results: Among the 10 proteins, MCP-1, eotaxin, MIP-1β, TNF-α, and PGE2 were significantly different between IC/BPS and control, while IL-8, CXCL10, BDNF, IL-6, and RANTES were significantly higher in HIC than non-HIC patients. The receiver operating characteristic curve was used to analyze each urine biomarker in the patients with IC/BPS and controls. Among the 10 urine biomarkers, MIP-1β and TNF-α had an area under curve of >0.70 to predict IC/BPS from controls, however, the predictive values of these urine biomarkers to predict HIC from non-HIC were low. Combined cut-off values of MIP-1β and TNF-α can only have a 50% sensitivity and 39.6% specificity in identifying HIC from non-HIC. Conclusion: The results of this study demonstrate that urine cytokines and chemokines may be useful to discriminate patients with HIC from controls. An elevation of urine levels of IL-8, CXCL 10, BDNF, IL-6, and RANTES in IC/BPS patients should prompt physicians to consider the diagnosis of HIC.

Lectins as Biomarkers of IC/BPS Disease: A Comparative Study of Glycosylation Patterns in Human Pathologic Urothelium and IC/BPS Experimental Models

Pathophysiology of interstitial cystitis/bladder pain syndrome (IC/BPS) remains poorly understood, as well as its effective diagnosis and therapy. Studying changes in tissue glycosylation patterns under pathological conditions is a promising way of discovering novel biomarkers and therapeutic targets. The glycobiology of IC/BPS is largely understudied, therefore we compared glycosylation patterns of normal human urothelium with the urothelium of IC/BPS patients using a selection of 10 plant-based lectins with different monosaccharide preferences. We also compared lectin binding to human urothelium with the two most cited experimental models of IC/BPS, specifically, TNFα-treated human urothelial cell line RT4 and cyclophosphamide-induced chronic cystitis in C57BL6/J mice. Furthermore, binding of four of the selected lectins (ConA, DSL, Jacalin and WGA) was evaluated qualitatively by means of fluorescence microscopy, and quantitatively by fluorescence intensity (F.I.) measurements. Our results reveal a significant reduction in F.I. of Jacalin, as well as a prominent change in the WGA labeling pattern in the urothelium of IC/BPS patients, suggesting their potential use as promising additional biomarkers for histopathological diagnosis of IC/BPS. We have also shown that urothelial glycosylation patterns between selected experimental models and patients with IC/BPS are similar enough to offer an adequate platform for preclinical study of IC/BPS glycobiology.

Bladder Microbiome in the Context of Urological Disorders—Is There a Biomarker Potential for Interstitial Cystitis?

Since the development of modern cultivation and sequencing techniques, the human microbiome has increasingly become the focus of scientific attention. Even in the bladder, long considered to be a sterile niche, a highly variable and complex microbial colonization has now been demonstrated. Especially in the context of diseases such as interstitial cystitis, whose etiopathogenesis is largely unknown, and whose diagnosis is based on a process of exclusion of confusable diseases, science hopes to gain far-reaching insights for etiology and diagnosis, including the identification of potential biomarkers. While for functional disorders such as urge urinary incontinence and overactive bladder syndrome, initial associations have been demonstrated between reduced microbial diversity and increased symptomatology, as well as shifts in the abundance of specific microorganisms such as Lactobacillus or Proteus, studies in interstitial cystitis show conflicting results and have failed to identify a putative organism or urotype that clearly distinguishes the urinary microbiome of patients with IC/BPS from that of healthy controls. At the present time, therefore, the new insights into the bladder microbiome and its potential influence on urologic disease cannot yet be used in the context of elucidating possible etiopathogenetic causes, as well as in the use of a biomarker for diagnostic or prognostic purposes. Further studies should focus primarily on uniform procedures and detection methods to achieve better comparability of results and increase the likelihood of detecting hidden patterns.

Unsupervised Machine Learning Approaches Reveal Distinct Phenotypes of Perceived Bladder Pain: A Pilot Study

Interstitial cystitis/bladder pain syndrome (IC/BPS) is defined as an unpleasant sensation perceived to be related to the bladder with associated urinary symptoms. Due to difficulties discriminating pelvic visceral sensation, IC/BPS likely represents multiple phenotypes with different etiologies that present with overlapping symptomatic manifestations, which complicates clinical management. We hypothesized that unique bladder pain phenotypes or "symptomatic clusters" would be identifiable using machine learning analysis (unsupervised clustering) of validated patient-reported urinary and pain measures. Patients (n = 145) with pelvic pain/discomfort perceived to originate in the bladder and lower urinary tract symptoms answered validated questionnaires [OAB Questionnaire (OAB-q), O'Leary-Sant Indices (ICSI/ICPI), female Genitourinary Pain Index (fGUPI), and Pelvic Floor Disability Index (PFDI)]. In comparison to asymptomatic controls (n = 69), machine learning revealed three bladder pain phenotypes with unique, salient features. The first group chiefly describes urinary frequency and pain with the voiding cycle, in which bladder filling causes pain relieved by bladder emptying. The second group has fluctuating pelvic discomfort and straining to void, urinary frequency and urgency without incontinence, and a sensation of incomplete emptying without urinary retention. Pain in the third group was not associated with voiding, instead being more constant and focused on the urethra and vagina. While not utilized as a feature for clustering, subjects in the second and third groups were significantly younger than subjects in the first group and controls without pain. These phenotypes defined more homogeneous patient subgroups which responded to different therapies on chart review. Current approaches to the management of heterogenous populations of bladder pain patients are often ineffective, discouraging both patients and providers. The granularity of individual phenotypes provided by unsupervised clustering approaches can be exploited to help objectively define more homogeneous patient subgroups. Better differentiation of unique phenotypes within the larger group of pelvic pain patients is needed to move toward improvements in care and a better understanding of the etiologies of these painful symptoms.

The O'Leary-Sant Interstitial Cystitis Symptom Index is a clinically useful indicator of treatment outcome in patients with interstitial cystitis/bladder pain syndrome with Hunner lesions: A post hoc analysis of the Japanese phase III trial of KRP-116D, 50% dimethyl sulfoxide solution

OBJECTIVES

To evaluate the efficacy of intravesical KRP-116D, 50% dimethyl sulfoxide solution, in interstitial cystitis/bladder pain syndrome patients with Hunner lesions (Hunner-type interstitial cystitis), and to evaluate the correlations between efficacy variables and global response assessment to determine what constitutes a minimal clinically important change.

METHODS

We performed a post hoc analysis of the Japanese phase III trial of KRP-116D. Changes at Week 12 from baseline in objective and subjective outcomes were compared between the KRP-116D and placebo groups in Hunner-type interstitial cystitis or non-Hunner-type interstitial cystitis patients. Correlations between efficacy variables at Week 12 and global response assessment were analyzed. Area under the receiver operating characteristic curve and the cut-off value of efficacy valuables were calculated to determine clinically meaningful changes.

RESULTS

The effectiveness of intravesical treatment with KRP-116D was demonstrated in Hunner-type interstitial cystitis, but not in non-Hunner-type interstitial cystitis patients. Global response assessment was closely correlated with subjective outcomes including O'Leary-Sant Interstitial Cystitis Symptom Index, O'Leary-Sant Interstitial Cystitis Problem Index, and a numeric rating scale for bladder pain, but was less correlated with voiding variables including micturition frequency, voided volume, and maximum voided volume. In the receiver operating characteristic curve analyses, the cut-off value for the O'Leary-Sant Interstitial Cystitis Symptom Index was -5 (sensitivity 81.3%, specificity 83.3%).

CONCLUSIONS

Clinical benefit of intravesical KRP-116D in Hunner-type interstitial cystitis patients was confirmed in this post hoc analysis. A five-point reduction in O'Leary-Sant Interstitial Cystitis Symptom Index is a clinically meaningful indicator for assessing patient satisfaction with KRP-116D treatment in patients with Hunner-type interstitial cystitis.

A nomogram for bladder pain syndrome/interstitial cystitis based on netrin-1

Purpose

This study aimed to combine plasma netrin-1 and clinical parameters to construct a diagnostic model for bladder pain syndrome/interstitial cystitis (BPS/IC).

Methods

We analyzed the independent diagnostic value of netrin-1 and the correlation with clinical symptom scores of BPS/IC. Clinical parameters were selected using LASSO regression, and a multivariate logistic regression model based on netrin-1 was established, and then a nomogram of BPS/IC prevalence was constructed. The nomogram was evaluated using calibration curves, the C-index, and decision curve analysis (DCA). Finally, the model was validated using an internal validation method.

Results

The area under the curve for the ability of netrin-1 to independently predict BPS/IC diagnosis was 0.858 (p < 0.001), with a sensitivity of 85% and specificity of 82%. The predicted nomogram included three variables: age, CD3 + /CD4 + T lymphocyte ratio, and netrin-1. The C-index of this nomogram was 0.882, and the predicted values were highly consistent with the actual results in the calibration curve. In addition, the internally validated C-index of 0.870 confirms the high reliability of the model. DCA results show that the net patient benefit of the netrin-1 combined with other clinical parameters was higher than that of the single netrin-1 model.

Conclusion

Netrin-1 can be used as a diagnostic marker for BPS/IC and is associated with pain. The nomogram constructed by combining netrin-1 and clinical parameters was able to predict BPS/IC with great accuracy. In addition, Netrin-1 may also serve as a novel therapeutic target for BPS/IC.

MRI as a Tool to Assess Interstitial Cystitis Associated Bladder and Brain Pathologies

Interstitial cystitis/bladder pain syndrome (IC/BPS) is a chronic, often incapacitating condition characterized by pain seeming to originate in the bladder in conjunction with lower urinary tract symptoms of frequency and urgency, and consists of a wide range of clinical phenotypes with diverse etiologies. There are currently no diagnostic tests for IC/BPS. Magnetic resonance imaging (MRI) is a relatively new tool to assess IC/BPS. There are several methodologies that can be applied to assess either bladder wall or brain-associated alterations in tissue morphology and/or pain. IC/BPS is commonly associated with bladder wall hyperpermeability (BWH), particularly in severe cases. Our group developed a contrast-enhanced magnetic resonance imaging (CE-MRI) approach to assess BWH in preclinical models for IC/BPS, as well as for a pilot study for IC/BPS patients. We have also used the CE-MRI approach to assess possible therapies to alleviate the BWH in preclinical models for IC/BPS, which will hopefully pave the way for future clinical trials. In addition, we have used molecular-targeted MRI (mt-MRI) to quantitatively assess BWH biomarkers. Biomarkers, such as claudin-2, may be important to assess and determine the severity of BWH, as well as to assess therapeutic efficacy. Others have also used other MRI approaches to assess the bladder wall structural alterations with diffusion-weighted imaging (DWI), by measuring changes in the apparent diffusion coefficient (ADC), diffusion tensor imaging (DTI), as well as using functional MRI (fMRI) to assess pain and morphological MRI or DWI to assess anatomical or structural changes in the brains of patients with IC/BPS. It would be beneficial if MRI-based diagnostic tests could be routinely used for these patients and possibly used to assess potential therapeutics.

Biomarkers in Interstitial Cystitis/Bladder Pain Syndrome with and without Hunner Lesion: A Review and Future Perspectives

Interstitial cystitis/bladder pain syndrome (IC/BPS) is a debilitating urinary bladder condition that presents with a wide variety of clinical phenotypes. It is commonly characterized by persistent pelvic pain and lower urinary tract symptoms, such as urinary frequency and urgency. Current clinicopathological and genomic evidence has indicated that IC/BPS with Hunner lesions is a clinically relevant distinct subtype with proven bladder pathology of subepithelial chronic inflammatory changes that are characterized by enhanced local immune responses and epithelial denudation. However, other forms of IC/BPS lacking Hunner lesions are a symptom syndrome complex of non-inflammatory conditions with little evidence of bladder etiology, characterized by aberrant neural activity in neurotransmission systems which leads to central nervous sensitization with potential involvement of urothelial malfunction, or clinical presentation of somatic and/or psychological symptoms beyond the bladder. Given such distinct potential pathophysiology between IC/BPS subtypes, disease biomarkers of IC/BPS should be provided separately for subtypes with and without Hunner lesions. Tailored approaches that target characteristic immunological inflammatory processes and epithelial denudation for IC/BPS with Hunner lesions, or the sensitized/altered nervous system, urothelial malfunction, association with other functional somatic syndromes, and psychosocial problems for IC/BPS without Hunner lesions, are essential to identify optimal and reliable disease-specific IC/BPS biomarkers.

B6 Mouse Strain: The Best Fit for LPS-Induced Interstitial Cystitis Model

Interstitial cystitis (IC) is a chronic inflammatory disease characterized by bladder pain and increased urinary frequency. Although the C57BL/6J (B6) and FVB/NJ (FVB) mouse strains are commonly used as animal models for studies involving the urinary system, few reports have compared their lower urinary tract anatomy, despite the importance of such data. Our study aimed to characterize bladder function changes in FVB and B6 mouse strains with lipopolysaccharide (LPS)-induced IC, to understand mouse model-based bladder research. The bladder function parameters were measured by cystometrogram. Histological assay was examined by hematoxylin and eosin stain, Masson’s trichrome stain, and immunofluorescence staining. Results indicated that the two strains in the control group exhibited different bladder structures and functions, with significant anatomical differences, including a larger bladder size in the FVB than in the B6 strain. Furthermore, cystometry tests revealed differences in bladder function pressure. LPS-treated B6 mice presented significant changes in peak pressure, with decreased intercontraction intervals; these results were similar to symptoms of IC in humans. Each strain displayed distinct characteristics, emphasizing the care required in choosing the appropriate strain for bladder-model studies. The results suggested that the B6 mouse strain is more suitable for IC models.

Possible Association between Bladder Wall Morphological Changes on Computed Tomography and Bladder-Centered Interstitial Cystitis/Bladder Pain Syndrome

This study aimed to evaluate the clinical significance of urinary bladder wall thickening on computed tomography (CT) among patients with interstitial cystitis/bladder pain syndrome (IC/BPS). Patients with IC/BPS were prospectively enrolled and classified into three groups according to bladder CT finding: smooth bladder wall, focal bladder thickening, and diffuse bladder thickening. Among the 100 patients with IC/BPS, 49, 36, and 15 had smooth bladder wall, focal bladder thickening, and diffuse bladder thickening on CT, respectively. Patients with Hunner’s lesion showed a higher proportion of diffuse and focal bladder thickening compared to those without the same (p < 0.001). Patients with diffuse bladder thickening displayed smaller first sensation of filling, cystometric bladder capacity, and voided volume compared to the rest (all p < 0.001). Patients with focal and diffuse thickening had a higher proportion of inflammatory cell infiltration, uroepithelial cell denudation, and granulation tissue compared to those with smooth bladder wall (p = 0.045, 0.002, and 0.005, respectively). Bladder wall thickening on CT was correlated with clinical phenotypes of IC/BPS, including histopathological findings. Focal or diffuse bladder wall thickening on CT might indicate the presence of chronic bladder wall inflammation and fibrosis and could be used to differentiate bladder-centered IC/BPS.

Interstitial cystitis/bladder pain syndrome patient is associated with subsequent increased risks of outpatient visits and hospitalizations: A population-based study

Interstitial cystitis/bladder pain syndrome (IC/BPS) is not only a chronic urinary bladder pain syndrome but is also associated with multifactorial etiology. Our study aimed to test the hypothesis that IC/BPS is associated with subsequent increased risks of outpatient visits and hospitalizations. Using nationwide database, the diagnoses were based on the International Classification Codes (ICD-9-CM) (595.1) of at least three outpatient services during 2002-2008, (n = 27,990) and cystoscopic finding Hunner type and/or glomerulation with pre-audit criteria. All recruited cases monitored for subsequent outpatient visits and hospitalizations for 2 years, including all-cause and specialty-specific departments, were classified according to medical specialty and age group (<40, 40-60, ≥60 years of age). IC/BPS patients have more overall outpatient department (OPD) visits and an overall adjusted incidence rate ratio (IRR) of 1.64. As for specialty, IRRs were higher in psychiatry (2.75), Chinese medicine (2.01), and emergency medicine (2.00), besides urology and gynecology. The IRRs decreased as age advanced (2.01, 1.71, and 1.44, respectively), except for gynecology (2.42, 2.52, and 2.81). A similar phenomenon happens in hospitalization with IRR of 1.69. Due to claim data characteristics, whether ulcer type IC/BPS findings can be deductive to non-ulcer type remains inclusive. Current results indicate the impacts of healthcare burden in broad spectrum about IC/PBS patients. IC/BPS has been suggested to be associated with lower threshold of healthcare visits and some coexisting disease and is comprised of systemic dysregulation, and is beyond the scope of local bladder-urethra disease. Adequate recognition of associated or comorbid factors and possible recommendation or referral for IC/BPS patients can help provide better healthcare quality.

A Systematic Review of Therapeutic Approaches Used in Experimental Models of Interstitial Cystitis/Bladder Pain Syndrome

Interstitial cystitis/bladder pain syndrome (IC/BPS) is a multifactorial, chronic bladder disorder with limited therapeutic options currently available. The present review provides an extensive overview of therapeutic approaches used in in vitro, ex vivo, and in vivo experimental models of IC/BPS. Publications were identified by electronic search of three online databases. Data were extracted for study design, type of treatment, main findings, and outcome, as well as for methodological quality and the reporting of measures to avoid bias. A total of 100 full-text articles were included. The majority of identified articles evaluated therapeutic agents currently recommended to treat IC/BPS by the American Urological Association guidelines (21%) and therapeutic agents currently approved to treat other diseases (11%). More recently published articles assessed therapeutic approaches using stem cells (11%) and plant-derived agents (10%), while novel potential drug targets identified were proteinase-activated (6%) and purinergic (4%) receptors, transient receptor potential channels (3%), microRNAs (2%), and activation of the cannabinoid system (7%). Our results show that the reported methodological quality of animal studies could be substantially improved, and measures to avoid bias should be more consistently reported in order to increase the value of preclinical research in IC/BPS for potential translation to a clinical setting.

Omics in urology: An overview on concepts, current status and future perspectives

Recent technological advances in molecular biology have led to great progress in the knowledge of structure and function of cells and their main constituents. In this setting, 'omics' is standing out in order to significantly improve the understanding of etiopathogenetic mechanisms of disease and contribute to the development of new biochemical diagnostics and therapeutic tools. 'Omics' indicates the scientific branches investigating every aspect of cell's biology, including structures, functions and dynamics pathways. The main 'omics' are genomics, epigenomics, proteomics, transcriptomics, metabolomics and radiomics. Their diffusion, success and proliferation, addressed to many research fields, has led to many important acquisitions, even in Urology. Aim of this narrative review is to define the state of art of 'omics' application in Urology, describing the most recent and relevant findings, in both oncological and non-oncological diseases, focusing the attention on urinary tract infectious, interstitial cystitis, urolithiasis, prostate cancer, bladder cancer and renal cell carcinoma. In Urology the majority of 'omics' applications regard the pathogenesis and diagnosis of the investigated diseases. In future, its role should be implemented in order to develop specific predictors and tailored treatments.

Pycnogenol® Supplementation Prevents Recurrent Urinary Tract Infections/Inflammation and Interstitial Cystitis

This open pilot registry study aimed to evaluate and compare the prophylactic effects of Pycnogenol® or cranberry extract in subjects with previous, recurrent urinary tract infections (UTI) or interstitial cystitis (IC). Methods. Inclusion criteria were recurrent UTI or IC. One subject group was supplemented with 150 mg/day Pycnogenol®, another with 400 mg/day cranberry extract, and a group served as a control in a 2-month open follow-up. Results. 64 subjects with recurrent UTI/IC completed the study. The 3 groups of subjects were comparable at baseline. All subjects had significant symptoms (minor pain, stranguria, repeated need for urination, and lower, anterior abdominal pain) at inclusion. In the course of the study, the subjects reported no tolerability problems or side effects. The incidence of UTI symptoms, in comparison with the period before inclusion in the standard management (SM) group, decreased significantly; there was a more pronounced decrease in the rate of recurrent infections in the Pycnogenol® group (p < 0.05). The improvement in patients supplemented with Pycnogenol® was significantly superior to the effects of cranberry. At the end of the study, all subjects in the Pycnogenol® group were infection-free (p < 0.05vs. cranberry). Significantly, more subjects were completely symptom-free after 2 months of management with Pycnogenol® (20/22) than with SM (18/22) and cranberry (16/20). Conclusions. This pilot registry suggests that 60 days of Pycnogenol® supplementation possibly decrease the occurrence of UTIs and IC without side effects and with an efficacy superior to cranberry.

Hydrodistention does not alter bladder gene expression profiles in patients with non-Hunner lesion interstitial cystitis/bladder pain syndrome

AIMS

Gene expression profiling of bladder biopsies in patients with interstitial cystitis/bladder pain syndrome (IC/BPS), typically obtained following therapeutic bladder hydrodistention (HOD), is used to improve our understanding of molecular phenotypes. The objective of this study was to determine if the HOD procedure itself impacts the biopsy gene expression profile and, by extension, whether biopsies from non-HOD bladders are appropriate controls.

METHODS

Bladder biopsies were obtained just before HOD and immediately following HOD from 10 consecutively recruited IC/BPS patients undergoing therapeutic HOD. Biopsies were also obtained from four non-IC/BPS patients who did not undergo HOD (controls). Total RNA was isolated from each of the 24 samples and used to query whole-genome microarrays. Differential gene expression analysis was performed to compare expression profiles of IC/BPS biopsies before and after HOD, and between IC/BPS and control biopsies.

RESULTS

Principal component analysis revealed complete separation between gene expression profiles from IC/BPS and control samples (q ≤ 0.05) and while IC/BPS samples before and after HOD showed no significant differences in expressed genes, 68 transcripts were found to be significantly different between IC/BPS and control samples (q ≤ 0.05).

CONCLUSIONS

The bladder HOD procedure itself does not significantly change gene expression within the IC/BPS patient bladder, a finding that provides evidence to support the use of biopsies from non-IC/BPS patients that have not undergone HOD as controls for gene expression studies.

Efficacy and safety of intravesical instillation of KRP-116D (50% dimethyl sulfoxide solution) for interstitial cystitis/bladder pain syndrome in Japanese patients: A multicenter, randomized, double-blind, placebo-controlled, clinical study

Objective

To evaluate the efficacy and safety of intravesical KRP‐116D, 50% dimethyl sulfoxide solution compared with placebo, in interstitial cystitis/bladder pain syndrome patients.

Methods

Japanese interstitial cystitis/bladder pain syndrome patients with an O’Leary‐Sant Interstitial Cystitis Symptom Index score of ≥9, who exhibited the bladder‐centric phenotype of interstitial cystitis/bladder pain syndrome diagnosed by cystoscopy and bladder‐derived pain, were enrolled. Patients were allocated to receive either KRP‐116D (n = 49) or placebo (n = 47). The study drug was intravesically administered every 2 weeks for 12 weeks.

Results

For the primary endpoint, the change in the mean O’Leary‐Sant Interstitial Cystitis Symptom Index score from baseline to week 12 was −5.2 in the KRP‐116D group and −3.4 in the placebo group. The estimated difference between the KRP‐116D and placebo groups was −1.8 (95% confidence interval −3.3, −0.3; P = 0.0188). Statistically significant improvements for KRP‐116D were also observed in the secondary endpoints including O’Leary‐Sant Interstitial Cystitis Problem Index score, micturition episodes/24 h, voided volume/micturition, maximum voided volume/micturition, numerical rating scale score for bladder pain, and global response assessment score. The adverse drug reactions were mild to moderate, and manageable.

Conclusions

This first randomized, double‐blind, placebo‐controlled trial shows that KRP‐116D improves symptoms, voiding parameters, and global response assessment, compared with placebo, and has a well‐tolerated safety profile in interstitial cystitis/bladder pain syndrome patients with the bladder‐centric phenotype.

Relationship between the frequency of electrocautery of Hunner lesions and changes in bladder capacity in patients with Hunner type interstitial cystitis

Electrocautery is a promising treatment option for patients with Hunner type interstitial cystitis (HIC), but frequently requires multiple sessions due to recurrence of the lesions. In the present study, we assessed the relationship between the frequency of electrocautery of Hunner lesions and changes in maximum bladder capacity (MBC) at hydrodistension in a large cohort of 118 HIC patients. Three mixed-effect linear regression analyses were conducted for MBC against (1) the number of sessions; (2) the number of sessions and the time between each session and the first session; and (3) other relevant clinical parameters in addition to the Model (2). The mean number of sessions was 2.8 times. MBC decreased approximately 50 mL for each additional electrocautery session, but this loss was offset by 10 mL for each year the subsequent session was postponed. MBC of < 400 mL at the first session was a significant risk factor for MBC loss with further sessions. No other clinical parameters were associated with MBC over time. This study demonstrates a significant relationship between the frequency of electrocautery of Hunner lesions and MBC changes in HIC patients. Low MBC at the first session is a poor prognostic marker for MBC loss over multiple sessions.

Autoimmunity to urothelial antigen causes bladder inflammation, pelvic pain, and voiding dysfunction: a novel animal model for Hunner-type interstitial cystitis

Recent evidence revealed that Hunner-type interstitial cystitis (HIC) is a robust inflammatory disease potentially associated with enhanced immune responses and histologically characterized by epithelial denudation and lymphoplasmacytic infiltration with frequent clonal expansion of infiltrating B cells. To date, few animal models that reproduce the histological and clinical correlates of HIC have yet been established. In the present study, we aimed to develop a novel animal model for HIC via autoimmunity to the bladder urothelium using the transgenic mouse model (URO-OVA) that expresses the membrane form of the model antigen ovalbumin (OVA) as a self-antigen on the bladder urothelium. OVA-specific lymphocytes (splenocytes) were generated by immunization of C57BL/6 mice with OVA protein and injected intravenously into URO-OVA mice. The splenocytes from OVA-immunized C57BL/6 mice showed increased interferon (IFN)-γ production in response to OVA stimulation in vitro. URO-OVA mice adoptively transferred with OVA-primed splenocytes developed cystitis exhibiting histological chronic inflammatory changes such as remarkable mononuclear cell infiltration predominantly composed of T and B lymphocytes, increased vascularity, and mucosal hyperemia in the bladder at days 7-28 with a peak at day 21 tested. No systemic inflammation was found in cystitis-induced URO-OVA mice, nor was any inflammation found in wild-type C57BL/6 mice adoptively transferred with OVA-primed splenocytes. Along with bladder inflammation, URO-OVA mice demonstrated significantly increased pelvic nociceptive responses, voiding dysfunction, and upregulated mRNA expression levels for IFN-γ, tumor necrosis factor-α (TNF-α), and substance P precursor in the bladder. This model reproduces the histological and clinical features of human HIC, providing a novel model for HIC research.

Biomaterial-assisted drug delivery for interstitial cystitis/bladder pain syndrome treatment

Interstitial cystitis/bladder pain syndrome (IC/BPS) is a chronic and painful bladder condition afflicting patients with increased urinary urgency and frequency as well as incontinence. Owing to the elusive pathogenesis of IC/BPS, obtaining effective therapeutic outcomes remains challenging. Current administrational routes such as intravesical-bladder injection improve the treatment efficacy and reduce systemic side effects. However, the bladder permeability barrier hinders drug penetration into the bladder wall to meet the desired therapeutic expectation. These issues can be addressed by encapsulating drugs into biomaterials. When appropriately exploited, they would increase the drug dwelling time in the bladder, enhance the penetration of mucosa and improve the therapeutic response of IC/BPS. In this review, we first elucidate the pathogenesis and animal models of IC/BPS. Then, we highlight recent representative biomaterial-assisted drug delivery systems for IC/BPS treatment. Finally, we discuss the challenges and outlook for further developing biomaterial-based delivery systems for IC/BPS management.

Managing Interstitial Cystitis/Bladder Pain Syndrome in Older Adults

In this review, the current literature regarding pharmacotherapy treatment strategies available for the management of interstitial cystitis/bladder pain syndrome in older adults is addressed. The focus is on those treatments described by the American Urologic Association guidelines, organized according to clinical phenotype. Symptoms at presentation can vary with age, with older adults being more likely to experience nocturia, urinary incontinence, and Hunner's lesions than their younger counterparts. As such, treatment of interstitial cystitis/bladder pain syndrome should follow an individualized multimodal plan based on the patient's unique phenotype(s), starting with the most conservative options and escalating as needed. The side-effect profile and medication interactions should be reviewed, especially when treating older adults, requesting the aid of pharmacists or the primary care physician as needed to safely provide treatment.

In vivo and ex vivo assessment of bladder hyper-permeability and using molecular targeted magnetic resonance imaging to detect claudin-2 in a mouse model for interstitial cystitis

OBJECTIVES

To determine if the URO-MCP-1 mouse model for bladder IC/BPS is associated with in vivo bladder hyper-permeability, as measured by contrast-enhanced MRI (CE-MRI), and assess whether molecular-targeted MRI (mt-MRI) can visualize in vivo claudin-2 expression as a result of bladder hyper-permeability. Interstitial cystitis/bladder pain syndrome (IC/BPS) is a chronic, painful condition of the bladder that affects primarily women. It is known that permeability plays a substantial role in IC/BPS. Claudins are tight junction membrane proteins that are expressed in epithelia and endothelia and form paracellular barriers and pores that determine tight junction permeability. Claudin-2 is a molecular marker that is associated with increased hyperpermeability in the urothelium.

MATERIALS AND METHODS

CE-MRI was used to measure bladder hyper-permeability in the URO-MCP-1 mice. A claudin-2-specific mt-MRI probe was used to assess in vivo levels of claudin-2. The mt-MRI probe consists of an antibody against claudin-2 conjugated to albumin that had Gd-DTPA (gadolinium diethylenetriamine pentaacetate) and biotin attached. Verification of the presence of the mt-MRI probe was done by targeting the biotin moiety for the probe with streptavidin-horse radish peroxidase (SA-HRP). Trans-epithelial electrical resistance (TEER) was also used to assess bladder permeability.

RESULTS

The URO-MCP-1 mouse model for IC/BPS was found to have a significant increase in bladder permeability, following liposaccharide (LPS) exposure, compared to saline-treated controls. mt-MRI- and histologically-detectable levels of the claudin-2 probe were found to increase with LPS -induced bladder urothelial hyper-permeability in the URO-MCP-1 IC mouse model. Levels of protein expression for claudin-2 were confirmed with immunohistochemistry and immunofluorescence imaging. Claudin-2 was also found to highly co-localize with zonula occlidens-1 (ZO-1), a tight junction protein.

CONCLUSION

The combination of CE-MRI and TEER approaches were able to demonstrate hyper-permeability, a known feature associated with some IC/BPS patients, in the LPS-exposed URO-MCP-1 mouse model. This MRI approach could be clinically translated to establish which IC/BPS patients have bladder hyper-permeability and help determine therapeutic options. In addition, the in vivo molecular-targeted imaging approach can provide invaluable information to enhance our understanding associated with bladder urothelium hyper-permeability in IC/BPS patients, and perhaps be used to assist in developing further therapeutic strategies.

Presenting an atlas of Hunner lesions in interstitial cystitis which can be identified with office cystoscopy

AIM

To assist clinicians in proper visual diagnosis of Hunner lesions by providing an atlas of representative images of the variability in Hunner lesion appearance.

METHODS

Available cystoscopic images of Hunner lesions were reviewed from patients with interstitial cystitis or bladder pain syndrome (IC/BPS) treated by a single clinician between 2011 and 2020. For most patients, initial cystoscopy was performed in the office under local anesthesia. Images were categorized by variations in appearance. Data including Hunner lesion descriptions and patient demographics were retrospectively collected from the medical record. Only patients who had images available, received triamcinolone injection and/or fulguration of Hunner lesions, and reported improvement of their symptoms following treatment were included in the atlas.

RESULTS

Thirty-one IC/BPS patients with Hunner lesions had cystoscopic images available for review. We created an atlas of representative images. Variations in appearance include classic lesions with or without a central coagulum, inflamed lesions, non-inflamed lesions, groupings of lesions, and lesions with a red waterfall bleeding appearance.

CONCLUSION

There is variation in cystoscopic appearance of Hunner lesions. Most Hunner lesions can be identified during office visits using flexible cystoscopy and local anesthesia without hydrodistention or general anesthesia. Proper visual diagnosis of Hunner lesions is of upmost importance as these patients with IC/BPS respond greatly to endoscopic intervention. This atlas will serve as a reference for clinicians and researchers, so they are able to better identify and manage these patients.

Bladder pain syndrome/interstitial cystitis in contemporary UK practice: Outcomes of phenotype-directed management

OBJECTIVES

Problem bladder pain syndrome/interstitial cystitis (BPS/IC) is a heterogeneous disorder with variation in management worldwide. Phenotyping aims to personalize therapy and optimize outcomes. The most well-described phenotype is Hunner lesion disease (HLD). The prevalence of HLD and outcome of phenotype-directed management in the UK is not well-studied. We describe the management of a contemporary cohort of patients with BPS/IC in the UK.

METHODS

Retrospective analysis of all patients with BPS/IC from January 2015-November 2018. Outcomes of patients who underwent laser ablation to Hunner lesions were collected using the Global Response Assessment tool.

RESULTS

One hundred and sixty-three patients (mean age of 43 years [20-85]) were included. 78% were female and patients had experienced symptoms for an average 6 years (1-30) prior to specialist assessment. Eighty-three percent of patients had pelvic imaging (44% ultrasound, 42% magnetic resonance imaging and 14% computed tomography), and a relevant abnormality was found in five (4%). Twenty-two patients (14%) had HLD (International Society for the Study of BPS [ESSIC] 3), with a mean bladder capacity of 373 mL (175-650 mL); 77% were ESSIC C on histopathology. All patients with HLD underwent laser ablation, with 55% experiencing a moderate/marked improvement in symptoms, with a mean duration of effect of 10 months (3-36); 27% of patients had a repeat treatment.

CONCLUSIONS

The presence of HLD in patients with BPS/IC is not uncommon. Pelvic imaging rarely identifies any cause for pain and so cystoscopy under anesthesia is essential for accurate phenotyping. Phenotype-directed management with holmium laser ablation to Hunner lesions has good short-term efficacy in improving pain, but re-intervention is often required.