Sensory Hyperinnervation Distinguishes Bladder Pain Syndrome/Interstitial Cystitis from Overactive Bladder Syndrome

Recurrent infections drive persistent bladder dysfunction and pain via sensory nerve sprouting and mast cell activity

Urinary tract infections (UTIs) account for almost 25% of infections in women. Many are recurrent (rUTI), with patients frequently experiencing chronic pelvic pain and urinary frequency despite clearance of bacteriuria after antibiotics. To elucidate the basis for these bacteria-independent bladder symptoms, we examined the bladders of patients with rUTI. We noticed a notable increase in neuropeptide content in the lamina propria and indications of enhanced nociceptive activity. In mice subjected to rUTI, we observed sensory nerve sprouting that was associated with nerve growth factor (NGF) produced by recruited monocytes and tissue-resident mast cells. Treatment of rUTI mice with an NGF-neutralizing antibody prevented sprouting and alleviated pelvic sensitivity, whereas instillation of native NGF into naïve mice bladders mimicked nerve sprouting and pain behavior. Nerve activation, pain, and urinary frequency were each linked to the presence of proximal mast cells, because mast cell deficiency or treatment with antagonists against receptors of several direct or indirect mast cell products was each effective therapeutically. Thus, our findings suggest that NGF-driven sensory sprouting in the bladder coupled with chronic mast cell activation represents an underlying mechanism driving bacteria-independent pain and voiding defects experienced by patients with rUTI.

Overactive bladder syndrome symptoms in youth with abdominal pain-associated disorders of gut-brain interaction

The purpose of the current study was to assess the frequency of overactive bladder syndrome (OBS) symptoms and their relationship to gastrointestinal symptoms in youth with abdominal pain-associated disorders of gut-brain interaction (AP-DGBI). This is a retrospective study of 226 youth diagnosed with an AP-DGBI. As part of standard care, all patients completed a symptom questionnaire regarding gastrointestinal and non-gastrointestinal symptoms including increased urinary frequency, nighttime urination, and urinary urgency. Overall, 54% of patients reported at least one OBS symptom. Increased frequency of urination was reported by 19%, urinary urgency by 34%, and nighttime urination by 36%. Increased frequency of urination and urinary urgency were associated with a change in stool form, a change in stool frequency, and in those fulfilling criteria for IBS. Increased frequency of urination was reported more frequently in those reporting predominantly loose stools (33% vs. 12%). Urinary symptoms are common in youth with AP-DGBI. Increased urinary frequency and urinary urgency are specifically associated with IBS, with increased urinary frequency being primarily associated with diarrhea predominant IBS. Further studies are needed to determine the impact of OBS on AP-DGBI severity and quality of life, and whether they impact DGBI treatment.

EBV infection mediated BDNF expression is associated with bladder inflammation in interstitial cystitis/bladder pain syndrome with Hunner's lesion

Interstitial cystitis/bladder pain syndrome with Hunner's lesion (HIC) is characterized by chronic inflammation and nerve hyperplasia; however, the pathogenesis of HIC remains a mystery. In this study, we detected both Epstein-Barr virus (EBV) latency infection genes EBNA-1 and LMP-1 and EBV lytic infection BZLF-1 and BRLF-1 expression in the HIC bladders, indicating the coexistence of EBV persistence and reactivation in the B cells in HIC bladders. Upregulation of EBV-associated inflammatory genes in HIC bladders, such as TNF-α and IL-6, suggests EBV infection is implicated in the pathogenesis of bladder inflammation. Nerve hyperplasia and upregulation of brain-derived neurotrophic factor (BDNF) were noted in the HIC bladders. Double immunochemical staining and flow cytometry revealed the origin of BDNF to be EBV-infected B cells. Inducible BDNF expression was noted in B cells upon EBV infection, but not in the T cells. A chromatin immunoprecipitation study revealed BDNF transcription could be promoted by cooperation between EBV nuclear antigens, chromatin modifiers, and B-cell-specific transcription. Knockdown of BDNF in EBV-infected B cells resulted in the inhibition of cell proliferation and viability. Downregulation of phosphorylated SMAD2 and STAT3 after BDNF knockdown may play a role in the mechanism. Implantation of latent EBV-infected B cells into rat bladder walls resulted in a higher expression level of CD45 and PGP9.5, suggesting tissue inflammation and nerve hyperplasia. In contrast, implantation of BDNF depleted EBV-infected B cells abrogated these effects. This is the first study to provide insights into the mechanisms underlying the involvement of EBV-infected B cells in HIC pathogenesis. © 2022 The Pathological Society of Great Britain and Ireland.

Changes in nerve growth factor signaling in female mice with cyclophosphamide-induced cystitis

IC/BPS is a chronic inflammatory pelvic pain syndrome characterized by lower urinary tract symptoms including unpleasant sensation (pain, pressure, or discomfort) in the suprapubic or bladder area, as well as increased urinary frequency and urgency, and decreased bladder capacity. While its etiology remains unknown, increasing evidence suggests a role for changes in nerve growth factor (NGF) signaling. However, NGF signaling is complex and highly context dependent. NGF activates two receptors, TrkA and p75NTR, which activate distinct but overlapping signaling cascades. Dependent on their coexpression, p75NTR facilitates TrkA actions. Here, we show effects of CYP treatment and pharmacological inhibition of p75NTR (via LM11A-31) and TrkA (ARRY-954) on NGF signaling-related proteins: NGF, TrkA, phosphorylated (p)-TrkA, p75NTR, p-ERK1/2, and p-JNK. Cystitis conditions were associated with increased urothelial NGF expression and decreased TrkA and p75NTR expression as well as altering their co-expression ratio; phosphorylation of ERK1/2 and JNK were also altered. Both TrkA and p75NTR inhibition affected the activation of signaling pathways downstream of TrkA, supporting the hypothesis that NGF actions during cystitis are primarily TrkA-mediated. Our findings, in tandem with our recent companion paper demonstrating the effects of TrkA, TrkB, and p75NTR inhibition on bladder function in a mouse model of cystitis, highlight a variety of potent therapeutic targets and provide further insight into the involvement of NGF signaling in sustained conditions of bladder inflammation.

Overlaps with bladder pain syndrome and irritable bowel syndrome are associated with higher symptom burden and reduced quality of life in functional dyspepsia

BACKGROUND

Functional dyspepsia and bladder pain syndrome are well-known to overlap with irritable bowel syndrome. Whether functional dyspepsia overlaps with bladder pain syndrome remains unknown. Our aim was to evaluate the presence of bladder pain syndrome in functional dyspepsia patients and its impact.

METHODS

All consecutive patients with investigated dyspeptic symptoms in our tertiary care center between March 2015 and November 2018 were studied. Functional dyspepsia and irritable bowel syndrome were diagnosed according to Rome III and IV criteria while bladder pain syndrome was diagnosed using ESSIC criteria. Validated questionnaires were filled to assess quality of life (GIQLI), anxiety and depression (HADS), sleep (PSQI), and insomnia (ISI). Dyspeptic symptoms severity was assessed individually for eight dyspeptic complaints.

KEY RESULTS

Among 1453 patients with dyspeptic symptoms, 61.4% fulfilled Rome criteria for functional dyspepsia. Bladder pain syndrome was present in 16.0% of the patients not fulfilling diagnostic criteria for functional dyspepsia, 22.2% of patients with functional dyspepsia alone, and 36.4% of patients with overlapping functional dyspepsia and irritable bowel syndrome (p-values <0.0001). In patients with bladder pain syndrome overlapping with functional dyspepsia, dyspeptic symptoms severity, anxiety, depression, and insomnia levels were higher while quality of life and sleep quality were reduced (p-values <0.0001). These results were even more pronounced in case of overlap with irritable bowel syndrome (p-values <0.0001).

CONCLUSIONS AND INFERENCES

Bladder pain syndrome is present in 26.9% of functional dyspepsia patients and is associated with higher gastrointestinal, psychological distresses, and sleep symptom burdens, and with reduced quality of life.

Urinary brain-derived neurotrophic factor and nerve growth factor as noninvasive biomarkers of overactive bladder in children

Introduction

Overactive bladder (OAB) is the most common urinary disorder and the leading cause of functional daytime intermittent urinary incontinence in children. The aim of this study was to determine whether urinary brain-derived neurotrophic factor (BDNF) and nerve growth factor (NGF) concentrations, normalized to urine creatinine, could be used as biomarkers for diagnosis and treatment monitoring of OAB in children.

Materials and methods

Urine samples of 48 pediatric patients with OAB were collected at the start of anticholinergic therapy (baseline), at follow-up visits (3 and 6 months), and from 48 healthy controls. Urinary BDNF and NGF concentrations were determined by ELISA method (Merck, Darmstadt, Germany) and Luminex method (Thermo Fisher Scientific, Waltham, USA). Differences of frequency between quantifiable analyte concentrations between subject groups were determined using Fisher’s exact test.

Results

There was no statistically significant difference between quantifiable analyte concentrations between patients at baseline and the control group for BDNF and NGF by either the ELISA or Luminex method (P = 1.000, P = 0.170, P = 1.000, and P = N/A, respectively). There was a statistically significant difference between quantifiable BDNF by the ELISA method between patients at baseline and complete success follow-up (P = 0.027), while BDNF by Luminex method and NGF by both methods were not statistically significant (P = 0.078, P = 0.519, and P = N/A, respectively).

Conclusions

This study did not demonstrate that urinary BDNF and NGF concentrations, can be used as biomarkers for diagnosis and therapy monitoring of OAB in children.

Clinical Approach to Recurrent Voiding Dysfunction, Dysuria, and Pelvic Pain Persisting for at Least 3 Months

There are several patients with urination problems and urethral and pelvic discomfort. Usually, these patients’ symptoms are persistent and ambiguous; therefore, it is difficult to find underlying diseases associated with the patient’s symptoms. In addition, there are various conditions such as overactive bladder, cystitis, and interstitial cystitis/bladder pain syndrome (IC/BPS). Sometimes patients with other chronic disorders such as fibromyalgia, inflammatory bowel syndrome, and vulvodynia show urination problems and pelvic pain. Thus, a patient-centered approach is important to find the cause of chronic urination problems and pelvic pain. Moreover, IC/BPS should be considered during the diagnostic process because the clinical characteristics of IC/BPS are diverse. In this narrative review, we suggest an integral approach for the diagnosis and treatment of IC/ BPS.

Current Understanding of the Pathophysiology and Novel Treatments of Interstitial Cystitis/Bladder Pain Syndrome

The pathophysiology of interstitial cystitis/bladder pain syndrome (IC/BPS) is multifactorial. Identifying the clinical characteristics and cystoscopic findings of bladder-centered IC/BPS facilitates optimal treatment strategies targeting the diseased urinary bladder. Patients with Hunner’s lesion (HIC) and without Hunner’s lesion (NHIC) should be treated differently. Based on the histopathological findings, NHIC can be treated with intravesical instillation of urothelial protective agents, such as hyaluronic acid, to cover the urothelial defects. In non-responders, chronic inflammation and higher urothelial dysfunction can be treated with intravesical botulinum toxin A injection, platelet-rich plasma injection, or low-energy shock wave treatment to reduce inflammation, increase tissue regeneration, and improve the urothelial barrier. Patients with HIC should be treated with electrocauterization first; augmentation enterocystoplasty should only be used in end-stage HIC when the contracted bladder is refractory to other treatments. The antiviral agent, valacyclovir, can be used in patients with HIC, small bladder capacity, and high-grade glomerulations. In addition, behavioral modification is always recommended from the beginning of treatment. Treatment with cognitive behavioral therapy interventions in combination with bladder therapy can reduce anxiety and improve treatment outcomes. Herein, recent advances in the pathophysiology and novel treatments for IC/BPS are reviewed.

Prospective randomized controlled trial comparing fulguration versus fulguration and hydrodistension for Hunner-type interstitial cystitis/bladder pain syndrome

PURPOSE

In Hunner-type interstitial cystitis/bladder pain syndrome (IC/BPS), it is unclear whether suburothelial afferents underlying normal-appearing background areas contribute to symptom development. We examined whether adding hydrodistension (HD) to transurethral fulguration (TUF) of Hunner lesions, for the purpose of treating the background areas, is superior to TUF alone.

METHODS

This randomized controlled trial included 52 patients with Hunner-type IC/BPS allocated at a 1:1 (TUF:TUF+HD) ratio. HD was performed at 80 cmH₂O for 8 min before TUF in the TUF+HD group. Thirty-three patients remained until the end of the 6-month observational period. The primary endpoint was the visual analogue scale (VAS) pain score at 1 month. Major secondary endpoints were the treatment-failure rate, VAS pain scores at ≥ 2 months, and frequency-volume chart parameters.

RESULTS

Both TUF and TUF+HD showed significant improvement in VAS pain score at 1 month (95% confidence interval [CI]: - 1.62 to 0.16, P = 0.106). VAS pain scores were significantly lower in TUF+HD than TUF at 2 (95% CI: - 1.97 to - 0.28, P = 0.011), 4 (95% CI: - 2.83 to - 0.72, P = 0.002), and 6 (95% CI: - 3.11 to - 0.07, P = 0.040) months. Treatment-failure rate was higher in TUF (36.4%) than TUF+HD (17.4%), without significance (odds ratio: 2.714, 95% CI: 0.68 to 10.84, P = 0.189). Functional capacity and urgency were not significantly different between groups.

CONCLUSION

The addition of HD to TUF tended to be superior to TUF monotherapy for controlling pain in Hunner-type IC/BPS. This indicates that not only Hunner lesions but also normal-appearing background areas may have a role in the pain of IC/BPS.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT03987594, date of registration: 2019-06-17 (retrospectively registered).

Non-Hunner's Interstitial Cystitis Is Different from Hunner's Interstitial Cystitis and May Be Curable by Uterosacral Ligament Repair

Background

The posterior fornix syndrome (PFS) was first described in 1993 as a predictably occurring group of symptoms: chronic pelvic pain (CPP), urge, frequency, nocturia, emptying difficulties/urinary retention, caused by uterosacral ligament (USL) laxity, and cured by repair thereof.

Summary

Our hypothesis was that non-Hunner's interstitial cystitis (IC) and PFS are substantially equivalent conditions. The primary objective was to determine if there was a causal relationship between IC and pelvic organ prolapse (POP). The secondary objective was to assess whether other pelvic symptoms were present in patients with POP-related IC and if so, which ones? How often did they occur? A retrospective study was performed in 198 women who presented with CPP, uterine/apical prolapse (varying degrees), and PFS symptoms, all of whom had been treated by posterior USL sling repair. We compared their PFS symptoms with known definitions of IC, CPP, and bladder symptoms. To check our hypothesis for truth or falsity, we used a validated questionnaire, “simulated operations” (mechanically supporting USLs with a vaginal speculum test to test for reduction of urge and pain), transperineal ultrasound and urodynamics.

Key Messages

198 patients had CPP and 313 had urinary symptoms which conformed to the definition for non-Hunner's IC. The cure rate after USL sling repair was CPP 74%, urge incontinence 80%, frequency 79.6%, abnormal emptying 53%, nocturia 79%, obstructive defecation 80%. Our findings seem to support our hypothesis that non-Hunner's IC and PFS may be similar conditions; also, non-Hunner IC/BPS may be a separate or lesser disease entity from “Hunner lesion disease”. More rigorous scientific investigation, preferably by RCT, will be required.

Integrated mRNA-miRNA transcriptome analysis of bladder biopsies from patients with bladder pain syndrome identifies signaling alterations contributing to the disease pathogenesis

Background

Interstitial cystitis, or bladder pain syndrome (IC/BPS), is a chronic bladder disorder characterized by lower abdominal pain associated with the urinary bladder and accompanied by urinary frequency and urgency in the absence of identifiable causes. IC/PBS can be separated into the classic Hunner’s ulcerative type and the more prevalent non-ulcerative disease. Our aim was to unravel the biological processes and dysregulated cell signaling pathways leading to the bladder remodeling in non-ulcerative bladder pain syndrome (BPS) by studying the gene expression changes in the patients’ biopsies.

Methods

We performed paired microRNA (miRNA) and mRNA expression profiling in the bladder biopsies of BPS patients with non-Hunner interstitial cystitis phenotype, using comprehensive Next-generation sequencing (NGS) and studied the activated pathways and altered biological processes based on the global gene expression changes. Paired mRNA-miRNA transcriptome analysis delineated the regulatory role of the dysregulated miRNAs by identifying their targets in the disease-induced pathways.

Results

EIF2 Signaling and Regulation of eIF4 and p70S6K Signaling, activated in response to cellular stress, were among the most significantly regulated processes during BPS. Leukotriene Biosynthesis nociceptive pathway, important in inflammatory diseases and neuropathic pain, was also significantly activated. The biological processes identified using Gene Ontology over-representation analysis were clustered into six main functional groups: cell cycle regulation, chemotaxis of immune cells, muscle development, muscle contraction, remodeling of extracellular matrix and peripheral nervous system organization and development. Compared to the Hunner’s ulcerative type IC, activation of the immune pathways was modest in non-ulcerative BPS, limited to neutrophil chemotaxis and IFN-γ-mediated signaling. We identified 62 miRNAs, regulated and abundant in BPS and show that they target the mRNAs implicated in eIF2 signalling pathway.

Conclusions

The bladders of non-ulcerative BPS patients recruited in this study had alterations consistent with a strong cell proliferative response and an up-regulation of smooth muscle contractility, while the contribution of inflammatory processes was modest. Pathway analysis of the integrated mRNA-miRNA NGS dataset pinpointed important regulatory miRNAs whose dysregulation might contribute to the pathogenesis. Observed molecular changes in the peripheral nervous system organization and development indicate the potential role of local bladder innervation in the pain perceived in this type of BPS.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12894-021-00934-0.

Comparison of deep phenotyping features of UCPPS with and without Hunner lesion: A MAPP-II Research Network Study

OBJECTIVE

To use the phenotyping data from the MAPP-II Symptom Patterns Study (SPS) to compare the systemic features between urologic chronic pelvic pain syndrome (UCPPS) with Hunner lesion (HL) versus those without HL.

METHODS

We performed chart review on 385 women and 193 men with UCPPS who enrolled in the MAPP-II SPS. 223 had cystoscopy and documentation of HL status. Among them, 12.5% had HL and 87.5% did not.

RESULTS

UCPPS participants with HL were older, had increased nocturia, higher Interstitial Cystitis Symptom and Problem Indexes, and were more likely to report "painful urgency" compared with those without HL. On the other hand, UCPPS without HL reported more intense nonurologic pain, greater distribution of pain outside the pelvis, greater numbers of comorbid chronic overlapping pain conditions, higher fibromyalgia-like symptoms, and greater pain centralization, and were more likely to have migraine headache than those with HL. UCPPS without HL also had higher anxiety, perceived stress, and pain catastrophizing than those with HL. There were no differences in sex distribution, UCPPS symptom duration, intensity of urologic pain, distribution of genital pain, pelvic floor tenderness on pelvic examination, quality of life, depression, pain characteristics (nociceptive pain vs. neuropathic pain), mechanical hypersensitivity in the suprapubic area during quantitative sensory testing, and 3-year longitudinal pain outcome and urinary outcome between the two groups.

CONCLUSIONS

UCPPS with HL displayed more bladder-centric symptom profiles, while UCPPS without HL displayed symptoms suggesting a more systemic pain syndrome. The MAPP-II SPS phenotyping data showed that Hunner lesion is a distinct phenotype from non-Hunner lesion.

Increased Transient Receptor Potential Melastatin 8 Expression in the Development of Bladder Pain in Patients With Interstitial Cystitis/Bladder Pain Syndrome

OBJECTIVE

To explore the role of transient receptor potential melastatin 8 (TRPM8) in the occurrence and development of bladder pain in interstitial cystitis/bladder pain syndrome (IC/BPS) patients. The differences in the content and location distribution of TRPM8 in bladder were compared between IC/BPS and control group.

METHODS

All enrolled patients answered questionnaire such as O'leary-Sant symptom index, visual analog scale (VAS), quality of life (QOL), and pelvic pain and urinary urgency frequency (PUF) score, then bladder specimens were collected. Analyses such as qRT-PCR, western blot, and immunofluorescence were performed to determine the changes in TRPM8 content and expression in neurons and sensory nerves between the IC/BPS and control group, and the relationships between TRPM8 and various clinical scores were also analyzed.

RESULTS

There were significant differences in the O'leary-Sant score, PUF score, VAS, and QOL score between IC/BPS and the control group (P < .05). Compared with the control group, the expression levels of TRPM8 mRNA and protein were significantly increased in the IC/BPS bladder tissues (P < .01). Immunofluorescence examination also revealed that (1) the number of neurons and sensory nerves displayed a significant upward trend in the bladder tissue of IC/BPS patients (2) the expression levels of TRPM8 on neurons and sensory nerves also increased significantly in IC/BPS group.

CONCLUSION

In IC/BPS patients, TRPM8 content increased significantly and mainly expressed on increased neurons and sensory nerves in bladder tissue. These results may indicate a mechanism by which bladder pain is more easily to spread in IC/BPS patients, and may also indicate an important mechanism for pain sensitization in such patients.

[Diagnosis and treatment of interstitial cystitis (IC/PBS) : S2k guideline of the German Society of Urology]

In this review article, the authors describe all relevant aspects of the new S2k guideline from the German Society of Urology (Deutschen Gesellschaft für Urologie, DGU) for the diagnosis and treatment of IC/PBS (interstitial cystitis/painful bladder syndrome). A list of necessary and optional examinations and the necessity of diagnosis of exclusion are summarized and evaluated. The treatment options listed (ranging from conservative, oral drug, and complementary medicine to interventional surgical procedures) also give the reader a good overview of the contents of the guideline and possible therapeutic approaches. Finally, the recommendations including consensus of the guideline group are also summarized in various information boxes.

[Diagnosis and treatment of interstitial cystitis (IC/PBS) : S2k guideline of the German Society of Urology]

In this review article, the authors describe all relevant aspects of the new S2k guideline from the German Society of Urology (Deutschen Gesellschaft für Urologie, DGU) for the diagnosis and treatment of IC/PBS (interstitial cystitis/painful bladder syndrome). A list of necessary and optional examinations and the necessity of diagnosis of exclusion are summarized and evaluated. The treatment options listed (ranging from conservative, oral drug, and complementary medicine to interventional surgical procedures) also give the reader a good overview of the contents of the guideline and possible therapeutic approaches. Finally, the recommendations including consensus of the guideline group are also summarized in various information boxes.

Pharmacological management of interstitial cystitis /bladder pain syndrome and the role cyclosporine and other immunomodulating drugs play

INTRODUCTION

Interstitial cystitis/bladder pain syndrome (IC/BPS) is a symptomatic disorder characterized by pelvic pain and urinary frequency. Immunological responses are considered as one of the possible etiologies of IC/BPS. In this review, we focused on emerging targets, especially on those modulating immunological mechanisms for the treatments of IC/BPS. Area covered: This review was based on the literature search of PubMed/MEDLINE, for which key words following bladder pain syndrome, interstitial cystitis, and/or cyclosporine A (CyA) were used. We discussed current treatments and the drugs targeting the immune responses including CyA and other drugs with different mechanisms including NGF antibodies and P2X3 antagonists. Expert commentary: IC/BPS is often difficult to treat by current treatments. Immunosuppression agents, especially CyA are considered as effective treatments for IC/BPS with Hunner's lesion because these drugs suppress the inflammatory responses in the bladder underlying urinary symptoms of the disease. Base on the previous literatures, we should use CyA for the refractory IC/BPS, especially that with Hunner's lesion due to its side effects. New drugs targeting other mechanisms such as urothelial or afferent nerve dysfunction or new delivery systems such as sustained drug releasing devices or gene therapy techniques may be promising for the future treatments of IC/BPS.

Inflammatory Renin-Angiotensin System Disruption Attenuates Sensory Hyperinnervation and Mechanical Hypersensitivity in a Rat Model of Provoked Vestibulodynia

Vestibulodynia is characterized by perivaginal mechanical hypersensitivity, hyperinnervation, and abundant inflammatory cells expressing renin-angiotensin system proteins. We developed a tractable rat model of vestibulodynia to further assess the contributions of the renin-angiotensin system. Complete Freund's adjuvant injected into the posterior vestibule induced marked vestibular hypersensitivity throughout a 7-day test period. Numbers of axons immunoreactive for PGP9.5, calcitonin gene-related peptide, and GFRα2 were increased. Numbers of macrophages and T cells were also increased whereas B cells were not. Renin-angiotensin-associated proteins were abundant, with T cells as well as macrophages contributing to increased renin and angiotensinogen. Media conditioned with inflamed vestibular tissue promoted neurite sprouting by rat dorsal root ganglion neurons in vitro, and this was blocked by the angiotensin II receptor type 2 receptor antagonist PD123319 or by an angiotensin II function blocking antibody. Sensory axon sprouting induced by inflamed tissue was dependent on activity of angiotensin-converting enzyme or chymase, but not cathepsin G. Thus, vestibular Complete Freund's adjuvant injection substantially recapitulates changes seen in patients with provoked vestibulodynia, and shows that manipulation of the local inflammatory renin-angiotensin system may be a useful therapeutic strategy.

PERSPECTIVE

This study provides evidence that inflammation of the rat vestibule induces a phenotype recapitulating behavioral and cytological features of human vestibulodynia. The model confirms a crucial role of the local inflammatory renin-angiotensin system in hypersensitivity and hyperinnervation. Targeting this system holds promise for developing new nonopioid analgesic treatment strategies.

Diagnostic value of urinary CXCL10 as a biomarker for predicting Hunner type interstitial cystitis

AIM

To investigate the feasibility of chemokines and cytokines potentially elevated in the bladder tissue of Hunner type interstitial cystitis (HIC) as urinary markers for distinguishing HIC from non-Hunner type interstitial cystitis (NHIC) METHODS: Urine specimens were collected from 41 HIC patients, 25 NHIC patients, and 31 healthy volunteers (control). The supernatants of urine specimens were subjected to ELISA kits for measurements of 10 cytokines and chemokines, whose gene expression was known to be elevated in HIC bladder tissue. Urinary levels normalized by urinary creatinine (Cr) concentration were compared among three groups. Efficiency in differentiating IC and IC subtypes was explored by ROC analysis. The correlation of marker levels with symptom severity, assessed by O'Leary-Sant's symptom index (OSSI) and problem index (OSPI), was examined.

RESULTS

The urinary levels of CXCL10 and NGF were significantly higher in HIC than NHIC. CXCL10 and NGF differentiated HIC against NHIC with AUC of 0.78 and 0.68, respectively. Combination of CXCL10 and NGF levels yielded an AUS of 0.81. The CXCL10 cut-off of 53.2 pg/mg Cr had sensitivity of 46.1%, specificity of 93.7%, positive predictive value of 97.7%, and negative predictive value of 60.0%. The urinary level of other cytokines showed no significant difference between HIC and NHIC. Significant correlation with symptoms was detected for CXCL10 alone.

CONCLUSION

The results suggested that increased urinary level of CXCL10 combined with or without high NGF level could be a promising supplementary biomarker for differentiating HIC from NHIC with modest sensitivity and high specificity.

Neuronal cytoskeletal gene dysregulation and mechanical hypersensitivity in a rat model of Rett syndrome

Children with Rett syndrome show abnormal cutaneous sensitivity. The precise nature of sensory abnormalities and underlying molecular mechanisms remain largely unknown. Rats with methyl-CpG binding protein 2 (MeCP2) mutation, characteristic of Rett syndrome, show hypersensitivity to pressure and cold, but hyposensitivity to heat. They also show cutaneous hyperinnervation by nonpeptidergic sensory axons, which include subpopulations encoding noxious mechanical and cold stimuli, whereas peptidergic thermosensory innervation is reduced. MeCP2 knockdown confined to dorsal root ganglion sensory neurons replicated this phenotype in vivo, and cultured MeCP2-deficient ganglion neurons showed augmented axonogenesis. Transcriptome analysis revealed dysregulation of genes associated with cytoskeletal dynamics, particularly those controlling actin polymerization and focal-adhesion formation necessary for axon growth and mechanosensory transduction. Down-regulation of these genes by topoisomerase inhibition prevented abnormal axon sprouting. We identified eight key affected genes controlling actin signaling and adhesion formation, including members of the Arhgap, Tiam, and cadherin families. Simultaneous virally mediated knockdown of these genes in Rett rats prevented sensory hyperinnervation and reversed mechanical hypersensitivity, indicating a causal role in abnormal outgrowth and sensitivity. Thus, MeCP2 regulates ganglion neuronal genes controlling cytoskeletal dynamics, which in turn determines axon outgrowth and mechanosensory function and may contribute to altered pain sensitivity in Rett syndrome.

A Prospective, Multicenter, Double-Blind, Randomized Trial of Bladder Instillation of Liposome Formulation OnabotulinumtoxinA for Interstitial Cystitis/Bladder Pain Syndrome

PURPOSE

Intravesical instillation of liposomal formulated botulinum toxin A (lipotoxin) has shown therapeutic effects as treatment of refractory overactive bladder without needle injections. We assessed lipotoxin to treat refractory interstitial cystitis/bladder pain syndrome.

MATERIALS AND METHODS

This 2-center, double-blind, randomized, placebo controlled, physician initiated study enrolled patients with refractory interstitial cystitis/bladder pain syndrome. A total of 31 patients were assigned to intravesical instillation of lipotoxin (onabotulinumtoxinA 200 U with 80 mg sphingomyelin), 28 were assigned to onabotulinumtoxinA 200 U in normal saline and 31 were assigned to normal saline alone. The primary end point was the average change in O'Leary-Sant symptom scores, including ICSI (Interstitial Cystitis Symptom Index) and ICPI (Interstitial Cystitis Problem Index) between baseline and 4 weeks after treatment. Other end points included the average changes in a 3-day voiding diary, a visual analog scale for pain and a global response assessment of patient satisfaction.

RESULTS

Improvements in the pain scale and O'Leary-Sant symptom scores occurred in all 3 groups by 4 weeks after treatment. Lipotoxin instillation was associated with a statistically significant decrease in O'Leary-Sant symptom scores (mean ± SD 7.38 ± 8.75), ICSI (4.00 ± 4.28), ICPI (3.35 ± 5.11) and the visual analog scale pain scale (1.64 ± 2.52), and an increase in the global response assessment (1.35 ± 1.28). However, there was no difference in improvement among the 3 groups. No significant adverse events were found in any group.

CONCLUSIONS

Lipotoxin failed to demonstrate a positive proof of concept compared to onabotulinumtoxinA or placebo. However, a single intravesical instillation of lipotoxin was associated with decreased interstitial cystitis/bladder pain syndrome symptoms compared to baseline in patients with moderate to severe interstitial cystitis/bladder pain syndrome. The effect was likely due to a significant placebo effect.

Childhood trauma perpetrated by close others, psychiatric dysfunction, and urological symptoms in patients with interstitial cystitis/bladder pain syndrome

BACKGROUND

A psychosocial phenotype of interstitial cystitis/bladder pain syndrome (IC/BPS), a urogenital condition without known organic causes, was proposed. While psychosocial variables, including interpersonal maltreatment and negative affect, were studied in association with IC/BPS, the specificities of the relationships between childhood trauma by close others, psychiatric dysfunctions (negative affect and post-traumatic psychopathology), and urogenital symptoms have not been established.

METHODS

94 IC/BPS patients were recruited together with 47 patients with acute cystitis who served as clinical controls. Standardized scales were used to assess various potentially traumatizing events in childhood and adulthood as well as psychiatric (dissociation and negative affect) and urogenital symptoms.

RESULTS

Among the potentially traumatizing events, those perpetrated by close others during childhood were found to be the most salient features discriminating the IC/BPS group from the control group. When divided into 2 subgroups according to their history of childhood trauma by close others, only IC/BPS patients with childhood trauma by close others had more dissociative and anxiety symptoms compared with the control group. These two subgroups did not differ in urogenital symptom severity.

CONCLUSIONS

Childhood trauma by close others, rather than other types of interpersonal trauma, was a differentiating characteristic in IC/BPS patients, and a childhood trauma related psychosocial phenotype with a distinct clinical profile of dissociation and anxiety proneness was identified. Future studies should investigate whether a distinct set of pathogenic factors exists in IC/BPS patients with a history of childhood trauma by close others, even if this subgroup is not readily differentiated by urogenital symptoms.