The role of urinary potassium in the pathogenesis and diagnosis of interstitial cystitis

Use of Urinary Biomarkers in Discriminating Interstitial Cystitis/Bladder Pain Syndrome from Male Lower Urinary Tract Dysfunctions

To analyze the urinary biomarkers in men with lower urinary-tract symptoms (LUTS) and identify interstitial cystitis/bladder pain syndrome (IC/BPS) from the other lower urinary-tract dysfunctions (LUTDs) by the levels of characteristic urinary biomarkers. In total, 198 men with LUTS were prospectively enrolled and urine samples were collected before intervention or medical treatment. Videourodynamic studies were routinely performed and the LUTDs were diagnosed as having bladder-outlet obstruction (BOO) such as bladder-neck dysfunction, benign prostatic obstruction, or poor relaxation of external sphincter (PRES); and bladder dysfunction such as detrusor overactivity (DO), hypersensitive bladder (HSB), and IC/BPS. Patients suspicious of IC/BPS were further confirmed by cystoscopic hydrodistention under anesthesia. The urine samples were investigated for 11 urinary inflammatory biomarkers including eotaxin, IL-6, IL-8, CXCL10, MCP-1, MIP-1β, RANTES, TNF-α, NGF, BDNF, and PGE2; and 3 oxidative stress biomarkers 8-OHdG, 8-isoprostane, and TAC. The urinary biomarker levels were analyzed between LUTD subgroups and IC/BPS patients. The results of this study revealed that among the patients, IC/BPS was diagnosed in 48, BOO in 66, DO in 25, HSB in 27, PRES in 15, and normal in 17. Patients with BOO had a higher detrusor pressure and BOO index than IC/BPS, whereas patients with IC/BPS, BOO, and DO had a smaller cystometric bladder capacity than the PRES and normal subgroups. Among the urinary biomarkers, patients with IC/BPS had significantly higher levels of eotaxin, MCP-1, TNF-α, 8-OHdG, and TAC than all other LUTD subgroups. By a combination of different characteristic urinary biomarkers, TNF-α, and eotaxin, either alone or in combination, had the highest sensitivity, specificity, positive predictive value, and negative predictive value to discriminate IC/BPS from patients of all other LUTD subgroups, BOO, DO, or HSB subgroups. Inflammatory biomarker MCP-1 and oxidative stress biomarkers 8-OHdG and TAC, although significantly higher in IC/BPS than normal and PRES subgroups, did not have a diagnostic value between male patients with IC/BPS and the BOO, DO, or HSB subgroups. The study concluded that using urinary TNF-α and eotaxin levels, either alone or in combination, can be used as biomarkers to discriminate patients with IC/BPS from the other LUTD subgroups in men with LUTS.

Comparison of the Clinical Efficacy and Adverse Events between Intravesical Injections of Platelet-Rich Plasma and Botulinum Toxin A for the Treatment of Interstitial Cystitis Refractory to Conventional Treatment

BACKGROUND

Intravesical injection of Botulinum toxin A (BoNT-A) and platelet-rich plasma (PRP) have been reported to alleviate bladder pain and decrease nocturia in patients with refractory interstitial cystitis/bladder pain syndrome (IC/BPS). Both treatments are novel and there has no comparison between them. This study compared the therapeutic effects and adverse events between IC/BPS patients receiving PRP or BoNT-A injections.

MATERIALS AND METHODS

This study retrospectively analyzed female patients with IC/BPS who were refractory to conventional treatment and received BoNT-A (n = 26) or PRP (n = 30) injections within the previous two years. Patients were arbitrarily treated with four monthly injections of PRP or a single injection of 100 U of BoNT-A. All injections were followed by cystoscopic hydrodistention. The primary endpoint was the global response assessment (GRA), and secondary endpoints were changes in the O'Leary-Sant IC symptom score, visual analog score (VAS) of bladder pain, voiding diary, and uroflow measures from baseline to six months after the first injection day.

RESULTS

The baseline demographics revealed no significant difference between groups. The GRA at one, three, and six months was similar between groups. A significant improvement in IC symptom scores was noted in both groups. Although VAS was significantly improved in overall patients, no significant difference was noted between the PRP and BoNT-A groups at 6 months. Only half of the study cohort had a GRA ≥2 at six months. An increase in the post-void residual was noted one month after the BoNT-A injection, but there was no difference between groups at three and six months. More patients reported dysuria (19.2% vs. 3.3%, p = 0.086) and urinary tract infection (UTI, 15.4% vs. 0%, p = 0.041) after BoNT-A injection than after the PRP injections. The time from the first injection to receiving alternative treatment was similar between groups.

CONCLUSION

Both intravesical PRP and BoNT-A injections have similar efficacy in IC symptom improvement. However, only half of the study cohort had a GRA of ≥2 at the six-month follow-up BoNT-A injection carries a potential risk of UTI after treatment.

The efficacy and safety of intravesical chondroitin sulphate solution in recurrent urinary tract infections

BACKGROUND

Urinary tract infections are among the most common indications for antibiotic therapy. The emergence of resistant uropathogens indicates the need for treatment alternatives. Replenishment of the glycosaminoglycan layer of the bladder, achieved by intravesical instillation of e.g. chondroitin sulphate (CS), is described to be a cornerstone in the therapy of cystitis. To retrospectively evaluate the efficacy of a therapy with 0.2% CS in patients suffering recurrent urinary tract infections (rUTI) in comparison to a treatment with low-dose long-term antibiotics (LDLTAB) and a combination of both.

METHODS

A total of 151 patients with recurrent UTI who underwent intravesical therapy at Diaconesse hospital in Leiden, The Netherlands were included. 50 patients had been treated with CS, 51 patients had received LDLTAB, and 50 patients had received a combination therapy (LDLTABCS). Data recorded for baseline, after 6, and 12 months of treatment were evaluated. Descriptive statistics were calculated. Exploratory comparisons between groups and within groups were performed by using one-tailed and paired t-tests. Patients filled in a standardized quality of life questionnaire (EQ-5D).

RESULTS

We found a statistically significant reduction of number of infections from 7.10 ± 0.50 SEM to 0.45 ± 0.07 SEM after 12 months therapy with CS compared to 12 months therapy with LDLTAB (from 7.04 ± 0.47 SEM to 1.8 ± 0.15 SEM). The number of visits to the urologist significantly decreased in the CS group from 7.46 ± 0.80 SEM to 1.28 ± 0.11 SEM and from 4.10 ± 0.29 SEM to 1.35 ± 0.11 SEM in the LDLTABCS group. In addition, a significant increase in Quality of life (QoL) was seen in the CS-group (from 58.2 ± 0.82 SEM to 80.43 ± 0.82 SEM) and in the LDLTABCS group (from 62.4 ± 0.97 SEM to 76.73 ± 1.06 SEM). There was no improvement in QoL with LDLTAB (from 58.24 ± 1.08 SEM to 58.96 ± 1.19 SEM). Evaluation's evidence is limited due to its retrospective character.

CONCLUSIONS

Retrospective analysis of data from patients that underwent therapy for rUTIs confirms the safety and efficacy of CS and indicate a superiority to antibiotic treatment of rUTIs.

Therapeutic Efficacy of Intravesical Platelet-Rich Plasma Injections for Interstitial Cystitis/Bladder Pain Syndrome-A Comparative Study of Different Injection Number, Additives and Concentrations

Purpose: Intravesical platelet-rich plasma (PRP) injections have been demonstrated effective in relieving symptoms among patients with interstitial cystitis/bladder pain syndrome (IC/BPS). This study compared the clinical efficacy among different injection number, adding solution, and concentrations of PRP.

Methods: A total of 63 patients with IC/BPS were enrolled and randomly allocated to four subgroups who received single high-dose PRP (from 100 ml whole blood) plus 10 ml of normal saline or plasma injected over 20 or 40 sites. Patients were followed up at 1, 3, and 6 months for changes in the IC symptom index (ICSI) and problem index (ICPI), visual analog scale (VAS), global response assessment (GRA), and urodynamic parameters. Furthermore, we compared the clinical outcome with our previous study in a group of 55 IC/BPS patients who underwent four monthly low-dose PRP (from 50 ml whole blood) injections.

Results: The result of this study showed significant improvements in IC symptoms (ICSI 11.9 ± 4.4 vs. 10.2 ± 4.9, p = 0.009; ICPI 12.3 ± 3.4 vs. 10.6 ± 4.7, p = 0.003); VAS (5.46 ± 2.96 vs. 3.83 ± 3.1, p 0.000), and maximum flow rate (10.4 ± 4.9 vs. 17.1 ± 11.5 ml/s, p = 0.000) at 3 months after single high-dose PRP injection. However, no significant differences in therapeutic results were observed among subgroups, regardless of the added component or injecting site. The improvements of ICSI, ICPI, and GRA at 6 months were lower in comparison with the results of four low-dose PRP injections. All patients were free of dysuria, urinary retention, or urinary tract infection after PRP treatment.

Conclusion: Intravesical PRP injection is effective for IC/BPS. The addition of normal saline or plasma and injection site had no influence on therapeutic efficacy. However, the symptom improvement and GRA after a single high-dose PRP injection was lower than that after four low-dose PRP injections 6 months after the first treatment. Limitation of the study is lack of sham control group.

Roles of mesenchymal stem cells and exosomes in interstitial cystitis/bladder pain syndrome

Interstitial cystitis/bladder pain syndrome (IC/BPS) is characterized by several symptoms of higher sensitivity of the lower urinary tract, such as bladder pain/discomfort, urgency, urinary frequency, pelvic pain and nocturia. Although the pathophysiology of IC/BPS is not fully understood, the hypothesis suggests that mast cell activation, glycosaminoglycan (GAG) layer defects, urothelium permeability disruption, inflammation, autoimmune disorder and infection are potential mechanisms. Mesenchymal stem cells (MSCs) have been proven to protect against tissue injury in IC/BPS by migrating into bladders, differentiating into key bladder cells, inhibiting mast cell accumulation and cellular apoptosis, inhibiting inflammation and oxidative stress, alleviating collagen fibre accumulation and enhancing tissue regeneration in bladder tissues. In addition, MSCs can protect against tissue injury in IC/BPS by secreting various soluble factors, including exosomes and other soluble factors, with antiapoptotic, anti-inflammatory, angiogenic and immunomodulatory properties in a cell-to-cell independent manner. In this review, we comprehensively summarized the current potential pathophysiological mechanisms and standard treatments of IC/BPS, and we discussed the potential mechanisms and therapeutic effects of MSCs and MSC-derived exosomes in alleviating tissue injury in IC/BPS models.

Prevalence of Bladder Pain Syndrome-like Symptoms: a Population-based Study in Korea

OBJECTIVES

To investigate the prevalence of bladder pain syndrome (BPS)-like symptoms in the general population of South Korea.

METHODS

Between April 16, 2016 and April 29, 2016, we conducted an online survey and computer-assisted personal interviews with adults aged 40-79 years in Korea using structured questionnaires. The sample size was 3,000 (95% confidence level standard error ± 1.79%), and the sampling method was simple randomization according to sex, age, and residential area in proportion to the resident registration demographics of the Korean Ministry of Interior and Safety as of March 2016. All participants were surveyed using the Korean version of the Pelvic Pain and Urgency/Frequency (PUF) Patient Symptom Scale and Geriatric Depression Scale (GDS). The primary outcome was the prevalence of BPS-like symptoms, defined as a total PUF score of ≥ 12.

RESULTS

Overall, the prevalence of BPS-like symptoms was 16.4% (483 of 3,000 participants). Women (21.4%) had a significantly higher prevalence of BPS-like symptoms than men (10.7%) (P < 0.01). The prevalence by age was significantly higher in the 70s group than in the other age groups (P < 0.01), and increased significantly with the increasing severity of depression on the GDS (P < 0.01). The prevalence of BPS-like symptoms according to the marital status was significantly different, that is, the prevalence among divorced/bereaved individuals was higher than those of married or unmarried individuals (P < 0.01).

CONCLUSION

Our large, representative population-based study showed that BPS-like symptoms are widespread among the general population of South Korea. BPS is considered a disease that deserves greater attention as it is far more common than previously thought and can negatively affect many people's quality of life.

Acyloxyacyl hydrolase is a host determinant of gut microbiome-mediated pelvic pain

Dysbiosis of gut microbiota is associated with many pathologies, yet host factors modulating microbiota remain unclear. Interstitial cystitis/bladder pain syndrome (IC/BPS) is a debilitating condition of chronic pelvic pain often with comorbid urinary dysfunction and anxiety/depression, and recent studies find fecal dysbiosis in patients with IC/BPS. We identified the locus encoding acyloxyacyl hydrolase, Aoah, as a modulator of pelvic pain severity in a murine IC/BPS model. AOAH-deficient mice spontaneously develop rodent correlates of pelvic pain, increased responses to induced pelvic pain models, voiding dysfunction, and anxious/depressive behaviors. Here, we report that AOAH-deficient mice exhibit dysbiosis of gastrointestinal (GI) microbiota. AOAH-deficient mice exhibit an enlarged cecum, a phenotype long associated with germ-free rodents, and a "leaky gut" phenotype. AOAH-deficient ceca showed altered gene expression consistent with inflammation, Wnt signaling, and urologic disease. 16S sequencing of stool revealed altered microbiota in AOAH-deficient mice, and GC-MS identified altered metabolomes. Cohousing AOAH-deficient mice with wild-type mice resulted in converged microbiota and altered predicted metagenomes. Cohousing also abrogated the pelvic pain phenotype of AOAH-deficient mice, which was corroborated by oral gavage of AOAH-deficient mice with stool slurry of wild-type mice. Converged microbiota also alleviated comorbid anxiety-like behavior in AOAH-deficient mice. Oral gavage of AOAH-deficient mice with anaerobes cultured from IC/BPS stool resulted in exacerbation of pelvic allodynia. Together, these data indicate that AOAH is a host determinant of normal gut microbiota, and dysbiosis associated with AOAH deficiency contributes to pelvic pain. These findings suggest that the gut microbiome is a potential therapeutic target for IC/BPS.

Voiding dysfunctions in patients with non-Hunner's ulcer interstitial cystitis/bladder pain syndrome do not affect long-term treatment outcome

PURPOSE

The role of urodynamic study in the diagnosis and prognostication of interstitial cystitis/bladder pain syndrome (IC/BPS) is still controversial. This study evaluated the correlation of the baseline voiding dysfunctions and long-term treatment outcome in patients with non-Hunner's ulcer IC (NHIC).

MATERIALS AND METHODS

A total of 211 NHIC patients were enrolled. All patients underwent videourodynamic (VUDS) examination at baseline to identify their voiding conditions and received subsequent treatments. The primary endpoint was Global Response Assessment (GRA) at the interview. Secondary endpoints included O'Leary-Sant symptom score (OSS), Visual Analogue Scale (VAS) for pain and the rate of IC symptom flare-up.

RESULTS

The mean age was 56.8 ± 12.8 years, and mean duration of IC was 16.0 ± 9.9 years. At baseline, 83 (39.3%) patients had a voiding dysfunction and 132 (62.7%) had 1 to 3 co-morbidities. The duration, co-morbidities, treatments, changes in OSS and VAS, maximum bladder capacity (MBC), glomerulations, GRA and flare-up rate showed no significant difference among different subgroups. When we divided patients by their storage and voiding conditions, patients with non-hypersensitivity bladder (HSB) (n = 32) had significantly greater MBC (P = .002) whereas those with HSB with (n = 76) or without (n = 103) voiding dysfunction had higher glomerulation (P = .021). When we analysed voiding dysfunction subgroups by GRA, patients with a GRA of ≥2 had a significantly shorter duration of disease (13.9 ± 8.6 years, P = .021). There were also significant associations between GRA and the changes of OSS (P < .001) and VAS (P < .001).

CONCLUSIONS

VUDS can disclose voiding dysfunction in 39.3% of NHIC patients. With adequate therapy, the voiding dysfunctions in NHIC patients do not affect long-term treatment outcome.

Painful Bladder Syndrome/Interstitial Cystitis and High Tone Pelvic Floor Dysfunction

This article provides an overview of 2 conditions that defy straightforward characterization and treatment: interstitial cystitis/painful bladder syndrome often coexists with high tone pelvic floor dysfunction. These conditions are common in gynecologic patients who present with chronic pelvic pain and are often misdiagnosed due to their syndromic nature and amorphous definitions. Clinicians should maintain a high level of suspicion for these processes in patients with chronic pelvic pain or recurrent urinary tract infection symptoms. Optimal treatment uses a multimodal approach to alleviate symptoms.

The Value of Cystoscopy in the Assessment of Interstitial Cystitis/Bladder Pain Syndrome

Background. There are significant differences in the diagnosis of interstitial cystitis/painful bladder syndrome (IC/ BPS), in particular, controversy regarding the diagnostic role of cystoscopy or hydrodistension cystoscopy.

The aim of the study was to evaluate the results of cystoscopy with hydrodistension in women with IC/BPS.

Materials and methods. The study involved 126 women with IC/BPS, mean age – 46.7 ± 14.0 years. The duration of the disease was 6.0 ± 2.8 years. Questionnaires PUF, VAS, USS, and potassium test were used. Cystoscopy and urinary bladder hydrodistension were performed.

Results. The sum of points on the PUF scale was 8.14 ± 1.76, on the VAS scale – 5.45 ± 0.93, on the USS scale – 2.63 ± 0.91. A positive potassium test was detected in 91.3 % of cases, the sensitivity of the test was 86.5 %, the specificity – 84.6 %. The anatomical bladder capacity was 308.0 ± 77.5 ml. The average indicator of maximum bladder filling in women with mild pain was higher than in moderate and severe pain by 30.9 % (p < 0.05) and 53.0 % (p < 0.01), respectively. In 11.9 % of cases, polyps were detected at the external opening of the urethra. During cystoscopy, diffuse mucosal bleeding was detected in 39.8 % of cases, diffuse submucosal bleeding – in 21.4 %, rare glomerulations – in 14.3 %, Gunner’s lesions in 12.7 % of cases. After hydrodistension, the changes were more often diffuse (n = 57). There was a significant relationship (r = –0.57, p < 0.01) between the maximum filling of the bladder and the degree of severity of mucosal abnormalities. The severity of changes in the mucous membrane of the bladder positively correlated with the sum of points on the PUF questionnaire (r = +0.61, p = 0.003), on the VAS questionnaire (r = +0.59, p = 0.008) and according to the USS questionnaire (r = +0.66, p = 0.005).

Conclusion. Cystoscopy can be used to examine IC/BPS in accordance with the recommendations of international societies. The obtained data can help to improve the effectiveness of IC/PBS diagnostics. 

Role of urinary cations in the etiology of interstitial cystitis: A multisite study

OBJECTIVE

To determine whether patients with interstitial cystitis have elevated levels of toxic urinary cations, to identify and quantify these cationic metabolites, and to assess their cytotoxicity.

METHODS

Isolation of cationic fraction was achieved by solid phase extraction using an Oasis MCX cartridge on urine specimens from interstitial cystitis patients and controls. C₁₈ reverse phase high-performance liquid chromatography was used to profile cationic metabolites, and they were quantified by the area under the peaks and normalized to creatinine. Major cationic fraction peaks were identified by reverse phase high-performance liquid chromatography and liquid chromatography-mass spectrometry. HTB-4 urothelial cells were used to determine the cytotoxicity of cationic fraction and of individual metabolites.

RESULTS

The reverse phase high-performance liquid chromatography analysis was carried out on cationic fraction metabolites isolated from urine samples of 70 interstitial cystitis patients and 34 controls. The mean for controls versus patients was 3.84 (standard error of the mean 0.20) versus 6.71 (0.37) mAU*min/µg creatinine, respectively (P = 0.0001). The cationic fraction cytotoxicity normalized to creatinine for controls versus patients in mean percentage was -7.79% (standard error of the mean 3.32%) versus 20.03% (standard error of the mean 2.75%; P < 0.0005). The major toxic cations were 1-methyladenosine, 1-methylguanine, N² ,N² -dimethylguanosine and L-tryptophan.

CONCLUSIONS

These data confirm significant elevation of toxic cations in the urine of interstitial cystitis patients. These toxic cations likely represent a primary cause of interstitial cystitis, as they can injure the bladder mucus and initiate an epithelial leak.

Improving the barrier function of damaged cultured urothelium using chondroitin sulfate

AIMS

To determine whether glycosaminoglycan (GAG) replenishment is able to improve recovery of a deficient urothelial barrier, chondroitin sulfate (CS) instillations were tested using an in vitro model. Porcine urothelial cells (Ucells) were terminally differentiated in culture conditions to construct a urothelial layer with a functional barrier. This layer was damaged to compromise barrier function to simulate a key characteristic of bladder pain syndrome/interstitial cystitis. The functional effect of subsequent treatment with CS was evaluated.

METHODS

Primary porcine Ucells were isolated and cultured on inserts. Differentiation of cells was evaluated with immunohistochemical analysis for the presence of umbrella cells, tight junctions and CS. Transepithelial electrical resistance (TEER) measurements were performed to evaluate barrier function. Protamine was used to simulate mild urothelial damage. CS 0.2% (vol/vol), a GAG, was subsequently instilled in the treatment group. The recovery of barrier function was further evaluated with TEER measurements. The Student t test was used for the analysis of results.

RESULTS

After induction of differentiation, the Ucells expressed barrier markers and a functional barrier was established (measured by high TEER). TEER decreased significantly after instillation with protamine. CS instillation improved recovery of TEER significantly measured after 7 hours (84% vs 22% in controls). After 24 hours; however, the TEER was comparable in both experimental groups.

CONCLUSION

CS instillation improves the recovery of the urothelial barrier after damage in vitro. This functional experiment shows that CS improves recovery of damaged urothelial function, which supports the hypothesis behind the mechanism of action of GAG-replenishment therapy.

No. 164-Consensus Guidelines for the Management of Chronic Pelvic Pain

OBJECTIVE

To improve the understanding of chronic pelvic pain (CPP) and to provide evidence-based guidelines of value to primary care health professionals, general obstetricians and gynaecologists, and those who specialize in chronic pain.

BURDEN OF SUFFERING

CPP is a common, debilitating condition affecting women. It accounts for substantial personal suffering and health care expenditure for interventions, including multiple consultations and medical and surgical therapies. Because the underlying pathophysiology of this complex condition is poorly understood, these treatments have met with variable success rates.

OUTCOMES

Effectiveness of diagnostic and therapeutic options, including assessment of myofascial dysfunction, multidisciplinary care, a rehabilitation model that emphasizes achieving higher function with some pain rather than a cure, and appropriate use of opiates for the chronic pain state.

EVIDENCE

Medline and the Cochrane Database from 1982 to 2004 were searched for articles in English on subjects related to CPP, including acute care management, myofascial dysfunction, and medical and surgical therapeutic options. The committee reviewed the literature and available data from a needs assessment of subjects with CPP, using a consensus approach to develop recommendations.

VALUES

The quality of the evidence was rated using the criteria described in the Report of the Canadian Task Force on the Periodic Health Examination. Recommendations for practice were ranked according to the method described in that report (Table 1).

RECOMMENDATIONS

The recommendations are directed to the following areas: (a) an understanding of the needs of women with CPP; (b) general clinical assessment; (c) practical assessment of pain levels; (d) myofascial pain; (e) medications and surgical procedures; (d) principles of opiate management; (f) increased use of magnetic resonance imaging (MRI); (g) documentation of the surgically observed extent of disease; (h) alternative therapies; (i) access to multidisciplinary care models that have components of physical therapy (such as exercise and posture) and psychology (such as cognitive-behavioural therapy), along with other medical disciplines, such as gynaecology and anesthesia; G) increased attention to CPP in the training of health care professionals; and (k) increased attention to CPP in formal, high-calibre research. The committee recommends that provincial ministries of health pursue the creation of multidisciplinary teams to manage the condition.

Functional effects of blocking VEGF/VEGFR2 signaling in the rat urinary bladder in acute and chronic CYP-induced cystitis

High expression of VEGF is associated with immature angiogenesis within the urinary bladder wall and bladder afferent nerve sensitization, leading to visceral hyperalgesia and pelvic pain. Research suggests a shift in VEGF alternative splice variant (VEGF-A_xxxa and VEGF-A_xxxb) expression with several pathologies (e.g., neuropathic pain and inflammation) as well as differing effects on pain. Translational studies have also demonstrated increased total VEGF expression in the bladders of women with interstitial cystitis/bladder pain syndrome. In the present study, we quantified VEGF alternative splice variant expression in lower urinary tract tissues under control conditions and with cyclophosphamide (CYP)-induced cystitis. Using conscious cystometry and intravesical instillation of a potent and selective VEGF receptor 2 (VEGFR2) tyrosine kinase inhibitor (Ki-8751, 1 mg/kg) in Wistar rats (male and female) with acute and chronic CYP-induced cystitis and control (no CYP) rats, we further determined the functional effects of VEGFR2 blockade on bladder function. With VEGFR2 blockade, bladder capacity increased (P ≤ 0.01) in male and female control rats as well as in male and female rats with acute (P ≤ 0.05) or chronic (P ≤ 0.01 or P ≤ 0.05, respectively) CYP-induced cystitis. Void volume also increased in female control rats (P ≤ 0.01) and female rats with acute (P ≤ 0.05) or chronic (P ≤ 0.05) CYP-induced cystitis as well as in male control rats (P ≤ 0.05) and male rats with chronic CYP-induced cystitis (P ≤ 0.01). These data suggest that VEGF may be a biomarker for interstitial cystitis/bladder pain syndrome and that targeting VEGF/VEGFR2 signaling may be an effective treatment.

Single nucleotide polymorphism analysis in interstitial cystitis/painful bladder syndrome

INTRODUCTION

Interstitial Cystitis (IC) is a chronic condition diagnosed based on the presence of symptoms, such as suprapubic/ pelvic pain, pressure or discomfort in association with urgency and increased urinary frequency. Confusable diseases must be excluded. However, there is no objective test or marker to establish the presence of the disease. Diagnosis and patient management is often difficult, given the poor understanding of IC pathogenesis and its unknown etiology and genetics. As an attempt to find biomarkers related to IC, we assessed the association between 20 selected single nucleotide polymorphism (SNPs) with IC and pain severity.

OBJECTIVES

To assess the presence of SNPs in IC patients' blood samples and correlate them with the disease and chronic pain condition.

METHODS

A case-control study was conducted. We selected 34 female patients with IC diagnosed according to NIDDK criteria and 23 patients in the control group (previously healthy women with only stress urinary incontinence). IC patients were allocated into two groups according to reported chronic pain severity. We selected the following SNPs for analysis: rs1800871, rs1800872, rs1800896, rs1800471, rs1800629, rs361525, rs1800497, rs6311, rs6277, rs6276, rs6313, rs2835859, rs11127292, rs2243248, rs6887695, rs3212227, rs1799971, rs12579350, rs3813034, and rs6746030. Genotyping was performed by real-time PCR (q-PCR).

RESULTS

The polymorphic allele of SNP rs11127292 exhibited a higher frequency in subjects with IC than in controls (p:0.01). The polymorphic allele of SNP rs6311 was more frequent in patients with severe pain (p:0.03). The frequency of the wild-type allele of SNP rs1799971 was higher in patients with mild to moderate pain (p:0.04).

CONCLUSION

The results indicated differences in SNP frequency among subjects, suggesting that SNPs could serve either as a marker of IC or as a marker of pain severity in IC patients. The study showed promising results regarding IC and polymorphism associations. These associations have not been previously reported.

Urinary K+ promotes irritative voiding symptoms and pain in the face of urothelial barrier dysfunction

The internal surface of the bladder is lined by the urothelium, a stratified epithelium that forms an impermeable barrier to water and urine constituents. Abnormalities in the urothelial barrier have been described in certain forms of cystitis and were hypothesized to contribute to irritative voiding symptoms and pain by allowing the permeation of urinary K+ into suburothelial tissues, which then alters afferent signaling and smooth muscle function. Here, we examined the mechanisms underlying organ hyperactivity and pain in a model of cystitis caused by adenoviral-mediated expression of claudin-2 (Cldn2), a tight junction protein that forms paracellular pores and increases urothelial permeability. We found that in the presence of a leaky urothelium, intravesical K+ sensitizes bladder afferents and enhances their response to distension. Notably, dietary K+ restriction, a maneuver that reduces urinary K+, prevented the development of pelvic allodynia and inflammation seen in rats expressing Cldn2. Most importantly, intravesical K+ causes and is required to maintain bladder hyperactivity in rats with increased urothelial permeability. Our study demonstrates that in the face of a leaky urothelium, urinary K+ is the main determinant of afferent hyperexcitability, organ hyperactivity and pain. These findings support the notion that voiding symptoms and pain seen in forms of cystitis that coexist with urothelial barrier dysfunction could be alleviated by cutting urinary K+ levels.

Visceral Pain

Most of us live blissfully unaware of the orchestrated function that our internal organs conduct. When this peace is interrupted, it is often by routine sensations of hunger and urge. However, for >20% of the global population, chronic visceral pain is an unpleasant and often excruciating reminder of the existence of our internal organs. In many cases, there is no obvious underlying pathological cause of the pain. Accordingly, chronic visceral pain is debilitating, reduces the quality of life of sufferers, and has large concomitant socioeconomic costs. In this review, we highlight key mechanisms underlying chronic abdominal and pelvic pain associated with functional and inflammatory disorders of the gastrointestinal and urinary tracts. This includes how the colon and bladder are innervated by specialized subclasses of spinal afferents, how these afferents become sensitized in highly dynamic signaling environments, and the subsequent development of neuroplasticity within visceral pain pathways. We also highlight key contributing factors, including alterations in commensal bacteria, altered mucosal permeability, epithelial interactions with afferent nerves, alterations in immune or stress responses, and cross talk between these two adjacent organs.

Role of NLRP3 inflammasome in the development of bladder pain syndrome interstitial cystitis

Although it has been proposed that NOD-like receptor protein 3 (NLRP3) inflammasome activation may have an important contribution to the onset of bladder pain syndrome/interstitial cystitis (BPS/IC), as of today there is still insufficient evidence to accept or to reject this hypothesis. However, taking into consideration that inflammasomes have been already shown as important mediators of cyclophosphamide-induced bladder inflammation and that some studies have also revealed human bladder epithelium expresses high levels of NLRP3, such a hypothesis seems to be reasonable. The purpose of this review is to discuss a scenario that NLRP3 inflammasome is a crucial player in the development of this disease. Identification of a novel mediator of bladder inflammation and pain could lead to emerging new therapeutic strategy and the first causative therapy.

Mechanisms Underlying Overactive Bladder and Interstitial Cystitis/Painful Bladder Syndrome

The bladder is innervated by extrinsic afferents that project into the dorsal horn of the spinal cord, providing sensory input to the micturition centers within the central nervous system. Under normal conditions, the continuous activation of these neurons during bladder distension goes mostly unnoticed. However, for patients with chronic urological disorders such as overactive bladder syndrome (OAB) and interstitial cystitis/painful bladder syndrome (IC/PBS), exaggerated bladder sensation and altered bladder function are common debilitating symptoms. Whilst considered to be separate pathological entities, there is now significant clinical and pre-clinical evidence that both OAB and IC/PBS are related to structural, synaptic, or intrinsic changes in the complex signaling pathways that mediate bladder sensation. This review discusses how urothelial dysfunction, bladder permeability, inflammation, and cross-organ sensitisation between visceral organs can regulate this neuroplasticity. Furthermore, we discuss how the emotional affective component of pain processing, involving dysregulation of the HPA axis and maladaptation to stress, anxiety and depression, can exacerbate aberrant bladder sensation and urological dysfunction. This review reveals the complex nature of urological disorders, highlighting numerous interconnected mechanisms in their pathogenesis. To find appropriate therapeutic treatments for these disorders, it is first essential to understand the mechanisms responsible, incorporating research from every level of the sensory pathway, from bladder to brain.

Noninvasive experimental bladder pain assessment in painful bladder syndrome

OBJECTIVE

To compare bladder sensitivity between patients with pelvic pain and patients who were pain free, undergoing noninvasive, controlled bladder distension via diuresis. We also sought to measure potential mechanisms underlying bladder sensitivity.

DESIGN

Prospective observational study.

SETTING

Community teaching hospital.

POPULATION

Reproductive-age women with non-bladder chronic pelvic pain (CPP, n = 23), painful bladder syndrome (PBS, n = 23), and pelvic pain-free controls (n = 42) METHODS: Participants were compared on cystometric capacity, pelvic floor pressure-pain thresholds (PPTs), pelvic muscle function, O'Leary-Sant bladder questionnaire, and psychosocial instruments using Wilcoxon rank-sum tests. Multivariate regression was used to identify factors underlying bladder pain phenotypes.

MAIN OUTCOME MEASURES

Pelvic floor pain thresholds; self-reported bladder distension pain.

RESULTS

Participants with PBS exhibited higher bladder distension pain than those with CPP, with both groups reporting higher pain levels than controls (P < 0.05). No significant associations were found between bladder distension pain and pelvic muscle structure or pain sensitivity measures; however, bladder distension pain positively correlates with both vaginal PPTs adjacent to the bladder (r = 0.46) and pain with transvaginal bladder palpation (r = 0.56). Pain at maximal distension was less influenced by somatic sensitivity than bladder symptoms (r = 0.35 versus r = 0.59; P < 0.05). Multivariate regression identified three independent components of bladder symptoms in PBS: bladder distension pain, bladder sensation, and somatic symptoms.

CONCLUSIONS

Diuresis-induced bladder pain differentiates CPP from PBS. Experimental bladder pain is not predicted by pelvic floor sensitivity. Compared with patient-reported outcomes it appears less influenced by psychological factors. Further study is needed to determine whether screening for experimental bladder pain sensitivity could predict future risk of PBS.

TWEETABLE ABSTRACT

Controlled, water ingestion-provoked bladder pain can objectively identify visceral pain sensitivity.

Videourodynamic characteristics of interstitial cystitis/bladder pain syndrome-The role of bladder outlet dysfunction in the pathophysiology

AIMS

To investigate the characteristics of videourodynamic study (VUDS) in females with interstitial cystitis/bladder pain syndrome (IC/BPS) focusing on the etiologies of bladder outlet dysfunction (BOD) and their associations with clinical and urodynamic parameters.

METHODS

IC/BPS females with complete data on symptom assessment, VUDS, the potassium sensitivity test, and cystoscopic hydrodistention were reviewed retrospectively. Diagnoses of bladder dysfunction (hypersensitive bladder, HSB) and BOD including dysfunctional voiding (DV), poor relaxation of the external urethral sphincter (PRES), and bladder neck dysfunction (BND) were made by VUDS. The clinical and urodynamic parameters between patients with normal and abnormal VUDS diagnoses were analyzed.

RESULTS

A total of 348 IC/BPS female patients (mean age 48.8 ± 13.5) were enrolled. HSB was found in 307 (88.2%) patients and BOD in 209 (60.1%). The causes of BOD included DV in 40 (11.5%), PRES in 168 (48.3%), and BND in 1 (0.3%). Patients with DV and BND had higher, and those with PRES had lower detrusor pressures at maximum flow rate (Q_max ) than those with normal tracings. For all BOD patients, univariate logistic regression revealed a significant positive correlation of disease duration and negative correlations of urodynamic volume parameters with BOD in IC/BPS patients. Multivariate logistic regression found a cut-off value of Q_max  ≦ 11 mL/s predicted BOD in IC/BPS with a receiver operating characteristic area of 0.81 (sensitivity = 82.0%, specificity = 68.5%).

CONCLUSIONS

HSB and BOD are common findings on VUDS in IC/BPS females. BOD is associated with duration and hypersensitive bladder. A Q_max  ≦ 11 mL/s predicts BOD in IC/BPS.

Host Responses to Urinary Tract Infections and Emerging Therapeutics: Sensation and Pain within the Urinary Tract

Urinary tract infection (UTI) pathogenesis is understood increasingly at the level of the uropathogens and the cellular and molecular mediators of host inflammatory responses. However, little is known about the mediators of symptoms during UTI and what distinguishes symptomatic events from asymptomatic bacteriuria. Here, we review bladder physiology and sensory pathways in the context of an emerging literature from murine models dissecting the host and pathogen factors mediating pain responses during UTI. The bladder urothelium is considered a mediator of sensory responses and appears to play a role in UTI pain responses. Virulence factors of uropathogens induce urothelial damage that could trigger pain due to compromised bladder-barrier function. Instead, bacterial glycolipids are the major determinants of UTI pain independent of urothelial damage, and the O-antigen of lipopolysaccharide modulates pain responses. The extent of pain modulation by O-antigen can have profound effects, from abolishing pain responses to inducing chronic pain that results in central nervous system features reminiscent of neuropathic pain. Although these effects are largely dependent upon Toll-like receptors, pain is independent of inflammation. Surprisingly, some bacteria even possess analgesic properties, suggesting that bacteria exhibit a wide range of pain phenotypes in the bladder. In summary, UTI pain is a complex form of visceral pain that has significant potential to inform our understanding of bacterial pathogenesis and raises the specter of chronic pain resulting from transient infection, as well as novel approaches to treating pain.

Update on Urinary Tract Markers in Interstitial Cystitis/Bladder Pain Syndrome

Interstitial cystitis (IC)/painful bladder syndrome/bladder pain syndrome (BPS) is a chronic hypersensory condition of unknown etiology. Moreover, the optimal modality for diagnosing IC remains disputed. Several urinary markers have been investigated that may have potential utility in the diagnosis or confirmation of IC/BPS. Thus, inflammatory mediators, proteoglycans, urinary hexosamines, proliferative factors, nitric oxide (NO), BK polyomavirus family, and urothelial proinflammatory gene analysis have been found to correlate with varying degrees with the clinical diagnosis or cystoscopic findings in patients with IC/BPS. The most promising urinary biomarker for IC/BPS is antiproliferative factor, a sialoglycopeptide that has demonstrated inhibitory effects on urothelial cell proliferation and a high sensitivity and specificity for IC/BPS symptoms and clinical findings. In this article, we review the urinary markers, possible future therapies for IC/BPS, and the clinical relevance and controversies regarding the diagnosis of IC/BPS.

Glycosaminoglycans: how much do we know about their role in the bladder?

The urothelium is a unique lining in the body providing a protective barrier against the penetration of toxic agents, urine, and bacteria. The glycosaminoglycan (GAG) layer consists of a thick mucus layer of glycoproteins and proteoglycans on the surface of the urothelial cells. Damage to the GAG layer disrupts its protective barrier function giving rise to increased permeability into the deep layers of the urothelium and bladder, causing inflammation and pain. Replenishment of the GAG layer appears to restore normal permeability allowing for urothelial layer recovery.

Stem Cell Therapy for Interstitial Cystitis/Bladder Pain Syndrome

Interstitial cystitis/bladder pain syndrome (IC/BPS) is a disease characterized by pelvic pain, usually with urinary frequency. These symptoms make patients suffer from a poor quality of life. However, there is still a lack of consensus on the pathophysiology and curable treatment of IC/BPS. We have reviewed several candidates for the pathophysiology of this disease and also treatments that have been used. Although several oral medications, bladder instillation therapies, fulguration for Hunner's lesion, and hydrodistention have been tried as IC/BPS treatments, their outcomes have not been satisfactory. As the application of stem cell therapy is expanding into the urologic field, innovative strategies have been tested with animal models of IC/BPS and have shown promising therapeutic effects for reversing the symptoms of this disorder. Although several concerns about stem cell sources and their safety should be addressed before initiating human clinical trials, we introduce stem cell therapy as a valuable future treatment approach for IC/BPS.

In the absence of overt urothelial damage, chondroitinase ABC digestion of the GAG layer increases bladder permeability in ovariectomized female rats

Loss of integrity of the protective impermeability barrier in the urothelium has been identified as significant in bladder dysfunction. In this study, we tested the theory that the luminal layer of glycosaminoglycans (GAG) serves as an important component of barrier function. The peptide polycation protamine sulfate (PS), 1 mg/ml, was instilled intravesically for 10 min into rat bladders. Chondroitinase ABC (ChABC), 63 IU/ml, was instilled into an additional six rats for 30 min to digest the GAG layer. Unmanipulated controls and sham-injected controls were also performed. After 24 h, the rats were euthanized, the bladders were removed, and permeability was assessed in the Ussing chamber and by diffusion of FITC-labeled dextran (4 kDa) to measure macromolecular permeability. The status of tight junctions was assessed by immunofluorescence and electron microscopy. In control and sham treated rat bladders, the transepithelial electrical resistance were means of 2.5 ± 1.1 vs. 2.6 ± 1.1 vs 1.2 ± 0.5 and 1.01 ± 0.7 kΩ·cm(2) in the PS-treated and ChABC-treated rat bladders (P = 0.0016 and P = 0.0039, respectively). Similar differences were seen in dextran permeability. Histopathology showed a mild inflammation following PS treatment, but the ChABC-treated bladders were indistinguishable from controls. Tight junctions generally remained intact. ChABC digestion alone induced bladder permeability, confirming the importance of the GAG layer to bladder barrier function and supports that loss of the GAG layer seen in bladder biopsies of interstitial cystitis patients could be a significant factor producing symptoms for at least some interstitial cystitis/painful bladder syndrome patients.

Abnormal Akt signalling in bladder epithelial cell explants from patients with interstitial cystitis/bladder pain syndrome can be induced by antiproliferative factor treatment of normal bladder cells

OBJECTIVES

To determine whether protein kinase B (Akt) signalling and secretion of specific downstream effector proteins are abnormal in specific cell fractions of bladder epithelial cells from patients with interstitial cystitis/bladder pain syndrome (IC/BPS), as explanted bladder epithelial cells from patients with IC/BPS produce a frizzled 8-related glycopeptide antiproliferative factor (APF) that inhibits normal bladder epithelial cell proliferation and expression of several proteins known to be regulated by Akt signalling. A related secondary objective was to determine whether treatment of normal bladder epithelial cells with active synthetic asialo-antiproliferative factor (as-APF) induces similar changes in Akt signalling and specific downstream effector proteins/mRNAs.

PATIENTS AND METHODS

Cell proteins were extracted into four subcellular fractions from primary bladder epithelial explants of six patients who fulfilled modified National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) criteria for IC/BPS and six age- and gender-matched controls. Total and/or phosphorylated cellular Akt, glycogen synthase kinase 3β (GSK3β), and β-catenin; total cellular JunB; and secreted matrix metalloproteinase 2 (MMP2) and heparin-binding epidermal growth factor-like growth factor (HB-EGF) levels were determined by Western blot. MMP2, JunB, p53, uroplakin 3 (UPK3), and β-actin mRNAs were quantified by quantitative reverse transcriptase-polymerase chain reaction. Akt activity was determined by nonradioactive assay.

RESULTS

IC/BPS cells had lower Akt activity, along with lower Akt ser473- and GSK3β ser9-phosphorylation and higher β-catenin ser33,37/thr41-phosphorylation in specific fractions as compared with matched control cells. IC/BPS explants also had evidence of additional downstream abnormalities compared with control cells, including lower nuclear JunB; lower secreted MMP2 and HB-EGF; plus lower MMP2, JunB, and UPK3 mRNAs but higher p53 mRNA relative to β-actin. Each of these IC/BPS cell abnormalities was also induced in normal cells by as-APF.

CONCLUSION

These findings indicate that IC/BPS cells have abnormal Akt activity with downstream protein expression abnormalities including decreased MMP2 and HB-EGF secretion. They also support the hypothesis that APF plays a role in the pathogenesis of IC/BPS via its effects on cell Akt signalling and HB-EGF production.

Revisiting the Role of Potassium Sensitivity Testing and Cystoscopic Hydrodistention for the Diagnosis of Interstitial Cystitis

OBJECTIVES

To revisit the diagnostic roles of cystoscopic hydrodistention and the potassium sensitivity test (PST) for the diagnosis of interstitial cystitis (IC).

METHODS

We prospectively enrolled 214 patients clinically diagnosed with IC, 125 non-IC patients who underwent video urodynamic studies and PST, and another 144 non-IC patients who underwent cystoscopic hydrodistention before transurethral surgery. The sensitivity, specificity, and positive and negative predictive values were calculated for the PST and glomerulations after cystoscopic hydrodistention.

RESULTS

After cystoscopic hydrodistention, glomerulations developed in 211/214 (98.6%) IC patients and 61/144 (42.4%) of the non-IC patients including patients with stones (45/67, 67%), hematuria (2/5, 40%), and stress urinary incontinence (SUI) (6/17, 35%). When positive glomerulation was defined as grade 2 or more, the sensitivity was 61.7%. The PST was positive in 183/214 (85.5%) IC patients and 7/17 (41%) with hypersensitive bladder, 7/32 (22%) with detrusor overactivity, 5/27 (18%) with SUI, 2/21 (10%) with lower urinary tract symptoms, and 2/25 (8%) with bladder outlet obstruction. The PST had a sensitivity of 85.5% and a specificity of 81.6% for diagnosis of IC. IC patients with a positive PST had a significantly smaller urgency sensation capacity, smaller voided volume, and greater bladder pain score.

CONCLUSIONS

Both the PST and glomerulations after hydrodistention are sensitive indicators of IC, but the specificity of glomerulations in the diagnosis of IC is lower than that of the PST. A positive PST is associated with a more hypersensitive bladder and bladder pain, but not the grade of glomerulations in IC patients. Neither test provided 100% diagnostic accuracy for IC, we might select patients into different subgroups based on different PST and hydrodistention results, not for making a diagnosis of IC but for guidance of different treatments.

A Feasibility Study to Determine Whether Clinical Contrast Enhanced Magnetic Resonance Imaging can Detect Increased Bladder Permeability in Patients with Interstitial Cystitis

PURPOSE

Interstitial cystitis/bladder pain syndrome is a bladder pain disorder associated with voiding symptomatology and other systemic chronic pain disorders. Currently diagnosing interstitial cystitis/bladder pain syndrome is complicated as patients present with a wide range of symptoms, physical examination findings and clinical test responses. One hypothesis is that interstitial cystitis symptoms arise from increased bladder permeability to urine solutes. This study establishes the feasibility of using contrast enhanced magnetic resonance imaging to quantify bladder permeability in patients with interstitial cystitis.

MATERIALS AND METHODS

Permeability alterations in bladder urothelium were assessed by intravesical administration of the magnetic resonance imaging contrast agent Gd-DTPA (Gd-diethylenetriaminepentaacetic acid) in a small cohort of patients. Magnetic resonance imaging signal intensity in patient and control bladders was compared regionally and for entire bladders.

RESULTS

Quantitative assessment of magnetic resonance imaging signal intensity indicated a significant increase in signal intensity in anterior bladder regions compared to posterior regions in patients with interstitial cystitis (p <0.01) and significant increases in signal intensity in anterior bladder regions (p <0.001). Kurtosis (shape of probability distribution) and skewness (measure of probability distribution asymmetry) were associated with contrast enhancement in total bladders in patients with interstitial cystitis vs controls (p <0.05). Regarding symptomatology interstitial cystitis cases differed significantly from controls on the SF-36®, PUF (Pelvic Pain and Urgency/Frequency) and ICPI (Interstitial Cystitis Problem Index) questionnaires with no overlap in the score range in each group. ICSI (Interstitial Cystitis Symptom Index) differed significantly but with a slight overlap in the range of scores.

CONCLUSIONS

Data suggest that contrast enhanced magnetic resonance imaging provides an objective, quantifiable measurement of bladder permeability that could be used to stratify bladder pain patients and monitor therapy.

Increased urothelial paracellular transport promotes cystitis

Changes in the urothelial barrier are observed in patients with cystitis, but whether this leads to inflammation or occurs in response to it is currently unknown. To determine whether urothelial barrier dysfunction is sufficient to promote cystitis, we employed in situ adenoviral transduction to selectively overexpress the pore-forming tight junction-associated protein claudin-2 (CLDN-2). As expected, the expression of CLDN-2 in the umbrella cells increased the permeability of the paracellular route toward ions, but not to large organic molecules. In vivo studies of bladder function revealed higher intravesical basal pressures, reduced compliance, and increased voiding frequency in rats transduced with CLDN-2 vs. controls transduced with green fluorescent protein. While the integrity of the urothelial barrier was preserved in the rats transduced with CLDN-2, we found that the expression of this protein in the umbrella cells initiated an inflammatory process in the urinary bladder characterized by edema and the presence of a lymphocytic infiltrate. Taken together, these results are consistent with the notion that urothelial barrier dysfunction may be sufficient to trigger bladder inflammation and to alter bladder function.

NGF and HB-EGF: potential biomarkers that reflect the effects of fesoterodine in patients with overactive bladder syndrome

PURPOSE

To determine whether levels of nerve growth factor (NGF) and heparin-binding epidermal growth factor-like growth factor (HB-EGF) can be used to objectively assess overactive bladder syndrome (OAB) treatment outcome and to evaluate the effects of fixed-dose fesoterodine on OAB symptoms.

MATERIALS AND METHODS

This study included 124 participants (62 patients with OAB and 62 controls) in Severance Hospital between 2010 and 2012. In patients with OAB, 4 mg fesoterodine was administered once daily. Repeated evaluations of putative biomarker levels, urine creatinine (Cr) levels, and questionnaire responses, including the Overactive Bladder Symptom Score (OABSS) and the Overactive Bladder Questionnaire (OAB q), were performed from baseline to 16 weeks.

RESULTS

Urinary levels of NGF/Cr (OAB: 1.13±0.9 pg/mg; control: 0.5±0.29 pg/mg) and HB-EGF/Cr (OAB: 8.73±6.55 pg/mg; control: 4.45±2.93 pg/mg) were significantly higher in subjects with OAB than in controls (p<0.001). After 16 weeks of fixed-dose fesoterodine treatment, urinary NGF/Cr levels (baseline: 1.13±0.08 pg/mg; 16 weeks: 0.60±0.4 pg/mg; p=0.02) and HB-EGF/Cr levels significantly decreased (baseline: 8.73±6.55 pg/mg; 16 weeks: 4.72±2.69 pg/mg; p=0.03, respectively). Both the OABSS and OAB q scores improved (p<0.001). However, there were no a statistically significant correlations between these urinary markers and symptomatic scores.

CONCLUSION

Urinary levels of NGF and HB-EGF may be potential biomarkers for evaluating outcome of OAB treatment. Fixed-dose fesoterodine improved OAB symptoms. Future studies are needed to further examine the significance of urinary NGF and HB-EGF levels as therapeutic markers for OAB.

Urinary metabolite profiling combined with computational analysis predicts interstitial cystitis-associated candidate biomarkers

Interstitial cystitis/painful bladder syndrome (IC) is a chronic syndrome of unknown etiology that presents with bladder pain, urinary frequency, and urgency. The lack of specific biomarkers and a poor understanding of underlying molecular mechanisms present challenges for disease diagnosis and therapy. The goals of this study were to identify noninvasive biomarker candidates for IC from urine specimens and to potentially gain new insight into disease mechanisms using a nuclear magnetic resonance (NMR)-based global metabolomics analysis of urine from female IC patients and controls. Principal component analysis (PCA) suggested that the urinary metabolome of IC and controls was clearly different, with 140 NMR peaks significantly altered in IC patients (FDR < 0.05) compared to that in controls. On the basis of strong correlation scores, fifteen metabolite peaks were nominated as the strongest signature of IC. Among those signals that were higher in the IC group, three peaks were annotated as tyramine, the pain-related neuromodulator. Two peaks were annotated as 2-oxoglutarate. Levels of tyramine and 2-oxoglutarate were significantly elevated in urine specimens of IC subjects. An independent analysis using mass spectrometry also showed significantly increased levels of tyramine and 2-oxoglutarate in IC patients compared to controls. Functional studies showed that 2-oxoglutarate, but not tyramine, retarded growth of normal bladder epithelial cells. These preliminary findings suggest that analysis of urine metabolites has promise in biomarker development in the context of IC.

Diagnosing the bladder as the source of pelvic pain: successful treatment for adults and children

The key to successful therapy of interstitial cystitis (IC) is to correctly diagnose it. The significant majority of patients with IC have a dysfunctional bladder epithelium that allows urinary solutes (primarily potassium) to leak into the bladder wall, causing symptoms and tissue damage. Drugs that correct this dysfunction and suppress symptoms are important to achieve successful outcomes in patients. Today over 95% of females with IC are misdiagnosed as having gynecologic chronic pelvic pain, vulvodynia, vaginitis, endometriosis, overactive bladder or urinary tract infection. Men are misdiagnosed as having prostatitis. Often children are not diagnosed at all. Multimodal drug therapy may be required and can achieve successful resolution of IC in over 90% of patients. IC in children can be treated successfully with pentosan polysulfate.

Metabolomics insights into pathophysiological mechanisms of interstitial cystitis

Interstitial cystitis (IC), also known as painful bladder syndrome or bladder pain syndrome, is a chronic lower urinary tract syndrome characterized by pelvic pain, urinary urgency, and increased urinary frequency in the absence of bacterial infection or identifiable clinicopathology. IC can lead to long-term adverse effects on the patient's quality of life. Therefore, early diagnosis and better understanding of the mechanisms underlying IC are needed. Metabolomic studies of biofluids have become a powerful method for assessing disease mechanisms and biomarker discovery, which potentially address these important clinical needs. However, limited intensive metabolic profiles have been elucidated in IC. The article is a short review on metabolomic analyses that provide a unique fingerprint of IC with a focus on its use in determining a potential diagnostic biomarker associated with symptoms, a response predictor of therapy, and a prognostic marker.

Liposomal inhibition of acrolein-induced injury in rat cultured urothelial cells

PURPOSE

To study the protection offered by empty liposomes (LPs) alone against acrolein-induced changes in urothelial cell viability and explored uptake of LPs by primary (rat) urothelial cells.

METHODS

Acrolein was used as a means to induce cellular damage and reduce urothelial cellular viability. The effect of acrolein or liposomal treatment on cellular proliferation was studied using 5-bromo-2'-deoxy-uridine assay. Cytokine release was measured after urothelial cells were exposed to acrolein. Temperature-dependent uptake study was carried out for fluorescent-labeled LPs using confocal microscopy.

RESULTS

Liposome pretreatment protected against acrolein-induced decrease in urothelial cell proliferation. LPs also significantly affected the acrolein-induced cytokine (interferon-gamma) release offering protection to the urothelial cells against acrolein damage. We also observed a temperature-dependent urothelial uptake of fluorescent-labeled LPs occurred at 37 °C (but not at 4 °C).

CONCLUSIONS

Empty LPs alone provide a therapeutic efficacy against acrolein-induced changes in urothelial cell viability and may be a promising local therapy for bladder diseases. Hence, our preliminary evidence provides support for liposome-therapy for urothelial protection and possible repair.

Evidence for bladder urothelial pathophysiology in functional bladder disorders

Understanding of the role of urothelium in regulating bladder function is continuing to evolve. While the urothelium is thought to function primarily as a barrier for preventing injurious substances and microorganisms from gaining access to bladder stroma and upper urinary tract, studies indicate it may also function in cell signaling events relating to voiding function. This review highlights urothelial abnormalities in bladder pain syndrome/interstitial cystitis (BPS/IC), feline interstitial cystitis (FIC), and nonneurogenic idiopathic overactive bladder (OAB). These bladder conditions are typified by lower urinary tract symptoms including urinary frequency, urgency, urgency incontinence, nocturia, and bladder discomfort or pain. Urothelial tissues and cells from affected clinical subjects and asymptomatic controls have been compared for expression of proteins and mRNA. Animal models have also been used to probe urothelial responses to injuries of the urothelium, urethra, or central nervous system, and transgenic techniques are being used to test specific urothelial abnormalities on bladder function. BPS/IC, FIC, and OAB appear to share some common pathophysiology including increased purinergic, TRPV1, and muscarinic signaling, increased urothelial permeability, and aberrant urothelial differentiation. One challenge is to determine which of several abnormally regulated signaling pathways is most important for mediating bladder dysfunction in these syndromes, with a goal of treating these conditions by targeting specific pathophysiology.

Role of urinary cations in the aetiology of bladder symptoms and interstitial cystitis

OBJECTIVES

To identify and characterise urinary cationic metabolites, defined as toxic factors, in patients with interstitial cystitis (IC) and in control subjects. To evaluate the cytotoxicity of the urinary cationic metabolite fraction of patients with IC vs control subjects and of individual metabolites in cultured urothelial cells.

SUBJECTS AND METHODS

Cationic fractions (CFs) were isolated from the urine specimens of 62 patients with IC and 33 control subjects by solid-phase extraction. CF metabolites were profiled using C18 reverse-phase high performance liquid chromatography (RP-HPLC) with UV detection, quantified by area-under-the-peaks using known standards, and normalized to creatinine. RP-HPLC and liquid chromatography (LC)-mass spectrometry (MS)/tandem MS (MS/MS) were used to identify major CF peaks. HTB-4 urothelial cells were used to determine the cytotoxicity of CFs and of individual metabolites with and without Tamm-Horsfall protein (THP).

RESULTS

RP-HPLC analysis showed that metabolite quantity was twofold higher in patients with IC compared with control subjects. The mean (SEM) for control subjects vs patients was 3.1 (0.2) vs 6.3 (0.5) mAU*min/μg creatinine (P < 0.001). LC-MS identified 20 metabolites. Patients with IC had higher levels of modified nucleosides, amino acids and tryptophan derivatives compared with control subjects. The CF cytotoxicity was higher for patients with IC compared with control subjects. The mean (SEM) for control subjects vs patients was -2.3 (2.0)% vs 36.7 (2.7)% (P < 0.001). A total of 17 individual metabolites were tested for their cytotoxicity. Cytotoxicity data for major metabolites were all significant (P < 0.001): 1-methyladenosine (51%), 5-methylcytidine (36%), 1-methyl guanine (31%), N(4)-acetylcytidine (24%), N(7)-methylguanosine (20%) and L-Tryptophan (16%). These metabolites were responsible for higher toxicity in patients with IC. The toxicity of all metabolites was significantly lower in the presence of control THP (P < 0.001).

CONCLUSIONS

Major urinary cationic metabolites were characterised and found to be present in higher amounts in patients with IC compared with control subjects. The cytotoxicity of cationic metabolites in patients with IC was significantly higher than in control subjects, and control THP effectively lowered the cytotoxicity of these metabolites. These data provide new insights into toxic factor composition as well as a framework in which to develop new therapeutic strategies to sequester their harmful activity, which may help relieve the bladder symptoms associated with IC.

Tryptase activation of immortalized human urothelial cell mitogen-activated protein kinase

The pathogenesis of interstitial cystitis/painful bladder syndrome (IC/PBS) is multifactorial, but likely involves urothelial cell dysfunction and mast cell accumulation in the bladder wall. Activated mast cells in the bladder wall release several inflammatory mediators, including histamine and tryptase. We determined whether mitogen-activated protein (MAP) kinases are activated in response to tryptase stimulation of urothelial cells derived from human normal and IC/PBS bladders. Tryptase stimulation of normal urothelial cells resulted in a 2.5-fold increase in extracellular signal regulated kinase 1/2 (ERK 1/2). A 5.5-fold increase in ERK 1/2 activity was observed in urothelial cells isolated from IC/PBS bladders. No significant change in p38 MAP kinase was observed in tryptase-stimulated normal urothelial cells but a 2.5-fold increase was observed in cells isolated from IC/PBS bladders. Inhibition of ERK 1/2 with PD98059 or inhibition of p38 MAP kinase with SB203580 did not block tryptase-stimulated iPLA₂ activation. Incubation with the membrane phospholipid-derived PLA₂ hydrolysis product lysoplasmenylcholine increased ERK 1/2 activity, suggesting the iPLA₂ activation is upstream of ERK 1/2. Real time measurements of impedance to evaluate wound healing of cell cultures indicated increased healing rates in normal and IC/PBS urothelial cells in the presence of tryptase, with inhibition of ERK 1/2 significantly decreasing the wound healing rate of IC/PBS urothelium. We conclude that activation of ERK 1/2 in response to tryptase stimulation may facilitate wound healing or cell motility in areas of inflammation in the bladder associated with IC/PBS.

Voiding diary might serve as a useful tool to understand differences between bladder pain syndrome/interstitial cystitis and overactive bladder

OBJECTIVES

To identify the voiding characteristics of bladder pain syndrome/interstitial cystitis and overactive bladder.

METHODS

Between September 2005 and June 2010, 3-day voiding diaries of 49 consecutive bladder pain syndrome/interstitial cystitis patients and 301 overactive bladder patients were prospectively collected at an outpatient clinic and retrospectively analyzed.

RESULTS

The characteristics of the two groups were not significantly different. However, all voiding variables including volume and frequency were significantly different except for the total voided volume: patients with bladder pain syndrome/interstitial cystitis showed significantly higher voiding frequencies, smaller maximal and mean voided volume, and more constant and narrower ranges of voided volume compared with overactive bladder patients (P < 0.005). Furthermore, mean intervals between voiding in bladder pain syndrome/interstitial cystitis were shorter and more consistent during the day and night (P < 0.001), although mean night-time variances were greater than daytime variances. Logistic regression analysis showed that total night-time frequency, maximal night-time voided volume and mean variance of daytime voiding intervals most significantly differentiated the two groups.

CONCLUSIONS

Some voiding characteristics of bladder pain syndrome/interstitial cystitis and overactive bladder patients differ significantly according to 3-day voiding diary records. These findings provide additional information regarding the differences between these two diseases in the outpatient clinical setting.

Interstitial cystitis/bladder pain syndrome: diagnosis and management

INTRODUCTION AND HYPOTHESIS

The bladder pain syndrome (BPS) is a spectrum of urological symptoms characterised by bladder pain with typical cystoscopic features. Diagnosis and management of this syndrome may be difficult. There is no evidence-based management approach for the diagnosis or treatment of BPS. The objective of this study was to critically review and summarise the evidence relating to the diagnosis and treatment of the bladder pain syndrome.

METHODS

A review of published data on the diagnosis and treatment of the BPS was performed. Our search was limited to English-language articles, on the "diagnosis", and "management" or "treatment" of "interstitial cystitis" and the "bladder pain syndrome" in "humans."

RESULTS

Frequency, urgency and pain on bladder filling are the most common symptoms of BPS. All urodynamic volumes are reduced in patients with BPS. Associated conditions include psychological distress, depression, history of sexual assault, irritable bowel syndrome and fibromyalgia. Cystoscopy remains the test for definitive diagnosis, with visualisation of haemorrhage on cystoreduction. A multidisciplinary treatment approach is essential in the management of this condition. Orally administered amitriptyline is an efficacious medical treatment for BPS. Intravesical hyaluronic acid and local anaesthetic, with/without hydrodistension are among new treatment strategies. Sacral or pudendal neuromodulation is effective, minimally invasive and safe. Surgery is reserved for refractory cases.

CONCLUSIONS

There remains a paucity of evidence for the diagnosis and treatment of BPS. We encountered significant heterogeneity in the assessment of symptoms, duration of treatment and follow up of patients in our literature review.

Tamm-Horsfall protein-associated nucleotides in patients with interstitial cystitis

WHAT'S KNOWN ON THE SUBJECT? AND WHAT DOES THE STUDY ADD?: The nucleotides associated with Tamm-Horsfall protein (THP) identified in this study are 2'(3') isomers, which are uncommon and very little is known about their biochemical pathway and role in interstitial cystitis (IC). The current study provides additional evidence of our earlier finding that THP is abnormal in IC patients. This can adversely affect THP's protective function, and suggests that THP plays a role in the pathogenesis of the disease.

OBJECTIVE

To identify and characterise Tamm-Horsfall protein (THP)-associated metabolites present in patients with interstitial cystitis (IC). Identification of these metabolites would give us insight into the complex interaction of THP with urinary metabolites and its effect on the protective function of THP.

PATIENTS, SUBJECTS AND METHODS

THP was isolated from the urine specimens of 146 patients with IC and 87 control subjects, and was analysed for total sialic acid (SA) content by 1,2-diamino-4,5-methylenedioxybenzene. 2HCl (DMB)-high performance liquid chromatography (HPLC). THP-associated metabolites were isolated by Superdex-200 size-exclusion chromatography (SEC) as a second peak (SP2) and the SP2 was further fractionated into six major components by C18 reverse phase-HPLC. Ion-pair HPLC analysis was performed to identify and quantify THP-associated metabolites. The metabolite structures were confirmed by reversed-phase HPLC combined with electrospray ionization (ESI), liquid chromatography-tandem mass spectrometry (LC-MS and LC-MS/MS) and by high-resolution ESI-time of flight mass spectrometry (HR-ESI-TOFMS).

RESULTS

The THP-associated metabolites (SP2) were more prevalent in patients with IC than in the controls (40.4% vs 12.6%, P < 0.001) as determined by Superdex-200 SEC. Superdex-200 SEC showed higher SP2 content in patients with IC than in controls, as determined by area under the peak/100 μg of THP. The mean (sem), for patients was 84.3 (8.1) vs 18.0 (2.4) milli-absorption unit*min, for controls (P < 0.001). Total SA content of THP was much lower in SP2-positive patients with IC than those who were SP2-negative. The mean (sem) was 41.6 (3.2) vs 92.6 (2.2) nmol/mg THP, respectively (P < 0.001). Ion-pair HPLC identified SP2 metabolites as nucleotides, namely 5'-CMP, 3'-UMP, 3'-AMP, 3'-GMP, 2'-AMP and 2'-GMP. The total nucleotide content of SP2 was significantly higher in patients with IC than in controls. The mean (sem) was 25.3 (2.9) vs 2.2 (0.2) μg/mg THP, respectively (P < 0.001). LC-MS and LC-MS/MS confirmed the nucleotides based on retention time on HPLC, and mass to charge ratio (m/z) of the parent ion and the daughter ions. HR-ESI-TOFMS gave further confimation of the nucleotide sturctures with high mass accuracy.

CONCLUSIONS

In the THP of patients with IC, there is a direct correlation between reduced SA levels and high prevalence of nucleotides associated with it. The THP of patients with IC has a much higher content of these nucleotides than control, and these unique nucleotide isomers identified are very consistent in all SP2-positive patients with IC, suggesting biological significance. This study provides additional evidence that THP is abnormal in patients with IC.

How to avoid local side effects of bladder photodynamic therapy: impact of the fluence rate

PURPOSE

We studied how to avoid irritative bladder symptoms after bladder photodynamic therapy, such as urgency, frequency and pain, which are associated with the inflammation and destruction of normal urothelium.

MATERIALS AND METHODS

Rats bearing orthotopic bladder tumors were instilled with hexyl-aminolevulinate and illuminated with red light at a high vs low (100 vs 15 mW/cm(2)) fluence rate. Cystectomy specimens 48 hours after treatment were subjected to anatomopathological examination. Inflammatory reaction and apoptosis were evaluated. In vivo photobleaching was assessed during illumination at each fluence rate.

RESULTS

All superficial tumors were eradicated irrespective of light dose and fluence rate. High fluence rates induced necrosis with inflammatory reaction and absent normal urothelium. Low fluence rates did not provoke inflammation and resulted in apoptotic cell death with preserved urothelial integrity. This could be attributable to faster photobleaching of the photosensitizer in normal urothelium at low fluence rates.

CONCLUSIONS

Bladder photodynamic therapy at a low fluence rate minimizes side effects without hampering therapeutic efficacy.

Intravesical hyaluronic acid for interstitial cystitis/painful bladder syndrome: a comparative randomized assessment of different regimens

OBJECTIVES

To compare the clinical effectiveness of different regimens of intravesical hyaluronic acid instillation for patients with interstitial cystitis/painful bladder syndrome.

METHODS

A total of 60 patients (age 16-77 years) diagnosed with interstitial cystitis/painful bladder syndrome were enrolled in this prospective, randomized study. A total of 30 patients were assigned to receive four weekly intravesical instillations of 40 mg of hyaluronic acid followed by five monthly instillations (hyaluronic acid-9 group). Another 30 patients received 12 intravesical instillations of 40 mg hyaluronic acid every 2 weeks (hyaluronic acid-12 group). Symptomatic changes after hyaluronic acid treatments were assessed using Interstitial Cystitis Symptom and Problem Indexes, pain visual analog scale, functional bladder capacity, frequency and nocturia in voiding diary, maximum flow rate, voided volume, postvoid residual volume, and Quality of Life Index at 1, 3 and 6 months.

RESULTS

Of the 60 patients, 59 were evaluable at the end of the study. The Interstitial Cystitis Symptom Index, Interstitial Cystitis Problem Index and total score, pain visual analog scale, functional bladder capacity, maximum flow rate, and Quality of Life Index improved significantly after 6 months in both groups. The frequency and voided volume improved significantly only in the hyaluronic acid-12 group. However, patients with moderate and marked improvement were clinically similar in both groups. The measured variables did not differ between the two groups over the course of the study.

CONCLUSION

No significant difference was noted in the therapeutic effect between two hyaluronic acid instillation regimens for treatment of interstitial cystitis/painful bladder syndrome patients. Both groups showed significant improvement in symptom scores and Quality of Life Index.