An antiproliferative factor from interstitial cystitis patients is a frizzled 8 protein-related sialoglycopeptide

Approximately 1 million people in the United States suffer from interstitial cystitis, a chronic painful urinary bladder disorder characterized by thinning or ulceration of the bladder epithelial lining; its etiology is unknown. We have identified a glycosylated frizzled-related peptide inhibitor of cell proliferation that is secreted specifically by bladder epithelial cells from patients with this disorder. This antiproliferative factor (APF) profoundly inhibits bladder cell proliferation by means of regulation of cell adhesion protein and growth factor production. The structure of APF was deduced by using ion trap mass spectrometry (MS), enzymatic digestion, lectin affinity chromatography, and total synthesis, and confirmed by coelution of native and synthetic APF derivatives on microcapillary reversed-phase liquid chromatography (microRPLC)/MS. APF was determined to be an acidic, heat-stable sialoglycopeptide whose peptide chain has 100% homology to the putative sixth transmembrane domain of frizzled 8. Both synthetic and native APF had identical biological activity in normal bladder epithelial cells and T24 bladder cancer cells. Northern blot analysis indicated binding of a probe containing the sequence for the frizzled 8 segment with mRNA extracted from cells of patients with interstitial cystitis but not controls. APF is therefore a frizzled-related peptide growth inhibitor shown to contain exclusively a transmembrane segment of a frizzled protein and is a potential biomarker for interstitial cystitis.

Detection of Helicobacter pylori in bladder biopsy specimens of patients with interstitial cystitis by polymerase chain reaction

The cause of interstitial cystitis (IC) is still unknown. Several features suggest that it may be an infectious disease and it has compelling similarities to chronic gastritis. The identification of Helicobacter pylori as the cause of chronic gastritis focused attention on this organism. Many studies have been done investigating the role of H. pylori in the etiology of IC. Previous studies mostly determined the presence of H.pylori with antibodies in the serum samples of IC patients, but these methods may lead to false positive or negative results. We therefore investigated the presence of H.pylori in bladder biopsy specimens by using polymerase chain reaction (PCR), which is accepted as the most sensitive and specific test for detecting this organism. A total of 32 patients with IC were enrolled into the study. The PCR assay was performed on cold cup bladder biopsies of IC patients. Both positive and negative controls were included in each set of PCR reactions. Gastric biopsy specimens of peptic ulcer patients with proven H. pylori infection were used as positive controls. Bladder biopsies of all IC patients were negative for H. pylori DNA. PCR showed the presence of H. pylori in the positive controls in each cycle demonstrating that the PCR assay was working properly. Thus, there is no evidence that IC is the result of H. pylori infection. This study does not negate the possibility that other infectious agents may play a role in the etiology of IC.

Abnormal expression of molecular markers for bladder impermeability and differentiation in the urothelium of patients with interstitial cystitis

PURPOSE

Despite a lack of consensus concerning the etiology of interstitial cystitis (IC) the loss of impermeability and other abnormalities of the urothelium are features of the disease. In this study the distribution of proteins involved with epithelial adhesion, cellular differentiation and bladder impermeability in urothelial biopsies were explored by the immunohistochemical assessment of E-cadherin, ZO-1, uroplakin and chondroitin sulfate.

MATERIALS AND METHODS

Biopsies obtained from 27 patients with IC and 7 controls were immediately fixed in formalin, immunohistochemically labeled for the described proteins and scored for protein expression, morphology and differentiation.

RESULTS

Only 3 IC samples appeared completely normal, while 24 of the 27 showed an abnormality in at least 1 marker and in 6 all 4 markers were abnormal. In patients vs controls findings were abnormal for uroplakin in 13 of 27 vs 1 of 7 (p = 0.085), for E-cadherin (over expressed) in 18 of 27 vs 0 of 7 (p = 0.0021), for ZO-1 in 11 of 27 vs 0 of 7 (p = 0.046) and for chondroitin sulfate in 15 of 27 vs 0 of 7 (p = 0.0054). The morphology/polarity score significantly correlated with ZO-1 (Pearson r = 0.3935, p = 0.0423) and chondroitin sulfate (Pearson r = 0.7079, p <0.0001) expression. Chondroitin sulfate and ZO-1 showed a high correlation with each other (Pearson r = 0.5587, p = 0.0025). Uroplakin and E-cadherin expression were independent of all other markers.

CONCLUSIONS

The findings reported strongly suggest abnormal differentiation in the IC bladder. The disruption of ZO-1 is similar to that reported in feline IC. Elevated E-cadherin may represent an adaptation to increased bladder permeability.

Pathology of interstitial cystitis

In this workshop the participants were asked to consider the role of pathology in the diagnosis and management of interstitial cystitis (IC). Currently, the NIDDK definition of IC is made on clinical criteria; bladder biopsy is not required for the clinical work-up and histology is not used as a diagnostic criterion. The literature review described the most common pathological findings to be epithelial denudation or ulceration, mononuclear inflammation, edema, congestion, hemorrhage, and mast cell activation. These pathological changes were not universal or specific with 55% of IC subjects in one study having histology that was normal and indistinguishable from control subjects. Presentations were made which generally confirmed an association between abnormal pathology and more severe disease as determined by symptoms, cystoscopic capacity, and prognosis. During the workshop it was clear that whether or not a biopsy was performed depended on a number of factors, for example, country of origin, the research interest of the unit, and the desire to exclude malignancy on histological grounds. The consensus, which was not unanimous, was that bladder biopsy was a-non-mandatory test in the clinical work-up of the patient with IC but that urine cytology should be performed. It was discussed that bladder biopsy be an optional test and particularly relevant when one was suspicious of other conditions and in IC research. It was hoped that bladder biopsy pathology will give clues to contributory pathogenic processes such as epithelial dysfunction and inflammation; and in the future, with the help of molecular biology, may help determine etiology.

Interstitial cystitis antiproliferative factor (APF) as a cell-cycle modulator

Background

Interstitial cystitis (IC) is a chronic bladder disorder of unknown etiology. Antiproliferative factor (APF), a peptide found in the urine of IC patients, has previously been shown to decrease incorporation of thymidine by normal bladder epithelial cells. This study was performed to determine the effect of APF on the cell cycle of bladder epithelial cells so as to better understand its antiproliferative activity.

Methods

Explant cultures from normal bladder biopsy specimens were exposed to APF or mock control. DNA cytometry was performed using an automated image analysis system. Cell cycle phase fractions were calculated from the DNA frequency distributions and compared by two-way analysis of variance (ANOVA).

Results

APF exposure produced statistically significant increases in the proportion of tetraploid and hypertetraploid cells compared to mock control preparations, suggesting a G2 and/or M phase cell cycle block and the production of polyploidy.

Conclusions

APF has a specific effect on cell cycle distributions. The presence of a peptide with this activity may contribute to the pathogenesis of interstitial cystitis through disruption of normal urothelial proliferation and repair processes.

Small adrenal glands in cats with feline interstitial cystitis

PURPOSE

We documented the uncoupling of sympathetic nervous system activity from the hypothalamic-pituitary-adrenal axis in cats with feline interstitial cystitis (FIC). Altered hypothalamic-pituitary-adrenal activity was recently suggested in some humans with interstitial cystitis (IC) but to our knowledge no information exists on adrenal gland size and histopathology in this disease. To investigate further adrenal function in cats with FIC we determined cortisol responses to 125 microg synthetic adrenocorticotropic hormone (ACTH) as well as adrenal size and histology.

MATERIALS AND METHODS

ACTH stimulation studies were performed in 11 healthy cats and 20 with FIC. Adrenal glands obtained at autopsy in 8 healthy cats and 13 with FIC were weighed, measured and examined histologically.

RESULTS

Cats with FIC had significantly decreased responses to ACTH (2-way repeated measures ANOVA p <0.05). Mean weight +/- SD (58 +/- 50 vs 241 +/- 60 mg) and volume (264 +/- 72 vs 410 +/- 115 mm3) of adrenal glands were significantly smaller in cats with FIC than in healthy cats (p <0.05).

CONCLUSIONS

These results suggest that cats with FIC may have mild primary adrenal insufficiency. Decreased adrenal size has been observed in patients with chronic fatigue syndrome, which can be a co-morbid condition in some patients with IC. If these abnormalities are confirmed in humans with IC, hormone replacement therapy may be indicated in select patients.

Up-Regulation of P2X 3 Receptor During Stretch of Bladder Urothelial Cells From Patients With Interstitial Cystitis

PURPOSE

Extracellular adenosine triphosphate (ATP) can act through the purinergic receptor subtype P2X3 to transmit a pain signal to the central nervous system. Bladder urothelial cells (BUCs) from patients with interstitial cystitis (IC) patients have augmented release of ATP during in vitro stretch. We queried whether P2X3 receptor subtype exists on cultured BUCs. Furthermore, we asked whether P2X3 expression can be altered by in vitro stretch and whether there exists a difference in expression between IC and control BUCs.

MATERIALS AND METHODS

BUCs from 4 IC and 5 control subjects were cultured according to established cell culture techniques. After cells were grown to confluence they were stretched on an in vitro stretch machine at 20% elongation for up to 96 hours. Cells were harvested at various times, and immunofluorescence and Western blots were performed for P2X3 expression. Band densitometry normalized to the actin band was performed using software. To confirm P2X3 expression in a whole cell preparation flow cytometry and fluorescence activated cell sorter analysis were used.

RESULTS

P2X3 was expressed in cultured BUCs. With stretch P2X3 expression increased in IC BUCs more than in control BUCs. Using relative densitometry units normalized for actin expression in the Western blots stretch of IC BUCs resulted in 66% more expression of P2X3 than any other experimental condition (p = 0.003). By fluorescence activated cell sorter analysis stretched IC BUCs had the highest P2X3 fluorescence activity (30%) compared with unstretched IC (2.4%, p = 0.003), stretched control (9.7%, p = 0.009) and unstretched control (2.3%, p = 0.003) BUCs.

CONCLUSIONS

These data show that P2X3 subunits expressed by cultured IC BUCs are up-regulated during in vitro stretch. Augmented ATP signaling in the bladder may explain IC symptoms. Furthermore, this study further supports the hypothesis that urothelial cells can phenotypically mimic sensory neurons.

Gene Therapy for Bladder Pain With Gene Gun Particle Encoding Pro-Opiomelanocortin cDNA

PURPOSE

Interstitial cystitis is a bladder hypersensitivity disease associated with bladder pain that has been a major challenge to understand and treat. We hypothesized that targeted and localized expression of endogenous opioid peptide in the bladder could be useful for the treatment of bladder pain. Pro-opiomelanocortin (POMC) is one of such precursor molecules. In this study we developed a gene gun method for the transfer of POMC cDNA in vivo and investigated its therapeutic effect on acetic acid induced bladder hyperactivity in rats.

MATERIALS AND METHODS

Human POMC cDNA was cloned into a modified pCMV plasmid and delivered into the bladder wall of adult female rats by direct injection or the gene gun. Three days after gene therapy continuous cystometrograms were performed using urethane anesthesia by filling the bladder (0.08 ml per minute) with saline, followed by 0.3% acetic acid. Bladder immunohistochemical testing was used to detect endorphin after POMC cDNA transfer.

RESULTS

The intercontraction interval was decreased after intravesical instillation of acetic acid (73.1% or 68.1% decrease) in 2 control groups treated with saline or the gene gun without POMC cDNA, respectively. However, rats that received POMC cDNA via the gene gun showed a significantly decreased response (intercontraction interval 35% decreased) to acetic acid instillation, whereas this antinociceptive effect was not detected in the plasmid POMC cDNA direct injection group. This effect induced by POMC gene gun treatment was reversed by intramuscular naloxone (1 mg/kg), an opioid antagonist. Increased endorphin immunoreactivity with anti-endorphin antibodies was observed in the bladder of gene gun treated animals.

CONCLUSIONS

The POMC gene can be transferred in the bladder using the gene gun and increased bladder expression of endorphin can suppress nociceptive responses induced by bladder irritation. Thus, POMC gene gun delivery may be useful for the treatment of interstitial cystitis and other types of visceral pain.

Changes in human bladder epithelial cell gene expression associated with interstitial cystitis or antiproliferative factor treatment

Explanted bladder epithelial cells from patients with interstitial cystitis (IC) have been shown to differ from explanted control cells in several ways, including production of an antiproliferative factor (APF), altered production of certain epithelial growth factors, and rate of proliferation. To better understand the role of the APF in abnormal bladder epithelial cell proliferation in IC, we studied gene expression patterns in normal bladder epithelial cells treated with APF vs. mock APF and compared them to expression patterns in IC vs. normal cells using microarray analysis. Oligo-dT-primed total cellular RNA was labeled with [(33)P]dCTP and hybridized to GeneFilter GF211 microarray membranes (Research Genetics) containing cDNA for 3,964 human genes. Thirteen genes that function in epithelial cell proliferation or differentiation were consistently differentially expressed in both IC (compared with control) and APF-treated (compared with mock APF-treated) normal bladder epithelial cells. The general pattern of gene expression in IC and APF-treated cells suggested a less proliferative phenotype, with increased expression of E-cadherin, phosphoribosylpyrophosphate synthetase-associated protein 39, and SWI/SNF complex 170-kDa subunit, and decreased expression of vimentin, alpha2-integrin, alpha1-catenin, cyclin D1, and jun N-terminal kinase 1; these findings were confirmed for the structural gene products (E-cadherin, vimentin, alpha2-integrin, and alpha-catenin) by immunohistochemistry. These results are compatible with the previously noted decreased proliferation rate of IC and APF-treated normal cells, and indicate that the mechanism whereby APF inhibits cell proliferation may involve both downregulation of genes that stimulate cell proliferation along with upregulation of genes that inhibit cell growth.

Decreased in vitro proliferation of bladder epithelial cells from patients with interstitial cystitis

OBJECTIVES

To determine whether explanted bladder epithelial cells from patients with interstitial cystitis (IC) display intrinsically decreased rates of proliferation in vitro, and to compare the growth rates of untreated IC and normal bladder cells with the rates of normal cells treated with a purified antiproliferative factor (APF) at levels found in urine from patients with IC.

METHODS

Epithelial cell explants were prepared from the bladder biopsies of 4 patients with IC and 2 asymptomatic controls. Cell proliferation was determined by serial counting of trypan blue-negative cells. APF and mock APF were purified chromatographically, and activity was determined by (3)H-thymidine incorporation into primary normal bladder epithelial cells. Heparin-binding epidermal growth factor-like growth factor and epidermal growth factor were measured by enzyme-linked immunosorbent assay.

RESULTS

Bladder epithelial cells from patients with IC proliferated significantly less than did control cells by day 2 after serum starvation (P = 0.02). Similar inhibition of the proliferation rate was seen in control cells treated with APF; APF-induced changes in heparin-binding epidermal growth factor-like growth factor, but not epidermal growth factor, production by cells were associated with changes in growth rates.

CONCLUSIONS

The proliferation rate of explanted bladder epithelial cells from patients with IC in serum-free medium was significantly less than that of control cells, indicating an intrinsic abnormality in IC cell proliferation. This abnormality may be caused by APF, which induces reversible inhibition of heparin-binding epidermal growth factor-like growth factor production and normal bladder epithelial cell proliferation.

The ameliorating effect of melatonin on protamine sulfate induced bladder injury and its relationship to interstitial cystitis

PURPOSE

The pineal hormone melatonin was recently shown to have free radical scavenging ability and it reduces lipid peroxidation. In this morphological study we investigated the effects of melatonin on protamine sulfate (Sigma Chemical Co., St. Louis, Missouri) induced bladder injury.

MATERIALS AND METHODS

Albino Wistar female rats were catheterized and intravesically infused with phosphate buffered solution (control group) or protamine sulfate (bladder injury group) dissolved in phosphate buffered solution. In the protamine sulfate plus melatonin group after protamine sulfate instillation melatonin was injected intraperitoneally. Bladder morphology was investigated by light and electron microscopy. Tissue samples were also obtained to determine bladder malondialdehyde levels.

RESULTS

In the bladder injury group ulcerated areas, an irregular glycosaminoglycan layer, increased number of mast cells, vacuole formation, dilated perinuclear cistern, formation of pleomorphic and uniform microvilli, and dilated urothelial intercellular spaces were observed. In the bladder injury plus melatonin group a relatively normal urothelial topography, glycosaminoglycan layer and decreased number of mucosal mast cells, some dilatation between intercellular areas, less uniform microvilli and in most areas regular tight junctions were observed.

CONCLUSIONS

Increased malondialdehyde levels as a result of protamine sulfate induction lead us to propose that free radicals may have a critical role in this injury. The significant decrease in malondialdehyde levels in the protamine sulfate plus melatonin group was in accordance with morphological findings. Thus, melatonin appears to exert a urothelial protective activity in a bladder injury model.

[Two cases of interstitial cystitis complicated with fibromyalgia syndrome]

Two cases of interstitial cystitis complicated with fibromyalgia syndrome are reported. These diseases have some similar points regarding symptoms, treatment methods and neurotransmitters causatively involved. The symptoms are hardly recognized. It is important to have knowledge about the disease of fibromyalgia syndrome.

Indomethacin-induced morphologic changes in the rat urinary bladder epithelium

OBJECTIVES

To evaluate the morphologic changes in rat urothelium induced by indomethacin. Nonsteroidal anti-inflammatory drug-induced cystitis is a poorly recognized and under-reported condition. In addition to tiaprofenic acid, indomethacin has been reported to be associated with this condition.

METHODS

Three groups were established: a control group (n = 10), a high-dose group (n = 10), treated with one intraperitoneal injection of indomethacin 20 mg/kg, and a therapeutic dose group (n = 10) in which oral indomethacin was administered 3.25 mg/kg body weight daily for 3 weeks. The animals were then killed and the bladders removed for light and electron microscopic studies.

RESULTS

The light microscopic findings showed some focal epithelial degeneration that was more prominent in the high-dose group. When compared with the control group, both indomethacin groups revealed statistically increased numbers of mast cells in the mucosa (P <0.0001) and penetration of lanthanum nitrate through intercellular areas of the epithelium. Furthermore, the difference in mast cell counts between the high and therapeutic dose groups was also statistically significant (P <0.0001).

CONCLUSIONS

Indomethacin resulted in histopathologic findings typical of interstitial cystitis, such as leaky bladder epithelium and mucosal mastocytosis. The true incidence of nonsteroidal anti-inflammatory drug-induced cystitis in humans must be clarified by prospective clinical trials.

Toward a precise definition of interstitial cystitis: further evidence of differences in classic and nonulcer disease

PURPOSE

Interstitial cystitis is a bothersome condition in urological practice. There is continuous discussion on the extent and demarcation of this syndrome. Accumulated evidence indicates that interstitial cystitis is a heterogeneous syndrome. Today it is often divided into classic and nonulcer disease. Compared with classic interstitial cystitis the nonulcer type appears different in terms of demographic, endoscopic and histological findings as well as in the response to various types of treatment. However, in clinical series subdivision is not always performed, which makes it difficult to draw conclusions. We determined whether there are additional dissimilarities in clinical presentation in the 2 subtypes of interstitial cystitis.

MATERIALS AND METHODS

We evaluated 130 patients with classic and 101 with nonulcer interstitial cystitis diagnosed according to National Institute for Diabetes and Digestive and Kidney Diseases criteria by surveying the clinical records, including voiding diaries.

RESULTS

Patients with nonulcer disease were younger at diagnosis (p <0.0001) and at symptom onset. Furthermore, there was a marked and significant difference in bladder capacity while patients were under general anesthesia (p <0.0001).

CONCLUSIONS

The current findings together with previous findings clearly demonstrate that the 2 subtypes of interstitial cystitis represent separate entities. We suggest refining the National Institutes of Health-National Institute for Diabetes and Digestive and Kidney Diseases criteria, so that subtyping scientific materials is considered mandatory, hence, ensuring that the 2 subtypes are evaluated separately in clinical studies.

Leukocyte populations in interstitial cystitis and idiopathic reduced bladder storage

OBJECTIVES

Mast cells and leukocyte populations in bladder biopsies from women with interstitial cystitis (IC) or idiopathic reduced bladder storage (sensory urgency [SU]) were compared to determine whether any evidence of a common etiology between these conditions could be found.

METHODS

Biopsies from 40 patients (9 meeting the National Institute of Arthritis, Diabetes, Digestive and Kidney Diseases criteria [IC] and 31 who did not [SU]) and 20 controls (having colposuspension for stress incontinence) were stained with monoclonal antibodies against leukocyte antigens and mast cell tryptase. The median cell counts from 10 high power fields were calculated and compared between cases and controls. The clinical and urodynamic data were also compared.

RESULTS

Nocturia (odds ratio 26.7; 95% confidence interval 3.3 to 245.5) and bladder pain (odds ratio 18.5; 95% confidence interval 1.8 to 193.1) were associated with significant odds ratios for disease (IC or SU compared with controls) in logistic regression analysis. Patients with IC were significantly older than those with SU (P = 0.05). Leukocyte populations showed only increased CD20+ cells in patients with IC compared with the others (P = 0.03).

CONCLUSIONS

The analysis of the clinical, urodynamic, and cystoscopic data showed no differences between patients with IC and those with SU, except for age. Nocturia or bladder pain discriminated between patients and controls. The lymphocytic infiltrate in SU is similar to that seen in IC but with fewer CD20+ cells. These data support the work of others and may indicate that SU has a common etiology with IC.

Interstitial cystitis: current issues and controversies in diagnosis

Current tests for the diagnosis of interstitial cystitis (IC) are reviewed, including clinical assessment, urodynamic testing, cystoscopy, bladder biopsy, and urinary markers. A MEDLINE search was performed of all studies dealing with the diagnosis of IC. These studies were critically reviewed with the goal of arriving at a utilitarian approach to IC diagnosis. IC is being diagnosed with increasing frequency. However, the diagnostic criteria are nonuniform and there is significant overlap between chronic pelvic pain syndromes in men and women and IC. Diagnosis of IC can be made clinically and by cystoscopy and hydrodistention. The sensitivity and specificity of urinary markers have not been prospectively studied. Individual practitioners continue to use the various diagnostic tests. There is a clear need for uniform diagnostic criteria for clinical diagnosis as well as epidemiologic and research studies.

Delayed toxicity of cyclophosphamide on the bladder of DBA/2 and C57BL/6 female mouse

The present study describes the delayed development of a severe bladder pathology in a susceptible strain of mice (DBA/2) but not in a resistant strain (C57BL/6) when both were treated with a single 300 mg/kg dose of cyclophosphamide (CY). Inbred DBA/2 and C57BL/6 female mice were injected with CY, and the effect of the drug on the bladder was assessed during 100 days by light microscopy using different staining procedures, and after 30 days by conventional electron microscopy. Early CY toxicity caused a typical haemorrhagic cystitis in both strains that was completely repaired in about 7-10 days. After 30 days of CY injection ulcerous and non-ulcerous forms of chronic cystitis appeared in 86% of DBA/2 mice but only in 4% of C57BL/6 mice. Delayed cystitis was characterized by infiltration and transepithelial passage into the lumen of inflammatory cells and by frequent exfoliation of the urothelium. Mast cells appeared in the connective and muscular layers of the bladder at a much higher number in DBA/2 mice than in C57BL/6 mice or untreated controls. Electron microscopy disclosed the absence of the typical discoidal vesicles normally present in the cytoplasm of surface cells. Instead, numerous abnormal vesicles containing one or several dark granules were observed in the cytoplasm of cells from all the epithelial layers. Delayed cystitis still persisted in DBA/2 mice 100 days after treatment. These results indicate that delayed toxicity of CY in female DBA/2 mice causes a bladder pathology that is not observed in C57BL/6 mice. This pathology resembles interstitial cystitis in humans and could perhaps be used as an animal model for studies on the disease.

In vivo models of interstitial cystitis

PURPOSE

We systematically identified and evaluated various animal models that have been studied to help identify the underlying mechanisms of and possible treatment options for interstitial cystitis.

MATERIALS AND METHODS

Models of interstitial cystitis published between 1983 and 2001 were obtained by searching MEDLINE and other Internet databases using cystitis and model as the primary key words. Models with characteristics of interstitial cystitis similar to those defined by National Institutes of Arthritis, Diabetes, Digestive and Kidney Diseases criteria were reviewed. Some articles describing animal models with similar pathological conditions in other organs were also included to enlarge the base of potentially relevant material.

RESULTS

We identified and evaluated some 16 animal models of interstitial cystitis, which we categorized as bladder inflammation induced by intravesical administration of an irritant or immune stimulant, systemic and environmentally induced inflammation, and a naturally occurring model of interstitial cystitis that occurs in cats. Some abnormalities identified in humans and cats with interstitial cystitis can be reproduced in healthy animals using luminal, systemic or environmental stimuli. At the level of the bladder the source of stimulation cannot be discriminated. Variability in the extent of bladder distention complicated the interpretation of some studies. In addition, the noxious stimuli used can affect many epithelial surfaces as well as the urothelium, suggesting they are nonspecific responses to injury rather than specific to interstitial cystitis.

CONCLUSIONS

No model in bladder injury in healthy animals currently reproduces as many features of interstitial cystitis as the naturally occurring disease in cats. While induced models of relative injury may help to provide insight into the bladder response to injury, feline interstitial cystitis follows a similar chronic waxing and waning time course as does interstitial cystitis in humans, which may be more suitable for studying the effects of stressors on the severity of clinical signs as well as newly proposed therapies.

Interstitial cystitis

Appropriate diagnostic tests for interstitial cystitis remain uncertain. One or more promising markers for this disease have been described which may provide a noninvasive means for diagnosis as well as clues to pathogenesis of this disease. Treatment remains empiric.

Incidence of Helicobacter pylori in patients with interstitial cystitis

OBJECTIVE

Chronic gastritis has compelling similarities to interstitial cystitis (IC). It is characterised by chronic pain in a tubular organ. Histologically, epithelial damage, inflammatory response in the lamina propria and epithelial ulcerations are seen. An infective cause was rarely considered until the emergence of Helicobacter pylori over the past 15 years. We have had experience of patients with bladder pain and irritability reporting improvement with antihistamines. It has also been reported that IC symptoms improved dramatically after treatment for H. pylori infection. Previous studies have determined the incidence of H. pylori antibodies in women with IC but we examined bladder material histologically and performed the Campylobacter-like organism (CLO) test on the biopsy specimens.

MATERIALS AND METHODS

A prospective controlled study was performed. Patients with urinary symptoms fulfilling the National Institute of Diabetes and Digestive and Kidney Diseases criteria for IC underwent GA cystoscopy at which the macroscopic appearance of the bladder was noted and biopsies were taken. The biopsy material underwent histological examination and CLO test. Control patients who were undergoing cystoscopy for reasons other than investigation of IC also had biopsy taken and the CLO test was performed on these specimens.

RESULTS

Five of 15 patients with symptoms and signs of IC had a positive CLO test. Three of 15 patients of the control group had a positive CLO test. With the 2-sided chi(2) test there was no statistical difference between the 2 groups.

CONCLUSION

Our small prospective control study does not support the hypothesis that H. pylori is an important component in the pathogenesis of interstitial cystitis.

Prognosis of conservative therapy of advanced interstitial cystitis: experience of five cases

BACKGROUND

It is generally believed that surgical procedures, particularly the more invasive ones, should be reserved for patients who fail to respond to conservative therapy by several established modalities. We studied whether conservative therapy was applicable to patients with interstitial cystitis (IC) in which an individual's awake bladder capacity decreases to 100 mL or less with vesicoureteral reflux (VUR).

METHODS

Five cases that satisfied the criteria proposed by the National Institutes of Health were examined. The maximum awake bladder capacity was 50-100 mL (average, 74 mL). The bladder capacity under anesthesia was 70-300 mL (average, 199 mL). Only conservative treatments were carried out.

RESULTS

The observation period ranged from 3 to 16 years with an average of 9 years. The awake bladder capacity ranged from 200 to 300 mL (average, 250 mL). The symptom index total score, which was previously 18.5, decreased to 5.5 and the problem index total score, which was previously 14.3, decreased to 3.5. Symptoms of bladder irritation improved. In four cases, VUR disappeared as the bladder capacity increased. Vesicoureteral reflux persisted in one case although its severity decreased and there was no fever.

CONCLUSION

The patients treated with conservative therapy were able to maintain an awake bladder capacity that was sufficient for acceptable quality of life and their symptoms of bladder irritation improved. This suggests that we should regenerate the original remaining bladder using conservative therapy, even if IC is in a late stage.

Urinary bladder biopsies in spinal cord injured patients

STUDY DESIGN

A series of 94 urinary bladder biopsies in spinal cord injured (SCI) patients were histopathologically and statistically analysed.

OBJECTIVES

The following hypotheses were examined: (1) The number of clinical bladder infections per year in each patient does not influence the histopathological type of inflammation of the urinary bladder; (2) The duration of the spinal cord lesion does not have a strong effect on the type of inflammation; (3) The different neurological levels (upper and lower motor neuron lesions) do not relate to a specific histopathology.

SETTINGS

All patients received their treatment at the Swiss Paraplegic Centre in Nottwil, near Lucerne (Switzerland).

METHODS

The samples were taken from the bladder fundus during endoscopic urologic operations. Histopathological standard procedures were carried out. Statistical analysis including Kruskal-Wallis and Chi-square tests were performed.

RESULTS

Histopathological analysis showed abnormal alterations of the urinary bladder mucosa in 86 SCI-patients: (91.5%). 63 cases (67.0%) showed a chronic type and 23 cases (24.5%) showed a subacute type of inflammation. A normal urinary bladder was found in eight cases (8.5%). The three hypotheses were statistically not rejected.

CONCLUSION

Results demonstrated no correlation between the number of bladder infections per year, the period since injury, the neurologic level of the spinal cord lesion and the histopathology of the urinary bladder mucosa.

Interstitial cystitis: urgency and frequency syndrome

Interstitial cystitis is a chronic, severely debilitating disease of the urinary bladder. Excessive urgency and frequency of urination, suprapubic pain, dyspareunia, chronic pelvic pain and negative urine cultures are characteristic of interstitial cystitis. The course of the disease is usually marked by flare-ups and remissions. Other conditions that should be ruled out include bacterial cystitis, urethritis, neoplasia, vaginitis and vulvar vestibulitis. Interstitial cystitis is diagnosed by cystoscopy and hydrodistention of the bladder. Glomerulations or Hunner's ulcers found at cystoscopy are diagnostic. Oral treatments of interstitial cystitis include pentosan polysulfate, tricyclic antidepressants and antihistamines. Intravesicular therapies include hydrodistention, dimethyl sulfoxide and heparin, or a combination of agents. Referral to a support group should be offered to all patients with interstitial cystitis.

Cimetidine in painful bladder syndrome: a histopathological study

OBJECTIVE

To determine whether oral cimetidine, which reportedly improves symptoms in 60-70% of patients with painful bladder syndrome/interstitial cystitis has a similar mechanism of action on the human bladder and involving a similar peptidergic pathway as it has in human stomach, where it alters histamine-gastrin reactions mediated via H2 receptors and a proton pump.

PATIENTS AND METHODS

Fourteen patients (13 women and one man, mean age 51 years) with refractory bladder pain and irritative urinary symptoms were treated with cimetidine. The response to cimetidine was assessed by outpatient follow-up and an analogue pain score. Bladder biopsies from eight patients were stained with haematoxylin and eosin, and a polyclonal antibody to gastrin, with counterstaining using toluidine blue, to detect mast cell granules containing histamine. Biopsies from normal areas of the bladder from an age-matched control group of patients with transitional cell carcinoma of the bladder were stained similarly. Human stomach and colon were used as positive controls for gastrin and toluidine blue, respectively. The clinical response to cimetidine was compared with the histology in a blinded fashion.

RESULTS

Eight of the patients responded well to cimetidine; none of the biopsies showed evidence of carcinoma in situ. Although G cells in the stomach stained well for gastrin none of the bladder biopsies showed gastrin-like immunoreactivity, apart from some nonspecific urothelial staining. Numerous mast cells with crimson granules and pale nuclei were visible in three patients and fewer in three others; their presence or absence did not correlate with the symptomatic response.

CONCLUSIONS

Cimetidine is a useful medical treatment for bladder pain but the presence or absence of gastrin or histamine-like immunoreactivity does not explain its therapeutic benefit.

Biopsy features are associated with primary symptoms in interstitial cystitis: results from the interstitial cystitis database study

The purpose of this study was to investigate associations between bladder biopsy features and urinary symptoms for patients enrolled in the Interstitial Cystitis Database (ICDB) Study. Bladder biopsies were obtained during baseline screening in the ICDB Study and were evaluated for histopathologic features. Multivariable models for nighttime voiding frequency, urinary urgency, and pain were developed, incorporating biopsy features from the most diseased area of the bladder as predictors, adjusting for significant clinical factors, and clinical center variation. Among 204 interstitial cystitis (IC) patients providing biopsy specimens, cystoscopic pathology findings were not statistically associated (P >0.1) with primary IC symptoms, although the presence of Hunner's ulcer (n = 12) was suggestive of increased urinary frequency. Within a multivariable predictive model for nighttime voiding frequency, adjusting for age and minimum volume per void, 4 pathology features were noted: (1) mast cell count in lamina propria on tryptase stain; (2) complete loss of urothelium; (3) granulation tissue in lamina propria; and (4) vascular density in lamina propria on factor VIII (F8) stain were statistically significant (P <0.01). Similarly, in a multivariable model for urinary urgency, minimum volume, and percentage of submucosal granulation tissue remained statistically significant (P <0.01). Finally, the percentage of mucosa denuded of urothelium and the percentage of submucosal hemorrhage remained highly associated (P <0.01) with pain in a multivariable predictive model. The fact that the presence or severity of glomerulations was not selected for any of these predictive models suggests that cystoscopic findings of glomerulations are not predictive of IC symptoms. Furthermore, these results suggest an important role for certain pathologic features in the predictive modeling of IC symptoms.

Mast cell involvement in interstitial cystitis: a review of human and experimental evidence

Interstitial cystitis (IC) is a heterogeneous syndrome of unknown etiology. Altered bladder glycosaminoglycans lining and bladder mastocytosis have been documented in IC. The objective of this article is to critically examine the published data on bladder mastocytosis in clinical, experimental, and animal studies, with particular emphasis on morphologic evidence of mast cell increase and activation. The literature on bladder mastocytosis and mast cell activation in IC is critically reviewed with particular reference to staining methodology, tryptase immunoreactivity, and electron microscopy. Data from humans and animal models of IC are included. Mastocytosis in IC is best documented by tryptase immunocytochemical staining. Standard surgical stains such as Giemsa and toluidine blue routinely underestimate the degree of mastocytosis. Mast cells are 6- to 8-fold higher in the detrusor compared with controls in "classic IC," and 2- to 3-fold higher in "nonulcerative" IC. Detrusor mastocytosis occurs in both classic and nonulcer IC. Mucosal mast cell increase is present in nonulcerative IC. Mast cell activation without typical exocytosis occurs in the mucosa and submucosa. Activation of mast cells, irrespective of bladder location or degree of mastocytosis, is significant. Mast cell-derived vasoactive and proinflammatory molecules may contribute to the pathogenesis of IC.

Comparison of cystoscopic and histological findings in patients with suspected interstitial cystitis

PURPOSE

Although the exact etiology of interstitial cystitis remains elusive, bladder inflammation appears to be common in many patients. The National Institutes of Health (NIH) have established diagnostic criteria for interstitial cystitis based on the presence of irritative voiding symptoms in the absence of other identifiable pathology. Cystoscopic examination with hydrodistention performed in patients under anesthesia is part of the NIH diagnostic criteria. We determine if the severity of cystoscopic findings correlated with histological evidence of inflammation in patients with suspected interstitial cystitis.

MATERIALS AND METHODS

A total of 69 patients who met NIH symptom criteria for interstitial cystitis and underwent cystoscopy, hydrodistention and bladder biopsy under anesthesia were reviewed. There were 2 investigators blinded to the histological data who independently reviewed operative reports. A urological pathologist blinded to the clinical data reviewed biopsies for inflammation severity. Cystoscopic and histological findings were then converted to a numeric scale. Numeric data were analyzed using the Pearson correlation coefficient.

RESULTS

Cystoscopic examination revealed no evidence of interstitial cystitis in 6 patients (9%), mild changes in 27 (39%), moderate changes in 23 (33%) and severe changes in 13 (19%). Histological examination revealed no inflammation in 21 patients (30%), mild inflammation in 28 (41%), moderate inflammation in 11 (16%) and severe inflammation in 9 (13%). Histological scores correlated poorly with total and scaled cystoscopic severity scores (r = 0.295 and 0.349, respectively).

CONCLUSIONS

Severity of cystoscopic findings observed during hydrodistention with anesthesia does not appear to correlate with the degree of inflammation identified histologically in patients with suspected interstitial cystitis.

Bladder epithelial cells from patients with interstitial cystitis produce an inhibitor of heparin-binding epidermal growth factor-like growth factor production

PURPOSE

The etiology of interstitial cystitis is unknown. We previously identified an interstitial cystitis urine factor, antiproliferative factor, that inhibits proliferation of bladder epithelial cells in vitro and complex changes in epithelial growth factor levels, including profound decreases in heparin-binding epidermal growth factor-like growth factor (HB-EGF). Bladder and renal pelvic catheterization of patients with interstitial cystitis indicated that the antiproliferative factor is made and/or activated in the distal ureter or bladder. Therefore, we determined whether bladder epithelial cells from interstitial cystitis cases produced the antiproliferative factor and whether purified antiproliferative factor could alter production of growth factors known to be abnormal in interstitial cystitis.

MATERIALS AND METHODS

Antiproliferative factor activity was determined by 3H-thymidine incorporation into primary bladder epithelial cells. The antiproliferative factor was purified by size fractionation followed by sequential chromatography involving ion exchange, hydrophobic interaction and high performance liquid chromatography. HB-EGF, epidermal growth factor, insulin-like growth factor and insulin-like growth factor binding protein 3 levels were determined by enzyme-linked immunosorbent assay.

RESULTS

Bladder epithelial cells from patients with interstitial cystitis produced a single antiproliferative factor with the same purification profile as that purified from interstitial cystitis urine. Purified antiproliferative factor specifically inhibited HB-EGF production by bladder epithelial cells in vitro, and the effect of interstitial cystitis urine or purified antiproliferative factor on bladder cell proliferation was inhibited by recombinant human HB-EGF in a dose dependent manner. Similar to urine HB-EGF, serum HB-EGF was also significantly lower in interstitial cystitis cases than in controls.

CONCLUSIONS

Bladder epithelial abnormalities in interstitial cystitis may be caused by a negative autocrine growth factor that inhibits cell proliferation by down-regulating HB-EGF production. Furthermore, decreased levels of urine and serum HB-EGF indicate that interstitial cystitis may be a urinary tract manifestation of a systemic disorder.

Intravesical bacillus Calmette-Guerin and dimethyl sulfoxide for treatment of classic and nonulcer interstitial cystitis: a prospective, randomized double-blind study

PURPOSE

We conducted a prospective, double-blind study with a crossover design of intravesical bacillus Calmette-Guerin (BCG) and dimethyl sulfoxide to determine whether patients with classic and nonulcer interstitial cystitis, respectively, might benefit from either regimen.

MATERIALS AND METHODS

A total of 21 patients, including 11 with classic and 10 with nonulcer interstitial cystitis, randomly underwent treatments with intravesical BCG or dimethyl sulfoxide and, if not improved, were treated with the other substance after a washout period. All 21 patients were evaluated with symptom questionnaires, including a visual analog pain scale and voiding diaries.

RESULTS

Regardless of regimen, there was no improvement in maximal functional capacity. There was a reduction in urinary frequency following dimethyl sulfoxide treatment but only in the classic subtype (p <0.05), whereas no reduction was seen following BCG in either subtype. A substantial pain decrease was noted in classic (p <0.05) as well as nonulcer (p <0.05) interstitial cystitis following dimethyl sulfoxide.

CONCLUSIONS

Intravesical BCG has been presented as a promising new option for treatment of interstitial cystitis. We failed to demonstrate benefit from this treatment. Dimethyl sulfoxide had no positive effect on maximal functional capacity but resulted in a significant reduction in pain and urinary frequency, although only in patients with classic interstitial cystitis.

Subtypes of bladder mast cells in interstitial cystitis

BACKGROUND

Because the types of mast cells present in the bladder of patients with interstitial cystitis (IC) have not been elucidated, we have used immunohistochemical techniques to determine which of the mast cell types is present in biopsy specimens.

METHODS

For all patients diagnosed with IC (n = 10; female) their symptoms satisfied the criteria proposed by the National Institutes of Health criteria of IC and six patients suffering from bladder tumors were selected as control patients. Adjacent sections of paraffin-embedded tissues that had been fixed in Carnoy's solution were reacted with either antitryptase or antichymase antibodies.

RESULTS

In detrusor and in mucosa, the number of tryptase-positive and chymase-negative mast cells (MC(T)) was 146+/-25 and 81+/-31 cells/mm2, respectively, and the number of tryptase-positive and chymase-positive mast cells (MC(TC)) was 124+/-50 and 54+/-20 cells/mm2, respectively. These numbers were significantly greater than those of the control group. A significant negative correlation (P<0.005; R = 0.943) was observed between the number of MC(TC) and the bladder capacity. The number of mast cells obtained by toluidine blue staining in detrusor and in mucosa was 95+/-68 and 71+/-39 cells/mm2, respectively, suggesting that staining with toluidine blue underestimated the number of mast cells.

CONCLUSIONS

Mast cells were significantly increased in number in both the mucosa and detrusor of bladder specimens from IC patients compared with those from control. The MC(TC) may be the type of mast cell dominantly present in the bladder of IC patients. The MC(TC) in detrusor increased with the progression of contracted bladder.

Percutaneous sacral third nerve root neurostimulation improves symptoms and normalizes urinary HB-EGF levels and antiproliferative activity in patients with interstitial cystitis

OBJECTIVES

A highly effective treatment for interstitial cystitis (IC) remains elusive. We determined whether sacral third nerve root (S3) percutaneous neurostimulation (PNS) might be effective in relieving symptoms of IC, as well as in normalizing urinary factors that are specifically altered in IC.

METHODS

Six consecutive patients with symptoms and cystoscopic findings compatible with IC underwent 5 days of continuous S3 neurostimulation by way of leads placed percutaneously into the S3 foramen. Patients filled out voiding frequency diaries and pain and urgency questionnaires before PNS and at the end of PNS when the leads were removed. Urine specimens were collected at these two time points and measured for heparin-binding epidermal growth factor-like growth factor (HB-EGF) by enzyme-linked immunosorbent assay and for antiproliferative factor (APF) activity by (3)H-thymidine uptake by normal human bladder urothelial cells.

RESULTS

S3 PNS significantly improved all measured parameters toward normal values. Voiding frequency decreased twofold from 23.1 +/- 4.6 to 10.6 +/- 4.0 voids daily during PNS (P = 0.0001). Pelvic pain on a scale of 1 to 10 decreased from 7.0 +/- 1.6 to 2.3 +/- 3.2 (P = 0.05). Urinary urgency on a scale of 1 to 10 decreased from 6.0 +/- 2.2 to 1.8 +/- 1.7 (P = 0. 02). Urinary HB-EGF concentration increased sevenfold from 1.5 +/- 2. 1 to 11.0 +/- 1.7 ng/mL (P <0.0001), and urinary APF activity decreased from -76.1% +/- 31% to -4.5% +/- 8.8% (P = 0.005).

CONCLUSIONS

S3 PNS significantly decreased symptoms and normalized urinary HB-EGF and APF activity in patients with IC. These results suggest that permanent S3 PNS may be beneficial in treating IC.

Urothelial pathophysiological changes in feline interstitial cystitis: a human model

Unique barrier properties of the urothelial surface membrane permit urine storage. Interstitial cystitis causes disabling dysuria, and frequency. Similarly, feline interstitial cystitis (FIC) occurs in cats. These studies define the permeability and structural properties of normal and FIC urothelium. To determine the effects of bladder filling, groups were studied before and after hydrodistention. Normal urothelium with or without hydrodistention exhibited high transepithelial resistances (TER) and low water and urea permeabilities, resembling other species. Fluorescence confocal microscopy revealed localization of the marker AE-31 to the apical surface of all umbrella cells in normal urothelium, with the tight junction protein ZO-1 localized to tight junctions. Scanning and transmission electron microscopy revealed uniform distribution of luminal cells with characteristic apical membrane and tight junction morphology. Urothelium in FIC animals displayed reduced TER and increased water and urea permeability following hydrodistention. Structural studies in FIC revealed denuded urothelium, with appearance of AE-31 in underlying epithelial cells. The results demonstrate severe epithelial damage and dysfunction in FIC and suggest novel approaches toward examining the etiology and therapy of IC.

Recruitment, distribution and phenotypes of mast cells in interstitial cystitis

PURPOSE

Interstitial cystitis (IC) is a chronic disabling condition of unknown etiology. One of its major characteristics is an increase in mast cells (MC) showing signs of activation. It has been suggested that the proteinase content defines two MC types: MC(TC), containing chymase and tryptase, and MC(T), which contains tryptase but lacks chymase. Here, we investigated the MC distribution and the MC proteinase expression in IC together with the tissue expression of the major MC growth factors, stem cell factor (SCF) and interleukin-6 (IL-6).

MATERIALS AND METHODS

MC were enumerated in bladder specimens from patients with classic IC, nonulcer IC and controls. MC were visualized in terms of metachromasia, reflecting glycosaminoglycan content, and immunohistochemically, visualizing tryptase, chymase and IL-6 as well as the surface markers CD117 and SCF.

RESULTS

Classic IC displayed a 6 to 10-fold increase of MC identified by proteinase content while in nonulcer IC there were twice as many MC as in controls. In contrast to nonulcer IC and controls, classic IC displayed an abundance of epithelial MC. Fewer CD117+ than proteinase+ MC were detected in IC but not in controls. Classic IC coexpressed SCF and IL-6 in the epithelium and displayed numerous SCF and IL-6+ cells in the mucosa and detrusor muscle, many of which were MC.

CONCLUSIONS

Redistribution of MC into the epithelium and a high bladder wall MC density distinguish classic IC from nonulcer IC. Our findings suggest an SCF/IL-6-driven MC response in IC. They also indicate a downregulation of the SCF receptor in IC.

Neurokinin-1 (NK-1) receptor is required in antigen-induced cystitis

Interstitial cystitis (IC) is a debilitating disease that has been adversely affecting the quality of women's lives for many years. The trigger in IC is not entirely known, and a role for the sensory nerves in its pathogenesis has been suggested. In addition to inflammation, increased mast cell numbers in the detrusor muscle have been reported in a subset of IC patients. Experimentally, several lines of evidence support a central role for substance P and neurokinin-1 (NK-1) receptors in cystitis. The availability of mice genetically deficient in neurokinin-1 receptor (NK-1R(-/-)) allows us to directly evaluate the importance of substance P in cystitis. An unexpected finding of this investigation is that NK-1R(-/-) mice present increased numbers of mast cells in the bladder when compared with wild-type control mice. Despite the increase in mast cell numbers, no concomitant inflammation was observed. In addition, bladder instillation of wild-type mice with a sensitizing antigen induces activation of mast cells and an acute inflammatory response characterized by plasma extravasation, edema, and migration of neutrophils. Antigen-sensitized NK-1R(-/-) mice also exhibit bladder mast cell degranulation in response to antigen challenge. However, NK-1R(-/-) mice are protected from inflammation, failing to present bladder inflammatory cell infiltrate or edema in response to antigen challenge. This work presents the first evidence of participation of NK-1 receptors in cystitis and a mandatory participation of these receptors on the chain of events linking mast cell degranulation and inflammation.

Interstitial cystitis provoked by tiaprofenic acid

A patient developed clinical and histological interstitial cystitis as an adverse effect of treatment with tiaprofenic acid for rheumatism. After cessation of the drug, full symptomatic recovery was obtained. Bladder biopsies 6 months later demonstrated normalization of detrusor muscle histology.

The effects of cold-restraint stress on urinary bladder wall compared with interstitial cystitis morphology

Stress is associated with many diseases of unknown aetiology. This study demonstrates the effects of cold-restraint stress on the morphology of the urinary bladder. Additionally, it compares the results obtained with the morphology of the interstitial cystitis. The animals were subjected to three hours of cold-restraint stress and then starved for 48 h. The morphology and histochemistry of the urinary bladder was investigated with light and electron microscopy. The proliferative activity was analysed via flow cytometry. Increased and degranulated mast cells in the mucosa, leucocyte infiltration in the lamina propria, vacuole formation in the urothelial cells, loose tight junction, dilated intercellular spaces and altered proliferative activity were observed in the stress group when compared with the control. The increase in the number of mast cells and especially degranulated mast cells and vacuole formation and the loose tight junction of the urothelium correlated with the histopathological findings of interstitial cystitis.

Bladder microvasculature in women with interstitial cystitis

PURPOSE

A cardinal cystoscopic finding in women with interstitial cystitis is mucosal small vessel hemorrhage or glomerulations after hydrodistention. We quantified and compared microvascular density and endothelial proliferation in the bladder biopsies of women with interstitial cystitis and a control group of women who were undergoing incontinence or prolapse surgery.

MATERIALS AND METHODS

We performed computer assisted image analysis and immunohistochemical studies to compare differences in the blood vessel count, and proportional area in the bladder suburothelium and deeper submucosa of bladder biopsies of 52 women, including 26 with interstitial cystitis. Routine light microscopy features were examined and correlated with microvascular density.

RESULTS

In the bladder biopsies of women with interstitial cystitis there was a lower blood vessel count (p = 0.01), and a lower proportion of the total image consisted of blood vessel wall (p = 0.03) in the suburothelium than in control biopsies. We noted no difference in the blood vessel count of the deeper submucosa or in the degree of endothelial cell proliferation. Suburothelial blood vessel differences correlated with the degree of histological change, such as edema, inflammatory infiltrate and vascular congestion.

CONCLUSIONS

We found decreased microvascular density in the suburothelium but not in the deeper submucosa in bladder biopsies of women with interstitial cystitis.