Detrusor mast cells in refractory idiopathic instability

Sympathetic nervous system and chronic bladder pain: a new tune for an old song

Chronic bladder pain (CBP) patients present with pelvic pain or discomfort during bladder filling, for at least a period of 6 months, which may be accompanied by lower urinary tract symptoms such as frequency, nocturia, and urgency. However, both the etiology of CBP and pathophysiological mechanisms are not well described. A number of clinical and basic animal model findings support involvement of sympathetic nervous system in chronic pain syndromes such as CBP. Examples include sympathetic overactivity and high plasma or urinary catecholamine levels that have a high correlation with nociceptive symptoms. In this review, we explored the current evidence in support of the involvement of sympathetic overactivity in CBP. As bladder inflammation often occurs among subgroups of CBP patients, we discuss the possible role of sympathetic nervous system in mastocytosis as well examples examples of animal models that further support the involvement of sympathetic dysfunction in CBP. As there is substantive evidence for cross-organ sensitization in the pelvis can lead to co-morbidity of genitourinary and gastrointestinal dysfunctions, we also include how sympathetic dysfunction may play a role in a number of co-morbid chronic pain syndromes.

Potential urine and serum biomarkers for patients with bladder pain syndrome/interstitial cystitis

There is a lack of consensus on the pathophysiology of bladder pain syndrome/interstitial cystitis. The chronic pain symptoms of bladder pain syndrome/interstitial cystitis refractory to local treatment could be a result of central nervous system sensitization and persisting abnormalities in the bladder wall, which activate the afferent sensory system. Evidence also shows that bladder pain syndrome/interstitial cystitis is a heterogeneous syndrome and that the two subtypes, the ulcerative (classic) and non-ulcerative types, represent different disease entities. There is a need for non-invasive markers for the differential diagnoses of the subtypes of bladder pain syndrome/interstitial cystitis, and between bladder pain syndrome/interstitial cystitis and bladder sensory disorders, such as hypersensitive bladder syndrome or overactive bladder. Bladder pain syndrome/interstitial cystitis, but not overactive bladder, involves an aberrant differentiation program in the bladder urothelium that leads to altered synthesis of several proteoglycans, cell adhesion and tight junction proteins, and bacterial defense molecules. These findings have led to the rationale for identifying urinary biomarkers to detect bladder pain syndrome/interstitial cystitis in patients with frequency urgency syndrome. Recently, the markers that have been the focus of the most research are antiproliferative factor, epidermal growth factor, heparin-binding epidermal growth factor, glycosaminoglycans and bladder nitric oxide. In addition, inflammatory proteins in the urine and serum play important roles in the pathogenesis of bladder pain syndrome/interstitial cystitis. The urinary proteome is an easily accessible source of biomarkers for differentiation between inflammatory bladder disorders. Analysis of multiple urinary proteins and serum cytokines could provide a diagnostic basis for bladder pain syndrome/interstitial cystitis, and could be a tool for the differential diagnosis of bladder pain syndrome/interstitial cystitis and other sensory bladder disorders.

Decreased intravesical adenosine triphosphate in patients with refractory detrusor overactivity and bacteriuria

PURPOSE

Although several studies have examined the relationship between adenosine triphosphate release from the urothelium and bladder sensations including painful filling and urgency, the association between bacteriuria and urothelial adenosine triphosphate release has not been well studied. We evaluated women with refractory detrusor overactivity who were experiencing an acute exacerbation of detrusor overactivity symptoms including frequency, urgency and nocturia (and/or urge incontinence). We measured changes in intravesical adenosine triphosphate levels in these women with and without bacteriuria.

MATERIALS AND METHODS

In this prospective cohort study women with refractory detrusor overactivity were invited to our unit during acute symptomatic exacerbation. On presentation a catheter urine specimen was collected and 50 ml normal saline instilled into the bladder to evoke gentle stretch, with removal after 5 minutes. Adenosine triphosphate concentrations were determined on fresh washings using a bioluminescence assay.

RESULTS

The incidence of bacteriuria 10(3) cfu/ml or greater was 27% (15 of 56 specimens) during the 16-month study period. Adenosine triphosphate concentrations were lower during episodes of bacteriuria in the overall cohort (p = 0.0013) and paired samples from individual patients (p = 0.031) compared to episodes of sterile urine.

CONCLUSIONS

In the first study on the subject to our knowledge, we demonstrated a striking difference between adenosine triphosphate levels measured in the presence and absence of bacteriuria in this patient group.

Immunocytochemical characterisation of cultures of human bladder mucosal cells

Background

The functional role of the bladder urothelium has been the focus of much recent research. The bladder mucosa contains two significant cell types: urothelial cells that line the bladder lumen and suburothelial interstitial cells or myofibroblasts. The aims of this study were to culture these cell populations from human bladder biopsies and to perform immunocytochemical characterisation.

Methods

Primary cell cultures were established from human bladder biopsies (n = 10). Individual populations of urothelial and myofibroblast-like cells were isolated using magnetic activated cell separation (MACS). Cells were slow growing, needing 3 to 5 weeks to attain confluence.

Results

Cytokeratin 20 positive cells (umbrella cells) were isolated at primary culture and also from patients' bladder washings but these did not proliferate. In primary culture, proliferating cells demonstrated positive immunocytochemical staining to cytokeratin markers (AE1/AE3 and A0575) as well fibroblasts (5B5) and smooth muscle (αSMA) markers. An unexpected finding was that populations of presumptive urothelial and myofibroblast-like cells, isolated using the MACS beads, stained for similar markers. In contrast, staining for cytokeratins and fibroblast or smooth muscle markers was not co-localised in full thickness bladder sections.

Conclusions

Our results suggest that, in culture, bladder mucosal cells may undergo differentiation into a myoepithelial cell phenotype indicating that urothelial cells have the capacity to respond to environmental changes. This may be important pathologically but also suggests that studies of the physiological function of these cells in culture may not give a reliable indicator of human physiology.

Can we predict which patient will fail drug treatment for overactive bladder? A think tank discussion

The treatment of overactive bladder (OAB) has evolved over the past 20 years to include a number of behavioral, pharmacological, and minimally invasive treatments. After behavioral therapy, pharmacological therapy with antimuscarinics remains the mainstay of treatment. Despite this, a large number of patients will "fail" or be unsatisfied with drugs therapy. It would be extremely helpful to patients and clinicians to be able to predict who those patients are. However, there are a number of barriers. First and foremost are defining "success" and "failure" and this can vary dramatically from one patient to another. Endpoints other than the traditional variables used in clinical trials may be more effective in evaluating treatments and helping to predict outcomes. Along similar lines, there are various definitions for OAB that is "refractory" to conventional treatments and this term needs clarification. In many cases, response to therapy may be affected by factors such as comorbidities, metabolism of drugs, concurrent therapies, etc. These factors are sometimes obvious and sometimes not, and for a variety of reasons it can be quite difficult to predict or determine their effect on outcome. Finally, many patients with OAB include have mixed (stress and urgency) symptoms. It is important to sort out the OAB component of mixed symptoms and mixed urinary incontinence (MUI) when determining effects of therapy.

Efficacy of oral doxepin and piroxicam treatment for interstitial cystitis

OBJECTIVE

To establish the efficacy of a multidrug oral treatment with the tricyclic antidepressant agent doxepin and the cyclooxygenase (COX) inhibitor piroxicam in patients with interstitial cystitis (IC), who had failed standard therapy in an open, prospective, nonrandomized study.

METHODS

A total of 37 patients diagnosed with IC received 75 mg doxepin and 40 mg piroxicam daily. The treatment was termed DOXCAM. Effectiveness of therapy was assessed with frequency-volume charts, an IC symptom score and with cystometry prior to treatment, 8 weeks after the start and 4 weeks after termination of drug treatment.

RESULTS

Medication was not tolerated by five patients. Twenty-six of 32 patients have experienced virtual total remission of symptoms (81%) and six patients had significant relief (19%). DOXCAM treatment resulted in a significant percent decrease in pain (65% versus 21%). Daytime frequency decreased from 17.6+/-5.7 to 11.3+/-3.6 voids while nocturia did not improve significantly. Twenty-three of the 26 patients who became symptom free and four of the six patients who showed significant improvement had a return of symptoms after cessation of therapy.

CONCLUSION

It is reasonable to consider oral treatment with DOXCAM in those patients who have failed first-line therapies.

The tachykinin NK-2 receptor antagonist SR48968 does not block noncholinergic contractions in unstable human bladder

Concentration-response curves to acetylcholine, and responses to electrical field stimulation (EFS) were compared in detrusor muscle strips, from control patients and those with idiopathic detrusor instability (IDI). Responses were similar in both groups. However, atropine abolished responses to EFS in 80% of control but only 33% of IDI patients (P>0.05), with the residual atropine-resistant response in most IDI patients abolished by tetrodotoxin. The post-atropine residual response was unaffected by the tachykinin NK-2 receptor antagonist SR48968. Despite the known existence of NK-2 receptors in the human detrusor, there was no evidence for tachykinin contribution to EFS-induced contractions.

Use of meta-analytic results to facilitate shared decision making

OBJECTIVES

Describe and evaluate an Internet-based approach to patient decision support using mathematical models that predict the probability of successful treatment on the basis of meta-analytic summaries of the mean and standard deviation of symptom response.

DESIGN

An Internet-based decision support tool was developed to help patients with benign prostatic hypertrophy (BPH) determine whether they wanted to use alpha blockers. The Internet site incorporates a meta-analytic model of the results of randomized trials of the alpha blocker terazosin. The site describes alternative treatments for BPH and potential adverse effects of alpha blockers. The site then measures patients' current symptoms and desired level of symptom reduction. In response, the site computes and displays the probability of a patient's achieving his objective by means of terazosin or placebo treatment.

SETTING

Self-identified BPH patients accessing the site over the Internet.

MAIN OUTCOME MEASURES

Patients' perceptions of the usefulness of information.

RESULTS

Over a three-month period, 191 patients who were over 50 years of age and who reported that they have BPH used the decision support tool. Respondents had a mean American Urological Association (AUA) score of 18.8 and a desired drop in symptoms of 10.1 AUA points. Patients had a 40 percent chance of achieving treatment goals with terazosin and a 20 percent chance with placebo. Patients found the information useful (93 percent), and most (71 percent) believed this type of information should be discussed before prescribing medications.

CONCLUSIONS

Interactive meta-analytic summary models of the effects of pharmacologic treatments can help patients determine whether a treatment offers sufficient benefits to offset its risks.

Interstitial cystitis: a critique of current concepts with a new proposal for pathologic diagnosis and pathogenesis

Interstitial cystitis (IC) has continued to be an unresolved problem in clinical urology despite intense investigation over the past 16 or more years. Its etiology and pathogenesis are still undetermined, and its pathologic diagnosis is essentially one of exclusion, with no specific or clear criteria. In this review, current concepts of the etiology/pathogenesis and pathology are critically analyzed, new pathologic observations summarized, and a proposal of neurogenic inflammation as the primary pathogenetic factor is presented in the context of all currently available information. The popular postulate attributing IC to a deficient or defective glycosaminoglycan urothelial surface layer is not substantiated by morphologic, experimental, clinical, or therapeutic observations. Although the consensus seems to discount an infectious etiology, there is sufficient evidence that a microbial factor-short of a bona fide clinical infection-may have a role. Both autoimmunity and mast cell infiltration also appear to have a role, despite the lack of evidence that either is involved as the primary etiologic factor. Claims that the so-called feline urologic syndrome may represent a natural animal model of IC are shaky. As it now stands, there is no natural or induced animal model that duplicates IC as it occurs in humans. No specific or diagnostic light microscopic pathologic features are provided by either routine histopathology or immunohistochemistry. Increasingly, it has been recognized that detrusor mast cell count has little or no diagnostic value. On the other hand, electron microscopy has provided important new observations: (a) presence of mast cells, activated by piecemeal degranulation, in close proximity to intrinsic nerves-particularly in suburothelium: (b) distinctive pathologic changes in urothelium, suburothelium, and muscularis in biopsy samples obtained after diagnostic bladder hydrodistension; (c) constant associated changes in venules, capillaries, and neural elements in the same biopsy samples; and (d) diffuse involvement of bladder wall, with the most evident and profound pathologic changes in posthydrodistension biopsy samples obtained from cystoscopically obvious lesions (glomerulations). These features are sufficiently distinctive to allow definitive pathologic diagnosis of IC, and provide a firm basis for primary involvement of neurogenic inflammation in its pathogenesis. A proposal is presented regarding the mechanisms invoked by neurogenic inflammation. This proposal revolves around sensory nerve excitation, the release of neuropeptides, and activated differential secretion of potent mast cell mediators. This proposal can account for the heterogeneity and variability of observed pathologic features, and upholds the tacit acceptance of IC as a disease of pluricausal etiology and multifactorial pathogenesis.

Diagnosis and treatment for children who cannot control urination

Primary NE is probably a condition rooted in biologic problems. There is a strong hereditary component. Altered nervous system function may lead to disorganization of how bladder function is controlled and how vasopressin is released. In extreme cases, this disorganization may also be reflected in psychologic issues, such as attention-deficit disorder. Primary NE should not be viewed as laziness of the child, but as an obstacle the child needs professional help to hurdle. The practitioner should collaborate with a pediatrician, urologist, and psychologist in managing children who wet. Routine office evaluation should exclude incontinence as a cause of wetting. When a screening ultrasonogram is normal, this helps the practitioner determine that striking birth defects are unlikely. Follow-up of management by interview with interested staff is necessary. Wetting is reliably correctable and probably best addressed by combination treatment structured as an ETP. Specific treatments vary according to personal preferences. The treatment with strongest scientific research, desmopressin, may be the least effective for cure. The most effective treatment for cure, alarm with behavior reinforcement, is the least often prescribed. A miscellany of adjunctive treatments should be suggested when there are abnormalities in functional bladder capacity, defecation, urethritis, vulvitis, diet sensitivity, upper-airway obstruction, and other areas.