Clinical presentation, videourodynamic characteristics, and treatment outcome in men with interstitial cystitis-like lower urinary tract symptoms

Pathophysiology and potential multimodal therapeutic strategies for IC/BPS

Interstitial cystitis/bladder pain syndrome (IC/BPS) is a bladder disorder with no definite aetiology and currently no effective treatment. Its clinical symptoms vary widely, and the bladder condition and extra-bladder dysfunction also show different clinical presentations. This condition is considered to have multiple factors affecting the bladder and clinical symptoms, including urothelial dysfunction, mast cell activation, autoimmune response, neurogenic inflammation, viral or bacterial infection, autonomic nervous dysfunction and central nervous sensitization. Several non-pharmacological, medical, intravesical and novel bladder therapies have been advocated, but the efficacy and durability of these treatments have not been well elucidated. Multimodal therapy has been suggested based on possible pathological mechanisms; however, the most appropriate therapeutic strategy for this disorder has not been well defined. Thus, a rational algorithm for concomitant multimodal therapy for IC/BPS has been proposed.

Videourodynamics - role, benefits and optimal practice

Videourodynamics (VUDS) is an advanced diagnostic procedure that simultaneously combines functional and anatomical evaluation of the lower urinary tract. The goal of this synchronous assessment is to promote accurate diagnosis of the aetiology responsible for patient symptoms, improving therapeutic decision-making. Overall, high-quality VUDS is advocated when other tests such as traditional urodynamics might not provide sufficient data to guide therapy, particularly in patients with complex, persistent or recurrent dysfunctions of the lower urinary tract. Additionally, VUDS is often crucial in the follow-up monitoring of many patients with these dysfunctions. A VUDS study is frequently considered a gold standard in patients with neurogenic lower urinary tract dysfunction, female bladder outlet obstruction or congenital anomalies of the lower urinary tract. Nevertheless, this specialized test should be limited to patients in whom VUDS data add value. Particularly, reliable studies comparing the effect of diagnosis with and without imaging on management outcomes are lacking, and no standardized procedures for undertaking VUDS are available. Additionally, patients should be carefully selected for VUDS evaluation, considering the increased cost and risks associated with radiological imaging. In routine practice, clinicians should balance the additional value of synchronous imaging and the enhanced diagnostic precision of VUDS against the limitations of this approach, which mainly include an uncertain effect of VUDS on final treatment outcomes.

Focal or diffuse bladder wall thickness on bladder computed tomography indicates more severe bladder wall inflammation in patients with interstitial cystitis

PURPOSE

The classification of different phenotypes of interstitial cystitis/ bladder pain syndrome (IC/BPS) provides different pathophysiology and associated treatment strategies. Most clinical studies have focused on bladder symptoms and cystoscopic findings. This study analyzed bladder wall thickness (BWT) and compared bladder conditions, urinary biomarkers, and histopathology among patients of IC/BPS with different BWT.

METHODS

A total of 182 patients with cystoscopy-proven IC/BPS underwent abdominal computed tomography (CT) before intervention. The BWT on CT was classified as smooth, focal thickness, and diffuse thickness. Clinical symptoms, urodynamic findings, cystoscopic characteristics, presence of Hunner's lesion, urinary biomarkers, and bladder histopathology were compared among the three subgroups.

RESULTS

Among the patients, 85 had smooth, 64 had focal, and 33 had diffuse BWT. There was a significant trend of patients with focal and diffuse BWT being significantly older with higher symptom scores, smaller bladder capacity, higher grade of glomerulations, and incidence of Hunner's IC. Pathological findings revealed that patients with diffused BWT, followed by those with focal thickness, had the greatest uroepithelial cell denudation and plasma cell infiltration. Patients with diffuse BWT has higher rate of inflammatory cell infiltration, nerve bundle hyperplasia, and granulation tissue. The urinary levels of tumor necrosis factor-alpha and oxidative stress biomarkers in IC/BPS patients with different BWT were significantly higher than those in the controls.

CONCLUSION

BWT in CT scans can reflect chronic inflammation of the bladder wall in patients with IC/BPS, which is clinically relevant for the diagnosis and treatment of IC subtypes.

Definition Change and Update of Clinical Guidelines for Interstitial Cystitis and Bladder Pain Syndrome

The clinical guidelines for interstitial cystitis (IC) and bladder pain syndrome (BPS) have been revised by updating our previous guidelines. The symptoms of IC and BPS, collectively called as hypersensitive bladder (HSB) symptoms, are virtually indistinguishable between IC and BPS; however, IC and BPS should be considered as a separate entity of disorders. We define IC as a bladder disease with Hunner lesions, usually associated with HSB symptoms and bladder inflammation, and BPS as a condition with HSB symptoms in the absence of Hunner lesions and any confusable diseases. Pathophysiology totally differs between IC and BPS. IC involves immunological inflammation probably resulting from autoimmunity, while BPS is associated with the interaction of multiple factors such as neurogenic inflammation, exogenous substances, urothelial defects, psychological stress, and neural hyperactivity. Histopathology also differs between IC and BPS. IC is associated with severe inflammation of the whole bladder accompanied by plasma cell infiltration and urothelial denudation, while BPS shows little pathological changes. Management should begin with a differential diagnosis of IC or BPS, which would require cystoscopy to determine the presence or absence of Hunner lesions. The patients should be treated differently based on the diagnosis following the algorithm, although pain management would be common to IC and BPS. Clinical studies are also to be designed and analyzed separately for IC and BPS.

Urine biomarker could be a useful tool for differential diagnosis of a lower urinary tract dysfunction

A precision diagnosis of lower urinary tract dysfunctions (LUTD) such as bladder outlet obstruction, detrusor overactivity (DO), interstitial cystitis/bladder pain syndrome (IC/BPS), dysfunctional voiding (DV), or detrusor underactivity (DU) needs invasive videourodynamic study. Exploring non-invasive tools to help screening LUTD is necessary for clinicians in their daily practice. This article reviews recently clinical studies of using urinary inflammatory proteins and oxidative stress biomarkers in the identification of specific LUTD among men and women with lower urinary tract symptoms (LUTS). Some important findings have been reported: (1) Using urine chemokines CXCL-1 and interleukin-8 (IL-8), we may discriminate overactive bladder (OAB) symptoms in women between DO and urinary tract infection. (2) Urinary levels of oxidative stress biomarkers such as 8-hydroxydeoxyguanosine (8-OHdG) and 8-isoprostane have a potential being used as a tool to identify women with mixed DO and stress urinary incontinence. (3) Urine levels of total antioxidant capacity (TAC), and prostaglandin E2 (PGE2) are positively correlated with voiding detrusor pressure in patients with DU. (4) Urine levels of brain-derived neurotrophic factor (BDNF) and PGE2 were significantly higher in the DU patients with detrusor function recovery. (5) Women with DV had higher urinary levels of tumor necrosis factor-alpha (TNF-α) and 8-OHdG, and urinary IL-2 level was significantly lower. (6) Urine level of 8-isoprostane was higher in the patients with idiopathic DO and neurogenic DO. (7) Higher urine cytokine levels of monocyte chemoattractant protein-1 (MCP-1), regulated on activation, normal T-cell expressed and secreted (RANTES), CXCL-10, IL-7, and eotaxin-1 in patients with IC/BPS than controls. (8) The urine levels of IL-8, CXCL-10, BDNF, IL-6, and RANTES were significantly higher in patients with Hunner's IC than non-Hunner's IC. (9) Male patients with IC/BPS had a significantly higher level of eotaxin, MCP-1, TNF-α, 8-OHdG, and TAC. Combining a higher eotaxin and a higher TNF-α can provide a satisfactory diagnostic value in discriminating IC/BPS from other LUTD in men. These studies provide evidence that measurement of cluster of urine biomarkers could be used as a diagnostic tool to differentiate different LUTD in patients with similar LUTS.

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.

Hyaluronan nanoplatelets exert an intrinsic anti-inflammatory activity in a rat model of bladder painful syndrome/interstitial cystitis

Glycosaminoglycan (GAG) replenishment therapy consists of the instillation of GAG solutions directly in the bladder to alleviate Bladder Painful Syndrome/Interstitial Cystitis (BPS/IC). However, several issues were reported with this strategy because the GAG solutions are rapidly eliminated from the bladder by spontaneous voiding, and GAG have low bioadhesive behaviors. Herein, GAG nanomaterials with typical flattened morphology were obtained by a self-assembly process. The formation mechanism of those nanomaterials, denoted as nanoplatelets, involves the interaction of α-cyclodextrin cavity and alkyl chains covalently grafted on the GAG. Three GAG were used in this investigation, hyaluronan (HA), chondroitin sulfate (CS), and heparin (HEP). HA NP showed the best anti-inflammatory activity in an LPS-induced in vitro inflammation model of macrophages. They also exhibited the best therapeutic efficacy in a BPS/IC rat inflammation model. Histological examinations of the bladders revealed that HA NP significantly reduced bladder inflammation and regenerated the bladder mucosa. This investigation could open new perspectives to alleviate BPS/IC through GAG replenishment therapy.