Biomarkers for interstitial cystitis/painful bladder syndrome

Bioenergetic profiles of peripheral mononuclear cells and systemic inflammation in women with Interstitial Cystitis/Bladder Pain Syndrome (IC/BPS)

Inflammation is thought to contribute to the etiology of interstitial cystitis/bladder pain syndrome (IC/BPS). It is well-known that disruption in metabolism in immune cells contributes to inflammation in several inflammatory diseases. The purpose of this study was to investigate whether cellular bioenergetics is altered in monocytes and lymphocytes from women with IC/BPS, and if these alterations correlate with systemic inflammatory markers. Age and BMI matched adult healthy women (HS; n = 18) and women with IC/BPS (n = 18) were included in the study. Blood was collected to assess cellular bioenergetics in monocytes and lymphocytes using a Seahorse XF96 Analyzer and plasma cytokine levels were measured using Meso Scale Discovery immunoassays. The correlation between bioenergetic parameters, cytokines, and demographics was determined using Pearson correlation coefficients. Means of the two groups were compared using the two-group t-test. Patients with IC/BPS had reduced monocyte oxygen consumption rates and glycolytic rates compared to healthy subjects. In contrast, lymphocytes from these patients had increased oxygen consumption rates and glycolytic rates. Several cytokines and chemokines including Interferon-gamma (IFN-ɣ), tumor necrosis factor alpha (TNF-ɑ), Interleukin-6 (IL-6), Interleukin-8 (IL-8) and vascular endothelial growth factor (VEGF) levels were significantly elevated in the plasma of patients with IC/BPS. However, Transforming growth factor (TGF-β) and Interleukin-10 (IL-10) levels were significantly decreased in IC/BPS patients compared to HS. In addition, Interferon gamma (IFN-ɣ), TNF-ɑ, IL-8, and TGF-β levels correlated with several bioenergetic parameters in monocytes or lymphocytes from healthy subjects. In contrast, TNF-ɑ and IL-8 correlated with bioenergetic parameters in monocytes from IC/BPS patients. Monocyte and lymphocyte cellular bioenergetics and plasma cytokine levels are different in patients with IC/PBS compared to HS. It appears that systemic inflammation is greater in this cohort which may negatively impact immune cell function. The relationship between cellular bioenergetics and inflammation in monocytes and lymphocytes could be important in understanding the pathogenesis of IC/PBS and warrants further investigation.

Gender differences in the experience of interstitial cystitis/bladder pain syndrome

Aims

This study assessed gender differences in a debilitating urologic pain condition, interstitial cystitis/bladder pain syndrome (IC/BPS). We aimed to (1) evaluate how pain, symptom, and distress profiles of IC/BPS may differ between genders and (2) obtain in-depth firsthand accounts from patients to provide additional insight into their experiences that may explain potential gender differences.

Methods

A mixed methods approach combined validated patient-reported outcome measures with a single timepoint 90-min focus group. Tests of summary score group differences between men and women were assessed across questionnaires measuring urologic symptoms, pain, emotional functioning, and diagnostic timeline. Qualitative analysis applied an inductive-deductive approach to evaluate and compare experiences of living with IC/BPS Group narratives were coded and evaluated thematically by gender using the biopsychosocial model, providing insight into the different context of biopsychosocial domains characterizing the male and female experience of IC/BPS.

Results

Thirty-seven participants [women (n = 27) and men (n = 10)] completed measures and structured focus group interviews across eight group cohorts conducted from 8/2017 to 3/2019. Women reported greater pain intensity (p = 0.043) and extent (p = 0.018), but not significantly greater impairment from pain (p = 0.160). Levels of psychological distress were significantly elevated across both genders. Further, the duration between time of pain symptom onset and time to diagnosis was significantly greater for women than men (p = 0.012). Qualitative findings demonstrated key distinctions in experiences between genders. Men appeared not to recognize or to deter emotional distress while women felt overwhelmed by it. Men emphasized needing more physiological treatment options whilst women emphasized needing more social and emotional support. Interactions with medical providers and the healthcare system differed substantially between genders. While men reported feeling supported and involved in treatment decisions, women reported feeling dismissed and disbelieved.

Conclusion

The findings indicate different pain experiences and treatment needs between genders in persons experiencing urologic pain and urinary symptoms, with potential intervention implications. Results suggest gender health inequality in medical interactions in this urologic population needing further investigation.

Components of the Endogenous Cannabinoid System as Potential Biomarkers for Interstitial Cystitis/Bladder Pain Syndrome

Interstitial cystitis/bladder pain syndrome (IC/BPS) is a chronic condition causing bladder pressure and pain. The condition is of unknown etiology and is often accompanied by other symptoms, including chronic pelvic pain, increased urinary urgency, and frequency. There is no definitive diagnosis for IC/BPS, and treatment options are currently limited to physical therapy and medications to help alleviate symptoms. The endogenous cannabinoid system (ECS) is an important regulator of numerous physiological systems, including the urinary system. Modulations of the ECS have been shown to be beneficial for IC/BPS-associated pain and inflammation in rodents. As an attempt to identify potential biomarkers for IC/BPS, we reviewed experimental studies where the components of the ECS have been quantified in experimental models of IC/BPS. Further investigations using well-defined animal models and patients’ data are required to obtain stronger evidence regarding the potential for ECS components to be definitive biomarkers for IC/BPS.

A nomogram for bladder pain syndrome/interstitial cystitis based on netrin-1

Purpose

This study aimed to combine plasma netrin-1 and clinical parameters to construct a diagnostic model for bladder pain syndrome/interstitial cystitis (BPS/IC).

Methods

We analyzed the independent diagnostic value of netrin-1 and the correlation with clinical symptom scores of BPS/IC. Clinical parameters were selected using LASSO regression, and a multivariate logistic regression model based on netrin-1 was established, and then a nomogram of BPS/IC prevalence was constructed. The nomogram was evaluated using calibration curves, the C-index, and decision curve analysis (DCA). Finally, the model was validated using an internal validation method.

Results

The area under the curve for the ability of netrin-1 to independently predict BPS/IC diagnosis was 0.858 (p < 0.001), with a sensitivity of 85% and specificity of 82%. The predicted nomogram included three variables: age, CD3 + /CD4 + T lymphocyte ratio, and netrin-1. The C-index of this nomogram was 0.882, and the predicted values were highly consistent with the actual results in the calibration curve. In addition, the internally validated C-index of 0.870 confirms the high reliability of the model. DCA results show that the net patient benefit of the netrin-1 combined with other clinical parameters was higher than that of the single netrin-1 model.

Conclusion

Netrin-1 can be used as a diagnostic marker for BPS/IC and is associated with pain. The nomogram constructed by combining netrin-1 and clinical parameters was able to predict BPS/IC with great accuracy. In addition, Netrin-1 may also serve as a novel therapeutic target for BPS/IC.

Sensory pudendal nerve stimulation increases bladder capacity through sympathetic mechanisms in cyclophosphamide-induced cystitis rats

AIMS

Interstitial cystitis and bladder pain syndrome is a prevalent health concern with inadequate treatments. Neuromodulation has emerged as a therapeutic option to treat patients refractory to standard care. The objective of this study was to determine the efficacy and mechanism(s) of sensory pudendal nerve stimulation on bladder function in cystitis rats.

METHODS

Female rats were administered saline (n = 8) or cyclophosphamide (CYP, 150 mg/kg IP, n = 16) and single-trial cystometry experiments were conducted under urethane anesthesia 48 h after injection. Electrical stimulation (0.02-0.22 mA, 10-20 Hz) was delivered to the sensory branch of the pudendal nerve and its effect on the bladder and external urethral sphincter were measured. Stimulation trials were also conducted following bilateral hypogastric nerve transection (HGNT) or pharmacological inhibition of beta-adrenergic receptors (propranolol, 1 mg/kg IV) to determine the mechanisms of bladder inhibition.

RESULTS

CYP-induced cystitis decreased bladder capacity (P = 0.0352) and bladder compliance (P = 0.024) by up to 38% of control. Electrical stimulation of the sensory pudendal nerve increased bladder capacity (P < 0.0001) in control and CYP rats by up to 51-52% of their respective baselines. HGNT did not influence bladder inhibition generated by sensory pudendal nerve stimulation in control rats, whereas HGNT and propranolol decreased the efficacy of electrical stimulation in CYP rats.

CONCLUSIONS

Sympathetic reflex activity mediates sensory pudendal nerve stimulation in CYP treated but not control rats. These studies demonstrate an alternative approach to neuromodulation in cystitis and establish mechanistic changes during stimulation that may enable the development of novel therapeutics.

Ozone therapy ameliorates inflammation and endometrial injury in rats with pelvic inflammatory disease

As a common cause of infertility, pelvic inflammatory disease (PID) is characterized by chronic pain, ectopic pregnancy as well as inflammation and infection of the female upper genital tract. Ozone water, also known as O_3, has been previously reported to be a distinctly effective agent in treating inflammation. During the present study, we asserted the hypothesis that O₃ could be applied by pelvic inflammation and works to regulate the expression of inflammatory factors including interleukin-6 (IL-6), IL-2 and tumor necrosis factor-α (TNF-α). In an attempt to evaluate the effect of O₃ on PID, an acute PID rat model was subsequently established. O₃ at concentrations of 45 μg/mL and 60 μg/mL in addition to levofloxacin (LVLX) was injected respectively into the PID rats in a bid to alter the contents of inflammatory factors and immunologic markers. Hematoxylin-eosin (HE) staining was applied to analyze endometrial inflammation. Reductions to the contents of IL-6 and TNF-α were recorded, while that of IL-2, IgA, IgG, IgM, C3 and C4, and E rosette formation rate and transformation rate of T lymphocytes exhibited notably elevated levels after the PID rats had been injected with 45 μg/mL O₃, 60 μg/mL O₃ or LVLX. The pathological condition of the endometrium in rats with PID was alleviated among the PID rats after injected with the 45 μg/mL O₃, 60 μg/mL O₃ or LVLX. Taken together, the key findings of the current study present evidence demonstrating that the administration of O₃ to the pelvic cavity ameliorated the PID conditions among rat models via inhibition of the necrosis of the endometrial epithelial cells as well as alleviated the inflammatory reactions, highlighting a potential novel PID treatment target.

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

PURPOSE

Pain is the key symptom that distinguishes bladder pain syndrome/interstitial cystitis from overactive bladder syndrome but overlap occurs. To find a discriminating marker for these bladder diseases we examined sensory hyperinnervation and neurotrophin receptor expression in bladder biopsies as well as nerve growth factor levels in urine.

MATERIALS AND METHODS

Bladder biopsies from patients with bladder pain syndrome/interstitial cystitis, including 12 with and 19 without Hunner lesions, 13 with overactive bladder syndrome and 12 healthy controls, were analyzed by immunohistochemistry with antibodies to the nerve cell marker PGP9.5 (neuron-specific protein gene product 9.5), p75^NTR (p75 neurotrophin receptor), the B-lymphocyte marker CD20 and mast cell tryptase. Urinary nerve growth factor was quantified by enzyme-linked immunosorbent assay.

RESULTS

Subepithelial sensory hyperinnervation on PGP9.5 staining had 97% sensitivity and 76% specificity, increased lymphocytic infiltration had 90% sensitivity and 80% specificity, and urothelial defects had 97% sensitivity and 76% specificity to distinguish bladder pain syndrome/interstitial cystitis with and without Hunner lesions from overactive bladder syndrome and healthy controls. Increased sensory innervation was associated with submucosal mast cell localization. Staining of p75^NTR in basal urothelial cells was indicative of bladder pain syndrome/interstitial cystitis. Urinary nerve growth factor levels were below the detection level and did not differentiate bladder diseases from healthy controls.

CONCLUSIONS

Sensory hyperinnervation and basal urothelial p75^NTR staining together with assessment of inflammatory lymphocytes and urothelial integrity allow for the differentiation of bladder pain syndrome/interstitial cystitis and overactive bladder syndrome even in the absence of Hunner lesions. Furthermore, these histopathological criteria enable the identification of early disease stages or oligosymptomatic/asymptomatic cases and may permit timely treatment to prevent disease progress.

Implantable Devices for Sustained, Intravesical Drug Delivery

In clinical settings, intravesical instillation of a drug bolus is often performed for the treatment of bladder diseases. However, it requires repeated instillations to extend drug efficacy, which may result in poor patient compliance. To alleviate this challenge, implantable devices have been developed for the purpose of sustained, intravesical drug delivery. In this review, we briefly summarize the current trend in the development of intravesical drug-delivery devices. We also introduce the most recently developed devices with strong potential for intravesical drug-delivery applications.