Infiltrating lipid-rich macrophage subpopulations identified as a regulator of increasing prostate size in human benign prostatic hyperplasia.

Macrophages exhibit marked phenotypic heterogeneity within and across disease states, with lipid metabolic reprogramming contributing to macrophage activation and heterogeneity. Chronic inflammation has been observed in human benign prostatic hyperplasia (BPH) tissues, however macrophage activation states and their contributions to this hyperplastic disease have not been defined. We postulated that a shift in macrophage phenotypes with increasing prostate size could involve metabolic alterations resulting in prostatic epithelial or stromal hyperplasia. Single-cell RNA-seq of CD45+ transition zone leukocytes from 10 large (>90 grams) and 10 small (<40 grams) human prostates was conducted. Macrophage subpopulations were defined using marker genes. BPH macrophages do not distinctly categorize into M1 and M2 phenotypes. Instead, macrophages with neither polarization signature preferentially accumulate in large versus small prostates. Specifically, macrophage subpopulations with altered lipid metabolism pathways, demarcated by TREM2 and MARCO expression, significantly accumulate with increased prostate volume. TREM2 + and MARCO + macrophage abundance positively correlates with patient body mass index and urinary symptom scores. TREM2+ macrophages have significantly higher neutral lipid than TREM2- macrophages from BPH tissues. Lipid-rich macrophages were observed to localize within the stroma in BPH tissues. In vitro studies indicate that lipid-loaded macrophages increase prostate epithelial and stromal cell proliferation compared to control macrophages. These data define two new BPH immune subpopulations, TREM2+ and MARCO+ macrophages, and suggest that lipid-rich macrophages may exacerbate lower urinary tract symptoms in patients with large prostates. Further investigation is needed to evaluate the therapeutic benefit of targeting these cells in BPH.

Enhanced clinical decisions for management of benign prostatic hyperplasia using patient-reported outcomes: protocol for a prospective observational study.

BACKGROUND: Lower urinary tract symptoms (LUTS) due to benign prostatic hyperplasia (BPH) significantly impact quality of life among older men. Despite the prevalent use of the American Urological Association Symptom Index (AUA-SI) for BPH, this measure overlooks key symptoms such as pain and incontinence, underscoring the need for more comprehensive patient-reported outcome (PRO) tools. This study aims to integrate enhanced PROs into routine clinical practice to better capture the spectrum of LUTS, thereby improving clinical outcomes and patient care. METHODS: This prospective observational study will recruit men with LUTS secondary to BPH aged ≥ 50 years from urology clinics. Participants will be stratified into medical and surgical management groups, with PRO assessments scheduled at regular intervals to monitor LUTS and other health outcomes. The study will employ the LURN Symptom Index (SI)-29 alongside the traditional AUA-SI and other non-urologic PROs to evaluate a broad range of symptoms. Data on comorbidities, symptom severity, and treatment efficacy will be collected through a combination of electronic health records and PROs. Analyses will focus on the predictive power of these tools in relation to symptom trajectories and treatment responses. Aims are to: (1) integrate routine clinical tests with PRO assessment to enhance screening, diagnosis, and management of patients with BPH; (2) examine psychometric properties of the LURN SIs, including test-retest reliability and establishment of clinically meaningful differences; and (3) create care-coordination recommendations to facilitate management of persistent symptoms and common comorbidities measured by PROs. DISCUSSION: By employing comprehensive PRO measures, this study expects to refine symptom assessment and enhance treatment monitoring, potentially leading to improved personalized care strategies. The integration of these tools into clinical settings could revolutionize the management of LUTS/BPH by providing more nuanced insights into patient experiences and outcomes. The findings could have significant implications for clinical practices, potentially leading to updates in clinical guidelines and better health management strategies for men with LUTS/BPH. TRIAL REGISTRATION: This study is registered in ClinicalTrials.gov (NCT05898932).

Enhanced Clinical Decisions for Management of Benign Prostatic Hyperplasia using Patient-Reported Outcomes: Protocol for a Prospective Observational Study.

Background: Lower urinary tract symptoms (LUTS) due to benign prostatic hyperplasia (BPH) significantly impact quality of life among older men. Despite the prevalent use of the American Urological Association Symptom Index (AUA-SI) for BPH, this measure overlooks key symptoms such as pain and incontinence, underscoring the need for more comprehensive patient-reported outcome (PRO) tools. This study aims to integrate enhanced PROs into routine clinical practice to better capture the spectrum of LUTS, thereby improving clinical outcomes and patient care. Methods: This prospective observational study will recruit men with LUTS secondary to BPH aged ≥ 50 years from urology clinics. Participants will be stratified into medical and surgical management groups, with PRO assessments scheduled at regular intervals to monitor LUTS and other health outcomes. The study will employ the LURN Symptom Index (SI)-29 alongside the traditional AUA-SI and other non-urologic PROs to evaluate a broad range of symptoms. Data on comorbidities, symptom severity, and treatment efficacy will be collected through a combination of electronic health records and PROs. Analyses will focus on the predictive power of these tools in relation to symptom trajectories and treatment responses. Aims are to: (1) integrate routine clinical tests with PRO assessment to enhance screening, diagnosis, and management of patients with BPH; (2) examine psychometric properties of the LURN SIs, including test-retest reliability and establishment of clinically meaningful differences; and (3) create care-coordination recommendations to facilitate management of persistent symptoms and common comorbidities measured by PROs. Discussion: By employing comprehensive PRO measures, this study expects to refine symptom assessment and enhance treatment monitoring, potentially leading to improved personalized care strategies. The integration of these tools into clinical settings could revolutionize the management of LUTS/BPH by providing more nuanced insights into patient experiences and outcomes. The findings could have significant implications for clinical practices, potentially leading to updates in clinical guidelines and better health management strategies for men with LUTS/BPH. Trial registration: This study is registered in ClinicalTrials.gov (NCT05898932).

An observational, patient-reported outcome study of sleep quality and depression among individuals with overactive bladder syndrome.

INTRODUCTION: Overactive bladder (OAB) can adversely affect health-related quality-of-life (HRQoL) and adherence to treatments; however, the extent of their association is unknown. This study sought to characterize Sleep Disturbance, Depression, Fatigue, and patient-reported medication adherence among adults with OAB in the United States. MATERIALS AND METHODS: In this descriptive, observational study, patients completed patient-reported outcome (PRO) measures of urinary symptoms, anxiety, depression, fatigue, sleep quality, and medication adherence. PRO scores were compared across age, sex, body mass index, and sleep and antidepressant medication-taking subgroups. Exploratory analyses compared PRO scores between groups and estimated the effect size of differences. RESULTS: Of 1013 patients contacted, 159 completed the assessments (female: 67.3%; ≥65 years of age: 53.5%; most severe OAB symptom: nocturia). Scale scores for Sleep Disturbance, Fatigue, and Depression were consistent with US population norms. No correlations of moderate or greater magnitude were observed between the severity of lower urinary tract symptoms and Sleep Disturbance, Fatigue, or Depression. When comparing individuals receiving antidepressants with those who were not, almost all outcomes including urinary symptoms, anxiety, and depression were significantly worse. Patients taking antidepressants also had poorer adherence to their OAB medications. CONCLUSION: In this cohort of individuals with OAB, Sleep Disturbance, Fatigue, and Depression scores were in line with general population reference values; however, among the subgroups analyzed, patients on antidepressants had worse HRQoL and more substantial impacts on medication adherence, highlighting the importance of the assessment and management of depression in this population.

Aquablation versus TURP: 5-year outcomes of the WATER randomized clinical trial for prostate volumes 50-80 mL.

INTRODUCTION: To report the 5-year efficacy and safety of Aquablation compared with transurethral resection of the prostate for the management of lower urinary tract symptoms secondary to benign prostatic hyperplasia in men with prostate volumes 50-80 mL. MATERIALS AND METHODS: In a large double-blinded, multicenter, and prospective randomized controlled trial, 96 randomized men with 50-80 mL prostates who underwent Aquablation or transurethral prostate resection were prospectively identified for subgroup analysis. Follow up was performed for up to 5 years. The primary efficacy endpoint was the reduction in International Prostate Symptom Score (IPSS) at 6 months. The primary safety endpoint was the occurrence of Clavien-Dindo (CD) postoperative complications grade 1 persistent and grade 2 or higher at 3 months. RESULTS: Both groups had comparable baseline characteristics. Reduction in IPSS score was significantly higher in the Aquablation group across 5 years of follow up (-14.1 vs. -10.8, p = 0.02). The Aquablation group achieved a significantly lower rate of CD1P and CD2 or higher events at 3 months follow up (risk difference of -23.1%). Among recorded adverse events, de novo postoperative ejaculatory dysfunction was notably lower in Aquablation (risk difference of -21.9%), while the risk of bleeding remained similar after 6 months. The surgical and medical retreatment rate at 6 months was also lower in Aquablation (risk difference of -14.4%). CONCLUSIONS: In the 50-80 mL prostate volume subgroup, Aquablation yields superior long-term symptom relief and lower complication rates than standard transurethral resection, with notably lower rates of ejaculatory dysfunction. This further supports the adoption of Aquablation for men with medium-sized prostates.

Systematic review of reported association studies of monogenic genes and bladder cancer risk and confirmation analysis in a large population cohort.

Objectives: To evaluate which of previously reported monogenic genes are associated with increased bladder cancer risk, we reviewed published papers on associations of genes and bladder cancer risk and performed a confirmation study of these genes in a large population-based cohort. Subjects and methods: A systematic review of published papers prior to June 2022 was performed first to identify all genes where germline mutations were associated with bladder cancer risk. The associations of these candidate genes with bladder cancer risk were then tested among 1695 bladder cancer cases and 186 271 controls in the UK Biobank (UKB). The robust SKAT-O, a gene-based analysis that properly controls for type I error rates due to unbalanced case-control ratio, was used for association tests adjusting for age at recruitment, gender, smoking status, and genetic background. Results: The systematic review identified nine genes that were significantly associated with bladder cancer risk in at least one study (p < 0.05), including MUTYH, MSH2, MSH6, MLH1, ATM, BRCA2, ERCC5, TGFB1 and CHEK2. When pathogenic/likely pathogenic mutations were aggregated within each gene, the association was confirmed for three genes in the UKB at p < 0.0056 (Bonferroni correction for nine tests), including CHEK2, ATM and BRCA2, all also known to be associated with hereditary breast cancer. Suggestive evidence of association was found for two other genes, including MLH1 (p = 0.006) and MSH2 (p = 0.007), both known to be associated with Lynch syndrome. Among these five genes, the bladder cancer risks range from 1.60 (ATM) to 4.88 (MLH1), and mutation carrier rates in cases range from 0.06% (MSH2) to 2.01% (CHEK2). Conclusion: This study provides statistical evidence for association of previously reported genes and bladder cancer risk and has clinical utility for risk assessment and genetic counselling.

Phenotyping of Urinary Urgency Patients Without Urgency Incontinence, and Their Comparison to Urgency Incontinence Patients: Findings From the LURN Study.

PURPOSE: We characterize patients with urinary urgency with vs without urgency urinary incontinence who presented to clinics actively seeking treatment for their symptoms. MATERIALS AND METHODS: Participants who enrolled in the Symptoms of Lower Urinary Tract Dysfunction Research Network were categorized into urinary urgency with vs without urgency urinary incontinence. Participants were followed for 1 year; their urinary symptoms, urological pain, psychosocial factors, bowel function, sleep disturbance, physical activity levels, physical function, and quality of life were compared. Mixed effects linear regression models were used to examine the relationships between urgency urinary incontinence and these factors. RESULTS: Among 683 participants with urinary urgency at baseline, two-thirds (n=453) also had urgency urinary incontinence; one-third (n=230) had urinary urgency-only without urgency urinary incontinence. No differences were detected in urological pain between urinary urgency-only and urgency urinary incontinence. Those with urgency urinary incontinence had more severe urgency and frequency symptoms, higher depression, anxiety, perceived stress scores, more severe bowel dysfunction and sleep disturbance, lower physical activity levels, lower physical function, and worse quality of life than those with urinary urgency-only. Among those with urinary urgency-only at baseline, 40% continued to have urinary urgency-only, 15% progressed to urgency urinary incontinence, and 45% had no urgency at 12 months. Fifty-eight percent with urgency urinary incontinence at baseline continued to report urgency urinary incontinence at 12 months, while 15% improved to urinary urgency-only, and 27% had no urgency. CONCLUSIONS: Patients with urgency urinary incontinence have severe storage symptoms, more psychosocial symptoms, poorer physical functioning, and worse quality of life. Our data suggested urgency urinary incontinence may be a more severe manifestation of urinary urgency, rather than urinary urgency and urgency urinary incontinence being distinct entities.

The 10-item LURN Symptom Index (LURN SI-10) Detects Additional Symptoms and Shows Convergent Validity With the IPSS in Men Presenting With Lower Urinary Tract Symptoms.

OBJECTIVE: To determine how the LURN-SI-10, a novel questionnaire developed by the Symptoms of Lower Urinary Tract Dysfunction Research Network (LURN), compares with the International Prostate Symptom Score (IPSS) in men with lower urinary tract symptoms (LUTS) attributed to benign prostatic hyperplasia (BPH). Specifically, to assess convergent validity and determine how frequently the LURN-SI-10 identifies symptoms not captured by the IPSS. MATERIALS AND METHODS: Men presenting with BPH/LUTS were prospectively administered LURN-SI-10 and IPSS questionnaires. Urinary incontinence (UI) including post-void dribbling (PVD), urgency urinary incontinence (UUI), stress urinary incontinence (SUI), as well as bladder pain were considered present if the patient reported "about half the time or more" on LURN-SI-10. Correlations between LURN-SI-10 and IPSS were assessed as continuous and categorical variables. Multivariable linear regression analysis was performed to determine associations with symptom scores. RESULTS: LURN-SI-10 and IPSS were highly correlated in men with BPH/LUTS (r = 0.82, n = 429), as were respective bother and quality of life scores (ρ = 0.74). The LURN-SI-10 identified additional symptoms including PVD (24%), UUI (13%), SUI (2%), and pain (8%). Men with any UUI, SUI, or PVD had on average a 7.6-point higher LURN-SI-10 score than those without UI (P<.001) and 8.0-point higher IPSS score than those without UI (P<.001). CONCLUSION: The LURN-SI-10 correlates strongly with the IPSS, but the LURN-SI-10 identifies additional important symptomatology in men with LUTS. This additional information may improve the evaluation and treatment of men with BPH/LUTS. Further prospective studies of the LURN-SI-10 is warranted.

Subtyping of common complex diseases and disorders by integrating heterogeneous data. Identifying clusters among women with lower urinary tract symptoms in the LURN study.

We present a methodology for subtyping of persons with a common clinical symptom complex by integrating heterogeneous continuous and categorical data. We illustrate it by clustering women with lower urinary tract symptoms (LUTS), who represent a heterogeneous cohort with overlapping symptoms and multifactorial etiology. Data collected in the Symptoms of Lower Urinary Tract Dysfunction Research Network (LURN), a multi-center observational study, included self-reported urinary and non-urinary symptoms, bladder diaries, and physical examination data for 545 women. Heterogeneity in these multidimensional data required thorough and non-trivial preprocessing, including scaling by controls and weighting to mitigate data redundancy, while the various data types (continuous and categorical) required novel methodology using a weighted Tanimoto indices approach. Data domains only available on a subset of the cohort were integrated using a semi-supervised clustering approach. Novel contrast criterion for determination of the optimal number of clusters in consensus clustering was introduced and compared with existing criteria. Distinctiveness of the clusters was confirmed by using multiple criteria for cluster quality, and by testing for significantly different variables in pairwise comparisons of the clusters. Cluster dynamics were explored by analyzing longitudinal data at 3- and 12-month follow-up. Five clusters of women with LUTS were identified using the developed methodology. None of the clusters could be characterized by a single symptom, but rather by a distinct combination of symptoms with various levels of severity. Targeted proteomics of serum samples demonstrated that differentially abundant proteins and affected pathways are different across the clusters. The clinical relevance of the identified clusters is discussed and compared with the current conventional approaches to the evaluation of LUTS patients. The rationale and thought process are described for the selection of procedures for data preprocessing, clustering, and cluster evaluation. Suggestions are provided for minimum reporting requirements in publications utilizing clustering methodology with multiple heterogeneous data domains.

TNF is a potential therapeutic target to suppress prostatic inflammation and hyperplasia in autoimmune disease.

Autoimmune (AI) diseases can affect many organs; however, the prostate has not been considered to be a primary target of these systemic inflammatory processes. Here, we utilize medical record data, patient samples, and in vivo models to evaluate the impact of inflammation, as seen in AI diseases, on prostate tissue. Human and mouse tissues are used to examine whether systemic targeting of inflammation limits prostatic inflammation and hyperplasia. Evaluation of 112,152 medical records indicates that benign prostatic hyperplasia (BPH) prevalence is significantly higher among patients with AI diseases. Furthermore, treating these patients with tumor necrosis factor (TNF)-antagonists significantly decreases BPH incidence. Single-cell RNA-seq and in vitro assays suggest that macrophage-derived TNF stimulates BPH-derived fibroblast proliferation. TNF blockade significantly reduces epithelial hyperplasia, NFκB activation, and macrophage-mediated inflammation within prostate tissues. Together, these studies show that patients with AI diseases have a heightened susceptibility to BPH and that reducing inflammation with a therapeutic agent can suppress BPH.

How I do it: Aquablation in very large prostates (> 150 mL).

Aquablation has been well-studied in prostates sizes up to 150 mL. Recently, American Urological Association guidelines distinguish surgical interventions for men with large prostates (80 mL-150 mL) and now very large prostates (> 150 mL). Readers will gain an understanding of how to use Aquablation in the very large prostate size category.

Impact of Sleep Disturbance, Physical Function, Depression and Anxiety on Male Lower Urinary Tract Symptoms: Results from the Symptoms of Lower Urinary Tract Dysfunction Research Network (LURN).

PURPOSE: The impact of nonurological factors on male lower urinary tract symptoms (LUTS) remains unclear. We investigated cross-sectional and longitudinal associations among anxiety, depression, physical function, sleep quality and urinary symptom subdomains. MATERIALS AND METHODS: Data from 518 men in the LURN (Symptoms of Lower Urinary Tract Dysfunction Research Network) study were analyzed to identify associations between Patient-Reported Outcomes Measurement Information System® (PROMIS®) depression, anxiety, sleep disturbance and physical function measures and LUTS subdomains, as derived from the American Urological Association Symptom Index and LUTS Tool. Multivariable linear regression was used to assess the relationships between PROMIS measures and LUTS subdomains at baseline and at 3- and 12-month followup. RESULTS: Baseline depression and anxiety were associated with urinary incontinence (p <0.001), voiding symptoms (p <0.001) and quality of life (p=0.002), whereas baseline sleep disturbance was associated with voiding and storage symptoms and quality of life (p <0.001 for all). Urinary symptom severity improved in all subdomains at 3 and 12 months. Similar associations between PROMIS measures and LUTS subdomains were observed at all time points, but baseline depression, anxiety, sleep disturbance and physical function measures were not associated with longitudinal trajectories of LUTS. CONCLUSIONS: Urinary symptom subdomains are independently associated with modifiable clinical variables including sleep quality and depression at all time points, but these variables do not predict the degree of improvement in LUTS following urological evaluation and treatment over the medium term. Bidirectional assessment and randomized experiments may improve our understanding of these relationships.

Prostatic abscess due to blastomycosis.

Blastomycosis is an endemic infection caused by Blastomyces dermatitidis, found primarily in the southeastern, south-central, and Midwest United States. While the majority of infections typically present with pulmonary manifestations, they rarely present with symptoms isolated to the prostate. In order to better understand the clinical presentation, evaluation, and treatment of blastomycosis of the prostate, we present a 59-year-old male with urinary retention and lower urinary tract symptoms (LUTS).

Mutation signatures to Pan-Cancer Atlas: Investigation of the genomic landscape of muscle-invasive bladder cancer.

The Cancer Genome Atlas (TCGA) for bladder cancer was published in 2014 with updated annotation of over 400 patients with muscle-invasive bladder cancer (MIBC) in 2017. This tremendous work established the foundation of the genomic landscape of MIBC. The next steps to utilize information from The Cancer Genome Atlas is to (1) identify the causes of mutation, (2) determine the significant differences and sources of heterogeneity, and (3) apply these tools toward patient care. In this review, we discuss the full spectrum of the genomic landscape of MIBC toward the goal of therapeutic application.

Men with lower urinary tract symptoms secondary to BPH undergoing Aquablation with very large prostates (> 150 mL).

INTRODUCTION: The AUA guidelines for benign prostatic hyperplasia distinguish treatments based upon prostate volume (PV), particularly for very large prostates (> 150 mL). While the clinical outcomes and benefits of Aquablation have been studied for men with average and large prostates, it is unknown whether this technology can be used for very large prostates. MATERIALS AND METHODS: Men with PV > 150 mL undergoing Aquablation were identified retrospectively from four North American hospitals. The surgical times and clinical outcomes of men with very large prostates (> 150 mL) were compared to data from men with average PV ≤ 80 mL (WATER study) and large PV 80 mL-150 mL (WATER II study). RESULTS: The average PV of men who underwent Aquablation with very large prostates was 209 mL ± 56 (n = 34, range 151-362 mL), large PV 107 mL ± 20 (n = 101, range 80-150 mL) and average PV 54 mL ± 16 (n = 116, range 30-80 mL). For men with PV > 150 mL, baseline IPSS was 19 ± 6. With a mean follow up of 7 ± 9 months, the IPSS improved to 7 ± 5 (p < 0.001). Peak urinary flow rate, Qmax, improved from 7 ± 4 mL/s to 19 ± 5 mL/s (p<0.001). Compared to the two other PV groups, there were no differences in terms of improvements in IPSS, quality of life, or uroflowmetry. There were no reports of transfusions (0%) in the cohort of men with very large prostates. CONCLUSIONS: In the present study, we demonstrate that Aquablation is effective and safe in prostates greater than 150 mL while showing consistent outcomes compared to average and large prostates sizes.

Surgeon Scorecards Improve Muscle Sampling on Transurethral Resection of Bladder Tumor and Recurrence Outcomes in Patients with Nonmuscle Invasive Bladder Cancer.

PURPOSE: The presence of detrusor muscle is essential for accurate staging of T1 cancers. Detrusor muscle presence can be a quality indicator of transurethral resection of bladder tumor for nonmuscle invasive bladder cancer. We hypothesized that increasing surgeon awareness of personal and institutional detrusor muscle sampling rates could improve resection quality and long-term oncologic outcomes. MATERIALS AND METHODS: A retrospective review of transurethral resections of bladder tumor from 1/2006 to 2/2018 was performed. The presence of detrusor muscle in the pathology report and transurethral resection specimen were extracted from records. Individual surgeon scorecards were created and distributed. Rates of detrusor muscle sampling were compared prior to and 12 months after distribution. Chart review was done to compare 3-year recurrence and progression outcomes before and after distribution of scorecards. RESULTS: The rate of detrusor muscle sampling increased from 36% (1,250/3,488) to 54% (202/373) (p=0.001) in the 12 months after scorecard distribution, ie from 30% (448/1,500) to 55% (91/165) (p <0.001) in Ta tumors and from 47% (183/390) to 72% (42/58) (p <0.001) in T1 tumors. Pathological reporting of muscle also improved for all samples (73%, 2,530/3,488 to 90%, 334/373, p <0.001), Ta (75%, 1,127/1,500 to 94%, 155/165, p <0.001) and T1 (93%, 362/390 to 100%, 58/58, p=0.04). On multivariate Cox regression analysis, the surgeon scorecard was associated with decreased 3-year risk of recurrence (HR 0.63, 95% CI 0.40-0.99). CONCLUSIONS: Creation and distribution of individual surgeon scorecards improved detrusor muscle sampling on transurethral resection and was associated with decreased risk of disease recurrence. Quality evaluation of transurethral resection of bladder tumor may contribute to improved outcomes of patients with nonmuscle invasive bladder cancer.

Antibody targeting of B7-H4 enhances the immune response in urothelial carcinoma.

Patients with locally advanced and metastatic urothelial carcinoma have a low survival rate (median 15.7 months, 13.1-17.8), with only a 23% response rate to monotherapy treatment with anti-PDL1 checkpoint immunotherapy. To identify new therapeutic targets, we profiled the immune regulatory signatures during murine cancer development using the BBN carcinogen and identified an increase in the expression of the T cell inhibitory protein B7-H4 (VTCN1, B7S1, B7X). B7-H4 expression temporally correlated with decreased lymphocyte infiltration. While the increase in B7-H4 expression within the bladder by CD11b+ monocytes is shared with human cancers, B7-H4 expression has not been previously identified in other murine cancer models. Higher expression of B7-H4 was associated with worse survival in muscle-invasive bladder cancer in humans, and increased B7-H4 expression was identified in luminal and luminal-papillary subtypes of bladder cancer. Evaluation of B7-H4 by single-cell RNA-Seq and immune mass cytometry of human bladder tumors found that B7-H4 is expressed in both the epithelium of urothelial carcinoma and CD68+ macrophages within the tumor. To investigate the function of B7-H4, treatment of human monocyte and T cell co-cultures with a B7-H4 blocking antibody resulted in enhanced IFN-γ secretion by CD4+ and CD8+ T cells. Additionally, anti-B7-H4 antibody treatment of BBN-carcinogen bladder cancers resulted in decreased tumor size, increased CD8+ T cell infiltration within the bladder, and a complimentary decrease in tumor-infiltrating T regulatory cells (Tregs). Furthermore, treatment with a combination of anti-PD-1 and anti-B7-H4 antibodies resulted in a significant reduction in tumor stage, a reduction in tumor size, and an increased level of tumor necrosis. These findings suggest that antibodies targeting B7-H4 may be a viable strategy for bladder cancers unresponsive to PD-1 checkpoint inhibitors.