Development of an interstitial cystitis risk score for bladder permeability

RESEARCH ARTICLE Development of an interstitial cystitis risk score for bladder permeability Laura E. Lamb1,2, Joseph J. Janicki3, Sarah N. Bartolone1, Kenneth M. Peters1,2, Michael B. Chancellor1,2* 1 Department of Urology, Beaumont Health System, Royal Oak, MI, United States of America, 2 Oakland University William Beaumont School of Medicine, Rochester Hills, MI, United States of America, 3 Underactive Bladder Foundation, Pittsburgh, PA, United States of America a1111111111 a1111111111 a1111111111 a1111111111 a1111111111 * Abstract Background OPEN ACCESS Citation: Lamb LE, Janicki JJ, Bartolone SN, Peters KM, Chancellor MB (2017) Development of an interstitial cystitis risk score for bladder permeability. PLoS ONE 12(10): e0185686. https:// doi.org/10.1371/journal.pone.0185686 Interstitial cystitis/bladder pain syndrome (IC) is a multifactorial syndrome of severe pelvic and genitalia pain and compromised urinary function; a subset of IC patients present with Hunner’s lesions or ulcers on their bladder walls (UIC). UIC is diagnosed by cystoscopy, which may be quite painful. The objective of this study was to determine if a calculated Bladder Permeability Defect Risk Score (BP-RS) based on non-invasive urinary cytokines could discriminate UIC patients from controls and IC patients without Hunner’s ulcers. Editor: Jayoung Kim, Cedars-Sinai Medical Center, UNITED STATES Received: April 13, 2017 Accepted: September 18, 2017 Published: October 31, 2017 Copyright: © 2017 Lamb et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Data Availability Statement: The data associated with this paper are available upon request for interested researchers from Dr. Graham Krasan, chair of Beaumont Health’s Institutional Review Board at 1-248-551-0662 or at graham. . Funding: This work is supported by the Taubman Research Fund. The funders had no role in the study design, data collection and analysis, decision to publish, or preparation of the manuscript. Methods A national crowdsourcing effort targeted IC patients and age-matched controls to provide urine samples. Urinary cytokine levels for GRO, IL-6, and IL-8 were determined using a Luminex assay. Results We collected 448 urine samples from 46 states consisting of 153 IC patients (147 female, 6 male), of which 54 UIC patients (50 females, 4 male), 159 female controls, and 136 male controls. A defined BP-RS was calculated to classify UIC, or a bladder permeability defect etiology, with 89% validity. Conclusions The BP-RS Score quantifies UIC risk, indicative of a bladder permeability defect etiology in a subset of IC patients. The Bladder Permeability Defect Risk Score is the first validated urine biomarker assay for interstitial cystitis/bladder pain syndrome. Competing interests: LEL, JJJ, and MBC have intellectual property associated with methods for PLOS ONE | https://doi.org/10.1371/journal.pone.0185686 October 31, 2017 1 / 15 Interstitial cystitis urine biomarker score diagnosing interstitial cystitis. All other authors have declared no conflicts of interest exist. This does not alter our adherence to PLOS ONE policies on sharing data and materials. Introduction Interstitial cystitis/bladder pain syndrome (IC) is a chronic, severely debilitating disease of the bladder characterized by urinary frequency and urgency, and severe suprapubic, external genitalia, and/or pelvic pain [1]. IC severely compromises sexual function, employment, and quality of life. The estimated prevalence of IC in the U.S. is between 3–8 million women and 1–4 million men [2–4]. Approximately 10% of IC patients present with Hunner’s lesions or ulcers (UIC), distinct areas of inflammation on the bladder wall. UIC is usually associated with more severe symptoms and changes in the urothelium that suggest increased bladder permeability [5]. UIC can often be diagnosed by cystoscopy with hydrodistension demonstrating the distinct inflammatory lesions typically on the dome or lateral sidewalls of the bladder [6]. Cystoscopy can be painful in the patient with UIC. Most often, Hunner’s ulcers are identified during a diagnostic hydrodistention under general or regional anesthesia. Some patients may experience painful urination, hematuria, urinary tract infection, and rare risk of bladder wall perforation. Identifying and treating Hunner’s lesions allows the clinician to use bladder directed therapies such as electrocautery, resection, or injection of these lesions with steroids. In an effort to limit invasive testing and to meaningfully classify IC patients, we sought to determine if a urine based test could be developed to distinguish UIC from IC without Hunner’s lesions (NUIC). We focused on urinary cytokines given our past expertise and the standardized methodology [7]. Several groups, including ours, have previously published on several urine based proteins that are altered in IC and UIC. Many of these studies focused on IC and did not specifically include UIC. Several investigations have focused on increased activity of anti-proliferative factor (measured by inhibition of thymidine incorporation), increased epidermal growth factor, and decreased heparin-binding epidermal growth factor-like growth factor (HB-EGF) in IC [8–11]. Pro-inflammatory interleukin (IL)-6 has been reported to be increased in IC patients and has been positively associated with pain scores [8, 12–14]. IL-8 has also been reported in some studies to be increased in IC [8, 14]. Ogawa et al demonstrated differential expression of several mRNAs in the bladder urothelium of UIC compared to controls, including CXCR3 binding chemokine and TNFSF14 [15]. Recently, metabolite etiocholan-3α-ol-17-one sulfate (Etio-S) has been described as a potential IC biomarker for females [16]. Others have been reviewed by Kuo et al [17]. However, none of these possible biomarkers have been used successfully in the clinic thus far due to 1) overlap between controls, NUIC, and UIC and 2) difficulty of implementing the assay methodology [18]. Lastly, the urine samples for these studies were collected at academic centers where they could be immediately spun down and frozen for shipment and storage prior to analysis. This cold chain processing may not always be feasible, thus a solution where urine samples could be collected, shipped, and stored at room temperature without prior centrifugation would be ideal. There is currently no commercially available test for IC or UIC. There are several innovations with this study. First, we validated a urine preservative method that allowed storage and shipment at ambient temperature. Second, we developed a crowdsource model in which participants collected and shipped urine samples to our laboratory toward joint development of an IC biomarker. Third, we used a machine learning (...truncated)