Serum-based Test Research Articles

Developing a Novel Non-invasive Serum-based Diagnostic Test for Early Detection of Colorectal Cancer

Abstract Introduction/Objective Colorectal cancer (CRC) is the third-most common cancer worldwide, and early detection is vital for successful treatment and improved outcomes. Current screening methods such as colonoscopy, fecal occult blood tests, and stool DNA tests have limitations such as patient discomfort, cost, and low sensitivity and specificity most commonly diagnosed cancer worldwide with a high mortality rate. Early detection remains a crucial factor in reducing the burden of CRC. Currently, the gold standard for CRC diagnosis is colonoscopy, but it may not be feasible for widespread screening due to its invasiveness, cost, and patient compliance issues. Therefore, there is a great need to identify reliable biomarkers that can detect CRC at an early stage. This study aimed to evaluate the effectiveness of updated novel biomarkers for early detection of CRC. Methods/Case Report This study was conducted on 158 patients with suspected or confirmed CRC. The study population included patients of both genders, aged above 18 years, and with a history of CRC or other relevant risk factors. Blood samples were collected from all included patients, and the biomarkers (CTCS, miRNAs, ctDNA, and Methylated DNA markers ) were measured using enzyme-linked immunosorbent assay (ELISA) and polymerase chain reaction (PCR) tests. Novel biomarkers compared their diagnostic performance with existing biomarkers such as fecal occult blood tests (FOBTs), fecal immunochemical tests (FITs), and CEA. Results (if a Case Study enter NA) The studied biomarkers (CTCs, microRNAs, ctDNA, and Methylated DNA markers) have high sensitivity from 78.8 % to 96.72% and accuracy from 83.76% to 94.83% as well as their cut-off which approved the objective of this study. Overall, these novel biomarkers show promise for early detection of colorectal cancer and may improve screening and early detection efforts. Conclusion The evaluation of the studied biomarkers (Circulating Tumor Cells, microRNAs, Circulating tumor DNA, and Methylated DNA markers) for early detection of CRC has substantial clinical and public health implications. The identification of reliable biomarkers for CRC screening can avoid unnecessary colonoscopies, reduce the burden on healthcare costs, and improve the detection of early-stage CRC.

A-364 The Utility of the Highly Sensitive Detection System for Immunochromatographic Assay by Addition of MPC polymer

Abstract Background Immunochromatographic assay (ICA) is frequently used as a point-of-care testing (POCT) in the field of infectious diseases, but it has a problem of low detection sensitivity. Many interfering substances in ICA test materials have been reported to case a decrease in detection sensitivity. For the purpose of increasing the sensitivity of ICA, bovine serum albumin or a polymer with phosphorylcholine groups (MPC polymer) has been used as an additive to a sample diluent. In this study, we evaluated the usability of the sensitizing effect for the addition of MPC polymer with a serum-based HBs antigen test kit. Methods A 2-fold dilution series of a commercially available control serum (Infectrol D, SeraCare Life Sciences, Inc. manufacturer's reference value 108.674 IU/mL) containing 0.05%, 0.10%, 0.5% of several MPC polymers (Biolipidure® from NOF Corporation) as final concentration were prepared with HBs antigen negative serum. The optimal type of MPC polymer and the concentrations added to the sera were determined by comparing the color intensity of their test lines in the evaluation of each test sample with a commercially available test kit (Quick Chaser® from MIZUHO MEDY Co., Ltd.). The color intensities of the test lines were quantified with an immunochromatographic reader. In addition, the correlation of two different test kits (ESPLINE® from FUJIREBIO and Quick Chaser® from MIZUHO MEDY Co., Ltd.) was evaluated with sera obtained from HBs antigen-positive patients regarding the three types of MPC polymer which were improved the detection sensitivity in the evaluation with the control serum. The measurements were performed in triplicate after 0.5% of MPC polymer as final concentration was added to each diluted serum. Results Antigen amount for diluted sera with MPC polymer were determined by CLEIA method, and no difference in the antigen amount was observed regardless of the addition or the types of MPC polymer. In addition, the color intensity in each dilution series was compared to the cutoff value, which is average value of the color intensity of negative control serum without MPC polymer. In the evaluation with control serum, the test line in the case without MPC polymer enabled to detect up to 2-fold diluted control serum while the test line in the case with MPC polymer enabled to detect up to 32-fold diluted control serum. The addition of MPC polymer in the evaluation with sera obtained from HBs antigen-positive patients was also confirmed that the detection sensitivity enhanced up to 8-fold higher in ESPLINE® and up to 4-fold higher in Quick Chaser®. Conclusion The color intensity of the test line enhanced by the addition of MPC polymer. In particular, when the highly hydrophilic and anionic MPC polymer was added, the test line was detected narrower and darker, and we believe that the increased color intensity resulted in improved sensitivity. By considering the influence of interfering substances in clinical materials and the physical properties of the MPC polymer (hydrophobicity, molecular size, etc.), it is expected that the sensitivity of the ICA will be increased to be more suitable for clinical materials.

Abstract 3346: Evaluation of a serum-based test integrating tumor tissue and gut microbiome derived metabolites for diagnosis of advanced colorectal adenoma

Abstract Background: Detection and endoscopic excision of colorectal precancerous lesions (advanced adenoma, AA) has been recognized as an effective way to prevent the occurrence of colorectal cancer (CRC) and reduce CRC induced mortality. Current DNA-based (mutations or methylations) tests exhibited compromised efficiency for AA diagnosis due to the late appearance of tumor-derived DNA biomarkers into stool or blood samples during tumorigenesis. Here, by integrating metabolic biomarkers associated with tumor tissue and colorectal neoplasia related gut microbiota, we established the serum metabolites-based test and examined its ability to detect advanced adenoma patients from normal, hyperplastic polyps and low-risk adenoma individuals. Methods: Consensus participants undergoing coloscopy were enrolled in this prospective study, and the result of colonoscope examination and histopathology from biopsied lesions were used as gold standard (ChiCTR2200058078). Serum metabolites were quantified by pseudo-targeted metabolomics based on LC-MS/MS method. By integrating abundances of these serum metabolites associated with tumor tissue and colorectal neoplasia related gut microbiota, a diagnostic model was established, and its performance for detecting advanced adenoma was validated using leave-one-out cross-validation. Results: In total, 803 participants, including 178 normal individuals, 167 patients with hyperplastic polyps, 203 patients with low-risk colorectal adenoma and 255 advanced colorectal adenoma patients, were enrolled in this study and subjected to the serum metabolites-based test. The diagnostic model achieved an AUC of 0.80 (95% CI: 0.77-0.83) for advanced adenoma, with a sensitivity of 44.7% at 88.9% specificity. Additionally, we also separately analyzed its performances for advanced adenoma with different histological subtypes, achieving a sensitivity of 37.0% for tubulous adenoma and a sensitivity of 53.3% for adenoma with villous structure, respectively. As for advanced adenoma with high-grade dysplasia, the model could achieve a sensitivity of 61.2%. In comparation, sensitivities of all current tests for advanced colorectal adenoma, either fecal or blood based, were less than 45% at a similar specificity. Conclusions: Based on integrating metabolic biomarkers associated with both tumor tissue and colorectal neoplasia related gut microbiota, we developed a novel blood-based test that can detect advanced colorectal adenoma with higher accuracy than all current fecal or blood-based tests. Citation Format: Jingyuan Xiang, Longsong Li, Xingting Guo, Xiaowei Li, Kai Lin, Liuyang Yang, Xudong Dai, Enqiang Linghu, Ningli Chai. Evaluation of a serum-based test integrating tumor tissue and gut microbiome derived metabolites for diagnosis of advanced colorectal adenoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 3346.

MP17-07 VALIDATION OF MICHECK PROSTATE FOR SIGNIFICANT PROSTATE CANCER IN AN AUSTRALIAN POPULATION

You have accessJournal of UrologyCME1 Apr 2023MP17-07 VALIDATION OF MICHECK PROSTATE FOR SIGNIFICANT PROSTATE CANCER IN AN AUSTRALIAN POPULATION David Gillatt, Dmitry Polikarpov, Ian Smith, Howard Lau, Lawrence Kim, Chi Can Huynh, Kheng Sit Lim, Jaya Siddireddy, Yanling Lu, Ninantao Deng, Douglas Campbell, Brad Walsh, and Manish Patel David GillattDavid Gillatt More articles by this author , Dmitry PolikarpovDmitry Polikarpov More articles by this author , Ian SmithIan Smith More articles by this author , Howard LauHoward Lau More articles by this author , Lawrence KimLawrence Kim More articles by this author , Chi Can HuynhChi Can Huynh More articles by this author , Kheng Sit LimKheng Sit Lim More articles by this author , Jaya SiddireddyJaya Siddireddy More articles by this author , Yanling LuYanling Lu More articles by this author , Ninantao DengNinantao Deng More articles by this author , Douglas CampbellDouglas Campbell More articles by this author , Brad WalshBrad Walsh More articles by this author , and Manish PatelManish Patel More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000003237.07AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: PSA screening and multi parametric MRI are widely used to identify patients with suspected prostate cancer who may benefit from prostate biopsy. Patients with PIRADs scores 3-5 are typically biopsied, however up to 17% of patients with PIRADs scores of 1-2 will harbour clinically significant cancers that would remain undiagnosed using these criteria, while up to 80% of PIRADs 3 patients do not have clinically significant cancers. Hence there is a requirement for additional tests better able to guide prostate biopsy decisions. MiCheck Prostate is a serum-based test for aggressive prostate cancer (GS3+4 or higher) developed by Minomic International that uses a proprietary algorithm to combine results from three standard blood markers with clinical factors to provide a risk score for clinically significant cancer. The current study was designed to assess the test performance of MiCheck Prostate in an Australian study cohort. METHODS: The study was conducted at Macquarie University Hospital (MUH, Ethics approval 5201500707). Serum samples were collected from patients undergoing prostate biopsies. Blood markers were measured at Douglass Hanley Moir (DHM) laboratories using Abbott Architect and Alinity immunoassays. RESULTS: 192 patient samples were collected: 78 (41%) had no cancer, 37 (19%) had insignificant cancer (Gleason 3+3) and 77 (40%) had Gleason 3+4 or higher. 2 (1%) patients had PIRADs 1, 16 (8%) had PIRADS 2, 23 (12%) PIRADs 3, 88 (46%) had PIRADs 4 and 55 (29%) had PIRADs 5 and 8 (4%) patients had no PIRADs data. When used prior to MRI, MiCheck Prostate had 92% sensitivity for detection of clinically significant cancers. The AUC for MiCheck Prostate was significantly higher than PSA (0.71 vs 0.58, p=0.03). When used post MRI, MiCheck Prostate showed sensitivity of 94% and specificity of 39% for detection of significant prostate cancer in the overall patient population. The AUC for MiCheck Prostate was significantly higher than PSA (0.79 vs 0.58, p<0.0001). In 49 patients with PIRADs score of 3 or lower, MiCheck Prostate showed sensitivity of 92% and specificity of 65%, with NPV of 96%. CONCLUSIONS: The current study demonstrates MiCheck Prostate has high sensitivity for detection of significant prostate cancer in an Australian population. MiCheck Prostate has high sensitivity in both the pre-MRI and post-MRI settings as well as in the PIRADs 1-3 subgroup. MiCheck Prostate provides additional information to urologists and patients in the decision to proceed to prostate biopsy with patients suspected of having prostate cancer. Source of Funding: Minomic International Ltd, Australian Government SIEF © 2023 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 209Issue Supplement 4April 2023Page: e215 Advertisement Copyright & Permissions© 2023 by American Urological Association Education and Research, Inc.MetricsAuthor Information David Gillatt More articles by this author Dmitry Polikarpov More articles by this author Ian Smith More articles by this author Howard Lau More articles by this author Lawrence Kim More articles by this author Chi Can Huynh More articles by this author Kheng Sit Lim More articles by this author Jaya Siddireddy More articles by this author Yanling Lu More articles by this author Ninantao Deng More articles by this author Douglas Campbell More articles by this author Brad Walsh More articles by this author Manish Patel More articles by this author Expand All Advertisement PDF downloadLoading ...

Serum non-coding RNAs for diagnosis and stage of liver fibrosis.

BackgroundAll chronic liver diseases could lead to liver fibrosis. Accurate diagnosis and stage of fibrosis were important for the medical determination, management, and therapy. Liver biopsy was considered to be the gold criteria of fibrosis diagnosis. However, liver biopsy was an invasive method with some drawbacks. Non‐invasive tests for liver fibrosis included radiologic method and serum‐based test. Radiologic examination was influenced by obesity, cost, and availability. Serum‐based test was widely used in the screening and diagnostic of liver fibrosis. However, the accuracy was still needed to be improved.MethodsRecent studies showed serum non‐coding RNAs: microRNA, long non‐coding RNA(lncRNA), and circular RNA(circRNA), which have the potentiality to be non‐invasive markers for liver fibrosis. The recent progress was summarized in this review.ResultsThese studies showed serum non‐coding RNAs exerted a good diagnostic performance for liver fibrosis. A panel that included several non‐coding RNAs could increase the accuracy of single marker.ConclusionsSerum microRNAs, lncRNAs, and circRNAs could be potential non‐invasive markers for diagnosis and stage of liver fibrosis. More high‐quality clinical study is needed for further research.

Abstract 520: Potential role of serum proteome in predicting immune-related adverse events from immunotherapy in non-small cell lung cancer

Abstract Early recognition of immune-related adverse events (irAEs) of immunotherapy is important. Circulating proteome reflects host response to diseases and is being explored as a marker for response to immunotherapy. We used a serum-based proteomics test, Primary Immune Response (PIR), to explore the associations between developing irAEs and immunotherapy in non-small cell lung cancer (NSCLC) patients. Data of 38 consented NSCLC patients with baseline PIR test done within one week prior to the start of immunotherapy were collected. Samples were grouped into either sensitive or intermediate/resistant (not sensitive) by PIR classification. We analyzed the durations from the immunotherapy initiation to the first episode of irAE, each individual irAE, and each irAE above grade 1 using log-rank test. IrAEs were graded according to Common Terminology Criteria for Adverse Events (CTCAE) v5.0. Among the 38 NSCLC patients, 21 patients (55%) experienced one or more irAEs. The total number of irAEs was 33 with the majority classified as either grade 1 (n=18, 55%) or grade 2 (n=11, 33%) (Table 1). PIR-sensitive group showed longer irAE free period with the median ‘Time to first irAE' being 54 weeks compared to 9.5 weeks in PIR-not sensitive (p=0.22, HR=0.56, 95% CI=0.24-1.34). The median ‘Time to each irAE' were 45 weeks and 12 weeks in PIR-sensitive and PIR-not sensitive, respectively (p=0.1, HR=0.55, 95% CI=0.28-1.1). The median ‘Time to each irAE above grade 1' demonstrated similar results with less differences between the two groups with median values of 54 weeks and 30 weeks in PIR-sensitive and PIR-not sensitive, respectively (p=0.28, HR=0.57, 95% CI=0.21-1.56). Our results demonstrated a trend that PIR-sensitive patients are more likely to tolerate immunotherapy longer without developing irAEs. It implies the potential value of the baseline PIR test in predicting the development of irAEs and selecting subsets of patients who need close monitoring with immunotherapy. Distribution of irAEs by PIR classificationVariablesSensitiveNot-sensitiveTotal number of patients, n1325Patients without irAE, n (%)7 (54%)10 (40%)Patients with irAE, n (%)6 (46%)15 (60%)Total number of irAEs, n1023Grade 1, n (%)5 (50%)13 (57%)Grade 2, n (%)5 (50%)6 (26%)Grade 3, n (%)02 (8%)Grade 4, n (%)01 (4%)Grade 5, n (%)01 (4%) Citation Format: Myungwoo Nam, Leeseul Kim, William Cheng, William H. Bae, Jin Young Hwang, Yoonhee Choi, Yeun Ho Lee, Won Kyung Hur, Chan Mi Jung, Heayoon S. Cho, Young Kwang Chae. Potential role of serum proteome in predicting immune-related adverse events from immunotherapy in non-small cell lung cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 520.

Potential role of serum proteome in predicting immune-related adverse events from immune checkpoint inhibitors in non-small cell lung cancer.

e21218 Background: Early recognition of immune-related adverse events (irAEs) of immune checkpoint inhibitors(ICI) is important. Circulating proteome reflects host response to diseases and is being explored as a marker for response to immunotherapy. We previously have reported that a serum-based proteomics test, Primary Immune Response (PIR) demonstrated a trend that PIR-sensitive patients are more likely to tolerate ICI treatment longer without developing irAEs in non-small cell lung cancer (NSCLC) patients. The VeriStrat test is another serum-based proteomic assay, which was reported to be predictive of survival outcomes for all treatment regimens and lines of therapy including ICI in NSCLC. We explored the associations between the VeriStrat test and developing irAEs in NSCLC patients treated with ICI. Methods: Data of 70 consented NSCLC patients treated with any regimens and lines of therapy including ICI were collected. Samples were grouped into either VeriStrat ‘Good’(VS-G) or VeriStrat ‘Poor’(VS-P). We analyzed the durations from the immunotherapy initiation to each episode of irAE and each irAE above grade 2 using log-rank test. IrAEs were graded according to Common Terminology Criteria for Adverse Events (CTCAE) v5.0. Results: Among the 70 patients, 18 patients (25%) experienced one or more irAEs. There was no significant difference in ‘Time to first irAE’ between VS-G and VS-P (p = 0.72, HR = 0.82, 95% CI = 0.29-2.32). Among 48 VS-G patients, 12(25%) had one or more irAE and 5(10%)had irAE graded over 2. Among 22 VS-P patients, 6(27%) had one or more irAE and 2(9%) had irAE graded over 2. There was no significant difference between VS-G and VS-P groups in the development of irAE and irAE graded over 2. Conclusions: There was no statistically significant association between the VeriStrat test and the development of irAEs. Further studies are warranted to investigate proper serum based proteomic assay to predict the development of irAE.

Blood-based biomarker analysis in high PD-L1 expressing NSCLC treated with PD-1/PD-L1 based therapy with or without the addition of platinum-based chemotherapy.

TPS9126 Background: Immunotherapy directed against the programmed death-1 / ligand-1 (PD-1/L1) axis has revolutionized the treatment of advanced non-small cell lung cancer (aNSCLC). Tumor PD-L1 is currently the only biomarker validated for predicting patient response to front line PD-1/L1 directed immunotherapy, yet 20% of patients with ≥50% PD-L1 expression die within six months of starting therapy (Reck et al. 2016). Blood-based agents such as autoantibodies and circulating inflammatory biomarkers have stratified patient outcomes on anti-PD-1/L1 immunotherapy in preliminary studies (Tarhoni, Kollipara et al. 2019; Tarhoni, Fidler et al. 2019). Moreover, a serum-based proteomic test that uses mass spectrometry and machine learning to provide three classifications (Good, Intermediate and Poor) has stratified non-treatment naïve aNSLCC patients treated with nivolumab based on their outcomes (Mueller et al. 2020) and identified a subset of patients who progressed rapidly. This study will evaluate these blood-based biomarkers as predictors of response and early progression in patients with &gt;50% PD-L1 positive aNSCLC treated with immunotherapy regimens. Methods: This is a prospective, observational, multicenter study (NCT04676386) designed to assess biomarkers (serum and plasma) as predictive of early progression in 390 patients with aNSCLC treated with anti-PD 1/PD-L1 immunotherapy with or without platinum-based chemotherapy. Key eligibility criteria are treatment naïve aNSCLC with tumor biopsy PD-L1 tumor proportion score &gt; 50%, Eastern Cooperative Oncology Group performance status (ECOG PS) 0-2, and ability to consent to participate. Prior to enrollment, tumor specimens will be tested for PD-L1 expression according to participating centers’ standard operating procedures. For each treatment cohort of 195 patients, enrollment will proceed in sub-cohorts to ensure a population with 20% patients with ECOG PS2 and a total of 40 patients with squamous cell carcinoma per treatment arm. Patients will be followed for a maximum of 3 years. Blood draw for biomarker assessment will be performed prior to treatment initiation, start of 3rd cycle and investigator assessed progression. Biomarker analysis will be performed retrospectively. As a secondary objective, this study will evaluate proteomic test performance in predicting early overall survival (OS) and rapid progression, and in stratifying patient survival and response. Exploratory analyses will correlate baseline and serial circulating protein analytes and autoantibodies with the proteomic test, response measures (RECIST 1.1) and toxicities. Enrollment opened in February 2021. Clinical trial information: NCT04676386.

Evaluation of a serum-based antigen test for tuberculosis in HIV-exposed infants: a diagnostic accuracy study

BackgroundNon-sputum methods are urgently needed to improve tuberculosis diagnosis and treatment monitoring in children. This study evaluated the ability of a serum assay quantifying a species-specific peptide of the Mycobacterium tuberculosis CFP-10 virulence factor via nanotechnology and matrix-assisted laser desorption ionization time-of-flight mass spectrometry to diagnose tuberculosis in HIV-infected and HIV-uninfected infants.MethodsSerum CFP-10 peptide signal was blinded evaluated in cryopreserved sera of 519 BCG-immunized, HIV-exposed infants (284 HIV-infected, 235 HIV-uninfected) from a multi-center randomized placebo-controlled isoniazid prophylaxis trial conducted in southern Africa between 2004 and 2008, who were followed up to 192 weeks for Mtb infection and TB. Children were classified as confirmed, unconfirmed, or unlikely tuberculosis cases using 2015 NIH diagnostic criteria for pediatric TB.ResultsIn HIV-infected infants, CFP-10 signal had 100% sensitivity for confirmed TB (5/5, 95% CI, 47.8–100) and 83.7% sensitivity for unconfirmed TB (36/43, 95% CI 69.3–93.2), with 93.1% specificity (203/218, 95% CI 88.9–96.1). In HIV-uninfected infants, CFP-10 signal detected the single confirmed TB case and 75.0% of unconfirmed TB cases (15/20; 95% CI 50.9–91.3), with 96.2% specificity (177/184, 95% CI, 92.3–98.5). Serum CFP-10 achieved 77% diagnostic sensitivity for confirmed and unconfirmed TB (13/17, 95% CI, 50–93%) at ≤ 24 weeks pre-diagnosis, and both CFP-10-positivity and concentration declined following anti-TB therapy initiation.ConclusionsSerum CFP-10 signal exhibited high diagnostic sensitivity and specificity for tuberculosis in HIV-infected and HIV-uninfected infants and potential utility for early TB detection and monitoring of anti-TB treatment responses.

Detection of hypoglycin A and MCPA‐carnitine in equine serum and muscle tissue: Optimisation and validation of a LC‐MS–based method without derivatisation

Measurement of hypoglycin A (HGA) and its toxic metabolite, methylenecyclopropylacetic acid (MCPA), in equine serum confirms a diagnosis of atypical myopathy (AM), a pasture-associated toxic rhabdomyolysis with high mortality linked to the ingestion of Acer trees plant material. Supportive diagnostic tests include plasma acyl-carnitine profiling and urine organic acid testing, but these are not specific for AM. Previously reported HGA and MCPA analytical techniques used liquid chromatography-mass spectrometry (LC-MS) with a derivatising step, but the latter prolongs testing and increases costs. To develop a rapid LCMS method for detection of serum and tissue HGA and MCPA that enables expedited diagnosis for horses with AM. Analytical test validation. Validation parameters to industry standards using as criteria precision, accuracy, linearity, reproducibility and stability in analyte-spiked samples were calculated on 9-calibration points and 3 different validation concentrations in both serum and muscle tissue. The test was successfully validated for the detection of HGA and MCPA-carnitine in equine serum and muscle. Test linearity was excellent (r2 =.999), accuracy was very good for both analytes (93%-108%), precision did not exceed 10% coefficient of variation and reproducibility met the requirements of the Horwitz equation. Stability was unaffected by storage at a range of temperatures. The spectrum of the tested analytes was limited to only two relevant analytes in favour of a quick and easy analysis. Linearity of the muscle method was not evaluated as calibration curves were not produced in this matrix. We report an optimised, simplified and validated method for detection of HGA and MCPA-carnitine in equine serum and muscle suitable for rapid diagnosis of suspected AM cases. The serum-based test should also enable risk assessment of toxin exposure in cograzing horses and assessment of horses with undiagnosed myopathies, while the tissue detection test should help to confirm cases post-mortem and to determine toxin distribution, metabolism and clearance across different tissues.

Evaluation of novel serological markers and autoantibodies in dogs with inflammatory bowel disease.

BackgroundThe use of serological markers to diagnose inflammatory bowel disease (IBD) in humans is well‐established. Because of the frequency of IBD in dogs and resources required for its diagnosis with current methods, new approaches are desired.ObjectiveThe goal is to evaluate novel serologic markers to differentiate clinical cohorts in dogs with gastrointestinal (GI) disease and assess their potential to develop a serum‐based IBD diagnostic test.AnimalsSeventy dogs diagnosed with biopsy‐confirmed IBD, 23 dogs with non‐IBD predominantly acute GI diseases, and 58 normal dogs.MethodsProspective control study. ELISA methods were developed to detect autoantibodies to polymorphonuclear leukocytes (APMNA) and calprotectin (ACNA), antibodies against gliadins (AGA), microbial outer membrane porin C (ACA), and flagellins (AFA) isolated from diseased dogs based on clinical and histopathological scoring.ResultsIBD dogs displayed a 39%‐76% prevalence of seropositivity against selected serologic markers that markedly decreased to 0%‐13% in non‐IBD and normal dogs. ROC analysis showed statistical significance in differentiating the cohorts, with seropositivity against OmpC being the highest single performance marker. The combination of markers such as OmpC and APMNA reached specificities of 93%‐99% and 79%‐98% and sensitivities of 76%‐97% and 66%‐86% when comparing IBD versus normal cohorts and non‐IBD cohorts, respectively.Conclusion and Clinical ImportanceSeropositivity of canine immunoglobulins A against selected serologic markers in dogs appears promising in the detection and differentiation of IBD versus other acute GI conditions. Among them, antibody reactivity to Escherichia coli OmpC and canine autoantibodies against polymorphonuclear leukocytes displayed the highest single marker discriminating performance.

A multicentric evaluation of dipstick test for serodiagnosis of visceral leishmaniasis in India, Nepal, Sri Lanka, Brazil, Ethiopia and Spain

Visceral leishmaniasis (VL) is one of the leading infectious diseases affecting developing countries. Colloidal gold-based diagnostic tests are rapid tools to detect blood/serum antibodies for VL diagnosis. Lack of uniformity in the performance of these tests in different endemic regions is a hurdle in early disease diagnosis. This study is designed to validate a serum-based dipstick test in eight centres of six countries, India, Nepal, Sri Lanka, Brazil, Ethiopia and Spain with archived and fresh sera from 1003 subjects. The dipstick detects antibodies against Leishmania donovani membrane antigens (LAg). The overall sensitivity and specificity of the test with 95% confidence intervals were found to be 97.10% and 93.44%, respectively. The test showed good sensitivity and specificity in the Indian subcontinent (>95%). In Brazil, Ethiopia, and Spain the sensitivity and specificity of the dipstick test (83.78–100% and 79.06–100%) were better as compared to the earlier reports of the performance of rK39 rapid test in these regions. Interestingly, less cross-reactivity was found with the cutaneous form of the disease in Spain, Brazil, and Sri Lanka demonstrating 91.58% specificity. This dipstick test can therefore be a useful tool for diagnosing VL from other symptomatically similar diseases and against cutaneous form of leishmaniasis.

Abstract 3352: Cost-effectiveness of current and potential serum based colorectal screening strategies: Can a serum based test do better

Abstract Background: Despite efficacy of colorectal cancer (CRC) screening, recent trends in screening rates have not improved. Furthermore, national society recommendations have not prioritized a single screening modality. Both flexible sigmoidoscopy (Flex-Sig) and guaiac fecal occult blood test (gFOBT)) have been recommended. Studies suggest that noninvasive tests may improve screening rates, however, compliance remains modest for such tests. A recent study found that health system transition from gFOBT to a fecal immunochemical test (FIT) moderately improved test compliance rates. However, FIT is an expensive substitute for gFOBT and sensitivity of fecal based tests for precursor lesions in the colon remain inferior to structural examinations. Serum-based blood tests (SBT) may provide higher compliance rates, but necessary accuracy for such a test to be a dominant or cost-effective screening strategy over current recommendations have not been determined. This study analyzed the cost-effectiveness of multiple CRC screening strategies and estimated minimum test characteristics of a hypothetical SBT to be a preferred screening strategy over current modalities. Methods: A Markov microsimulation model was developed to analyze the costs and effects, (quality-adjusted life-years, QALYs) of CRC screening following a hypothetical cohort of 10,000 individuals at age 50 until death. Our model considered three strategies: 1) initial colonoscopy followed by Flex-Sig every 5 years, 2) initial colonoscopy with yearly gFOBT, and 3) initial colonoscopy with yearly FIT. An initial colonoscopy with a hypothetical yearly SBT was also examined at a range of test sensitivities. A long-term payer perspective was assumed for professional and facility costs and lifetime costs of cancer treatment. Model probabilities and utility values were obtained from the literature or calculated from National Vital Statistics Reports. Results: Annual gFOBT was the least costly strategy ($3,242) while annual FIT was eliminated through extended dominance. Flex-Sig was the costliest strategy at $4,667 but had the highest expected QALYs at 19.68. The incremental cost-effectiveness ratio (ICER) of Flex-Sig relative to gFOBT was $35,615. Our secondary analysis demonstrated that a minimum joint sensitivity of 70% and 60% is required for an SBT at 80% and 100% compliance rates, respectively, to achieve extended dominance of both Flex-Sig and FIT by SBT and gFOBT. ICER’s of SBT ranged from $12,984 to $4,779 in these sensitivity ranges compared to gFOBT with expected QALYs as high as 19.96. Total individual costs in the model varied from $365 to $111,535. Conclusion: With improved sensitivity and high compliance rates, annual screening for CRC via a non-invasive SBT is a cost-effective approach compared to structural examinations and currently recommended gFOBT and FIT. Citation Format: Ali Jalali, Richard Nelson, Raminder Nirula. Cost-effectiveness of current and potential serum based colorectal screening strategies: Can a serum based test do better [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 3352.

Assessment of a Commercially Available Serum Pregnancy-Specific Protein B Test in Free-Ranging Elk (Cervus canadensis) in Pennsylvania, USA

Uterine examinations provide an inexpensive and reliable postmortem alternative to monitor pregnancy rates in free-ranging elk (Cervus canadensis). However, this technique may be insensitive during early pregnancies (i.e., <20 d postconception), relies on proper collection of tissues, and may not be comparable to antemortem approaches used throughout the rest of the year. To circumvent some of these issues, the sensitivity and specificity of a commercially available serum pregnancy-specific protein B (PSPB) enzyme-linked immunosorbent assay (ELISA) was determined relative to uterine examination. From 2013 to 2017, paired serum samples and uteri were collected from 245 harvested free-ranging cow elk in Pennsylvania, US in November. Uteri were examined to determine whether the cow was pregnant, and, if so, gestation age was estimated based on embryo crown-rump (CR) length. The serum PSPB ELISA testing was then performed. Since harvested elk could not be retested, samples with optical densities close to the threshold for pregnancy determination (i.e., high-recheck samples) were considered as both not pregnant and pregnant, and analyses were performed separately under each scenario. Overall, the PSPB ELISA had a sensitivity of 95% (high-recheck considered pregnant) and 93% (high-recheck considered not pregnant), and a specificity of 91% (high-recheck considered pregnant) and 93% (high-recheck considered not pregnant) relative to uterine examinations. Based on CR length, gestation age was <14 to 55 d. Our results indicated the PSPB ELISA was an accurate serum-based pregnancy test for elk.

04 DIAGNOSTIC ACCURACY OF THE SERUM-BASED MUCOSAL HEALING INDEX ASSAY IN CROHN’S DISEASE AND COMPARATIVE ACCURACY TO FECAL CALPROTECTIN IN ROUTINE PRACTICE

Biomarker-based management improves outcomes in Crohn’s disease (CD) compared to symptoms alone, but existing biomarkers have limitations. We assessed the diagnostic performance of the Mucosal Healing Index (MHI; PROMETHEUS MonitrTM) for detecting mucosal inflammation in CD. Serum, stool, and blinded disease activity data (clinical, endoscopic and histologic) were used from a prospectively maintained single-center biobank. MHI diagnostic accuracy (area under the receiver operating curve: AUROC) was assessed for endoscopic remission (ER; SES-CD ≤2, ≤1 per segment) and MH (ER + histologic remission: GHAS≤2) and were compared to fecal calprotectin (FC). Responsiveness (Spearman’s correlations) was assessed for changes in MHI, FC, and symptoms, to SES-CD. 211 patients with 290 endoscopic assessments were included. Symptom based indices had high diagnostic misclassification rates. AUROC estimates for the MHI were 0.70 for ER (95%CI 0.64-0.76) and 0.69 for MH (95%CI 0.59-0.79). The established MHI cutoff (>50) had 100% specificity for confirmation of mucosal inflammation. An MHI cutoff of 20 had 83% sensitivity for excluding mucosal inflammation. The comparative diagnostic accuracy of MHI to FC using matched samples (119 assessments) was not significantly different (ER: AUROC 0.78 vs. 0.84, p=0.35; MH: AUROC 0.76 vs. 0.80, p=0.61). MHI was responsive to changes in SESCD (r = 0.34, p=0.01), whereas symptoms (r = 0.18, p=0.42) and FC were not (r =0.17, p=0.61). The MHI, a serum-based biomarker test for CD, has good diagnostic accuracy for mucosal inflammation, was comparable to FC, and was responsive to changes in endoscopic disease activity. Further studies should validate comparative responsiveness between MHI, FC and symptoms. Sensitivity, Specificity, Positive and Negative Likelihood Ratios for MHI

04 DIAGNOSTIC ACCURACY OF THE SERUM-BASED MUCOSAL HEALING INDEX ASSAY IN CROHN’S DISEASE AND COMPARATIVE ACCURACY TO FECAL CALPROTECTIN IN ROUTINE PRACTICE

Biomarker-based management improves outcomes in Crohn’s disease (CD) compared to symptoms alone, but existing biomarkers have limitations. We assessed the diagnostic performance of the Mucosal Healing Index (MHI; PROMETHEUS MonitrTM) for detecting mucosal inflammation in CD. Serum, stool, and blinded disease activity data (clinical, endoscopic and histologic) were used from a prospectively maintained single-center biobank. MHI diagnostic accuracy (area under the receiver operating curve: AUROC) was assessed for endoscopic remission (ER; SES-CD ≤2, ≤1 per segment) and MH (ER + histologic remission: GHAS≤2) and were compared to fecal calprotectin (FC). Responsiveness (Spearman’s correlations) was assessed for changes in MHI, FC, and symptoms, to SES-CD. 211 patients with 290 endoscopic assessments were included. Symptom based indices had high diagnostic misclassification rates. AUROC estimates for the MHI were 0.70 for ER (95%CI 0.64-0.76) and 0.69 for MH (95%CI 0.59-0.79). The established MHI cutoff (>50) had 100% specificity for confirmation of mucosal inflammation. An MHI cutoff of 20 had 83% sensitivity for excluding mucosal inflammation. The comparative diagnostic accuracy of MHI to FC using matched samples (119 assessments) was not significantly different (ER: AUROC 0.78 vs. 0.84, p=0.35; MH: AUROC 0.76 vs. 0.80, p=0.61). MHI was responsive to changes in SESCD (r = 0.34, p=0.01), whereas symptoms (r = 0.18, p=0.42) and FC were not (r =0.17, p=0.61). The MHI, a serum-based biomarker test for CD, has good diagnostic accuracy for mucosal inflammation, was comparable to FC, and was responsive to changes in endoscopic disease activity. Further studies should validate comparative responsiveness between MHI, FC and symptoms.

Assessment of Advanced Liver Fibrosis and the Risk for Hepatic Decompensation in Patients With Congestive Hepatopathy.

Congestive hepatopathy (CH) arises from chronically elevated right-sided heart pressures transmitted to the liver by passive venous congestion. Over time, CH can lead to hepatic bridging fibrosis, decompensated cirrhosis, and hepatocellular carcinoma. Currently, there are no evidence-based guidelines to direct appropriate screening or management of patients with CH, partly because of the inability of current clinical tools (serum tests, imaging studies, liver stiffness measurements, and liver biopsy) to accurately estimate hepatic fibrosis or the risk for hepatic decompensation. The Model for End-Stage Liver Disease excluding international normalized ratio (MELD-XI) score is the only validated serum-based test to predict clinical outcomes in CH. Noninvasive liver stiffness measurements are proving to be of minimal utility as all patients with CH have elevated values that currently cannot differentiate between congestion and fibrosis. In addition, fibrosis staging by liver biopsy is difficult to standardize because of heterogeneous collagen deposition in CH. Moreover, liver biopsy results have little predictive value for post-heart transplant hepatic outcomes in patients with CH. Evaluating liver nodules and masses is also complicated in CH as the finding of delayed venous washout in nodules is not specific for hepatocellular carcinoma in the background of a congested liver, and these lesions may require biopsy to confirm the diagnosis. The lack of effective clinical tools for predicting liver fibrosis and liver function suggests the need for the development of novel biomarkers in patients with CH to assist in the management of this complicated disease. (Hepatology 2018; 00:000-000).

Health economic evaluation of a serum-based blood test for brain tumour diagnosis: exploration of two clinical scenarios

ObjectivesTo determine the potential costs and health benefits of a serum-based spectroscopic triage tool for brain tumours, which could be developed to reduce diagnostic delays in the current clinical pathway.DesignA...

MicroRNA-371a-3p as informative biomarker for the follow-up of testicular germ cell cancer patients

Purposeα-fetoprotein (AFP) and human chorionic gonadotropin subunit beta (B-HCG) are informative serum biomarkers for the primary diagnosis and follow-up of testicular germ cell cancer (TGCC) patients. About 20% of TGCC patients with a non-seminoma (NS) and about 80% with a seminoma (SE) are, however, negative for these biomarkers. Embryonic stem cell microRNAs (miRs) may serve as promising alternative serum biomarkers. Here we investigated a retrospective series of serum samples from selected TGCC patients who developed a relapse in time to test the possible additional value of the serum-based ampTSmiR test compared to the conventional serum-based protein biomarkers for follow-up.MethodsWe investigated 261 retrospective serum samples of six selected fully evaluated TGCC patients with a proven relapse using the ampTSmiR test for miR-371a-3p, miR-373-3p, and miR-367-3p and compared the results to those of the conventional protein biomarkers.ResultsAt primary diagnosis, elevated serum B-HCG, AFP and LDH levels were found to be informative in 4/6, 3/6 and 3/6 patients, respectively. At primary diagnosis the levels of miR-371a-3p and miR-373-3p were elevated in 4/4, and miR-367-3p in 3/4 patients. For two cases no starting serum sample was available for retrospective miR analysis. Residual disease (overlooked by histopathological examination) was detected in one case by miR-371a-3p only. The miR-371a-3p level was increased in one patient two months before detection of an intracranial metastasis. B-HCG was informative in 3/4 and the ampTSmiR test in 4/4 patients with a relapse or residual disease. None of the biomarkers were informative for the detection of residual mature teratoma.ConclusionsThe ampTSmiR test is more sensitive than the conventional TGCC protein biomarkers for the detection of residual disease and relapse, excluding mature teratoma.

P-279 - Metabolomics-based test accurately detects and differentiates adenomatous polyps from human sera

Introduction: Most colorectal cancers are believed to originate from adenomatous polyps that acquire distinct mutations and accumulate other molecular alterations that allow them to progress through distinct histopathologic stages before becoming invasive carcinomas. Adenomatous polyp detection and removal is the ultimate goal of colon cancer screening programs. However not all adenomas have the same potential to progress into carcinomas and thus a test that could detect more advanced adenomas with high sensitivity but could also separate advanced and non-advanced adenomas could be useful for screening purposes. The aim of our study was to show that metabolomic technology can be successfully used to distinguish persons with advanced adenomatous polyps from those without adenomas and the use of the technology could be further used for separation of patients with advanced adenomas from patients with non-advanced adenomas with potential to sub-categorization patients according to their pathological severity. Methods: Prospective serum samples were collected from 131 participants undergoing colonoscopy examination in a colon cancer screening program, from April 2016 to December 2016 at the Hospital Clínic de Barcelona. Colonoscopy reference standard identified 35 participants with no colonic polyps, 12 patients with hyperplastic polyps, 45 patients with non-advanced adenomas and 38 patients with advanced colonic adenomatous polyps. Mass-spectrometry based metabolite and lipid profiles were analysed to define a predictive metabolomic profile for advanced colonic adenomas and confirm if advanced adenoma patients could be separated from non-advanced adenoma patients. Serum metabolomic diagnostic test accuracy was defined for advanced colonic adenomatous polyps using Monte-Carlo 50-fold cross-validation with 70% samples used in a training and 30% of the samples in the validation set. Results: Using random forest algorithm on the metabolomic profile we could identify patients with colonic advanced adenomatous polyps from control patients with 87% sensitivity and 73% specificity. Additionally we could achieve identification of advanced adenoma patients from extended control set that included also patients with hyperplastic polyps and non-advanced adenomas with sensitivity of 81% and specificity of 70%. Additionally we could see clear distinction between advanced and non-advanced adenomas with sensitivity of 80% and specificity of 80%. Classification improvements could be observed even further when classifying adenomas into sub-groups according to severity of the pathology. Conclusion: We describe a proof-of-concept for serum-based metabolomic test that identifies patients with advanced adenomatous polyps with good level of sensitivity (87%) and allows distinction between advanced and non-advanced adenomas with sensitivity of 80% and allows further classification of different adenoma sub-groups according to their pathological severity.