Blood-based Assay Research Articles

Abstract 4621: Beyond tumor biomarkers: Multiparametric biophysical assessment of T cells from peripheral blood to inform checkpoint blockade therapy

Abstract Clinical decisions for immune checkpoint blockade (ICB) treatment currently rely on tumor-based biomarkers such as mutational burden, microsatellite instability, and PD-L1 expression. While these markers serve as valuable proxies for tumor antigenicity and the immune status of the tumor microenvironment, they fail to account for the fitness of a patient’s T cells, a critical factor in anti-tumor immunity. Direct assessment of T cell functional capacity could complement existing biomarkers to improve patient stratification and efficacy prediction for ICB therapies. Our previous work showed that single-cell mass measurements serve as a label-free means of assessing immune cell activation and ICB response. T cells from patients with various malignancies displayed significant variability in both their activation capacity and ICB response ex vivo, indicating that mass measurements capture key functional differences in T cells across patients.Here we present a next-generation platform that measures cell mass alongside linked measurements of volume, density, and morphological features. This platform incorporates fluorescence exclusion measurements to determine single-cell volume which, when combined with cell mass, enables precise determination of single-cell density. Additionally, we utilize inline brightfield imaging to capture images from individual cells and extract morphological features using an autoencoder-based reconstruction model.Our results show that multiparametric measurements significantly enhance the ability to characterize T cell functional states. In activation experiments using healthy donor T cells, these combined signatures reveal notable phenotypic changes as early as six hours after activation—changes that remain undetectable with mass measurements alone.In a cohort of peripheral blood samples from patients with advanced melanoma, we observed substantial heterogeneity in T cell biophysical signatures at baseline and following stimulation, with and without immune checkpoint blockade. These signatures were distinct from those observed in T cells derived from healthy donor PBMCs.These findings underscore the potential of a blood-based functional precision medicine assay to assess patients' baseline immune fitness. When integrated with existing clinical biomarkers, these unique functional signatures offer orthogonal insights that could improve patient stratification for immune checkpoint inhibitor therapies. Moreover, the multiparametric nature of these measurements aligns well with emerging multimodal AI approaches, paving the way for more effective identification of patients most likely to benefit from these treatments. Citation Format: Robert Kimmerling, Selim Olcum, Mark Stevens, Rachel LaBella, Madeleine Vacha, Katelin Katsis, Reginald Aikins, Steven Wasserman, Tatyana Sharova, Aleigha Lawless, Sonia Cohen, Genevieve Boland. Beyond tumor biomarkers: Multiparametric biophysical assessment of T cells from peripheral blood to inform checkpoint blockade therapy [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2025; Part 1 (Regular Abstracts); 2025 Apr 25-30; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2025;85(8_Suppl_1):Abstract nr 4621.

Abstract 4101: Blood based biomarkers of DNA methylation associated with platinum resistance in high grade serous ovarian cancer

Abstract High grade serous ovarian cancer (OC) is initially a responsive tumor to platinum (Pt)-based therapy. Tumor suppressor genes (TSGs) are implicated in OC initiation and progression and can be inactivated through genetic or epigenetic events. DNA methylation has been shown to silence TSGs and other cancer-related genes and is detectable in cancer cells and in blood. Here we aimed to develop a blood-based methylation assay associated with cancer and cancer recurrence in OC. We evaluated genome-wide DNA methylation in de-identified peripheral blood mononuclear cells (PBMCs) from women: without cancer (controls, n=20), newly diagnosed OC (prior to treatment, Pt-sensitive, n=50), and platinum-resistant recurrent HGSOC before and after treatment with a hypomethylating agent (HMA, Pt-resistant, n=31). The Pt-resistant patients were enrolled on NCT02901899 clinical trial testing guadecitabine and pembrolizumab. DNA extracted from PBMCs was analyzed by using Infinium MethylationEPIC BeadChips. DNA methylation analysis used R package SeSAMe to derive beta (β) values and identify differential methylated loci (DMLs) and differential methylated regions (DMRs) between groups. Bioinformatics analysis was conducted to identify biological pathways and processes, determined using Ingenuity Pathway Analysis (IPA) and KEGG, GO:BP, REAC databases. Deconvolution analyses used the HEpiDISH algorithm to determine the cellular make-up of the samples. Comparing controls vs. Pt-sensitive groups, there were 30, 369 DMLs (adj. p<0.05, β>10%), with most loci being demethylated. Enriched pathways related to presence of cancer included: mechanisms of cancer, neutrophil degranulation, and cancer-related signaling pathways (PI3K/AKT, STAT3, HGF, interleukins). The number of DMLs was greater (880, adj. p<0.05, β>10%) in Pt-resistant vs Pt-sensitive and enriched pathways associated with Pt-resistant OC included: pathways in cancer, metabolic pathways, platelet activation, ABC transporters and signaling pathways (calcium, PI3K/AKT, MAPK, Ras, ErbB, Hippo, Wnt). Massive genome-wide hypomethylation 5 days after treatment with the HMA was seen (13, 742, adj. p<0.05, β>10%), consistent with observed LINE1 hypomethylation in PBMCs, and genome-wide hypomethylation persisted 30 days after end of HMA treatment. Enriched pathways among hypomethylated genes included: Th17 cell differentiation, virus infection, focal adhesion, signaling (chemokine, cGMP-PKG, Rap1) and hormone (thyroid, parathyroid, oxytocin, growth hormone) pathways. Deconvolution analysis identified decreased B and NK cells, monocytes, and eosinophils and a trend towards decreased CD4+ and CD8+ cells in Pt-sensitive OC vs controls. In contrast, neutrophils were increased in cancer vs control patients. We propose new DMLs associated with Pt-sensitive vs. Pt-resistant OC. These findings can lead to new biomarkers for HGSOC. Citation Format: Daniela Matei, Horacio Cardenas, Elnaz Abbasi Farid, Zhen Fu, Collin M. Coon, Adam Vieth, Kenneth P. Nephew. Blood based biomarkers of DNA methylation associated with platinum resistance in high grade serous ovarian cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2025; Part 1 (Regular Abstracts); 2025 Apr 25-30; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2025;85(8_Suppl_1):Abstract nr 4101.

Abstract 6511: Immunocompetent large animal model of mesenchymal glioblastoma achieved through somatic gene editing technology

Glioblastoma multiforme (GBM) is the most common primary brain tumor. GBM tumors are invasive and highly proliferative, with less than 3% of patients surviving five years from initial diagnosis. Current standard of care treatment consists of surgical resection, radiation, and chemotherapy, and despite this aggressive treatment, nearly all patients succumb to disease recurrence. GBM tumors have heterogeneity, high mutation rates, infiltrating growth, and a complicated tumor-immune microenvironment making treatments difficult and complex. Additionally, therapies must cross the blood brain barrier, a significant problem preventing therapeutic efficacy. Novel drugs, promising therapeutic targets, and new targeting strategies frequently fail in late Phase 2 and Phase 3 clinical trials due to lack of efficacy. The therapies often show effectiveness in a subset of patients, but fail in the majority, leading to clinical trial failure. Because GBM clinical trials are not enrolled based on patient specific biomarkers or genetic subtypes, precision medicine approaches have faced an uphill battle for a patient population that is too small for multiple concurrent clinical trials and a disease with a severe lack of predictive preclinical models. GBM tumors fall into three subtypes, mesenchymal, classical and proneural, each with distinct genetic profiles. Variations in progression and survival and differences in therapeutic response suggest that each subtype should be treated with a regimen unique to that subtype. Roughly 30-50% of GBMs are characterized as mesenchymal, the most common and aggressive subtype. In this study, we demonstrate the development of a large animal (mini pig), immunocompetent model of mesenchymal GBM, using stereotactic delivery of gene editing reagents. 50% of injected animals rapidly develop reproducible tumors that genetically and immunologically resemble human tumors, making this an ideal preclinical model for therapeutic development and biomarker identification. Importantly, tumors can be detected within weeks of injection through a simple, cost-effective blood-based assay. Cell lines developed from these tumors show temozolomide sensitivity and provide an opportunity for high throughput drug screening prior to animal trials. Therillume is utilizing these animals to identify, develop, and validate novel drugs, prognostic and diagnostic biomarkers, therapeutic devices, and effective drug delivery strategies. In particular, Therillume has focused on identifying targeted therapies that previously failed in clinical trials, despite showing efficacy in a subset of patients, and validating the safety and efficacy of these therapies in animals that have a companion biomarker that predicts therapeutic efficacy, in hopes of developing new strategies for clinical trials that will enable biomarker-driven therapeutic development and success. Citation Format: Nicholas Koes, Mandy Taisto, Barbara R. Tschida, Daniel F. Carlson, Maryam Aftabizadeh, H Nayanga Thirimanne, Eric C. Holland, Massimo D'Apuzzo, Christine E. Brown, Adrienne L. Watson. Immunocompetent large animal model of mesenchymal glioblastoma achieved through somatic gene editing technology [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2025; Part 1 (Regular Abstracts); 2025 Apr 25-30; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2025;85(8_Suppl_1):Abstract nr 6511.

Real-world clinical utility of a multi-protein, blood-based biomarker assay for disease activity assessments in multiple sclerosis

Background Blood-based biomarkers have emerged as promising tools to optimize treatment decisions in multiple sclerosis (MS) including initiation, switch, or cessation of disease modifying therapies. Objectives The clinically validated MS disease activity (MSDA) test measures 18 proteins to derive a disease activity score. This study tests the clinical utility of MSDA in real-world practice. Methods Twenty clinicians from 14 clinics conducted a chart review utilizing a retrospective, longitudinal design, with a pre-post component. Chart reviews captured clinician decision-making before and after receipt of each MSDA result, while separate clinician assessments also captured the perceived impact of MSDA on MS management. Results A total of 352 charts were reviewed. The overall rate of clinical decision changes after MSDA testing (19.4%) exceeded predefined benchmarks. The proportion of patient time points where clinicians “strongly agreed” or “agreed” that MSDA results influenced their decision-making was greater when multiple longitudinal MSDA results were available compared to a single result: 69.2% (95%CI: [60.2%, 78.3%) vs. 59.8% (95%CI: [43.7%, 76.0%]), respectively. Conclusion When used in addition to standard of care, MSDA demonstrates clinical utility for real-world decision-making in MS management, based on objective changes in treatment plan and clinician - reported impact, which increases with longitudinal use.

Blood Biochemical Biomarkers in Fish Toxicology-A Review.

Blood-based biochemical assays are used as predictive and diagnostic methods to evaluate fish welfare in aquaculture and research. The variations of blood biochemical parameters in fish are commonly used as biomarkers of exposure to toxic agents. Blood biochemical parameters can help identify the magnitude of toxicity and the mechanisms by which particular toxic agents act on the organisms. Some parameters typically measured in the blood can also be evaluated in the whole body in the early developmental stages of fish (embryos and larvae) that are often used in toxicological studies. This review assessed the usefulness of various blood biochemical indices as toxicity biomarkers. Analysis of multiple studies showed that toxicity-induced changes in most blood biochemical parameters in fish often depend on toxic agent concentration and exposure duration. Also, various parameters manifest different sensitivity to intoxication, and diverse directions of changes may occur. Among biochemical parameters, some are biomarkers of general physiological stress, while others indicate dysfunctions of particular organs. Moreover, hormonal endpoints seem to be sensitive but nonspecific biomarkers of intoxication in fish.

A Blood-Based Assay for Detection of Patients with Advanced Adenomas.

Blood-based screening for colorectal cancer could improve testing uptake and outcomes. We propose novel methods to detect AAs in plasma using cfDNA fragmentation patterns, cancer-associated proteins, and aneuploidy with high specificity. Larger studies are needed to validate clinical utility.

Proof-of-principle of a technology transfer of a dried blood virus neutralisation assay to a Gavi-eligible country

BackgroundGlobal health clinical research is commonly led by high-income countries (HICs) as low- and middle-income countries (LMICs) face barriers to participate, including lack of financial and human capacity and lack...

Clinicopathological predictors of the presence of blood circulating tumor DNA in early-stage non-small cell lung cancers.

Clinicopathological predictors of the presence of blood circulating tumor DNA in early-stage non-small cell lung cancers.

Highlighting factors contributing to pregnancy loss in beef cattle

Pregnancy loss in beef cattle remains a costly problem for producers, leading to diminished calf crop uniformity and reduced percentages of cows with a calf at the end of calving season. Although several tools exist to ascertain pregnancy status, the first 30 days of pregnancy encompasses the period with the greatest proportion of pregnancy losses and these losses often occur before traditional methods permit pregnancy determination. The ability to accurately predict pregnancy failure remains a major limitation. Blood-based assays detecting chemical changes in maternal circulation have provided insight into embryonic and fetal monitoring and are used to make predictions for pregnancy loss. Although there are certain unknown aspects to the etiology of pregnancy loss, there is growing body of work to identify physiological biomarkers within the maternal, paternal, and embryonic systems to clarify risk factors for pregnancy failure. This review highlights a few of the factors contributing to pregnancy loss and the rapidly evolving methods utilized to predict pregnancy failure. Further, this review highlights a few of the changes to parental physiology after exposure to various environmental factors, the consequences on the physiology of pregnancy and the likelihood of pregnancy success.

Evaluation of EpiSwitch in predicting immunotherapy response in hepatocellular carcinoma and gastrointestinal tumors.

623 Background: The EpiSwitch Checkpoint Inhibitor Response Test (CiRT) is a blood-based assay that analyzes DNA conformations in immune cells to predict responses to immune checkpoint inhibitors (ICIs) targeting PD-L1/PD-1. CiRT has demonstrated superior predictive accuracy compared to traditional biomarkers, such as tumor mutational burden (TMB) and PD-L1 immunohistochemistry (IHC), for predicting responses in urothelial cancer (ESMO 2022). However, its role in hepatocellular carcinoma (HCC) and other gastrointestinal (GI) tumors remains unclear. As immunotherapy becomes more common in these cancers, identifying reliable predictive biomarkers is essential to optimize treatment outcomes. Methods: This retrospective study evaluates CiRT-predicted immunotherapy responses and clinical outcomes in patients with HCC and GI tumors, including cholangiocarcinoma, pancreatic adenocarcinoma, and gastric cancer. All patients received one or more lines of immunotherapy. CiRT responses were categorized into high probability (HP) and low probability (LP). Treatment response was assessed per RECIST 1.1 criteria. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), overall survival (OS), and progression-free survival (PFS) were analyzed. Results: 43 patients (24 HP, 19 LP) were included. HCC patients (n = 33) received varied immunotherapy regimens, such as combinations of bevacizumab with atezolizumab, tremelimumab with durvalumab, and nivolumab with ipilimumab. Non-HCC patients (n = 10) received combinations of immunotherapy and chemotherapy such as durvalumab with cisplatin and gemcitabine and nivolumab with oxaliplatin and capecitabine. Across all patients, CiRT revealed a sensitivity of 73.91%, a specificity of 65%, a PPV of 70.83%, and an NPV of 68.42%. In HCC, sensitivity was 70.59% and specificity was 68.75%. In non-HCC, sensitivity was 83.33% and specificity 50%. HP responders showed better treatment outcomes compared to LP responders, with higher rates of complete response (CR: 12.5% vs 0%), partial response (PR: 29.2% vs 21.1%), and stable disease (SD: 29.2% vs 10.5%), and a lower rate of progressive disease (PD: 29.2% vs 68.4%) (p = 0.0467). Overall, 70.83% of HP achieved CR, PR, or SD vs. 31.58% of LP (p = 0.0098). PFS was significantly better in HP (p = 0.044, Log-rank test; median PFS = 2.0 months for the LP group, mPFS not reached for the HP group). No statistically significant OS difference was noted due to the lack of events in the HP group. Conclusions: CiRT HP status was associated with improved response rates to immunotherapy, longer PFS, and better treatment outcomes in HCC and GI tumors. HP responders experienced notably better outcomes, suggesting that CiRT could serve as a promising predictive biomarker for immunotherapy response, addressing a critical unmet need for reliable biomarkers to treat HCC and other GI tumors.

Targeting tau in Alzheimer's and beyond: Insights into pathology and therapeutic strategies.

Targeting tau in Alzheimer's and beyond: Insights into pathology and therapeutic strategies.

A liquid biopsy analysis of exosomal miRNA to detect lymph node metastasis in early gastric cancer.

469 Background: Additional surgical resection is required to achieve a complete cure in patients with early gastric cancer (EGC) due to the potential risk for lymph node metastasis (LNM) after pathological analysis. However, LNM is estimated to occur in approximately 10% of patients with high-risk EGC. In this study, we investigated a blood-based liquid biopsy assay of exosomal miRNA for the noninvasive detection of LNM in patients with high-risk EGC. Methods: Two genome-wide miRNA expression profiling datasets (GSE164174 and TCGA) were analyzed to prioritize biomarkers in pretreatment plasma samples from clinical training and validation cohorts of GC patients. An integrated exosomal miRNA panel was developed and a risk stratification model combining the miRNA panel with clinical risk factors was established. Results: Using comprehensive expression profiling of public datasets, we identified a transcriptomic panel of four miRNAs (miR-34b, miR-130a, miR-375, and miR-627) that robustly identified patients with LNM [area under the curve (AUC) = 0.86, 95% confidence interval (CI) = 0.77-0.92]. We assessed panel performance in a training cohort (AUC=0.86, 95% CI=0.67-0.96) and validated it in an independent validation cohort (AUC=0.84, 95% CI=0.64-0.95). Our risk stratification model was more accurate than the panel and was an independent predictor of LNM identification (AUC=0.97). Conclusions: A novel noninvasive, liquid biopsy-based method for patients with EGC may predict those traditionally classified as high-risk patients with LNM who are unlikely to benefit from surgical resection.

A protein-based blood panel test for the early detection of colorectal cancer and advanced neoplasia.

46 Background: Early detection of colorectal cancer (CRC) is key to survival. CRC screening compliance is still low because of either the invasive procedure (colonoscopy) or the so-called "ick factor" (stool-based tests). Stool-based tests also lack ability to detect advanced adenoma (CRC precursor). A blood-based test could improve adherence to screening guidelines, but no one has so far been recommended due to a lack of sufficient sensitivity and specificity. Here we report the potential clinical utility of a blood-based biomarker panel providing high sensitivity (SE) and specificity (SP) for CRC and advanced adenomas (AA) as a screening triage option addressing positive patients to colonoscopy. Methods: A total of 241 retrospective serum samples (179 CRC, 22 adenoma, 40 healthy controls) were obtained from the Cooperative Human Tissue Network (CHTN) biobank and tested with a proprietary sandwich ELISA that detects dual CRC specific biomarkers (BF7 and CC3). A standard curve was generated and biomarkers concentration in the samples were calculated using a 4-parameter logistic method. The median biomarker concentration values in each patient group were compared to determine whether differences were statistically significant (p< 0.05). Statistical analysis of two-group and multi-group comparisons was carried out using the non-parametric Mann-Whitney U test and the Kruskal-Wallis test, respectively. Receiver operating characteristic (ROC) curves were calculated to evaluate the diagnostic performance, by determining sensitivity (SE), specificity (SP), area under the curve (AUC), and confidence interval (CI). Statistical analysis, ROC curves and scatter plots were performed with GraphPad Prism 7.0. Results: Both biomarker's median concentration difference between CRC versus healthy samples groups were found to be statistically significant (p<0.05). Both biomarkers were also elevated in AA as compared to healthy samples, but difference in median concentration was only statistically significant for CC3 (p<0.0001). BF7 serum levels in cancer patients were significantly associated with TMN stage (p=0.019), N stage (p=0.039) and M stage (p=0.0006). No significant associations were found between this biomarker levels and other clinical characteristics of the CRC patients including age. Our test discriminated CRC (all stages) from healthy individuals with a SE of 80% and a SP of 90%. Sensitivity for early (n=95) and late-stage CRC (n=80) was 79% and 84%, respectively. Our test was also able to detect 81% of serum from advanced adenoma patients who are at increased risk of CRC. Conclusions: This study illustrates the potential clinical utility of our blood-based assay for the early detection of CRC which has a better sensitivity for advanced adenoma than tests in current clinical use. A large prospective cohort study is planned to further validate the clinical performance of this test.

P0640 Development and characterization of LQ080, a novel extended half-life bispecific TL1A/IL-23 p19 single domain antibody for the treatment of IBD

Abstract Background Despite the effectiveness of current anti-TL1A treatments, unmet needs remain for effective therapeutics for IBD. Therapies simultaneously neutralizing TL1A and IL-23 might be better choices owing to their synergistic anti-inflammatory effects in the pathogenesis of IBD. Methods TL1A and IL-23 single domain antibodies (sdAbs) were selected from immunized sdAb Phage display libraries. A human whole blood-based assay measuring IFNγ secretion was used to assess functional blockade of TL1A. Mouse splenocytes based assay measuring mouse IL-17 release was used to evaluate functional blockade of IL-23. Dextran Sulfate Sodium (DSS) induced mouse bowel inflammatory model was used to judge the in vivo effect of anti-TL1A antibodies. Synergistic anti-inflammatory effect was evaluated in mouse dermatitis model. Half-life extension was measured via pharmacokinetic analysis in non-human primate (NHP) given a single bolus of LQ080 by subcutaneous administration. Results The TL1A sdAb, which binds to both soluble and membrane-bound TL1A in a pH dependent pattern, potently blocked TL1A/DR3 while leaving the TL1A/DcR3 binding undisturbed and illustrated better IFNγ release in human whole blood induced by TL1A than RVT-3101 and PRA023. In DSS model, the TL1A sdAb also demonstrated better anti-inflammation effect than RVT-3101. The TL1A/IL-23 p19 biparatropic sdAb, LQ080, showed better IFNγ secretion inhibition than RVT-3101 and PRA023, and better inhibition of mouse IL-17 induction than Risankizumab and Guselkumab. Synergistic effects were found using LQ080 in both IFNγ release inhibition in human PBMCs induced by IL-23 and TL1A and in the mouse dermatitis model. The half-life of LQ080 significantly extended of 2-3 folds in non-human primate (NHP) compared to that of RVT-3101. Besides, LQ080 did not form large immune complex in vitro when mixed with TL1A and IL-23. Moreover, LQ080 did not stimulate the release of pro-inflammatory cytokines in the cytokines release assay. Conclusion The TL1A sdAb demonstrated better bioactivity than RVT-3101 and PRA023. LQ080, a TL1A/IL-23 p19 biparatropic sdAb, illustrated synergistic anti-inflammation effect both in vitro and iv vivo for its simultaneous neutralization of TL1A/DR3 and IL-23/IL-23R pathways, which would greatly improve the clinical results of IBD patients. The pH dependent TL1A binding makes LQ080 very different from other anti-TL1A mAbs. LQ080 demonstrated extended half-life in NHP making infrequent dosing possible for IBD treatment. No large immune complex formation when mixed with TL1A and IL-23 would make LQ080 safer when administrated by SC route. Overall, LQ080 is a promising TL1A/IL-23 p19 sdAb for IBD treatment.

Clinical Sensitivity and Specificity of the PROSTest in an American Cohort.

Prostate cancer (PCa) is the most commonly diagnosed cancer in men in the United States, following skin cancer, with an incidence rate of 112.7 per 100,000 men per year. The need for a reliable, non-invasive diagnostic tool for early PCa detection (screening, biochemical residual disease) remains unmet due to the limitations of PSA testing, which often leads to overdiagnosis and overtreatment. The PROSTest is a novel, blood-based qPCR assay that assesses gene expression to diagnose PCa and predict patient outcomes to different treatments. This study aimed to validate the sensitivity and specificity of the PROSTest in a diverse cohort of US-based PCa patients compared to healthy controls. This prospective study included 143 PCa patients and 92 healthy controls. Blood samples were collected, and the PROSTest was conducted following RNA isolation and cDNA production, using a predefined 27-gene algorithm to provide a binary output. The assay's sensitivity and specificity were evaluated using receiver operating characteristic (ROC) analysis, with a 50% score cut-off distinguishing PCa from non-PCa patients. Analytical reproducibility was assessed with intra- and inter-assay comparisons of Ct values and PROSTest scores. The PROSTest demonstrated a sensitivity of 94% (95% CI 89-98%) and a specificity of 88% (95% CI 80-94%) in distinguishing PCa patients from controls, with an area under the ROC curve (AUROC) of 0.97. The false positive rate among controls was 12%. Intra- and inter-assay reproducibility was confirmed with no significant differences in Ct values or PROSTest scores between operators or assays. PROSTest scores were significantly higher in PCa patients compared to controls and in those undergoing treatment versus untreated patients. This validation study confirms the high sensitivity and specificity of the PROSTest in detecting PCa in a diverse USA cohort. The assay's robustness and reproducibility support its potential as a reliable diagnostic tool for PCa detection and monitoring. Further studies are warranted to evaluate its utility across broader populations and treatment settings.

Liquid biopsy to identify Barrett’s oesophagus, dysplasia and oesophageal adenocarcinoma: the EMERALD multicentre study

BackgroundThere is no clinically relevant serological marker for the early detection of oesophageal adenocarcinoma (EAC) and its precursor lesion, Barrett’s oesophagus (BE).ObjectiveTo develop and test a blood-based assay for EAC...

DNA Repair Capacity and Clinicopathological Characteristics in Puerto Rican Hispanic/Latino Patients with Metastatic Castration-Resistant Prostate Cancer.

Prostate cancer (PCa) accounts for 22% of the new cases diagnosed in Hispanic/Latino (H/L) men in the US. PCa has the highest incidence (38.3%) and mortality (16.4%) among all types of cancer diagnosed in Puerto Rico. We previously showed that PCa patients (n = 41) have a significant reduction of 59% in their levels of DNA repair capacity (DRC) when compared to controls (n = 14). This study aimed to evaluate DRC levels through the nucleotide excision repair (NER) pathway for the first time in 16 Puerto Rican H/L men with metastatic castration-resistant PCa (mCRPCa) while establishing comparisons with controls and PCa patients with indolent and aggressive disease. Blood samples and clinicopathological data from PCa cases (n = 71) and controls (n = 25) were evaluated. PCa cases were stratified into mCRPCa (n = 16), aggressive (n = 31), and indolent (n = 24). DRC levels through NER were measured in lymphocytes with the CometChip assay. The stratification by Gleason score (GS) was GS6 (n = 7), GS7 (n = 23), GS ≥ 8 (n = 20), and mCRPCa patients (n = 16). Significant statistical differences were found when comparing the DRC values of the controls with any other of the four PCa patient groups. mCRPCa patients had the lowest mean DRC level of all four patient groups studied. The mean DRC level of mCRPCa patients was 6.65%, and compared to the controls, this represented a statistically significant reduction of 62% (p < 0.0001). Further analysis was performed to evaluate the contributions of age, anthropometric measurements, and prostate-specific antigen (PSA) levels to the DRC. Kaplan-Meier curves of mCRPCa revealed that survival probability decreased by approximately 50% by 30 months. This pilot study uses a blood-based phenotypic assay to present the first report of mCRPCa in Puerto Rican men and at a global level of DRC levels of mCRPCa patients. This study evaluated DRC levels through the NER pathway for the first time in 16 Puerto Rican H/L men with mCRPCa. Significant differences in DRC values were found between the controls and the three PCa patient groups. Kaplan-Meier curves revealed that survival probability decreased by approximately 50% by 30 months, and only 20% of the cohort was alive at 50 months, confirming the lethality of mCRPCa in this H/L population. This pilot study represents the first report of metastatic PCa in Puerto Rican men at a global level of DRC levels of mCRPCa patients using a blood-based phenotypic assay.

Contemporary Use of ctDNA for the Colorectal Surgeon

AbstractWhile advances in treatment and diagnostics have improved prognosis in colorectal cancer (CRC), room for advancement remains, highlighting the importance of improving tools for early detection and treatment guidance. Current national guidelines rely on stage-based treatment recommendations but fail to identify patients with lower stage disease who have a higher likelihood of recurrence or those for whom additional therapy may not be beneficial. Circulating tumor DNA (ctDNA) is an emerging noninvasive blood-based assay, which can inform cancer status as a single time point and/or longitudinal biomarker. ctDNA can be used for the diagnosis of cancer, detection of minimal/molecular residual disease, molecular profiling, and assessing treatment response. In patients for whom operative management is indicated, detectable ctDNA is associated with worse survival outcomes. This review highlights the expanding field of ctDNA in CRC, underlining pivotal data and areas with the need for more research that are key for colorectal surgeons to understand.

Equivalence of plasma and serum for clinical measurement of p-tau217: comparative analyses of four blood-based assays.

Phosphorylated tau (p-tau) 217 is a promising blood biomarker for Alzheimer's disease (AD). However, most p-tau217 assays have been validated solely in ethylenediaminetetraacetic acid (EDTA) plasma, leaving the clinical applicability of serum p-tau217 largely unexplored despite serum being a preferred matrix in many clinical laboratories. To address this gap, we compared p-tau217 concentrations and diagnostic performances in matched plasma and serum samples using four research-use-only assays, including three from commercial sources i.e., Lumipulse, ALZpath, NULISA, and one from University of Pittsburgh. Paired plasma and serum samples were processed from the same venipuncture collection and assessed with the four p-tau217 assays following manufacturer-recommended procedures in two research cohorts (N=84). Plasma and serum p-tau217 levels varied across assays; the ALZpath, Pittsburgh, and NULISA methods showed significantly lower p-tau217 levels in serum compared with plasma (p<0.0001), while Lumipulse showed higher or non-significant differences in serum. Yet, strong correlations (rho >0.8) were observed between plasma and serum p-tau217 pairs. Both plasma and serum p-tau217 demonstrated strong classification accuracies to differentiate clinical AD from normal controls, with high AUC (up to 0.963) for all methods. The exception was the Pittsburgh assay, where plasma p-tau217 had superior AUC than serum p-tau217 (plasma: 0.912, serum: 0.844). The rest of the assays had equivalent accuracies in both matrices. Serum p-tau217 performs equivalently as plasma p-tau217 for most assessed assays. Serum can therefore be used in place of plasma for p-tau217 assessment for research and clinical purposes.

Blood-based quantification of Aβ oligomers indicates impaired clearance from brain in ApoE ε4 positive subjects

BackgroundQuantification of Amyloid beta (Aβ) oligomers in plasma enables early diagnosis of Alzheimer’s Disease (AD) and improves our understanding of underlying pathologies. However, quantification necessitates an extremely sensitive and selective technology because of very low Aβ oligomer concentrations and possible interference from matrix components.MethodsIn this report, we developed and validated a surface-based fluorescence distribution analysis (sFIDA) assay for quantification of Aβ oligomers in plasma.ResultsThe blood-based sFIDA assay delivers a sensitivity of 1.8 fM, an inter- and intra-assay variation below 20% for oligomer calibration standards and no interference with matrix components. Quantification of Aβ oligomers in 359 plasma samples from the DELCODE cohort reveals lower oligomer concentrations in subjective cognitive decline and AD patients than healthy Control participants.ConclusionsCorrelation analysis between CSF and plasma oligomer concentrations indicates an impaired clearance of Aβ oligomers that is dependent on the ApoE ε4 status.