Abstract Positron emission tomography (PET)-based molecular imaging is a clinically important tool for the evaluation of dementia and other neurodegenerative disorders, using radiotracers that target specific molecular and pathophysiological processes. Fluorodeoxyglucose brain PET has historically supported neurodegenerative disorder evaluation through detection of characteristic patterns of regional glucose hypometabolism. In recent years, the molecular imaging of protein aggregates has taken on an increasingly important role. This is evident with the widespread clinical adoption of amyloid PET and early use of tau PET to provide diagnostic and prognostic information for patients with suspected Alzheimer’s disease. Additional classes of radiotracers relevant to neurodegenerative diseases are under active investigation, including those targeting neuroinflammation, synaptic density, and α-synuclein aggregates. We review the major classes of PET radiotracers for neurodegenerative diseases, describing their molecular mechanisms, diagnostic performance, and their current and emerging clinical roles in dementia evaluation. Case examples for clinically used tracers illustrate imaging features relevant to diagnosis and characterization of prognosis and treatment effect. Finally, we discuss early developments and current challenges in the development of theranostic approaches and novel radiotracers for neurodegenerative diseases.
Extended normothermic machine perfusion preserves viability and tissue integrity of ex vivo human intestine segments
ABSTRACT Human intestinal diseases, including inflammatory bowel disease (IBD), are difficult to model because existing animal and in vitro systems do not capture the intestine’s integrated vascular, immune, and metabolic complexity. Here, we establish a custom normothermic machine perfusion platform that maintains surgically resected human intestinal tissue for up to 72 hours under near-physiological conditions. Discarded specimens from patients with nonmalignant intestinal diseases, including IBD and diverticulitis, were continuously perfused at 37°C with real-time hemodynamic and metabolic monitoring. Perfusion preserved tissue viability, mucosal architecture, epithelial integrity, oxygen consumption, metabolic activity, and vascular patency. Daily perfusate sampling enabled longitudinal profiling and experimental modulation of inflammatory mediators, revealing patient-specific immune states. This long-duration platform bridges reductionist in vitro models and clinical disease, enabling mechanistic studies of intestinal inflammation and future testing of personalized therapies in intact patient-derived tissue.
Longitudinal single-cell and spatial transcriptomics reveals intratumor heterogeneity, therapeutic response, and comparative value of canine marginal zone lymphoma
Diffuse B-cell lymphomas are the most prevalent canine hematologic malignancies, and their clinical presentation resembles that of human B-cell non-Hodgkin lymphomas (NHLs). However, a lack of a clear subtyping framework perpetuates imprecise treatment approaches that fail to address mechanisms of therapy resistance. Here, we employed deep phenotyping via serial sampling and longitudinal transcriptomics to evaluate intratumoral composition and therapy response in a 6-year-old neutered male goldendoodle with stage 5A marginal zone lymphoma (MZL). Following sequential treatment consisting of a single IV dose of oncolytic vesicular stomatitis virotherapy (VSV) and standard CHOP chemotherapy 30 days later, we performed scRNAseq on seven serial lymph node biopsies and spatial sequencing on a resection taken 10 days post-VSV treatment. B cells (>90%) comprised three transcriptionally distinct and temporally stable subpopulations, with specific copy number profiles and robust spatial organization despite disrupted lymph node architecture. Analysis across subpopulations revealed downregulation of the quiescence program including KLF2, suggesting similarity to KLF2-deficient human MZL. While VSV successfully reached target B cells, downstream transcriptional responses were predominantly localized to the T-cell compartment. T cells (≤6%) showed increased proliferation and upregulation of cytotoxicity markers post-VSV administration, enriching for leukocyte-mediated cytotoxicity pathways consistent with an anti-viral immune response. Ultimately, these results provide an in vivo proof-of-concept for the treatment paradigm in canine lymphoma, while emphasizing the need for improved subtyping frameworks and multidimensional treatment strategies targeting intratumoral heterogeneity.
Importance Elevated low-density lipoprotein cholesterol (LDL-C) is a modifiable risk factor for cardiovascular disease, the leading cause of premature death worldwide. Assessing the LDL-C–related burden is critical for guiding prevention and treatment strategies. Objectives To estimate the global, regional, and national burden of ischemic heart disease and ischemic stroke attributable to elevated LDL-C (relative to 35-54 mg/dL) from 1990 to 2023 and to quantify the contributions of population growth, aging, risk-deleted burden, and exposure changes to burden trends. Design, Setting, and Population This comparative risk assessment, part of the Global Burden of Disease Study 2023, estimated population-level LDL-C exposure and associated health loss in 204 countries and territories. Mean LDL-C levels were estimated using spatiotemporal gaussian process regression based on 806 studies across 161 countries. Relative risks were derived from meta-analyses of 38 randomized clinical trials. Population-attributable fractions for deaths and disability-adjusted life-years (DALYs) were estimated by age and sex for adults aged 25 years or older from 1990 to 2023, with 95% uncertainty intervals. Exposure Population-level LDL-C concentrations. Main Outcomes and Measures Population-attributable fractions, counts, and rates (all ages and age standardized per 100 000) of LDL-C–attributable deaths and DALYs from ischemic heart disease and ischemic stroke, with uncertainty intervals. Results In 2023, elevated LDL-C accounted for 3.6 million deaths (95% uncertainty interval, 2.2-5.4 million; 6.0% of global mortality) and 90.7 million DALYs (95% uncertainty interval, 58.9-123.3 million; 3.2% of DALYs). Although global all-ages rates remained stable, age-standardized death and DALY rates decreased by 45.6% and 39.5%, respectively, since 1990. In 2023, age-standardized LDL-C–attributable DALY rates were highest in Eastern Europe and lowest in high-income Asia-Pacific. One-third of the global LDL-C burden occurred in India and China. Population growth and aging drove the increasing burden, with notable regional disparities in LDL-C exposure and risk-deleted DALY rates shifting toward middle-sociodemographic settings. Conclusions and Relevance Despite declining age-standardized rates, the absolute LDL-C burden has increased since 1990 due to demographic changes and has shifted toward middle-sociodemographic countries. Measurement and surveillance gaps persist. Strengthened prevention, diagnosis, and treatment access strategies are essential to mitigate the health burden of LDL-C.
Cross-cohort analysis of expression and splicing quantitative trait loci in TOPMed
Most genetic variants associated with complex traits are hypothesized to regulate gene expression. To understand the genetics underlying gene expression variability, we characterized 14,324 RNA-sequencing samples from the Trans-Omics for Precision Medicine program and performed expression and splicing quantitative trait locus (e/sQTL) analyses in six tissues and cell types, including whole blood ( n = 6454) and lung ( n = 1291). We detected tens of thousands of secondary cis-e/sQTLs, showing that secondary cis-e/sQTL discovery remains unsaturated. We fine-mapped UK Biobank–derived genome-wide association study (GWAS) signals from 164 traits and identified e/sQTL colocalizations for 10,611 GWAS signals, including 7096 that colocalize with secondary e/sQTLs. Our results suggest that even larger e/sQTL analyses will uncover additional secondary e/sQTLs, further benefiting GWAS interpretation.
Abstract A043: Reduced KLF2 expression in canine marginal zone lymphoma mirrors human disease
Abstract Background: Canine nodal marginal zone lymphoma (MZL) is the second most common histologic diagnosis of diffuse B-cell lymphomas in dogs, but a molecular profile that can distinguish this condition from the more common canine diffuse large B-cell lymphoma (DLBCL) has been elusive. Here, we use single-cell sequencing to define the transcriptomic signatures of canine MZL before and after oncolytic virotherapy followed by traditional chemotherapy. Objective: The aims of this study were to define the canine MZL transcriptome at single cell resolution and to evaluate its changes in the face of selective pressures introduced by therapy. Methods: Longitudinal biopsies and fine needle aspirates were collected from a dog with MZL enrolled in an immunotherapy trial. Peripheral blood B-cells from healthy dogs served as reference controls. Single-cell sequencing was done using the 10x Genomics Chromium GEM X platform (v3.1), and data was aligned to the canFam4_Y genome. Quality control, clustering, and cell annotation were performed using Seurat in R (v4.4.0). Differential gene expression analysis (DGEA) was performed on 500 randomized MZL B-cells and 500 healthy canine B-cells. InferCNV was deployed on the longitudinal MZL samples for prediction of tumor B-cell CNV profiles. Results: When compared to normal peripheral blood B-cells, the tumor cells were characterized by downregulation of quiescence-associated genes, including KLF2. Copy number analysis uncovered loss on canine chromosome 20 (CFA20) encoding KLF2, gain on CFA13, and gains on CFA32 and CFA36. While an anti-viral T-cell response was identified after VSV treatment, the B-cell subpopulations retained stable transcriptomes, with a disappearance of proliferating B-cells after chemotherapy. Conclusion: This is the first report describing the molecular properties of canine MZL at single cell resolution. Clonal diversity was apparent in the tumor, with copy number loss on CFA20, presumably leading to loss of KLF2. The transcriptional features of the tumor cells remained stable even in the face of a T-cell response to an oncolytic virus. Taken together, the results document silencing of KLF2 as a key phenotypic homology between canine and human MZL, supporting the potential for comparative approaches to enhance our understanding of the significance of KLF2 silencing in this disease. Citation Format: Elise Weir, Grace Walker, Jaime F. Modiano, Aaron L. Sarver, Shruthi Naik, Amy Treeful. Reduced KLF2 expression in canine marginal zone lymphoma mirrors human disease [abstract]. In: Proceedings of the Fifth AACR International Meeting on Advances in Malignant Lymphoma: From Discovery to Clinical Impact; 2026 Jun 24-27; Philadelphia, PA. Philadelphia (PA): AACR; Blood Cancer Discov 2026;7(3_Suppl):Abstract nr A043.
Abstract A023: Different paths to the same destination: Molecular divergence and functional convergence in human and canine lymphomas
Abstract Introduction: Lymphomas are among the most common malignancies in dogs, and their morphologic and biological similarities to human counterparts have established them as widely accepted models of human disease. However, emerging molecular data suggest that conservation varies by subtype, and that many common lymphoma subtypes are principally convergent rather than homologous conditions, requiring a critical reassessment of when and how canine lymphomas provide relevant models of human disease. Methods: We employed conventional pathology, immunohistochemistry, and next generation sequencing platforms, including single-cell sequencing and spatial genomics, to characterize the transcriptional landscape and cellular organization of canine lymphomas, complemented by population metadata. Results: Our analysis revealed that canine DLBCL lacks the traditional GCB/ABC bifurcation seen in humans. While activation of NFκB pathways is seen commonly in these tumors, a germinal center-like DLBCL subtype is not apparent in dogs, and the transcriptional signatures are distinct from those of activated B-cell like DLBCL. Instead, we identified a novel canine-specific DLBCL subset driven by an AP-1-associated transcriptional signature, mirroring advanced human follicular lymphoma rather than human DLBCL. In contrast, emerging data suggest that downregulation of quiescence programs might be a shared feature of both human and canine MZLs, making this subtype a candidate for conserved disease mechanisms. While canine T-cell lymphomas exhibited extensive transcriptional heterogeneity, the samples in our dataset did not align with established human T-cell subgroups, suggesting that high incidence in dogs might not equate to molecular similarity. Conclusions: Our results suggest canine and human lymphomas are principally convergent rather than homologous diseases whose evolution and topological organization are constrained by developmental programs. The distinct transcriptional programs of canine and human DLBCLs reveal informative biological divergence, while potential shared features of MZL suggest contexts where comparative oncology may illuminate conserved disease mechanisms. Canine T-cell lymphomas exhibit extensive transcriptional heterogeneity that, at present, defies simple classification, mirroring challenges in their human counterparts and underscoring the need for larger studies to establish molecular patterns that inform causation, prognosis, and treatment. These findings highlight contexts where distinct and conserved molecular features between canine and human lymphoma can reveal shared and divergent disease mechanisms, ultimately underscoring the need for subtype-specific validation as canine lymphomas are adopted as models of human disease. Use of AI: Generative AI was used to improve clarity and readability of the abstract. AI was not used to conduct the study or to produce new text or material. Citation Format: Jaime F. Modiano, Amy E . Treeful, Grace E. Walker, Davis M. Seelig, Caitlyn M. Callaghan, Timothy D. O'Brien, Shruthi Naik, Aaron L. Sarver. Different paths to the same destination: Molecular divergence and functional convergence in human and canine lymphomas [abstract]. In: Proceedings of the Fifth AACR International Meeting on Advances in Malignant Lymphoma: From Discovery to Clinical Impact; 2026 Jun 24-27; Philadelphia, PA. Philadelphia (PA): AACR; Blood Cancer Discov 2026;7(3_Suppl):Abstract nr A023.
A75-20 Analysis of Data From a Prospective Medicare Approved Clinical Trial Registry Indicates That Use of Maintenance Extracorporeal Photopheresis Is Independently Associated With Enhanced Survival of Lung Allograft Recipients Who Have Developed Life-Thre
Abstract Rationale This Registry was designed to prospectively evaluate the efficacy of extracorporeal photopheresis (ECP) to arrest the rate of FEV1 decline (FEV1 decline) and prolong survival in lung allograft recipients with Bronchiolitis Obliterans refractory to standard of care therapy. Methods After IRB approval, 258 lung transplant recipients were enrolled from 20 US lung transplant centers. Subjects were assigned to ECP treatment (ECPRx) (i.e., 24 procedures over 6 months) at or a few months after enrollment based on spirometric criteria. Maintenance ECPRx (mECP) was at the discretion of managing clinicians. Rate of FEV1 decline in mL/month (FEV1 decline) was compared between 6 months prior to and 6 & 12 months after ECPRx initiation using linear mixed effects models. Time 0 for survival was set as the start of ECPRx for generation of Kaplan-Meier curves. Hazard Ratios (HR) with 95% confidence intervals (lower-upper) were generated using Cox Proportional Hazards Regression to characterize significant (p < 0.05) independent associations of mECP and/or any other covariates (i.e., demographic, operative, enrollment site, spirometric ) and survival. Results An 89% (78%-96%) decrease in the FEV1 decline was observed 12 months after ECPRx initiation in 191 participants assigned to ECPRx. FEV1 decline (-164 mL/month: 144-185) was greater (p < 0.001) in participants who expired within six months of Time 0 (n = 28) vs participants (-111 mL/month: 101-120) who died six months after Time 0 (n = 77). Of 159 participants who survived for at least six months after ECPRx initiation, 40 participants without mECP, who had up to 24 ECPRx (ECPRx: n = 19), had a lower survival HR: 2.43(1.75-3.4) (p < 0.001) relative to 119 participants who received mECP (ECPRx: n = 86)(see Figure). The response to ECPRx (% Change in FEV1 decline prior to and 6 months after 1st ECP) was similar between subcohorts (No mECP: -81 decrease vs mECP: -85%, p = 0.3). The association of mECP persisted after multivariate adjustment HR 1.8 (1.8-2.7)(p = 0.002) using significant covariates: FEV1 HR 0.37 (0.3-0.5), FEV1 decline HR 0.001 (0.001-0.04), Male Gender HR 2.4 (1.7-3.4); Reflux Disease HR 1.8 (1.2-2.8); Coronary Disease HR 1.8 (1.2-2.7). Conclusions This analysis indicates that mECP is independently associated with enhanced survival most likely due to attenuation of relapse six months after ECP initiation based on similar initial response to ECPRx. A risk-adjusted, control cohort is being pursued to facilitate submission of a scientifically rigorous petition to CMS to expand the ECP National Coverage Decision to include BOS predicated on CMS 2024 scientific guidelines. This abstract is funded by: Therakos Inc
Single‐Stage Modified Postauricular Flap Reconstruction for a Traumatic Helical Rim Defect Following a Human Bite: A Case Report
ABSTRACT Traumatic defects of the helical rim caused by human bites present significant reconstructive challenges because of tissue loss, infection risk, and the need to preserve auricular contour and symmetry. We report a 27‐year‐old man who presented with a middle‐third defect of the left helical rim following necrosis of an initially sutured avulsed flap caused by a human bite injury. After discussion of reconstructive options, including chondrocutaneous advancement and staged flap procedures, a single‐stage modified postauricular flap without skin grafting was selected to preserve ear size and minimize donor‐site morbidity. The flap was successfully inset with restoration of the helical contour, and postoperative follow‐up demonstrated stable healing, preserved auricular shape, and high patient satisfaction without complications. This case highlights that a single‐stage modified postauricular flap is a reliable and patient‐centered option for reconstruction of traumatic helical rim defects following human bite injuries.
Abstract 6746: Biomarker-driven restoration of tumor provisional matrix signaling network reverses resistance to checkpoint inhibition immunotherapy
Abstract Specialized immune niches located in the stroma-tumor junction promote interactions between tumor-resident antigen-presenting cells and effector lymphocytes that are required for immunotherapy efficacy. We have hypothesized that this stromal-based immune crosstalk may be regulated by provisional extracellular matrix signals, analogous to the early-stages of wound healing where provisional matrix hosts robust immune activity. A cardinal provisional matrix remodeling event, the regulated proteolysis of the large proteoglycan versican (VCAN) generates an immunomodulatory fragment (matrikine), versikine, that engages adaptive immunity. We have previously shown that VCAN proteolysis correlates with T-cell infiltration across multiple solid and liquid cancers with the most immune-evasive cancers showing low to negligible rates of VCAN proteolysis (e.g., 0% in pancreatic adenocarcinoma). A recent clinical trial generated informative prospective data linking VCAN proteolysis with immunotherapy outcomes: patients whose metastatic colorectal tumors categorized as VCAN proteolysis-weak (VPW, 60% of cases) demonstrated inferior responses to checkpoint inhibition (CPI, pembrolizumab) and worse outcomes compared to VCAN proteolysis-predominant (VPP, 40%) cases. Leveraging these prospective trial data, we hypothesized that versikine therapy may rationally reverse the immunosuppression associated with the prevalent VPW phenotype. To tailor versikine therapy to specific human biomarker-stratified tumor phenotypes, we studied experimental models replicating partially T-permissive VPW-VCANlo human cancers and poor-prognosis, immune-exclusionary VPW-VCANhi cancers. Across VPW-like tumors, versikine promoted the stromal accumulation of CD40lghiIcoshiFoxp3neg Tfh-like CD4+ T cells that engaged dendritic cells (DC) and CD8+ T cells in “immune triads” even at baseline (prior to CPI), concurrently with the intratumoral expansion of activated CD8+ T cells expressing cytolytic molecules (granzymes, perforin). In VPW-VCANlo tumors, versikine delivered as LNP-mRNA or recombinant protein demonstrated monotherapy activity, dependent on Batf3-lineage DC and CD8+ T cells. When combined with single-agent CPI, versikine cured most VPW-VCANlo tumors with memory to tumor re-challenge. In VPW-VCANhi tumors, versikine synergized with combination immunotherapy modulating “mature DCs enriched in immunoregulatory molecules” (mregDC). Our data provide mechanistic rationale for the biomarker-stratified, therapeutic restoration of a provisional matrix-regulated immune signaling network to reverse resistance to CPI. Moreover, the data highlight the need to reevaluate prior approaches to globally disrupt tumor stroma in favor of biomarker-driven, pathway-focused harnessing of stromal signals that modulate anti-tumor immunity. Citation Format: Daniel J. Lagal, Duncan Hong, Athanasios Papadas, Emma Geatches, George Yacu, Surabhi Naik, Alicia Gibbons, Alexander Cicala, Kersi Pestonjamasp, Peter Toth, Kristina Matkowskyj, Dustin A. Deming, Fotis Asimakopoulos. Biomarker-driven restoration of tumor provisional matrix signaling network reverses resistance to checkpoint inhibition immunotherapy [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2026; Part 1 (Regular Abstracts); 2026 Apr 17-22; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2026;86(7 Suppl):Abstract nr 6746.