Advances in methods for characterizing dietary patterns: A scoping review.

There is a growing focus on better understanding the complexity of dietary patterns and how they relate to health and other factors. Approaches that have not traditionally been applied to characterize dietary patterns, such as machine learning algorithms and latent class analysis methods, may offer opportunities to measure and characterize dietary patterns in greater depth than previously considered. However, there has not been a formal examination of how this wide range of approaches has been applied to characterize dietary patterns. This scoping review synthesized literature from 2005-2022 applying methods not traditionally used to characterize dietary patterns, referred to as novel methods. MEDLINE, CINAHL, and Scopus were searched using keywords including machine learning, latent class analysis, and least absolute shrinkage and selection operator (LASSO). Of 5274 records identified, 24 met the inclusion criteria. Twelve of 24 articles were published since 2020. Studies were conducted across 17 countries. Nine studies used approaches that have applications in machine learning to identify dietary patterns. Fourteen studies assessed associations between dietary patterns that were characterized using novel methods and health outcomes, including cancer, cardiovascular disease, and asthma. There was wide variation in the methods applied to characterize dietary patterns and in how these methods were described. The extension of reporting guidelines and quality appraisal tools relevant to nutrition research to consider specific features of novel methods may facilitate complete and consistent reporting and enable evidence synthesis to inform policies and programs aimed at supporting healthy dietary patterns.

A randomised controlled trial of Standard Of Care versus RadioAblaTion in Early Stage HepatoCellular Carcinoma (SOCRATES HCC).

BACKGROUND: Therapeutic options for early-stage hepatocellular carcinoma (HCC) in individual patients can be limited by tumor and location, liver dysfunction and comorbidities. Many patients with early-stage HCC do not receive curative-intent therapies. Stereotactic ablative body radiotherapy (SABR) has emerged as an effective, non-invasive HCC treatment option, however, randomized evidence for SABR in the first line setting is lacking. METHODS: Trans-Tasman Radiation Oncology Group (TROG) 21.07 SOCRATES-HCC is a phase II, prospective, randomised trial comparing SABR to other current standard of care therapies for patients with a solitary HCC ≤ 8 cm, ineligible for surgical resection or transplantation. The study is divided into 2 cohorts. Cohort 1 will compromise 118 patients with tumors ≤ 3 cm eligible for thermal ablation randomly assigned (1:1 ratio) to thermal ablation or SABR. Cohort 2 will comprise 100 patients with tumors > 3 cm up to 8 cm in size, or tumors ≤ 3 cm ineligible for thermal ablation, randomly assigned (1:1 ratio) to SABR or best other standard of care therapy including transarterial therapies. The primary objective is to determine whether SABR results in superior freedom from local progression (FFLP) at 2 years compared to thermal ablation in cohort 1 and compared to best standard of care therapy in cohort 2. Secondary endpoints include progression free survival, overall survival, adverse events, patient reported outcomes and health economic analyses. DISCUSSION: The SOCRATES-HCC study will provide the first randomized, multicentre evaluation of the efficacy, safety and cost effectiveness of SABR versus other standard of care therapies in the first line treatment of unresectable, early-stage HCC. It is a broad, multicentre collaboration between hepatology, interventional radiology and radiation oncology groups around Australia, coordinated by TROG Cancer Research. TRIAL REGISTRATION: anzctr.org.au, ACTRN12621001444875, registered 21 October 2021.

Early-onset pancreatic cancer and associated metabolic risk factors in the Middle East and North Africa: A 20-year analysis of the Global Burden of Disease Study.

BACKGROUND AND OBJECTIVE: Early-onset pancreatic cancer (EOPC) is associated with poor prognosis and high disease burden. Metabolic risk factors such as diabetes and obesity are considered risk factors of EOPC. Recently, there has been an increasing number of EOPCs worldwide. However, the analysis of EOPC, including its metabolic risk factors, in the Middle East and North Africa (MENA) region has not been fully addressed. METHODS: Data from the Global Burden of Disease Study between 2000 and 2019 was used to analyze the prevalence, incidence, deaths and disability-adjusted life years (DALYs) associated with EOPC and its metabolic risk factors. The analysis further categorized the data based on countries, income status and sex and examined the annual percentage change (APC). RESULTS: Approximately 2800 cases, 2400 deaths and 114,000 DALYs were attributable to EOPC in the MENA region. The incidence (APC + 3.42%), death (APC + 0.73%) and DALYs (APC + 3.23%) rates of EOPC increased. In addition, the death and DALY rates of EOPC attributable to obesity and diabetes increased. High and upper-middle-income countries exhibited a higher burden of EOPC than lower-income countries. CONCLUSION: Over the past two decades, the burden of EOPC and its associated metabolic risk factors has increased. There is an urgent need for region-wide policy development, including screening methods and risk factor reduction, to mitigate the high and rising burden of EOPC in the MENA region.

The Burden of Overweight and Obesity-Associated Gastrointestinal Cancers in Low and Lower-Middle-Income Countries: A Global Burden of Disease 2019 Analysis.

INTRODUCTION: Obesity is associated with cancer, including gastrointestinal (GI). Data from low (LICs) and lower-middle-income countries (MICs) are limited. METHODS: We utilized data from the Global Burden of Disease Study 2019 to determine the mortality from GI cancer risk of high body mass index (BMI) in these countries. RESULTS: Mortality rates of GI cancers from high BMI increased in LICs and lower MICs, while burdens decreased or remained stable in high and middle-income countries. DISCUSSION: The GI cancer-related burden from high BMI increased in LICs and lower MICs, necessitating a concerted effort to tackle the obesity pandemic.

Mixed representations of choice and outcome by GABA/glutamate cotransmitting neurons in the entopeduncular nucleus.

The basal ganglia (BG) are an evolutionarily conserved and phylogenetically old set of sub-cortical nuclei that guide action selection, evaluation, and reinforcement. The entopeduncular nucleus (EP) is a major BG output nucleus that contains a population of GABA/glutamate cotransmitting neurons (EP Sst+ ) that specifically target the lateral habenula (LHb) and whose function in behavior remains mysterious. Here we use a probabilistic switching task that requires an animal to maintain flexible relationships between action selection and evaluation to examine when and how GABA/glutamate cotransmitting neurons contribute to behavior. We find that EP Sst+ neurons are strongly engaged during this task and show bidirectional changes in activity during the choice and outcome periods of a trial. We then tested the effects of either permanently blocking cotransmission or modifying the GABA/glutamate ratio on behavior in well-trained animals. Neither manipulation produced detectable changes in behavior despite significant changes in synaptic transmission in the LHb, demonstrating that the outputs of these neurons are not required for on-going action-outcome updating in a probabilistic switching task.

Global epidemiology of early-onset upper gastrointestinal cancer: trend from the Global Burden of Disease Study 2019.

BACKGROUND AND AIM: In recent years, there has been a growing incidence of gastrointestinal cancer in young individuals. Despite its significant morbidity and mortality, research on upper gastrointestinal (UGI) cancer in young populations has been relatively limited. Therefore, studies on the epidemiological changes of this cancer are needed. METHODS: Using data from the Global Burden of Disease Study 2019, we examined the incidence, death, and disability-adjusted life years (DALYs) from UGI cancers in the young, namely, early-onset esophageal cancer (EOEC) and early-onset gastric cancer (EOGC). These results were stratified by sex, geographical region, country, and sociodemographic index. RESULTS: There was a total of 185 140 cases, 120 289 deaths, and 5.70 million DALYs attributable to early-onset UGI cancers globally. From 2010 to 2019, the global incidence, death, and DALYs rates of early-onset UGI cancers decreased. In contrast, the incidence rates increased in both EOEC (+1.15%) and EOGC (+0.21%) in the Eastern Mediterranean region. CONCLUSIONS: Over the past decade, the burden of UGI cancer in the young has decreased. However, it has increased in the Eastern Mediterranean region. Further research to elucidate the attributable risk factors in this population is warranted.

Temporal Trends in Body Composition and Metabolic Markers Prior to Diagnosis of Pancreatic Ductal Adenocarcinoma.

BACKGROUND & AIMS: Changes in body composition and metabolic factors may serve as biomarkers for the early detection of pancreatic ductal adenocarcinoma (PDAC). The aim of this study was to capture the longitudinal changes in body composition and metabolic factors before diagnosis of PDAC. METHODS: We performed a retrospective cohort study in which all patients (≥18 years) diagnosed with PDAC from 2002 to 2021 were identified. We collected all abdominal computed tomography scans and 10 different blood-based biomarkers up to 36 months before diagnosis. We applied a fully automated abdominal segmentation algorithm previously developed by our group for 3-dimensional quantification of body composition on computed tomography scans. Longitudinal trends of body composition and blood-based biomarkers before PDAC diagnosis were estimated using linear mixed models, compared across different time windows, and visualized using spline regression. RESULTS: We included 1690 patients in body composition analysis, of whom 516 (30.5%) had ≥2 prediagnostic computed tomography scans. For analysis of longitudinal trends of blood-based biomarkers, 3332 individuals were included. As an early manifestation of PDAC, we observed a significant decrease in visceral and subcutaneous adipose tissue (ß = -1.94 [95% confidence interval (CI), -2.39 to -1.48] and ß = -2.59 [95% CI, -3.17 to -2.02]) in area (cm2)/height (m2) per 6 months closer to diagnosis, accompanied by a decrease in serum lipids (eg, low-density lipoprotein [ß = -2.83; 95% CI, -3.31 to -2.34], total cholesterol [ß = -2.69; 95% CI, -3.18 to -2.20], and triglycerides [ß = -1.86; 95% CI, -2.61 to -1.11]), and an increase in blood glucose levels. Loss of muscle tissue and bone volume was predominantly observed in the last 6 months before diagnosis. CONCLUSIONS: This study identified significant alterations in a variety of soft tissue and metabolic markers that occur in the development of PDAC. Early recognition of these metabolic changes may provide an opportunity for early detection.

Utilization and Outcomes of Multigene Panel Testing in Patients With Pancreatic Ductal Adenocarcinoma.

PURPOSE: Guidelines recommend germline genetic testing (GT) for patients with pancreatic ductal adenocarcinoma (PDAC). This study aims to evaluate the utilization and outcomes of multigene panel GT in patients with PDAC. METHODS: This retrospective, multisite study included patients with PDAC diagnosed between May 2018 and August 2020 at Mayo Clinic Arizona, Florida, and Minnesota. Discussion, uptake, and outcomes of GT were compared before (May 1, 2018-May 1, 2019) and after (August 1, 2019-August 1, 2020) the guideline update, accounting for a transition period. RESULTS: The study identified 533 patients with PDAC, with 321 (60.2%) preguideline and 212 (39.8%) postguideline. Patient characteristics did not differ between the preguideline and postguideline periods. GT was discussed in 34.3% (110 of 321) of preguideline and 39.6% (84 of 212) of postguideline patients (odds ratio [OR], 1.26 [95% CI, 0.88 to 1.80]) and subsequently performed in 80.9% (89 of 110) of preguideline and 75.0% (63 of 84) of postguideline patients (OR, 1.10 [95% CI, 0.75 to 1.61]). Of 152 tested patients, 26 (17.1%) had a pathogenic variant (PV), of whom 17 (11.2%; 17 of 152) were PDAC-associated. Over the entire study period, GT was more likely in younger patients (65 v 70 years; P < .001), those seen by a medical oncologist (82.9% v 69.0%; P < .001), and those surviving more than 12 months from diagnosis (70.4% v 43.4%; P < .001). Demographics and personal/family cancer history were comparable between patients with and without a PDAC PV. CONCLUSION: GT remains underutilized despite National Comprehensive Cancer Network guideline recommendations. Given the poor prognosis of PDAC and potential implications of GT, efforts to increase utilization are needed to provide surveillance and support to both patients with PDAC and at-risk family members.

Estimating dynamic treatment regimes for ordinal outcomes with household interference: Application in household smoking cessation.

The focus of precision medicine is on decision support, often in the form of dynamic treatment regimes, which are sequences of decision rules. At each decision point, the decision rules determine the next treatment according to the patient's baseline characteristics, the information on treatments and responses accrued by that point, and the patient's current health status, including symptom severity and other measures. However, dynamic treatment regime estimation with ordinal outcomes is rarely studied, and rarer still in the context of interference - where one patient's treatment may affect another's outcome. In this paper, we introduce the weighted proportional odds model: a regression based, approximate doubly-robust approach to single-stage dynamic treatment regime estimation for ordinal outcomes. This method also accounts for the possibility of interference between individuals sharing a household through the use of covariate balancing weights derived from joint propensity scores. Examining different types of balancing weights, we verify the approximate double robustness of weighted proportional odds model with our adjusted weights via simulation studies. We further extend weighted proportional odds model to multi-stage dynamic treatment regime estimation with household interference, namely dynamic weighted proportional odds model. Lastly, we demonstrate our proposed methodology in the analysis of longitudinal survey data from the Population Assessment of Tobacco and Health study, which motivates this work. Furthermore, considering interference, we provide optimal treatment strategies for households to achieve smoking cessation of the pair in the household.

Recommencement of atezolizumab with associated pulmonary sarcoid-like reaction.

An 81 year old male with Child-Pugh A cirrhosis and metastatic hepatocellular carcinoma (HCC) treated with 3-weekly atezolizumab and bevacizumab developed a pulmonary sarcoid-like reaction (SLR) after 5 months. Atezolizumab, an immune checkpoint inhibitor, was identified as the likely culprit. He was treated with prednisolone, resulting in improvement, and was successfully rechallenged with both atezolizumab and bevacizumab.

The Pancreatic Cancer Early Detection (PRECEDE) Study is a Global Effort to Drive Early Detection: Baseline Imaging Findings in High-Risk Individuals.

BACKGROUND: Pancreatic adenocarcinoma (PC) is a highly lethal malignancy with a survival rate of only 12%. Surveillance is recommended for high-risk individuals (HRIs), but it is not widely adopted. To address this unmet clinical need and drive early diagnosis research, we established the Pancreatic Cancer Early Detection (PRECEDE) Consortium. METHODS: PRECEDE is a multi-institutional international collaboration that has undertaken an observational prospective cohort study. Individuals (aged 18-90 years) are enrolled into 1 of 7 cohorts based on family history and pathogenic germline variant (PGV) status. From April 1, 2020, to November 21, 2022, a total of 3,402 participants were enrolled in 1 of 7 study cohorts, with 1,759 (51.7%) meeting criteria for the highest-risk cohort (Cohort 1). Cohort 1 HRIs underwent germline testing and pancreas imaging by MRI/MR-cholangiopancreatography or endoscopic ultrasound. RESULTS: A total of 1,400 participants in Cohort 1 (79.6%) had completed baseline imaging and were subclassified into 3 groups based on familial PC (FPC; n=670), a PGV and FPC (PGV+/FPC+; n=115), and a PGV with a pedigree that does not meet FPC criteria (PGV+/FPC-; n=615). One HRI was diagnosed with stage IIB PC on study entry, and 35.1% of HRIs harbored pancreatic cysts. Increasing age (odds ratio, 1.05; P<.001) and FPC group assignment (odds ratio, 1.57; P<.001; relative to PGV+/FPC-) were independent predictors of harboring a pancreatic cyst. CONCLUSIONS: PRECEDE provides infrastructure support to increase access to clinical surveillance for HRIs worldwide, while aiming to drive early PC detection advancements through longitudinal standardized clinical data, imaging, and biospecimen captures. Increased cyst prevalence in HRIs with FPC suggests that FPC may infer distinct biological processes. To enable the development of PC surveillance approaches better tailored to risk category, we recommend adoption of subclassification of HRIs into FPC, PGV+/FPC+, and PGV+/FPC- risk groups by surveillance protocols.

Consensus statements on the current landscape of artificial intelligence applications in endoscopy, addressing roadblocks, and advancing artificial intelligence in gastroenterology.

BACKGROUND AND AIMS: The American Society for Gastrointestinal Endoscopy (ASGE) AI Task Force along with experts in endoscopy, technology space, regulatory authorities, and other medical subspecialties initiated a consensus process that analyzed the current literature, highlighted potential areas, and outlined the necessary research in artificial intelligence (AI) to allow a clearer understanding of AI as it pertains to endoscopy currently. METHODS: A modified Delphi process was used to develop these consensus statements. RESULTS: Statement 1: Current advances in AI allow for the development of AI-based algorithms that can be applied to endoscopy to augment endoscopist performance in detection and characterization of endoscopic lesions. Statement 2: Computer vision-based algorithms provide opportunities to redefine quality metrics in endoscopy using AI, which can be standardized and can reduce subjectivity in reporting quality metrics. Natural language processing-based algorithms can help with the data abstraction needed for reporting current quality metrics in GI endoscopy effortlessly. Statement 3: AI technologies can support smart endoscopy suites, which may help optimize workflows in the endoscopy suite, including automated documentation. Statement 4: Using AI and machine learning helps in predictive modeling, diagnosis, and prognostication. High-quality data with multidimensionality are needed for risk prediction, prognostication of specific clinical conditions, and their outcomes when using machine learning methods. Statement 5: Big data and cloud-based tools can help advance clinical research in gastroenterology. Multimodal data are key to understanding the maximal extent of the disease state and unlocking treatment options. Statement 6: Understanding how to evaluate AI algorithms in the gastroenterology literature and clinical trials is important for gastroenterologists, trainees, and researchers, and hence education efforts by GI societies are needed. Statement 7: Several challenges regarding integrating AI solutions into the clinical practice of endoscopy exist, including understanding the role of human-AI interaction. Transparency, interpretability, and explainability of AI algorithms play a key role in their clinical adoption in GI endoscopy. Developing appropriate AI governance, data procurement, and tools needed for the AI lifecycle are critical for the successful implementation of AI into clinical practice. Statement 8: For payment of AI in endoscopy, a thorough evaluation of the potential value proposition for AI systems may help guide purchasing decisions in endoscopy. Reliable cost-effectiveness studies to guide reimbursement are needed. Statement 9: Relevant clinical outcomes and performance metrics for AI in gastroenterology are currently not well defined. To improve the quality and interpretability of research in the field, steps need to be taken to define these evidence standards. Statement 10: A balanced view of AI technologies and active collaboration between the medical technology industry, computer scientists, gastroenterologists, and researchers are critical for the meaningful advancement of AI in gastroenterology. CONCLUSIONS: The consensus process led by the ASGE AI Task Force and experts from various disciplines has shed light on the potential of AI in endoscopy and gastroenterology. AI-based algorithms have shown promise in augmenting endoscopist performance, redefining quality metrics, optimizing workflows, and aiding in predictive modeling and diagnosis. However, challenges remain in evaluating AI algorithms, ensuring transparency and interpretability, addressing governance and data procurement, determining payment models, defining relevant clinical outcomes, and fostering collaboration between stakeholders. Addressing these challenges while maintaining a balanced perspective is crucial for the meaningful advancement of AI in gastroenterology.

The Global Burden of Early-Onset Pancreatic Cancer and Its Risk Factors: A Perspective From Global Burden of Disease Study 2019.

OBJECTIVES: Despite evidence of increased incidence of early-onset pancreatic cancer (EOPC), defined as pancreatic cancer diagnosed in patients below 50 years old, and its risk factors in the Western region, global epidemiological data addressing this issue is still lacking. MATERIALS AND METHODS: Utilizing data from the Global Burden of Disease Study 2019, we aimed to conduct a comprehensive analysis of the incidence, deaths, and disability-adjusted life years (DALYs) associated with EOPC and its risk factors, including smoking, obesity, and diabetes. The analysis examined the annual percentage change (APC) over the period. RESULTS: In 2019, the incidence of EOPC surpassed 35,000 cases worldwide. This burden of EOPC tends to be more prevalent in males, as well as in Europe and high SDI countries. However, there is a noticeable upward trend in the burden of EOPC in the Eastern Mediterranean. While there is a global decline in EOPC mortality attributed to smoking (APC -0.33%), there is a concerning increase in mortality associated with diabetes (APC +2.84%) and obesity (APC +2.12%). CONCLUSIONS: The burden of EOPC has been increasing. The mortality is rising mainly from metabolic factors. There is an urgent need for national policy development for reducing the burden of this disease.

New window into hepatitis B in Africa: Liver sampling combined with single cell omics enables deep and longitudinal assessment of intrahepatic immunity in Zambia.

In Lusaka, Zambia, we introduced liver fine needle aspiration (FNA) into a research cohort of adults with treatment-naïve chronic hepatitis B virus (HBV) infection, with and without HIV coinfection, as well as with acute HBV infection. Over 117 enrollment and 47 longitudinal FNAs (at 1 year follow-up), we established participant acceptability and safety. We also demonstrated the quality of the material through single cell RNA sequencing of selected enrollment FNAs, which revealed a range of immune cells. This approach can drive new insights into HBV immunology, informing cure strategies, and can improve our understanding of HBV natural history in Africa.

Drug-induced liver injury from selective androgen receptor modulators, anabolic-androgenic steroids and bodybuilding supplements in Australia.

BACKGROUND: Reports of DILI due to herbal and dietary supplements have been increasing over time. AIMS: To characterise clinical, laboratory and histopathological phenotypes and outcomes of drug-induced liver injury (DILI) due to anabolic-androgenic steroids (AAS), selective androgen receptor modulators (SARMs), and bodybuilding supplements (BBS) in Australia. METHODS: Retrospective case series. Patients presented to nine Australian tertiary hospitals, 2017-2023. DILI was defined biochemically and patients were included if their treating physician attributed DILI to preceding use of AAS, SARMs or BBS. Primary endpoint was time to normalisation of liver biochemistry. Secondary endpoints were hospitalisation for investigation or management of DILI, death attributable to liver injury, and liver transplantation. RESULTS: Twenty-three cases of DILI were identified, involving 40 drugs: 18 AAS, 14 SARMs and eight BBS. Patients were predominantly male (22/23), with median age 30 years (IQR 26-42). Most were symptomatic (21/23). Median latency of onset was 58 days (IQR 28-112 days) from drug commencement. Most patients (17/23) were admitted to hospital. Based on updated Roussel Uclaf Causality Assessment Method, DILI was possible in 17/23, probable in 2/23 and unlikely in 4/23. Median time to normalisation of liver biochemistry was 175 days (IQR 70-292 days) from presentation. Three (3/23) were treated with corticosteroids, 14/23 were treated for itch, and one (1/23) underwent liver transplantation. There were no deaths. CONCLUSIONS: The prognosis of DILI from AAS, SARMs and BBS is good although liver transplantation may rarely be required. A detailed drug history is important in uncovering DILI due to these supplements.

The Heart Has its Reasons Which Reason Knows Not: A Curious Case of Chest Pain.

BACKGROUND: Electrocardiographic (ECG) findings of T-wave inversions in V1-V3, with or without accompanying epsilon waves, often raise concerns for the rare, but potentially lethal, arrhythmogenic right ventricular cardiomyopathy (ARVC). However, this pattern may be found in pericardial agenesis, an even rarer pathology. Concomitant myocarditis can confuse this presentation further. CASE REPORT: We report a case of a previously healthy man who presented with left-sided chest pain, ECG findings suggestive of ARVC, and a final diagnosis of myocarditis with underlying partial pericardial agenesis. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: A growing number of cases have reported pericardial agenesis demonstrating ECG changes similar to ARVC. We discuss an approach to a diagnostically challenging patient. This case emphasizes the importance of a broad differential and the danger of premature closure.

Successful Liver Retransplantation in a Patient With Disseminated Aspergillosis and Nocardiosis: A Case Report.

BACKGROUND: Clinical guidelines list active fungal infection and sepsis as contraindications to liver transplantation due to the risk of worsening infection with immunosuppression postoperatively. Mortality from systemic opportunistic infections in transplant recipients is high, approaching 100% for disseminated aspergillosis. However, the optimal duration of treatment required before transplant is unclear. Additionally, delaying surgery while the infection is treated risks death from hepatic decompensation and physical deconditioning, preventing progression to transplantation. CASE REPORT: Here, we present a patient who underwent successful repeat liver transplantation for recurrent autoimmune hepatitis and graft rejection while undergoing treatment for disseminated aspergillosis and nocardiosis. He had pulmonary, hepatic, and central nervous system involvement. He had received 2 months of antimicrobials but had ongoing radiologic evidence of infection when listed for retransplantation. He remains well and infection-free 1 year postoperatively. CONCLUSION: Few cases of successful liver transplantation in the setting of disseminated aspergillosis have been reported previously. To our knowledge, this is the first successful liver transplant in a patient with disseminated nocardial infection.

Presence of onco-fetal neighborhoods in hepatocellular carcinoma is associated with relapse and response to immunotherapy.

Onco-fetal reprogramming of the tumor ecosystem induces fetal developmental signatures in the tumor microenvironment, leading to immunosuppressive features. Here, we employed single-cell RNA sequencing, spatial transcriptomics and bulk RNA sequencing to delineate specific cell subsets involved in hepatocellular carcinoma (HCC) relapse and response to immunotherapy. We identified POSTN+ extracellular matrix cancer-associated fibroblasts (EM CAFs) as a prominent onco-fetal interacting hub, promoting tumor progression. Cell-cell communication and spatial transcriptomics analysis revealed crosstalk and co-localization of onco-fetal cells, including POSTN+ CAFs, FOLR2+ macrophages and PLVAP+ endothelial cells. Further analyses suggest an association between onco-fetal reprogramming and epithelial-mesenchymal transition (EMT), tumor cell proliferation and recruitment of Treg cells, ultimately influencing early relapse and response to immunotherapy. In summary, our study identifies POSTN+ CAFs as part of the HCC onco-fetal niche and highlights its potential influence in EMT, relapse and immunotherapy response, paving the way for the use of onco-fetal signatures for therapeutic stratification.

Single-cell atlas of the liver myeloid compartment before and after cure of chronic viral hepatitis.

BACKGROUND & AIMS: Chronic viral infections present serious public health challenges; however, direct-acting antivirals (DAAs) are now able to cure nearly all patients infected with hepatitis C virus (HCV), representing the only cure of a human chronic viral infection to date. DAAs provide a valuable opportunity to study immune pathways in the reversal of chronic immune failures in an in vivo human system. METHODS: To leverage this opportunity, we used plate-based single-cell RNA-seq to deeply profile myeloid cells from liver fine needle aspirates in patients with HCV before and after DAA treatment. We comprehensively characterised liver neutrophils, eosinophils, mast cells, conventional dendritic cells, plasmacytoid dendritic cells, classical monocytes, non-classical monocytes, and macrophages, and defined fine-grained subpopulations of several cell types. RESULTS: We discovered cell type-specific changes post-cure, including an increase in MCM7+STMN1+ proliferating CD1C+ conventional dendritic cells, which may support restoration from chronic exhaustion. We observed an expected downregulation of interferon-stimulated genes (ISGs) post-cure as well as an unexpected inverse relationship between pre-treatment viral load and post-cure ISG expression in each cell type, revealing a link between viral loads and sustained modifications of the host's immune system. We found an upregulation of PD-L1/L2 gene expression in ISG-high neutrophils and IDO1 expression in eosinophils, pinpointing cell subpopulations crucial for immune regulation. We identified three recurring gene programmes shared by multiple cell types, distilling core functions of the myeloid compartment. CONCLUSIONS: This comprehensive single-cell RNA-seq atlas of human liver myeloid cells in response to cure of chronic viral infections reveals principles of liver immunity and provides immunotherapeutic insights. CLINICAL TRIAL REGISTRATION: This study is registered at ClinicalTrials.gov (NCT02476617). IMPACT AND IMPLICATIONS: Chronic viral liver infections continue to be a major public health problem. Single-cell characterisation of liver immune cells during hepatitis C and post-cure provides unique insights into the architecture of liver immunity contributing to the resolution of the first curable chronic viral infection of humans. Multiple layers of innate immune regulation during chronic infections and persistent immune modifications after cure are revealed. Researchers and clinicians may leverage these findings to develop methods to optimise the post-cure environment for HCV and develop novel therapeutic approaches for other chronic viral infections.