CD8+ T-cell differentiation and dysfunction inform treatment response in acute myeloid leukemia.

ABSTRACT: The interplay between T-cell states of differentiation, dysfunction, and treatment response in acute myeloid leukemia (AML) remains unclear. Here, we leveraged a multimodal approach encompassing high-dimensional flow cytometry and single-cell transcriptomics and found that early memory CD8+ T cells are associated with therapy response and exhibit a bifurcation into 2 distinct terminal end states. One state is enriched for markers of activation, whereas the other expresses natural killer (NK)-like and senescence markers. The skewed clonal differentiation trajectory toward CD8+ senescence was also a hallmark indicative of therapy resistance. We validated these findings by generating an AML CD8+ single-cell atlas integrating our data and other independent data sets. Finally, our analysis revealed that an imbalance between CD8+ early memory and senescent-like cells is linked to AML treatment refractoriness and poor survival. Our study provides crucial insights into the dynamics of CD8+ T-cell differentiation and advances our understanding of CD8+ T-cell dysfunction in AML.

Inhibition of the Sterol Regulatory Element Binding Protein SREBF-1 Overcomes Docetaxel Resistance in Advanced Prostate Cancer.

Resistance to antiandrogens and chemotherapy (Cx) limits therapeutic options for patients with hormone-sensitive and hormone-resistant prostate cancer (mCRPC). In this context, up-regulation of the glucocorticoid receptor has been identified as a potential bypass mechanism in mCRPC, and a combination of docetaxel and mifepristone (Doc + RU-486), an inhibitor of the glucocorticoid receptor, re-sensitized docetaxel-resistant cell models to Cx. This study was designed to elucidate the molecular mechanisms responsible for this phenomenon. RNA sequencing was performed in docetaxel-resistant prostate cancer cell models after Doc + RU-486 treatment with consecutive functional assays. Expression of selected proteins was verified in prostatic tissue from prostate cancer patients with progressive disease. Treatment with Doc + RU-486 significantly reduced cancer cell viability, and RNA sequencing revealed sterol regulatory element of binding transcription factor 1 (SREBF-1), a transcription factor of cholesterol and lipid biosynthesis, as a significantly down-regulated target. Functional assays confirmed that SREBF-1 down-regulation is partially responsible for this observation. In concordance, SREBF-1 knockdown and pharmacologic sterol regulatory element binding protein inhibition, together with other key enzymes in the cholesterol pathway, showed similar results. Furthermore, SREBF-1 expression is significantly elevated in advanced prostate cancer tissues, showing its potential involvement in tumor progression and emerging therapy resistance. Therefore, specific inhibition of cholesterol and lipid biosynthesis might also target Cx-resistant cancer cells and represents a potential additive future therapeutic option to improve mCRPC therapy.

Next-generation computational tools for interrogating cancer immunity.

The remarkable success of cancer therapies with immune checkpoint blockers is revolutionizing oncology and has sparked intensive basic and translational research into the mechanisms of cancer-immune cell interactions. In parallel, numerous novel cutting-edge technologies for comprehensive molecular and cellular characterization of cancer immunity have been developed, including single-cell sequencing, mass cytometry and multiplexed spatial cellular phenotyping. In order to process, analyse and visualize multidimensional data sets generated by these technologies, computational methods and software tools are required. Here, we review computational tools for interrogating cancer immunity, discuss advantages and limitations of the various methods and provide guidelines to assist in method selection.

Toll-Like Receptor 3 Mediates Aortic Stenosis Through a Conserved Mechanism of Calcification.

BACKGROUND: Calcific aortic valve disease (CAVD) is characterized by a phenotypic switch of valvular interstitial cells to bone-forming cells. Toll-like receptors (TLRs) are evolutionarily conserved pattern recognition receptors at the interface between innate immunity and tissue repair. Type I interferons (IFNs) are not only crucial for an adequate antiviral response but also implicated in bone formation. We hypothesized that the accumulation of endogenous TLR3 ligands in the valvular leaflets may promote the generation of osteoblast-like cells through enhanced type I IFN signaling. METHODS: Human valvular interstitial cells isolated from aortic valves were challenged with mechanical strain or synthetic TLR3 agonists and analyzed for bone formation, gene expression profiles, and IFN signaling pathways. Different inhibitors were used to delineate the engaged signaling pathways. Moreover, we screened a variety of potential lipids and proteoglycans known to accumulate in CAVD lesions as potential TLR3 ligands. Ligand-receptor interactions were characterized by in silico modeling and verified through immunoprecipitation experiments. Biglycan (Bgn), Tlr3, and IFN-α/ß receptor alpha chain (Ifnar1)-deficient mice and a specific zebrafish model were used to study the implication of the biglycan (BGN)-TLR3-IFN axis in both CAVD and bone formation in vivo. Two large-scale cohorts (GERA [Genetic Epidemiology Research on Adult Health and Aging], n=55 192 with 3469 aortic stenosis cases; UK Biobank, n=257 231 with 2213 aortic stenosis cases) were examined for genetic variation at genes implicated in BGN-TLR3-IFN signaling associating with CAVD in humans. RESULTS: Here, we identify TLR3 as a central molecular regulator of calcification in valvular interstitial cells and unravel BGN as a new endogenous agonist of TLR3. Posttranslational BGN maturation by xylosyltransferase 1 (XYLT1) is required for TLR3 activation. Moreover, BGN induces the transdifferentiation of valvular interstitial cells into bone-forming osteoblasts through the TLR3-dependent induction of type I IFNs. It is intriguing that Bgn-/-, Tlr3-/-, and Ifnar1-/- mice are protected against CAVD and display impaired bone formation. Meta-analysis of 2 large-scale cohorts with >300 000 individuals reveals that genetic variation at loci relevant to the XYLT1-BGN-TLR3-interferon-α/ß receptor alpha chain (IFNAR) 1 pathway is associated with CAVD in humans. CONCLUSIONS: This study identifies the BGN-TLR3-IFNAR1 axis as an evolutionarily conserved pathway governing calcification of the aortic valve and reveals a potential therapeutic target to prevent CAVD.

ExonSurfer: a web-tool to design primers at exon-exon junctions.

BACKGROUND: Reverse transcription quantitative PCR (RT-qPCR) with intercalating dyes is one of the main techniques to assess gene expression levels used in basic and applied research as well as in diagnostics. However, primer design for RT-qPCR can be complex due to the high demands on primer quality. Primers are best placed on exon junctions, should avoid polymorphic regions, be specific to the target transcripts and also prevent genomic amplification accurately, among others. Current software tools manage to meet all the necessary criteria only insufficiently. Here, we present ExonSurfer, a novel, user-friendly web-tool for qPCR primer design. RESULTS: ExonSurfer combines the different steps of the primer design process, encompassing target selection, specificity and self-complementarity assessment, and the avoidance of issues arising from polymorphisms. Amplification of potentially contaminating genomic DNA is avoided by designing primers on exon-exon junctions, moreover, a genomic alignment is performed to filter the primers accordingly and inform the user of any predicted interaction. In order to test the whole performance of the application, we designed primer pairs for 26 targets and checked both primer efficiency, amplicon melting temperature and length and confirmed the targeted amplicon by Sanger sequencing. Most of the tested primers accurately and selectively amplified the corresponding targets. CONCLUSION: ExonSurfer offers a comprehensive end-to-end primer design, guaranteeing transcript-specific amplification. The user interface is intuitive, providing essential specificity and amplicon details. The tool can also be used by command line and the source code is available. Overall, we expect ExonSurfer to facilitate RT-qPCR set-up for researchers in many fields.

Neuroendocrine Tumors of Unknown Primary in the Setting of Cytoreductive Hepatectomy.

BACKGROUND: Surgical cytoreduction for neuroendocrine tumor liver metastasis (NETLM) consistently shows positive long-term outcomes. Despite reservations in guidelines for surgery when the primary tumor is unidentified (UP-NET), this study compared the surgical and oncologic long-term outcomes between patients with these rare cases undergoing cytoreductive surgery and patients who had liver resection for known primaries. METHODS: The study identified 32 unknown primary liver metastases (UP-NETLM) in 522 retrospectively evaluated patients who underwent resection of well-differentiated NETLM between January 2000 and December 2020. Tumor and patient characteristics were compared with those in 490 cases of liver metastasis from small intestinal (SI-NETLM) or pancreatic (pNETLM) primaries. Survival analysis was performed to highlight long-term outcome differences. Surgical outcomes were compared between liver resections alone and simultaneous primary resections to assess surgical risk distinctions. RESULTS: The UP-NET patients had fewer NETLMs (p = 0.004), which on the average were larger than SI-NETLMs or pNETLMs (p = 0.002). Expression of Ki-67 was balanced among the groups. Major hepatectomy was performed more often in the UP-NETLM group (p = 0.017). The 10-year survival rate of 53% for UP-NETLM was comparable with that for SI-NETML (58%; p = 0.463) and pNETLMs (47%; p = 0.497). The median hepatic progression-free survival was 26 months for the UP-NETLM patients and 25 months for the SI-NETLM patients compared to 12 months for the pNETLM patients (p < 0.001). Perioperative mortality was lower than 2%, and severe postoperative morbidity occurred in 21%, similarly distributed among all the groups. CONCLUSION: The surgical risk and long-term outcomes for the UP-NETLM patients were comparable with those for other NETLM cases, affirming the validity of equally aggressive surgical cytoreduction as a therapeutic option in carefully selected cases.

Identification of regulatory networks and crosstalk factors in brown adipose tissue and liver of a cold-exposed cardiometabolic mouse model.

BACKGROUND: Activation of brown adipose tissue (BAT) has gained attention due to its ability to dissipate energy and counteract cardiometabolic diseases (CMDs). METHODS: This study investigated the consequences of cold exposure on the BAT and liver proteomes of an established CMD mouse model based on LDL receptor-deficient (LdlrKO) mice fed a high-fat, high-sucrose, high-cholesterol diet for 16 weeks. We analyzed energy metabolism in vivo and performed untargeted proteomics on BAT and liver of LdlrKO mice maintained at 22 °C or 5 °C for 7 days. RESULTS: We identified several dysregulated pathways, miRNAs, and transcription factors in BAT and liver of cold-exposed Ldlrko mice that have not been previously described in this context. Networks of regulatory interactions based on shared downstream targets and analysis of ligand-receptor pairs identified fibrinogen alpha chain (FGA) and fibronectin 1 (FN1) as potential crosstalk factors between BAT and liver in response to cold exposure. Importantly, genetic variations in the genes encoding FGA and FN1 have been associated with cardiometabolic-related phenotypes and traits in humans. DISCUSSION: This study describes the key factors, pathways, and regulatory networks involved in the crosstalk between BAT and the liver in a cold-exposed CMD mouse model. These findings may provide a basis for future studies aimed at testing whether molecular mediators, as well as regulatory and signaling mechanisms involved in tissue adaption upon cold exposure, could represent a target in cardiometabolic disorders.

Tumoral programmed cell death 1 (PD1) expression in endometrial carcinoma is a prognostic marker for patient outcome.

OBJECTIVE: Immune checkpoint inhibitors have recently demonstrated benefit in patients with advanced and recurrent endometrial carcinoma. This retrospective study investigated immune checkpoint molecules in endometrial carcinoma as they pertain to the molecular subtypes, clinical outcomes, and predictive value. METHODS: Tumoral RNA expression of genes controlling the immune checkpoint, programmed cell death 1 (PD1, encoded by PDCD1), its ligand (PDL1, encoded by CD274), and interferon gamma (IFNG) was determined in 239 endometrial carcinoma tissues by quantitative polymerase chain reaction (qPCR) and compared with endometrial tissue from 25 controls. A total of 81 endometrial carcinoma tissues were analyzed using the ProMiSe molecular classification, and patient trajectories were analyzed for the entire cohort. Findings were validated in an independent cohort from The Cancer Genome Atlas (TCGA; n=548). RESULTS: PD1, PDL1, and IFNG expression was significantly higher in endometrial carcinoma when compared with non-malignant control tissue with a mean expression of 0.12, 0.05, and 0.05 in control tissue and 0.44, 0.31, and 0.35 in endometrial carcinoma, respectively. POLE-mutated and mismatch repair-deficient (MMRd) (immunologically hot) tumors showed the highest expression of PD1 and IFNG. Increased expression of PD1, PDL1, and IFNG was associated with improved recurrence-free (HR 0.32, p<0.001; HR 0.30, p<0.001; HR 0.47, p=0.012, respectively), disease-specific (HR 0.38, p<0.001; HR 0.29, p<0.001; HR 0.45, p=0.017, respectively), and overall survival (HR 0.56, p=0.003; HR 0.38, p<0.001; HR 0.58, p=0.006, respectively). Cox regression confirmed the prognostic significance of PD1 for recurrence-free survival (HR 0.39, p=0.009) and PDL1 for overall survival (HR 0.55, p=0.037). The prognostic value of tumoral PD1 on recurrence-free survival, disease-specific survival, and overall survival was confirmed in the TCGA cohort. CONCLUSIONS: Tumoral gene expression controlling the PD1 immune checkpoint, particularly expressed in "hot tumors", predicted recurrence-free, disease-specific, and overall survival in patients with endometrial carcinoma in two independent cohorts. Evaluation of these genes could be used to stratify patients who qualify for immune checkpoint inhibitors, which warrants prospective clinical trials.

HMGB1-Mediated Cell Death-A Crucial Element in Post-Hepatectomy Liver Failure.

Liver resection (LR) is the primary treatment for hepatic tumors, yet posthepatectomy liver failure (PHLF) remains a significant concern. While the precise etiology of PHLF remains elusive, dysregulated inflammatory processes are pivotal. Therefore, we explored the theragnostic potential of extracellular high-mobility-group-box protein 1 (HMGB1), a key damage-associated molecular pattern (DAMP) released by hepatocytes, in liver recovery post LR in patients and animal models. Plasma from 96 LR patients and liver tissues from a subset of 24 LR patients were analyzed for HMGB1 levels, and associations with PHLF and liver injury markers were assessed. In a murine LR model, the HMGB1 inhibitor glycyrrhizin, was administered to assess its impact on liver regeneration. Furthermore, plasma levels of keratin-18 (K18) and cleaved cytokeratin-18 (ccK18) were quantified to assess suitability as predictive biomarkers for PHLF. Patients experiencing PHLF exhibited elevated levels of intrahepatic and circulating HMGB1, correlating with markers of liver injury. In a murine LR model, inhibition of HMGB1 improved liver function, reduced steatosis, enhanced regeneration and decreased hepatic cell death. Elevated levels of hepatic cell death markers K18 and ccK18 were detected in patients with PHLF and correlations with levels of circulating HMGB1 was observed. Our study underscores the therapeutic and predictive potential of HMGB1 in PHLF mitigation. Elevated HMGB1, K18, and ccK18 levels correlate with patient outcomes, highlighting their predictive significance. Targeting HMGB1 enhances liver regeneration in murine LR models, emphasizing its role in potential intervention and prediction strategies for liver surgery.

An APRI+ALBI Based Multivariable Model as Preoperative Predictor for Posthepatectomy Liver Failure.

OBJECTIVE AND BACKGROUND: Clinically significant posthepatectomy liver failure (PHLF B+C) remains the main cause of mortality after major hepatic resection. This study aimed to establish an APRI+ALBI, aspartate aminotransferase to platelet ratio (APRI) combined with albumin-bilirubin grade (ALBI), based multivariable model (MVM) to predict PHLF and compare its performance to indocyanine green clearance (ICG-R15 or ICG-PDR) and albumin-ICG evaluation (ALICE). METHODS: 12,056 patients from the National Surgical Quality Improvement Program (NSQIP) database were used to generate a MVM to predict PHLF B+C. The model was determined using stepwise backwards elimination. Performance of the model was tested using receiver operating characteristic curve analysis and validated in an international cohort of 2,525 patients. In 620 patients, the APRI+ALBI MVM, trained in the NSQIP cohort, was compared with MVM's based on other liver function tests (ICG clearance, ALICE) by comparing the areas under the curve (AUC). RESULTS: A MVM including APRI+ALBI, age, sex, tumor type and extent of resection was found to predict PHLF B+C with an AUC of 0.77, with comparable performance in the validation cohort (AUC 0.74). In direct comparison with other MVM's based on more expensive and time-consuming liver function tests (ICG clearance, ALICE), the APRI+ALBI MVM demonstrated equal predictive potential for PHLF B+C. A smartphone application for calculation of the APRI+ALBI MVM was designed. CONCLUSION: Risk assessment via the APRI+ALBI MVM for PHLF B+C increases preoperative predictive accuracy and represents an universally available and cost-effective risk assessment prior to hepatectomy, facilitated by a freely available smartphone app.

MIO: microRNA target analysis system for immuno-oncology.

SUMMARY: MicroRNAs have been shown to be able to modulate the tumor microenvironment and the immune response and hence could be interesting biomarkers and therapeutic targets in immuno-oncology; however, dedicated analysis tools are missing. Here, we present a user-friendly web platform MIO and a Python toolkit miopy integrating various methods for visualization and analysis of provided or custom bulk microRNA and gene expression data. We include regularized regression and survival analysis and provide information of 40 microRNA target prediction tools as well as a collection of curated immune related gene and microRNA signatures and processed TCGA data including estimations of infiltrated immune cells and the immunophenoscore. The integration of several machine learning methods enables the selection of prognostic and predictive microRNAs and gene interaction network biomarkers. AVAILABILITY AND IMPLEMENTATION: https://mio.icbi.at, https://github.com/icbi-lab/mio and https://github.com/icbi-lab/miopy. SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.

An angiogenic tumor phenotype predicts poor prognosis in ovarian cancer.

OBJECTIVE: Epithelial ovarian cancer (OC) is the deadliest gynecological malignancy worldwide. Blocking angiogenesis with bevacizumab, an antibody targeting vascular endothelial growth factor (VEGF), shows efficacy in different lines of OC therapy. This study investigates the clinical impact of tumoral expression of angiogenesis-related genes and their association with bevacizumab response in OC in retrospective analysis of three independent cohorts. METHODS: mRNA expression of seven angiogenic genes (VEGF, VEGFR2, PDGFA, PDGFB, PDGFRA, PDGFRB, KIT) was quantified in an inception OC cohort (n = 195) and a transcriptional tumor angiogenesis score from 0 to 3 was established and linked to progression-free survival (PFS) and overall survival (OS). This score was corroborated in an independent publicly available cohort from The Cancer Genome Atlas (TCGA, n = 582) and prediction of therapeutic efficacy of bevacizumab by the angiogenesis score was analyzed in the Gene Expression Omnibus (GEO) dataset GSE140082 (n = 380) from the ICON7-trial. RESULTS: The tumor angiogenesis score prognosticated PFS and OS in patients with OC from the inception cohort (p < 0.001, respectively). Tumoral PDGFA expression (PFS: HR 2.46, p = 0.005; OS: HR 2.26, p = 0.011) and a high tumoral transcriptional angiogenesis score (PFS: HR 1.41, p = 0.018) were identified as independent predictors of clinical outcome. The transcriptional angiogenesis score exhibited a significant though smaller effect size on PFS in the TCGA cohort. However, in the ICON7-trial, the angiogenesis score was not associated with benefit of bevacizumab treatment. CONCLUSIONS: Our study indicates that tumoral expression of angiogenic genes is unfavorable in OC. The established score could be used to identify patients who respond to targeted angiogenic therapies, a concept that warrants prospective controlled clinical trials.

The Addition of C-Reactive Protein and von Willebrand Factor to Model for End-Stage Liver Disease-Sodium Improves Prediction of Waitlist Mortality.

BACKGROUND AND AIMS: Patients with cirrhosis on the liver transplant (LT) waiting list may die or be removed because of complications of portal hypertension (PH) or infections. von Willebrand factor antigen (vWF-Ag) and C-reactive protein (CRP) are simple, broadly available markers of these processes. APPROACH AND RESULTS: We determined whether addition of vWF-Ag and CRP to the Model for End-Stage Liver Disease-Sodium (MELD-Na) score improves risk stratification of patients awaiting LT. CRP and vWF-Ag at LT listing were assessed in two independent cohorts (Medical University of Vienna [exploration cohort] and Mayo Clinic Rochester [validation cohort]). Clinical characteristics, MELD-Na, and mortality on the waiting list were recorded. Prediction of 3-month waiting list mortality was assessed by receiver operating characteristics curve (ROC-AUC). In order to explore potential mechanisms underlying the prognostic utility of vWF-Ag and CRP in this setting, we evaluated their association with PH, bacterial translocation, systemic inflammation, and circulatory dysfunction. In the exploration cohort (n = 269) vWF-Ag and CRP both improved the predictive value of MELD-Na for 3-month waitlist mortality and showed the highest predictive value when combined (AUC: MELD-Na, 0.764; MELD-Na + CRP, 0.790; MELD-Na + vWF, 0.803; MELD-Na + CRP + vWF-Ag, 0.824). Results were confirmed in an independent validation cohort (n = 129; AUC: MELD-Na, 0.677; MELD-Na + CRP + vWF-Ag, 0.882). vWF-Ag was independently associated with PH and inflammatory biomarkers, whereas CRP closely, and MELD independently, correlated with biomarkers of bacterial translocation/inflammation. CONCLUSIONS: The addition of vWF-Ag and CRP-reflecting central pathophysiological mechanisms of PH, bacterial translocation, and inflammation, that are all drivers of mortality on the waiting list for LT-to the MELD-Na score improves prediction of waitlist mortality. Using the vWFAg-CRP-MELD-Na model for prioritizing organ allocation may improve prediction of waitlist mortality and decrease waitlist mortality.

Consequences of Perioperative Serotonin Reuptake Inhibitor Treatment During Hepatic Surgery.

BACKGROUND AND AIMS: Platelet-stored serotonin critically affects liver regeneration in mice and humans. Selective serotonin reuptake inhibitors (SSRIs) and serotonin noradrenalin reuptake inhibitors (SNRIs) reduce intraplatelet serotonin. As SSRIs/SNRIs are now one of the most commonly prescribed drugs in the United States and Europe and given serotonin's impact on liver regeneration, we evaluated whether perioperative use of SSRIs/SNRIs affects outcome after hepatic resection. APPROACH AND RESULTS: Consecutive patients undergoing hepatic resection (n = 754) were retrospectively included from prospectively maintained databases from two European institutions. Further, an independent cohort of 495 patients from the United States was assessed to validate our exploratory findings. Perioperative intake of SSRIs/SNRIs was recorded, and patients were followed up for postoperative liver dysfunction (LD), morbidity, and mortality. Perioperative intraplatelet serotonin levels were significantly decreased in patients receiving SSRI/SNRI treatment. Patients treated with SSRIs/SNRIs showed a higher incidence of morbidity, severe morbidity, LD, and LD requiring intervention. Associations were confirmed in the independent validation cohort. Combined cohorts documented a significant increase in deleterious postoperative outcome (morbidity odds ratio [OR], 1.56; 95% confidence interval [CI], 1.07-2.31; severe morbidity OR, 1.86; 95% CI, 1.22-2.79; LD OR, 1.96; 95% CI, 1.23-3.06; LD requiring intervention OR, 2.22; 95% CI, 1.03-4.36). Further, multivariable analysis confirmed the independent association of SSRIs/SNRIs with postoperative LD, which was closely associated with postoperative 90-day mortality and 1-year overall survival. CONCLUSIONS: We observed a significant association of perioperative SSRI/SNRI intake with adverse postoperative outcome after hepatic resection. This indicates that SSRIs/SNRIs should be avoided perioperatively in patients undergoing hepatic resections.

Computational genomics tools for dissecting tumour-immune cell interactions.

Recent breakthroughs in cancer immunotherapy and decreasing costs of high-throughput technologies have sparked intensive research into tumour-immune cell interactions using genomic tools. The wealth of the generated data and the added complexity pose considerable challenges and require computational tools to process, to analyse and to visualize the data. Recently, various tools have been developed and used to mine tumour immunologic and genomic data effectively and to provide novel mechanistic insights. Here, we review computational genomics tools for cancer immunology and provide information on the requirements and functionality in order to assist in the selection of tools and assembly of analytical pipelines.

Circulating metabolites as a concept beyond tumor biology determining disease recurrence after resection of colorectal liver metastasis.

BACKGROUND: Micro-metastatic growth is considered the main source of early cancer recurrence. Nutritional and microenvironmental components are increasingly recognized to play a significant role in the liver. We explored the predictive potential of preoperative plasma metabolites for postoperative disease recurrence in colorectal cancer liver metastasis (CRCLM) patients. METHODS: All included patients (n = 71) had undergone R0 liver resection for colorectal cancer liver metastasis in the years between 2012 and 2018. Preoperative blood samples were collected and assessed for 180 metabolites using a preconfigured mass-spectrometry kit (Biocrates Absolute IDQ p180 kit). Postoperative disease-free (DFS) and overall survival (OS) were prospectively recorded. Patients that recurred within 6 months after surgery were defined as "high-risk" and, subsequently, a three-metabolite model was created which can assess DFS in our collective. RESULTS: Multiple lysophosphatidylcholines (lysoPCs) and phosphatidylcholines (PCs) significantly predicted disease recurrence within 6 months (strongest: PC aa C36:1 AUC = 0.83, p = 0.003, PC ae C34:0 AUC = 0.83, p = 0.004 and lysoPC a C18:1 AUC = 0.8, p = 0.006). High-risk patients had a median DFS of 183 days versus 522 days in low-risk population (p = 0.016, HR = 1.98 95% CI 1.16-4.35) with a 6 months recurrence rate of 47.6% versus 4.7%, outperforming routine predictors of oncological outcome. CONCLUSION: Circulating metabolites identified CRCLM patients at highest risk for 6 months disease recurrence after surgery. Our data also suggests that circulating metabolites might play a significant pathophysiological role in micro-metastatic growth and concomitant early tumor recurrences after liver resection. However, the clinical applicability and performance of this proposed metabolomic concept needs to be independently validated in future studies.

Hepatocellular carcinoma as predominant cancer subgroup accounting for sex differences in post-hepatectomy liver failure, morbidity and mortality.

BACKGROUND: Experimental evidence suggests sex dependent differences in liver regeneration. Limited evidence is available examining sex differences in post-hepatectomy liver failure (PHLF) and postoperative outcomes. Our aim was to assess the influence of sex on the outcomes after liver resection. METHODS: The hepatectomy targeted National Surgical Quality Improvement Program (NSQIP) database was assessed for associations between sex and outcomes. RESULTS: A total of 13,401 patients underwent elective hepatic resection between 2014-2017. PHLF was highest among male patients with hepatocellular carcinoma (HCC) (OR = 2.81,95%CI:1.40-5.62). Male sex was independently associated with increased PHLF (OR = 1.47,95%CI:1.15-1.88), major complications (OR = 1.25,95%CI:1.08-1.45), mortality (OR = 1.61,95%CI:1.03-2.50), and if only major resections were assessed (OR = 1.38,95%CI:1.03-1.84). Diagnosis specific subgroup analyses revealed that effects of sex were predominantly HCC associated. CONCLUSIONS: This is the largest series investigating the effects of gender on outcomes after hepatic resection. We documented that women undergoing liver resection have significantly lower risk of PHLF. This difference seemed influenced by the striking increase of PHLF in male HCC patients. These hypothesis suggest that sex might play a role in preoperative risk stratification.

The von Willebrand Factor Facilitates Model for End-Stage Liver Disease-Independent Risk Stratification on the Waiting List for Liver Transplantation.

BACKGROUND AND AIMS: The Model for End-Stage Liver Disease (MELD) is used for clinical decision-making and organ allocation for orthotopic liver transplantation (OLT) and was previously upgraded through inclusion of serum sodium (Na) concentrations (MELD-Na). However, MELD-Na may underestimate complications arising from portal hypertension or infection. The von Willebrand factor (vWF) antigen (vWF-Ag) correlates with portal pressure and seems capable of predicting complications in patients with cirrhosis. Accordingly, this study aimed to evaluate vWF-Ag as an adjunct surrogate marker for risk stratification on the waiting list for OLT. APPROACH AND RESULTS: Hence, WF-Ag at time of listing was assessed in patients listed for OLT. Clinical characteristics, MELD-Na, and mortality on the waiting list were recorded. Prediction of 3-month waiting-list survival was assessed by receiver operating characteristics and net reclassification improvement. Interestingly, patients dying within 3 months on the waiting list displayed elevated levels of vWF-Ag (P < 0.001). MELD-Na and vWF-Ag were comparable and independent in their predictive potential for 3-month mortality on the waiting list (area under the curve [AUC], vWF-Ag = 0.739; MELD-Na = 0.764). Importantly, a vWF-Ag cutoff at 413% identified patients at risk for death within 3 months of listing with a higher odds ratio (OR) than the previously published cutoff at a MELD-Na of 20 points (vWF-Ag, OR = 10.873, 95% confidence interval [CI], 3.160, 36.084; MELD-Na, OR = 7.594, 95% CI, 2.578, 22.372; P < 0.001, respectively). Ultimately, inclusion of vWF-Ag into the MELD-Na equation significantly improved prediction of 3-month waiting-list mortality (AUC, MELD-Na-vWF = 0.804). CONCLUSIONS: A single measurement of vWF-Ag at listing for OLT predicts early mortality. Combining vWF-Ag levels with MELD-Na improves risk stratification and may help to prioritize organ allocation to decrease waiting-list mortality.

Early postoperative arterial lactate concentrations to stratify risk of post-hepatectomy liver failure.

BACKGROUND: Post-hepatectomy liver failure (PHLF) represents the major determinant for death after liver resection. Early recognition is essential. Perioperative lactate dynamics for risk assessment of PHLF and associated morbidity were evaluated. METHODS: This was a multicentre observational study of patients undergoing hepatectomy with validation in international high-volume units. Receiver operating characteristics analysis and cut-off calculation for the predictive value of lactate for clinically relevant International Study Group of Liver Surgery grade B/C PHLF (clinically relevant PHLF (CR-PHLF)) were performed. Lactate and other perioperative factors were assessed in a multivariable CR-PHLF regression model. RESULTS: The exploratory cohort comprised 509 patients. CR-PHLF, death, overall morbidity and severe morbidity occurred in 7.7, 3.3, 40.9 and 29.3 per cent of patients respectively. The areas under the curve (AUCs) regarding CR-PHLF were 0.829 (95 per cent c.i. 0.770 to 0.888) for maximum lactate within 24 h (Lactate_Max) and 0.870 (95 per cent c.i. 0.818 to 0.922) for postoperative day 1 levels (Lactate_POD1). The respective AUCs in the validation cohort (482 patients) were 0.812 and 0.751 and optimal Lactate_Max cut-offs were identical in both cohorts. Exploration cohort patients with Lactate_Max 50 mg/dl or greater more often developed CR-PHLF (50.0 per cent) than those with Lactate_Max between 20 and 49.9 mg/dl (7.4 per cent) or less than 20 mg/dl (0.5 per cent; P < 0.001). This also applied to death (18.4, 2.7 and 1.4 per cent), severe morbidity (71.1, 35.7 and 14.1 per cent) and associated complications such as acute kidney injury (26.3, 3.1 and 2.3 per cent) and haemorrhage (15.8, 3.1 and 1.4 per cent). These results were confirmed in the validation group. Combining Lactate_Max with Lactate_POD1 further increased AUC (ΔAUC = 0.053) utilizing lactate dynamics for risk assessment. Lactate_Max, major resections, age, cirrhosis and chronic kidney disease were independent risk factors for CR-PHLF. A freely available calculator facilitates clinical risk stratification (www.liver-calculator.com). CONCLUSION: Early postoperative lactate values are powerful, readily available markers for CR-PHLF and associated complications after hepatectomy with potential for guiding postoperative care.Presented in part as an oral video abstract at the 2020 online Congress of the European Society for Surgical Research and the 2021 Congress of the Austrian Surgical Society.

Liver failure represents a major complication after liver resection and determines the risk of postoperative death, therefore early anticipation and risk stratification are highly relevant. This study, of 991 patients in three international centres, shows that the maximum lactate blood level within 24 h after surgery is a very strong factor predicting the further course after liver operations. Lactate could potentially aid in clinical decision making such as prophylactic treatment, intensified observation or early discharge of patients.

Noninvasive evaluation of intragraft immune responses in upper extremity transplantation.

In vascularized composite allotransplantation (VCA), invasive tissue biopsies remain the gold standard in diagnosing rejection carrying significant morbidity. We aimed to show feasibility of tape-stripping for noninvasive immune monitoring in VCA. Tape-stripping was performed on allografts and native skin of upper extremity transplant recipients. Healthy nontransplanted individuals served as controls. The technique was also used in swine on naïve skin in nontransplanted animals, native skin of treated, transplanted swine, nonrejecting VCAs, and rejecting VCAs. Extracted protein was analyzed for differences in cytokine expression using Luminex technology. Significantly decreased levels of INFγ and IL-1Ra were seen between human allograft samples and native skin. In swine, rejecting grafts had increased IL-1Ra compared to naïve and native skin, decreased levels of GM-CSF compared to native skin, and decreased IL-10 compared to nonrejecting grafts. Unsupervised hierarchical clustering revealed rejecting grafts separated from the nonrejecting (P = 0.021). Variable importance in projection scores identified GM-CSF, IL-1Ra, and IL-2 as the most important profiles for group discrimination. Differences in cytokine expression are detectable in human VCA patient native skin and VCA graft skin using a noninvasive tape-stripping method. Swine studies suggest that differences in cytokines between rejecting and nonrejecting grafts are discernable.