Perioperative Complications After Pediatric Liver Transplantation-A Retrospective Analysis of 421 Cases.

BACKGROUND: Due to the low incidence of pediatric liver transplantations, short- and long-term data regarding their outcome, details on early postoperative complications and their risk factors are under-represented in the literature. METHODS: We retrospectively reviewed 1645 LTx performed at Hannover Medical School between January 2005 and December 2021. Of these, 421 transplantations were performed in 405 pediatric recipients. Univariate and multivariate binary logistic regressions were performed to identify independent risk factors for the onset of selected perioperative complications requiring intervention within the first 30 days following transplantation and their influence on graft and patient survival. RESULTS: Pleural effusions represent the most common postoperative complication observed in 49.4% (n = 208) of cases, followed by vascular complications in 22.6% (n = 95) and biliary complications in 20.0% (n = 84) of cases. Donor age (OR: 1.019; p = 0.010) and recipient age between 3 and 12 years (OR: 1.849; p = 0.008) were identified as independent risk factors for the onset of pleural effusions. Retransplantations within the first year after LTx were necessary in 11.4% of all cases (n = 48). Twenty (4.8%) patients died within the first year after LTx. CONCLUSION: Pleural effusions requiring postoperative intervention were observed in approximately half of the pediatric recipients. Therefore, the preemptive intraoperative placement of a chest drain under sterile conditions and general anesthesia should be considered. Our data further indicate that a two-stage procedure for biliary reconstruction may be the preferred procedure in patients at risk of early bile duct complications and retransplantation within the first year.

Identification and functional validation of miR-190b-5p and miR-296-3p as novel therapeutic attenuators of liver fibrosis.

BACKGROUND & AIMS: Liver fibrosis and its end-stage form known as cirrhosis contributes to millions of deaths annually. The lack of robust anti-fibrotic molecules is in part attributed to absence of any functional screens to identify molecular regulators using patient-derived primary human hepatic myofibroblasts, which are key drivers of fibrosis. METHODS: Here, to identify robust regulators of fibrosis, we performed functional microRNA screenings in primary human hepatic myofibroblasts followed by in vivo validation in three independent mouse models of fibrosis (toxin, cholestasis and MASH). RESULTS: We identified miR-190b-5p and miR-296-3p as robust anti-fibrotic miRNAs that suppress liver fibrosis. Notably, the expression of miR-190b-5p and miR-296-3p was found significantly reduced in human livers with fibrosis. Mechanistically, we discovered hyaluronan synthase 2 (HAS2) and integrin alpha-6 (ITGA6) as novel targets of miR-190b-5p and miR-296-3p, respectively. Furthermore, we demonstrated that the anti-fibrotic properties of miR-190b-5p and miR-296-3p are, at least in part, dependent on HAS2 and ITGA6. Finally, we showed the anti-fibrotic function of both miRNAs in a human liver bud model, which mimics multiple features of human liver. CONCLUSIONS: Collectively, in our study we discovered miR-190b-5p and miR-296-3p as two novel anti-fibrotic miRNAs, and that HAS2 and ITGA6 contribute to miR-190b-5p- and miR-296-3p-mediated inhibition of liver fibrosis. These results provide a foundation for future research to explore the clinical utility of miR-190b-5p and miR-296-3p in liver injuries with fibrosis. IMPACT AND IMPLICATIONS: Liver fibrosis and cirrhosis contribute to millions of deaths world-wide and, till date, remain as unmet medical needs. In this study, we discovered two microRNAs, miR-190b-5p and miR-296-3p, which suppress liver fibrosis in preclinical mouse models and a human liver bud model. Our promising results encourage further studies that aim to develop both miRNAs for the treatment of liver fibrosis in patients.

The triglyceride-synthesizing enzyme diacylglycerol acyltransferase 2 modulates the formation of the hepatitis C virus replication organelle.

The replication organelle of hepatitis C virus (HCV), called membranous web, is derived from the endoplasmic reticulum (ER) and mainly comprises double membrane vesicles (DMVs) that concentrate the viral replication complexes. It also tightly associates with lipid droplets (LDs), which are essential for virion morphogenesis. In particular acyl-CoA:diacylglycerol acyltransferase 1 (DGAT1), a rate-limiting enzyme in triglyceride synthesis, promotes early steps of virus assembly. The close proximity between ER membranes, DMVs and LDs therefore permits the efficient coordination of the HCV replication cycle. Here, we demonstrate that exaggerated LD accumulation due to the excessive expression of the DGAT1 isozyme, DGAT2, dramatically impairs the formation of the HCV membranous web. This effect depended on the enzymatic activity and ER association of DGAT2, whereas the mere LD accumulation was not sufficient to hamper HCV RNA replication. Our lipidomics data indicate that both HCV infection and DGAT2 overexpression induced membrane lipid biogenesis and markedly increased phospholipids with long chain polyunsaturated fatty acids, suggesting a dual use of these lipids and their possible competition for LD and DMV biogenesis. On the other hand, overexpression of DGAT2 depleted specific phospholipids, particularly oleyl fatty acyl chain-containing phosphatidylcholines, which, in contrast, are increased in HCV-infected cells and likely essential for viral infection. In conclusion, our results indicate that lipid exchanges occurring during LD biogenesis regulate the composition of intracellular membranes and thereby affect the formation of the HCV replication organelle. The potent antiviral effect observed in our DGAT2 overexpression system unveils lipid flux that may be relevant in the context of steatohepatitis, a hallmark of HCV infection, but also in physiological conditions, locally in specific subdomains of the ER membrane. Thus, LD formation mediated by DGAT1 and DGAT2 might participate in the spatial compartmentalization of HCV replication and assembly factories within the membranous web.

Kidney re-transplantation in the ipsilateral iliac fossa: a surgeon's perspective on perioperative outcome.

Background: Compared with primary transplantation, ipsilateral renal re-transplantation is associated with an increased risk of surgical complications and inferior graft outcomes. This study investigates whether an ipsilateral re-transplantation approach per se is an independent risk factor for surgical complications and early graft loss. Methods: In this retrospective, single-centre analysis, surgical complications and early graft outcomes of ipsilateral kidney re-transplantations from January 2007 to December 2017 were compared with primary transplantations and contralateral re-transplantations. Univariate and multivariate binary logistic regression analyses were performed to identify risk factors for surgical complications requiring surgical revision and graft loss within the first year after transplantation. Results: Of the 1489 kidney transplantations, 51 were ipsilateral, 159 were contralateral re-transplantations and 1279 were primary transplantations. Baseline characteristics did not differ between the ipsilateral and contralateral re-transplant recipients except for current and highest panel reactive antibody levels. Major complications requiring surgical revision were significantly more frequent in ipsilateral re-transplantations (P = .010) than in primary transplantations but did not differ between ipsilateral and contralateral re-transplantations (P = .217). Graft loss within the first year after transplant was 15.7% in the ipsilateral versus 8.8% in the contralateral re-transplant group (P = .163) versus 6.4% in the primary transplantation group (P = .009). In a multivariate regression model, ipsilateral re-transplantation was not identified as an independent risk factor for complications requiring surgical revision or first-year graft loss. Conclusions: Ipsilateral renal re-transplantation is not a risk factor for inferior outcomes. Graft implantation into a pre-transplanted iliac fossa is a feasible and valid therapeutic option.

Preoperative nonalcoholic steatohepatitis and resolution of metabolic comorbidities after bariatric surgery.

BACKGROUND: Most patients undergoing bariatric surgery demonstrate elements of the metabolic syndrome (MetS) and can therefore be diagnosed with metabolically unhealthy obesity (MUO). Nonalcoholic fatty liver disease (NAFLD) and nonalcoholic steatohepatitis (NASH) as hepatic manifestations of the MetS occur in many patients with obesity, but their leverage on postoperative improvement to Metabolic Health (MH), defined as absence of any metabolic comorbidity, remains unclear. OBJECTIVES: The aim of this study was to assess the influence of liver health status, operative procedure, and sex on postoperative switch from a MUO to an MH phenotype. Secondary objective was weight loss to MH. SETTING: University Hospital, Germany. METHODS: Patients who underwent either Roux-en-Y gastric bypass (RYGB) or sleeve gastrectomy (SG) at our obesity surgery center were included in this retrospective study. Liver biopsy was taken and evaluated for presence of NAFLD/NASH. For diagnosis of MH, blood pressure and laboratory values referring to the MetS were assessed preoperatively and at 3, 6, 12, and 24 months' postoperatively. RESULTS: One hundred thirty-three patients (73% female) with a mean body mass index of 52.0 kg/m2 and mean age of 43 years were included in this study. A total of 55.6% underwent RYGB and 44.4% underwent SG. NAFLD was found in 51.1% of patients and NASH in 33.8%. All patients were diagnosed MUO at baseline. Postoperatively, 38.3% patients (n = 51) switched to a MH condition. Mean time to MH was 321 days and mean excess body mass index loss to MH was 63.8%. There were no differences regarding liver health status, operative procedure, or sex. CONCLUSIONS: Bariatric surgery can resolve MUO independent of liver health status, operative procedure, and sex. However, patients should be closely monitored to ensure sustainable long-term outcomes following the switch to the MH condition.

MicroRNAs modulate SARS-CoV-2 infection of primary human hepatocytes by regulating the entry factors ACE2 and TMPRSS2.

BACKGROUND AND AIMS: Severe acute respiratory syndrome coronavirus (SARS-CoV-2) preferentially infects the respiratory tract; however, several studies have implicated a multi-organ involvement. Hepatic dysfunctions caused by SARS-CoV-2 infection have been increasingly recognized and described to correlate with disease severity. To elucidate molecular factors that could contribute towards hepatic infection, we concentrated on microRNAs (miRNAs), a class of small non-coding RNAs that modulate various cellular processes and which are reported to be differentially regulated during liver injury. We aimed to study the infection of primary human hepatocytes (PHH) with SARS-CoV-2 and to evaluate the potential of miRNAs for modulating viral infection. METHODS: We analysed liver autopsies from a coronavirus disease 19 (COVID-19)-positive cohort for the presence of viral RNA using Nanopore sequencing. PHH were used for the infection with SARS-CoV-2. The candidate miRNAs targeting angiotensin converting enzyme 2 (ACE2) and transmembrane serine protease 2 (TMPRSS2) were identified using in silico approaches. To discover the potential regulatory mechanism, transfection experiments, qRT-PCRs, western blots and luciferase reporter assays were performed. RESULTS: We could detect SARS-CoV-2 RNA in COVID-19-positive liver autopsies. We show that PHH express ACE2 and TMPRSS2 and can be readily infected with SARS-CoV-2, resulting in robust replication. Transfection of selected miRNA mimics reduced SARS-CoV-2 receptor expression and SARS-CoV-2 burden in PHH. In silico and biochemical analyses supported a potential direct binding of miR-141-3p to the SARS-CoV-2 genome. CONCLUSION: We confirm that PHH are susceptible to SARS-CoV-2 infection and demonstrate selected miRNAs targeting SARS-CoV-2 entry factors and/or the viral genome reduce viral loads. These data provide novel insights into hepatic susceptibility to SARS-CoV-2 and associated dysfunctions in COVID-19.

Resection of intrahepatic cholangiocarcinoma in octogenarians: a single-center analysis.

The rapidly aging population in industrialized countries comes with an increased incidence of intrahepatic cholangiocarcinoma (iCC) which presents new challenges for oncological treatments especially in elderly patients. Thus, the question arises to what extent the benefit of surgical resections, as the only curative treatment option, outweighs possible perioperative risks in patients ≥ 80 years of age (octogenarians). We therefore retrospectively analyzed 311 patients who underwent resection for iCC at Hannover Medical School between January 1996 and December 2022. In total, there were 11 patients older than 80 years in our collective. Despite similar tumor size, octogenarians underwent comparatively less extensive surgery (54.5% major resections in octogenarians vs. 82.7% in all other patients; p = 0.033) with comparable rates of lymphadenectomy and tumor-free resection margins. Furthermore, we did not observe increased major postoperative morbidity (Clavien-Dindo ≥ IIIa complications: 27.3% vs. 34.3% in all other patients; p = 0.754) or mortality (estimated 1-year OS of 70.7% vs. 72.5% in all other patients, p = 0.099). The length of intensive care unit (ICU) or intermediate care unit (IMC) stay was significantly longer in octogenarians, however, with a comparable length in total hospital stay. The estimated overall survival (OS) did also not differ significantly, although a trend towards reduced long-term survival was observed (14.5 months vs. 28.03 months in all other patients; p = 0.099). In conclusion, primary resection is a justifiable and safe therapeutic option even in octogenarians but requires an even more thorough preoperative patient selection.

Phosphatidylinositol 4-Kinase III Alpha Governs Cytoskeletal Organization for Invasiveness of Liver Cancer Cells.

BACKGROUND & AIMS: High expression of phosphatidylinositol 4-kinase III alpha (PI4KIIIα) correlates with poor survival rates in patients with hepatocellular carcinoma. In addition, hepatitis C virus (HCV) infections activate PI4KIIIα and contribute to hepatocellular carcinoma progression. We aimed at mechanistically understanding the impact of PI4KIIIα on the progression of liver cancer and the potential contribution of HCV in this process. METHODS: Several hepatic cell culture and mouse models were used to study the functional importance of PI4KIIIα on liver pathogenesis. Antibody arrays, gene silencing, and PI4KIIIα-specific inhibitor were applied to identify the involved signaling pathways. The contribution of HCV was examined by using HCV infection or overexpression of its nonstructural protein. RESULTS: High PI4KIIIα expression and/or activity induced cytoskeletal rearrangements via increased phosphorylation of paxillin and cofilin. This led to morphologic alterations and higher migratory and invasive properties of liver cancer cells. We further identified the liver-specific lipid kinase phosphatidylinositol 3-kinase C2 domain-containing subunit gamma (PIK3C2γ) working downstream of PI4KIIIα in regulation of the cytoskeleton. PIK3C2γ generates plasma membrane phosphatidylinositol 3,4-bisphosphate-enriched, invadopodia-like structures that regulate cytoskeletal reorganization by promoting Akt2 phosphorylation. CONCLUSIONS: PI4KIIIα regulates cytoskeleton organization via PIK3C2γ/Akt2/paxillin-cofilin to favor migration and invasion of liver cancer cells. These findings provide mechanistic insight into the contribution of PI4KIIIα and HCV to the progression of liver cancer and identify promising targets for therapeutic intervention.

Unraveling the dynamics of hepatitis C virus adaptive mutations and their impact on antiviral responses in primary human hepatocytes.

Hepatitis C virus (HCV) infection progresses to chronicity in the majority of infected individuals. Its high intra-host genetic variability enables HCV to evade the continuous selection pressure exerted by the host, contributing to persistent infection. Utilizing a cell culture-adapted HCV population (p100pop) which exhibits increased replicative capacity in various liver cell lines, this study investigated virus and host determinants that underlie enhanced viral fitness. Characterization of a panel of molecular p100 clones revealed that cell culture adaptive mutations optimize a range of virus-host interactions, resulting in expanded cell tropism, altered dependence on the cellular co-factor micro-RNA 122 and increased rates of virus spread. On the host side, comparative transcriptional profiling of hepatoma cells infected either with p100pop or its progenitor virus revealed that enhanced replicative fitness correlated with activation of endoplasmic reticulum stress signaling and the unfolded protein response. In contrast, infection of primary human hepatocytes with p100pop led to a mild attenuation of virion production which correlated with a greater induction of cell-intrinsic antiviral defense responses. In summary, long-term passage experiments in cells where selective pressure from innate immunity is lacking improves multiple virus-host interactions, enhancing HCV replicative fitness. However, this study further indicates that HCV has evolved to replicate at low levels in primary human hepatocytes to minimize innate immune activation, highlighting that an optimal balance between replicative fitness and innate immune induction is key to establish persistence. IMPORTANCE: Hepatitis C virus (HCV) infection remains a global health burden with 58 million people currently chronically infected. However, the detailed molecular mechanisms that underly persistence are incompletely defined. We utilized a long-term cell culture-adapted HCV, exhibiting enhanced replicative fitness in different human liver cell lines, in order to identify molecular principles by which HCV optimizes its replication fitness. Our experimental data revealed that cell culture adaptive mutations confer changes in the host response and usage of various host factors. The latter allows functional flexibility at different stages of the viral replication cycle. However, increased replicative fitness resulted in an increased activation of the innate immune system, which likely poses boundary for functional variation in authentic hepatocytes, explaining the observed attenuation of the adapted virus population in primary hepatocytes.

Transplanting old organs promotes senescence in young recipients.

In clinical organ transplantation, donor and recipient ages may differ substantially. Old donor organs accumulate senescent cells that have the capacity to induce senescence in naïve cells. We hypothesized that the engraftment of old organs may induce senescence in younger recipients, promoting age-related pathologies. When performing isogeneic cardiac transplants between age-mismatched C57BL/6 old donor (18 months) mice and young and middle-aged C57BL/6 (3- or 12- month-old) recipients , we observed augmented frequencies of senescent cells in draining lymph nodes, adipose tissue, livers, and hindlimb muscles 30 days after transplantation. These observations went along with compromised physical performance and impaired spatial learning and memory abilities. Systemic levels of the senescence-associated secretory phenotype factors, including mitochondrial DNA (mt-DNA), were elevated in recipients. Of mechanistic relevance, injections of mt-DNA phenocopied effects of age-mismatched organ transplantation on accelerating aging. Single treatment of old donor animals with senolytics prior to transplantation attenuated mt-DNA release and improved physical capacities in young recipients. Collectively, we show that transplanting older organs induces senescence in transplant recipients, resulting in compromised physical and cognitive capacities. Depleting senescent cells with senolytics, in turn, represents a promising approach to improve outcomes of older organs.

Hepatitis C virus cell culture adaptive mutations enhance cell culture propagation by multiple mechanisms but boost antiviral responses in primary human hepatocytes.

Hepatitis C virus (HCV) infection progresses to chronicity in the majority of infected individuals. Its high intra-host genetic variability enables HCV to evade the continuous selection pressure exerted by the host, contributing to persistent infection. Utilizing a cell culture adapted HCV population (p100pop) which exhibits increased replicative capacity in various liver cell lines, this study investigated virus and host determinants which underlie enhanced viral fitness. Characterization of a panel of molecular p100 clones revealed that cell culture adaptive mutations optimize a range of virus-host interactions, resulting in expanded cell tropism, altered dependence on the cellular co-factor micro-RNA 122 and increased rates of virus spread. On the host side, comparative transcriptional profiling of hepatoma cells infected either with p100pop or its progenitor virus revealed that enhanced replicative fitness correlated with activation of endoplasmic reticulum stress signaling and the unfolded protein response. In contrast, infection of primary human hepatocytes with p100pop led to a mild attenuation of virion production which correlated with a greater induction of cell-intrinsic antiviral defense responses. In summary, long-term passage experiments in cells where selective pressure from innate immunity is lacking improves multiple virus-host interactions, enhancing HCV replicative fitness. However, this study further indicates that HCV has evolved to replicate at low levels in primary human hepatocytes to minimize innate immune activation, highlighting that an optimal balance between replicative fitness and innate immune induction is key to establishing persistence.

The matrix metalloproteinase ADAM10 supports hepatitis C virus entry and cell-to-cell spread via its sheddase activity.

Hepatitis C virus (HCV) exploits the four entry factors CD81, scavenger receptor class B type I (SR-BI, also known as SCARB1), occludin, and claudin-1 as well as the co-factor epidermal growth factor receptor (EGFR) to infect human hepatocytes. Here, we report that the disintegrin and matrix metalloproteinase 10 (ADAM10) associates with CD81, SR-BI, and EGFR and acts as HCV host factor. Pharmacological inhibition, siRNA-mediated silencing and genetic ablation of ADAM10 reduced HCV infection. ADAM10 was dispensable for HCV replication but supported HCV entry and cell-to-cell spread. Substrates of the ADAM10 sheddase including epidermal growth factor (EGF) and E-cadherin, which activate EGFR family members, rescued HCV infection of ADAM10 knockout cells. ADAM10 did not influence infection with other enveloped RNA viruses such as alphaviruses and a common cold coronavirus. Collectively, our study reveals a critical role for the sheddase ADAM10 as a HCV host factor, contributing to EGFR family member transactivation and as a consequence to HCV uptake.

Pushing the boundaries of innovation: the potential of ex vivo organ perfusion from an interdisciplinary point of view.

Ex vivo machine perfusion (EVMP) is an emerging technique for preserving explanted solid organs with primary application in allogeneic organ transplantation. EVMP has been established as an alternative to the standard of care static-cold preservation, allowing for prolonged preservation and real-time monitoring of organ quality while reducing/preventing ischemia-reperfusion injury. Moreover, it has paved the way to involve expanded criteria donors, e.g., after circulatory death, thus expanding the donor organ pool. Ongoing improvements in EVMP protocols, especially expanding the duration of preservation, paved the way for its broader application, in particular for reconditioning and modification of diseased organs and tumor and infection therapies and regenerative approaches. Moreover, implementing EVMP for in vivo-like preclinical studies improving disease modeling raises significant interest, while providing an ideal interface for bioengineering and genetic manipulation. These approaches can be applied not only in an allogeneic and xenogeneic transplant setting but also in an autologous setting, where patients can be on temporary organ support while the diseased organs are treated ex vivo, followed by reimplantation of the cured organ. This review provides a comprehensive overview of the differences and similarities in abdominal (kidney and liver) and thoracic (lung and heart) EVMP, focusing on the organ-specific components and preservation techniques, specifically on the composition of perfusion solutions and their supplements and perfusion temperatures and flow conditions. Novel treatment opportunities beyond organ transplantation and limitations of abdominal and thoracic EVMP are delineated to identify complementary interdisciplinary approaches for the application and development of this technique.

Modifying immune responses to adeno-associated virus vectors by capsid engineering.

De novo immune responses are considered major challenges in gene therapy. With the aim to lower innate immune responses directly in cells targeted by adeno-associated virus (AAV) vectors, we equipped the vector capsid with a peptide known to interfere with Toll-like receptor signaling. Specifically, we genetically inserted in each of the 60 AAV2 capsid subunits the myeloid differentiation primary response 88 (MyD88)-derived peptide RDVLPGT, known to block MyD88 dimerization. Inserting the peptide neither interfered with capsid assembly nor with vector production yield. The novel capsid variant, AAV2.MB453, showed superior transduction efficiency compared to AAV2 in human monocyte-derived dendritic cells and in primary human hepatocyte cultures. In line with our hypothesis, AAV2.MB453 and AAV2 differed regarding innate immune response activation in primary human cells, particularly for type I interferons. Furthermore, mice treated with AAV2.MB453 showed significantly reduced CD8+ T cell responses against the transgene product for different administration routes and against the capsid following intramuscular administration. Moreover, humoral responses against the capsid were mitigated as indicated by delayed IgG2a antibody formation and an increased NAb50. To conclude, insertion of the MyD88-derived peptide into the AAV2 capsid improved early steps of host-vector interaction and reduced innate and adaptive immune responses.

Janus kinase-inhibition modulates hepatitis E virus infection.

Hepatitis E virus (HEV) usually causes a self-limiting disease, but especially immunocompromised individuals are at risk to develop a chronic and severe course of infection. Janus kinase (JAK) inhibitors (JAKi) are a novel drug class for the treatment of autoimmune inflammatory rheumatic disease (AIRD). As JAKs play a key role in innate immunity, viral infections and reactivations are frequently reported during JAKi treatment in AIRD patients. The aim of this study was to characterize the influence of JAKis on HEV replication. To this end, we evaluated liver enzymes of an AIRD patient under JAKi therapy with hepatitis E. Further, experiments with HEV (Kernow-C1 p6) were performed by infection of primary human hepatocytes (PHHs) followed by immunofluorescence staining of viral markers and transcriptomic analysis. Infection experiments in PHHs displayed an up to 50-fold increase of progeny virus production during JAKi treatment and transcriptomic analysis revealed induction of antiviral programs during infection. Upregulation of interferon-stimulated genes (ISG) was perturbed in the presence of JAKis, concomitant with elevated HEV RNA levels. The obtained results suggest that therapeutic JAK inhibition increases HEV replication by modulating the HEV-triggered immune response. Therefore, JAKi treatment and the occurrence of elevated liver enzymes requires a monitoring of potential HEV infections.

Hepatitis D virus infection, innate immune response and antiviral treatments in stem cell-derived hepatocytes.

BACKGROUND: Human pluripotent stem cell (hPSC)-derived hepatocyte-like cells (HLCs) are a valuable model to investigate host-pathogen interactions of hepatitis viruses in a mature and authentic environment. Here, we investigate the susceptibility of HLCs to the hepatitis delta virus (HDV). METHODS: We differentiated hPSC into HLCs, and inoculated them with infectious HDV produced in Huh7NTCP . HDV infection and cellular response was monitored by RTqPCR and immunostaining. RESULTS: Cells undergoing hepatic differentiation become susceptible to HDV after acquiring expression of the viral receptor Na+ -taurocholate co-transporting polypeptide (NTCP) during hepatic specification. Inoculation of HLCs with HDV leads to detection of intracellular HDV RNA and accumulation of the HDV antigen in the cells. Upon infection, the HLCs mounted an innate immune response based on induction of the interferons IFNB and L, and upregulation of interferon-stimulated genes. The intensity of this immune response positively correlated with the level of viral replication and was dependant on both the JAK/STAT and NFκB pathway activation. Importantly, this innate immune response did not inhibit HDV replication. However, pre-treatment of the HLCs with IFNα2b reduced viral infection, suggesting that ISGs may limit early stages of infection. Myrcludex efficiently abrogated infection and blocked innate immune activation. Lonafarnib treatment of HDV mono infected HLCs on the other hand led to exacerbated viral replication and innate immune response. CONCLUSION: The HDV in vitro mono-infection model represents a new tool to study HDV replication, its host-pathogen interactions and evaluate new antiviral drugs in cells displaying mature hepatic functions.

Preoperative hemoglobin levels, extended resections and the body mass index influence survival after pancreaticoduodenectomy.

PURPOSE: The negative influence of perioperative transfusion of packed red blood cells on the prognosis of various malignancies is the focus of recent research interest. The development of a propensity score for the prediction of perioperative transfusion of packed red blood cells (pRBCs) and the identification of independent risk factors for survival, that can either be known prior to or during surgery in patients undergoing pancreaticoduodenectomy for pancreatic head cancer are the two objectives of this study. METHODS: Logistic regression analyses and Cox regression modeling were used to identify independent risk factors for perioperative transfusion of pRBCs and to determine individual risk factors for patient survival. A total of 101 adult patients who underwent surgery between 01/01/2016 and 12/31/2020 were investigated in a single-center retrospective analysis. RESULTS: Preoperative hemoglobin levels (OR: 0.472, 95%-CI: 0.312-0.663, p < 0.001) and extended resections (OR: 4.720, 95%-CI: 1.819-13.296, p = 0.001) were identified as independent risk factors for perioperative transfusion of pRBCs, enabling the prediction of pRBC transfusion with high sensitivity and specificity (AUROC: 0.790). The logit of the derived propensity model for the transfusion of pRBCs (HR: 9.231, 95%CI: 3.083-28.118, p < 0.001) and preoperative Body Mass Index (BMI) (HR, 0.925; 95%-CI: 0.870-0.981, p = 0.008) were independent risk factors for survival. CONCLUSIONS: Low preoperative hemoglobin levels, low BMI values, and extended resections are significant risk factors for survival that can be known and thus potentially be influenced prior to or during surgery. Patient blood management programs and prehabilitation programs should strive to increase preoperative hemoglobin levels and improve preoperative malnutrition.

EGF receptor modulates HEV entry in human hepatocytes.

BACKGROUND AND AIMS: Being the most common cause of acute viral hepatitis with >20 million cases per year and 70,000 deaths annually, HEV presents a long-neglected and underinvestigated health burden. Although the entry process of viral particles is an attractive target for pharmacological intervention, druggable host factors to restrict HEV entry have not been identified so far. APPROACH AND RESULTS: Here we identify the EGF receptor (EGFR) as a novel host factor for HEV and reveal the significance of EGFR for the HEV entry process. By utilizing RNAi, chemical modulation with Food and Drug Administration-approved drugs, and ectopic expression of EGFR, we revealed that EGFR is critical for HEV infection without affecting HEV RNA replication or assembly of progeny virus. We further unveiled that EGFR itself and its ligand-binding domain, rather than its signaling function, is responsible for the proviral effect. Modulation of EGF expression in HepaRG cells and primary human hepatocytes affected HEV infection. CONCLUSIONS: Taken together, our study provides novel insights into the life cycle of HEV and identified EGFR as a possible target for future antiviral strategies against HEV.