Targeting the eicosanoid pathway in hepatocellular carcinoma.

Liver cancer has variable incidence worldwide and high mortality. Histologically, the most common subtype of liver cancer is hepatocellular carcinoma (HCC). Approximately 30-40% of HCC patients are diagnosed at an advanced stage, and at present, there are limited treatment options for such patients. The current first-line therapy with tyrosine kinase inhibitors, sorafenib or lenvatinib, prolongs survival by a median of about 2.5-3 months after which the disease normally progresses. Additionally, many patients discontinue the use of tyrosine kinase inhibitors due to toxicity or may not be suitable candidates due to co-morbidity or frailty. It is, therefore, imperative to identify novel therapeutic targets for advanced HCC patients. Persistent injury to the liver as a result of insults such as hepatitis B or C viral (HBV or HCV) infections, alcohol abuse, and non-alcoholic fatty liver disease (NAFLD), results in chronic inflammation, which progresses to hepatic fibrosis and later, cirrhosis, provides the conditions for initiation of HCC. One of the key pathways studied for its role in inflammation and carcinogenesis is the eicosanoid pathway. In this review, we briefly outline the eicosanoid pathway, describe the mechanisms by which some pathway members either facilitate or counter the development of liver diseases, with the focus on NAFLD/hepatic fibrosis/cirrhosis, and HCC. We describe the link between the eicosanoid pathway, inflammation and these liver diseases, and identify components of the eicosanoid pathway that may be used as potential therapeutic targets in HCC.

Supplementation with Synbiotics and/or Branched Chain Amino Acids in Hepatic Encephalopathy: A Pilot Randomised Placebo-Controlled Clinical Study.

INTRODUCTION: Hepatic encephalopathy (HE) is common in patients with cirrhosis and is characterised by reduced hepatic ammonia clearance. This is accompanied by alterations in gut bacteria that may be ameliorated with synbiotics (pro- and prebiotics). Branched chain amino acids (BCAAs) are thought to have a role in the detoxification of ammonia. We investigated the effects of the administration of synbiotics and/or BCAAs in treating HE. METHODS: Participants with overt HE were randomised in a blinded placebo-controlled study to receive synbiotics, BCAAs, or a combination of BCAAs and Synbiotics. Relevant biochemical and nutritional data and depression and anxiety scores (DASS-21) were collected at entry, 4 weeks, and on completion, at 8 weeks. The Trail Making Test (TMT) and Inhibitory Control Test (ICT) were used to assess cognitive function in patients withHE. Results were analysed using linear mixed effects regression analyses. RESULTS: Sixty-one participants were enrolled and 49 who returned for at least 1 follow-up review were included in the intention to treat analysis. The mean age was 55.8 ± 6.1 years and 86% were males. Despite evidence of a placebo effect, there was significant improvement in TMT B and ICT weighted lures in participants who received combined synbiotics/BCAAs treatment compared to placebo at study completion (p ≤ 0.05). Cognitive improvement occurred without a significant change in ammonia levels. CONCLUSION: To our knowledge, this is the first study reporting that combined synbiotics and BCAAs improve HE, and that may be beneficial in the management of HE. A larger study is needed to confirm these results.

CD147 mediates intrahepatic leukocyte aggregation and determines the extent of liver injury.

BACKGROUND: Chronic inflammation is the driver of liver injury and results in progressive fibrosis and eventual cirrhosis with consequences including both liver failure and liver cancer. We have previously described increased expression of the highly multifunctional glycoprotein CD147 in liver injury. This work describes a novel role of CD147 in liver inflammation and the importance of leukocyte aggregates in determining the extent of liver injury. METHODS: Non-diseased, progressive injury, and cirrhotic liver from humans and mice were examined using a mAb targeting CD147. Inflammatory cell subsets were assessed by multiparameter flow cytometry. RESULTS: In liver injury, we observe abundant, intrahepatic leukocyte clusters defined as ≥5 adjacent CD45+ cells which we have termed "leukocyte aggregates". We have shown that these leukocyte aggregates have a significant effect in determining the extent of liver injury. If CD147 is blocked in vivo, these leukocyte aggregates diminish in size and number, together with a marked significant reduction in liver injury including fibrosis. This is accompanied by no change in overall intrahepatic leukocyte numbers. Further, blocking of aggregation formation occurs prior to an appreciable increase in inflammatory markers or fibrosis. Additionally, there were no observed, "off-target" or unpredicted effects in targeting CD147. CONCLUSION: CD147 mediates leukocyte aggregation which is associated with the development of liver injury. This is not a secondary effect, but a cause of injury as aggregate formation proceeds other markers of injury. Leukocyte aggregation has been previously described in inflammation dating back over many decades. Here we demonstrate that leukocyte aggregates determine the extent of liver injury.

The Role of Micronutrients in the Infection and Subsequent Response to Hepatitis C Virus.

Micronutrient deficiencies develop for a variety of reasons, whether geographic, socioeconomic, nutritional, or as a result of disease pathologies such as chronic viral infection. As micronutrients are essential for a strong immune response, deficiencies can significantly dampen both the innate and the adaptive arms of antiviral immunity. The innate immune response in particular is crucial to protect against hepatitis C virus (HCV), a hepatotropic virus that maintains chronic infection in up to 80% of individuals if left untreated. While many micronutrients are required for HCV replication, an overlapping group of micronutrients are also necessary to enact a potent immune response. As the liver is responsible for the storage and metabolism of many micronutrients, HCV persistence can influence the micronutrients' steady state to benefit viral persistence both directly and by weakening the antiviral response. This review will focus on common micronutrients such as zinc, iron, copper, selenium, vitamin A, vitamin B12, vitamin D and vitamin E. We will explore their role in the pathogenesis of HCV infection and in the response to antiviral therapy. While chronic hepatitis C virus infection drives deficiencies in micronutrients such as zinc, selenium, vitamin A and B12, it also stimulates copper and iron excess; these micronutrients influence antioxidant, inflammatory and immune responses to HCV.

Cellular Genomic Sites of Hepatitis B Virus DNA Integration.

Infection with the Hepatitis B Virus (HBV) is one of the strongest risk-factors for liver cancer (hepatocellular carcinoma, HCC). One of the reported drivers of HCC is the integration of HBV DNA into the host cell genome, which may induce pro-carcinogenic pathways. These reported pathways include: induction of chromosomal instability; generation of insertional mutagenesis in key cancer-associated genes; transcription of downstream cancer-associated cellular genes; and/or formation of a persistent source of viral protein expression (particularly HBV surface and X proteins). The contribution of each of these specific mechanisms towards carcinogenesis is currently unclear. Here, we review the current knowledge of specific sites of HBV DNA integration into the host genome, which sheds light on these mechanisms. We give an overview of previously-used methods to detect HBV DNA integration and the enrichment of integration events in specific functional and structural cellular genomic sites. Finally, we posit a theoretical model of HBV DNA integration during disease progression and highlight open questions in the field.

Hepatitis B Virus DNA Integration Occurs Early in the Viral Life Cycle in an In Vitro Infection Model via Sodium Taurocholate Cotransporting Polypeptide-Dependent Uptake of Enveloped Virus Particles.

Chronic infection by hepatitis B virus (HBV) is the major contributor to liver disease worldwide. Though HBV replicates via a nuclear episomal DNA (covalently closed circular DNA [cccDNA]), integration of HBV DNA into the host cell genome is regularly observed in the liver in infected patients. While reported as a prooncogenic alteration, the mechanism(s) and timing of HBV DNA integration are not well understood, chiefly due to the lack of in vitro infection models that have detectable integration events. In this study, we have established an in vitro system in which integration can be reliably detected following HBV infection. We measured HBV DNA integration using inverse nested PCR in primary human hepatocytes, HepaRG-NTCP, HepG2-NTCP, and Huh7-NTCP cells after HBV infection. Integration was detected in all cell types at a rate of >1 per 10,000 cells, with the most consistent detection in Huh7-NTCP cells. The integration rate remained stable between 3 and 9 days postinfection. HBV DNA integration was efficiently blocked by treatment with a 200 nM concentration of the HBV entry inhibitor Myrcludex B, but not with 10 µM tenofovir, 100 U of interferon alpha, or a 1 µM concentration of the capsid assembly inhibitor GLS4. This suggests that integration of HBV DNA occurs immediately after infection of hepatocytes and is likely independent of de novo HBV genome replication in this model. Site analysis revealed that HBV DNA integrations were distributed over the entire human genome. Further, integrated HBV DNA sequences were consistent with double-stranded linear HBV DNA being the major precursor. Thus, we have established an in vitro system to interrogate the mechanisms of HBV DNA integration.IMPORTANCE Hepatitis B virus (HBV) is a common blood-borne pathogen and, following a chronic infection, can cause liver cancer and liver cirrhosis. Integration of HBV DNA into the host genome occurs in all known members of the Hepadnaviridae family, despite this form not being necessary for viral replication. HBV DNA integration has been reported to drive liver cancer formation and persistence of virus infection. However, when and the mechanism(s) by which HBV DNA integration occurs are not clear. In this study, we have developed and characterized an in vitro system to reliably detect HBV DNA integrations that result from a true HBV infection event and that closely resemble those found in patient tissues. Using this model, we showed that integration occurs when the infection is first established. Importantly, we provide here a system to analyze molecular factors involved in HBV integration, which can be used to develop strategies to halt its formation.

Hepatitis Transmission Risk in Kidney Transplantation (the HINT study): A Cross-Sectional Survey of Transplant Clinicians in Australia and New Zealand.

BACKGROUND: Interpreting hepatitis serology and virus transmission risk in transplantation can be challenging. Decisions must balance opportunity to transplant against potential infection transmission. We aimed to survey understanding among the Australian and New Zealand medical transplant workforce of hepatitis risk in kidney donors and recipients. METHODS: An anonymous, self-completed, cross-sectional survey was distributed via electronic mailing lists to Australian and New Zealand clinicians involved in kidney transplantation (2014-2015). We compared interpretation of clinical scenarios with paired donor and recipient hepatitis B virus and hepatitis C virus serology to recommendations in clinical practice guidelines. We used logistic regression modeling to investigate characteristics associated with decisions on transplant suitability in scenarios with poor (<50%) guideline concordance (odds ratios [OR]). RESULTS: One hundred ten respondents had representative workforce demographics: most were male (63%) nephrologists (74%) aged 40 to 49 years. Although donor and recipient hepatitis status was largely well understood, transplant suitability responses varied among respondents. For a hepatitis B virus surface antigen-positive donor and vaccinated recipient, 44% suggested this was unsuitable for transplant (guideline concordant) but 35% suggested this was suitable with prophylaxis (guideline divergent). In 4 scenarios with transplant suitability guideline concordance less than 50%, acute transplant care involvement predicted guideline concordant responses (OR, 1.69; P = 0.04). Guideline concordant responses were chosen less by hepatologists, intensive care doctors (OR, 0.23, 0.35, respectively; P = 0.01), and New Zealanders (guideline concordant responses OR, 0.17; P < 0.01; alternative responses OR, 4.31; P < 0.01). CONCLUSIONS: Despite broadly consistent interpretations of hepatitis serology, transplant suitability decisions varied and often diverged from guidelines. Improved decision support may reduce clinician variability.

Patients with non-viral liver disease have a greater tumor burden and less curative treatment options when diagnosed with hepatocellular carcinoma.

AIM: To assess the impact of underlying liver disease etiology on the presenting features and outcomes in a large cohort of patients with hepatocellular carcinoma (HCC). METHODS: A prospective database of all patients with HCC was established from 1998 to March 2012. One thousand and seventy-eight patients were categorized into three groups, based on the etiology of their liver disease: hepatitis B virus (HBV), hepatitis C virus (HCV) and non-viral liver disease (NVLD). Overall survival was determined by Kaplan Meier analysis to time of death or last follow-up. RESULTS: HCC patients with HCV (85%) were more likely to be diagnosed as part of a surveillance program, compared to HBV or NVLD (both 71%) (P < 0.001). Patients with NVLD were more likely to receive best supportive care (29%) compared to those with HBV (21%) or HCV (20%) (P < 0.02). Twelve percent of NVLD and 13% of HBV patients underwent liver transplantation compared to 21% of HCV patients (P = 0.001). Median survival from presentation was lowest in NVLD (1.7 years) when compared to HBV (2.8 years) and HCV (2.6 years) (P < 0.05). In multivariate analysis, independent predictors of survival included Child Turcotte Pugh score, size of dominant lesion, absence of vascular invasion, and management with surgical resection or liver transplantation. Patient age and the etiology of the underlying liver disease were not independent predictors of survival. CONCLUSION: Patients with NVLD and HCC were less likely to be enrolled in a HCC surveillance program and are less likely to have curative therapies such as liver resection and transplantation after diagnosis with HCC, when compared to patients with Hepatitis B and Hepatitis C.

HBV DNA Integration: Molecular Mechanisms and Clinical Implications.

Chronic infection with the Hepatitis B Virus (HBV) is a major cause of liver-related morbidity and mortality. One peculiar observation in cells infected with HBV (or with closely­related animal hepadnaviruses) is the presence of viral DNA integration in the host cell genome, despite this form being a replicative dead-end for the virus. The frequent finding of somatic integration of viral DNA suggests an evolutionary benefit for the virus; however, the mechanism of integration, its functions, and the clinical implications remain unknown. Here we review the current body of knowledge of HBV DNA integration, with particular focus on the molecular mechanisms and its clinical implications (including the possible consequences of replication-independent antigen expression and its possible role in hepatocellular carcinoma). HBV DNA integration is likely to influence HBV replication, persistence, and pathogenesis, and so deserves greater attention in future studies.

Postreperfusion microcirculatory derangements after liver transplantation: Relationship to hemodynamics, serum mediators, and outcome.

Despite the growing data supporting the role of microcirculation in regulating liver function, little of this knowledge has been translated into clinical practice. The aim of this study is to quantify hepatic microcirculation in vivo using sidestream dark field (SDF) imaging and correlate these findings with hepatic blood flow, hemodynamic parameters, and soluble mediators. Postreperfusion hepatic microcirculation was assessed using SDF imaging. Hepatic microcirculation measurements included functional sinusoidal density (cm/cm2 ), sinusoidal diameter (µm), red blood cell velocity (µm/second), volumetric blood flow (pl/second), and flow heterogeneity (FH) index. The serum concentrations of endothelin 1 (ET-1) and other inflammatory markers were analyzed with Luminex technology. Portal venous and hepatic artery flows were measured using a flowmeter. Twenty-eight patients undergoing cadaveric liver transplantations have been included in this study. Early allograft dysfunction (EAD) occurred in 7 (25%) patients and was associated with microcirculatory dysfunction. Low arterial and portal flow, high dose of inotropes, cold ischemia time, steatosis, and high ET-1 levels were all associated with impaired microcirculation. The time interval between portal venous and hepatic arterial reperfusion significantly correlated with the changes of the liver grafts' microcirculation. EAD patients tended to have higher serum levels of ET-1 on postoperative days 1, 2, 5, and 7 (all P < 0.01). Serum levels of ET-1 correlated significantly with microcirculation parameters. In conclusion, postreperfusion hepatic microcirculation is a determinant of organ dysfunction after liver reperfusion and could be used to identify very early patients at risk of EAD. Liver Transplantation 23 527-536 2017 AASLD.

Aggressive nutrition intervention reduces ascites and frequency of paracentesis in malnourished patients with cirrhosis and ascites.

BACKGROUND AND AIM: Alterations in nutrient metabolism, nutritional requirements, and reduced dietary intakes are common in chronic liver disease (CLD). These result in malnutrition, sarcopenia, and exacerbate progression to decompensation and ascites. We aimed to investigate the effects of continuous tube feeding (TF) on nutritional status and levels of ascites in malnourished individuals with decompensated cirrhosis. METHODS: Fourteen malnourished patients with decompensated cirrhosis and ascites who failed to respond to standard oral nutritional interventions received supplementary continuous nasogastric TF for 7 ± 1 weeks. Liver disease severity was assessed by model for end-stage liver disease (MELD) and Child-Turcotte-Pugh (CTP) scores. RESULTS: Continuous TF occurred at home for 7 weeks (1.5-12 weeks). Prior to feeding, 12 patients had severe ascites, 10 required paracentesis, and 13 were severely malnourished. At completion of TF, five patients did not have ascites, four had mild ascites, four had moderate ascites, and only one had severe ascites and 10 no longer required paracentesis (P < 0.001). Median patient survival was 26 ± 7 months. Five survived to transplantation and three remained transplant-free at 8, 1.9, and 1.7 years. Seven patients were moderately malnourished at completion of TF with an overall improvement in hand grip strength from 51% to 65% of predicted (P = 0.02). CONCLUSION: Supplementary continuous TF may help to reduce ascites and paracentesis requirements and improve nutritional status. Supplementary continuous TF should be considered as a treatment for malnourished patients with decompensated cirrhosis and refractory ascites.

Accumulation of Deleterious Passenger Mutations Is Associated with the Progression of Hepatocellular Carcinoma.

In hepatocellular carcinoma (HCC), somatic genome-wide DNA mutations are numerous, universal and heterogeneous. Some of these somatic mutations are drivers of the malignant process but the vast majority are passenger mutations. These passenger mutations can be deleterious to individual protein function but are tolerated by the cell or are offset by a survival advantage conferred by driver mutations. It is unknown if these somatic deleterious passenger mutations (DPMs) develop in the precancerous state of cirrhosis or if it is confined to HCC. Therefore, we studied four whole-exome sequencing datasets, including patients with non-cirrhotic liver (n = 12), cirrhosis without HCC (n = 6) and paired HCC with surrounding non-HCC liver (n = 74 paired samples), to identify DPMs. After filtering out putative germline mutations, we identified 187±22 DPMs per non-diseased tissue. DPMs number was associated with liver disease progressing to HCC, independent of the number of exonic mutations. Tumours contained significantly more DPMs compared to paired non-tumour tissue (258-293 per HCC exome). Cirrhosis- and HCC-associated DPMs do not occur predominantly in specific genes, chromosomes or biological pathways and the effect on tumour biology is presently unknown. Importantly, for the first time we have shown a significant increase in DPMs with HCC.

Divergent Inflammatory, Fibrogenic, and Liver Progenitor Cell Dynamics in Two Common Mouse Models of Chronic Liver Injury.

Complications of end-stage chronic liver disease signify a major cause of mortality worldwide. Irrespective of the underlying cause, most chronic liver diseases are characterized by hepatocellular necrosis, inflammation, fibrosis, and proliferation of liver progenitor cells or ductular reactions. Vast differences exist between experimental models that mimic these processes, and their identification is fundamental for translational research. We compared two common murine models of chronic liver disease: the choline-deficient, ethionine-supplemented (CDE) diet versus thioacetamide (TAA) supplementation. Markers of liver injury, including serum alanine transaminase levels, apoptosis, hepatic fat loading, and oxidative stress, as well as inflammatory, fibrogenic and liver progenitor cell responses, were assessed at days 3, 7, 14, 21, and 42. This study revealed remarkable differences between the models. It identified periportal injury and fibrosis with an early peak and slow normalization of all parameters in the CDE regimen, whereas TAA-treated mice had pericentral patterns of progressive injury and fibrosis, resulting in a more severe hepatic injury phenotype. This study is the first to resolve two different patterns of injury and fibrosis in the CDE and TAA model and to indisputably identify the fibrosis pattern in the TAA model as driven from the pericentral vein region. Our data provide a valuable foundation for future work using the CDE and TAA regimens to model a variety of human chronic liver diseases.

Extracellular Vesicles: A New Frontier in Biomarker Discovery for Non-Alcoholic Fatty Liver Disease.

In recent years, the global burden of obesity and diabetes has seen a parallel rise in other metabolic complications, such as non-alcoholic fatty liver disease (NAFLD). This condition, once thought to be a benign accumulation of hepatic fat, is now recognized as a serious and prevalent disorder that is conducive to inflammation and fibrosis. Despite the rising incidence of NAFLD, there is currently no reliable method for its diagnosis or staging besides the highly invasive tissue biopsy. This limitation has resulted in the study of novel circulating markers as potential candidates, one of the most popular being extracellular vesicles (EVs). These submicron membrane-bound structures are secreted from stressed and activated cells, or are formed during apoptosis, and are known to be involved in intercellular communication. The cargo of EVs depends upon the parent cell and has been shown to be changed in disease, as is their abundance in the circulation. The role of EVs in immunity and epigenetic regulation is widely attested, and studies showing a correlation with disease severity have made these structures a favorable target for diagnostic as well as therapeutic purposes. This review will highlight the research that is available on EVs in the context of NAFLD, the current limitations, and projections for their future utility in a clinical setting.

Circulating CD147 predicts mortality in advanced hepatocellular carcinoma.

BACKGROUND AND AIM: The glycoprotein CD147 has a role in tumor progression, is readily detectable in the circulation, and is abundantly expressed in hepatocellular carcinoma (HCC). Advanced HCC patients are a heterogeneous group with some individuals having dismal survival. The aim of this study was to examine circulating soluble CD147 levels as a prognostic marker in HCC patients. METHODS: CD147 was measured in 277 patients (110 HCC, 115 chronic liver disease, and 52 non-liver disease). Clinical data included etiology, tumor progression, Barcelona Clinic Liver Cancer (BCLC) stage, and treatment response. Patients with HCC were stratified into two groups based upon the 75th percentile of CD147 levels (24 ng/mL). RESULTS: CD147 in HCC correlated inversely with poor survival (P = 0.031). Increased CD147 predicted poor survival in BCLC stages C and D (P = 0.045), and CD147 levels >24 ng/mL predicted a significantly diminished 90-day and 180-day survival time (hazard ratio [HR] = 6.1; 95% confidence interval [CI]: 2.1-63.2; P = 0.0045 and HR = 2.8; 95% CI: 1.2-12.6; P = 0.028, respectively). In BCLC stage C, CD147 predicted prognosis; levels >24 ng/mL were associated with a median survival of 1.5 months compared with 6.5 months with CD147 levels ≤24 ng/mL (P = 0.03). CD147 also identified patients with a poor prognosis independent from treatment frequency, modality, and tumor size. CONCLUSIONS: Circulating CD147 is an independent marker of survival in advanced HCC. CD147 requires further evaluation as a potential new prognostic measure in HCC to identify patients with advanced disease who have a poor prognosis.

An association of large-fibre peripheral nerve dysfunction with non-invasive measures of liver fibrosis secondary to non-alcoholic fatty liver disease in diabetes.

AIM: To examine for an association of elevated lower-limb vibration perception threshold (VPT) with NAFLD fibrosis. METHODS: Two cohorts from a tertiary diabetes centre were studied - Cohort 1, n=456 with type 1 or 2 diabetes, and Cohort 2, n=106 with type 2 diabetes mellitus. All underwent a detailed assessment, including VPT measurement. Cohort 2 also had liver ultrasound and transient elastography (TE). NAFLD Fibrosis Score (NFS) was calculated for all with available data. Follow-up VPT measurements on participants in Cohort 1 to 2014 were also collected if available. RESULTS: Adjusted risk of higher VPT category (≥25V but <50V, or ≥50V, c.f. < 25V) was greater for high-risk NFS in both cohorts (Cohort 1, OR 2.22 [95% CI 1.24-3.98, p=0.007] and Cohort 2, OR 4.51 [95% CI 1.08-18.87], p=0.039) and higher liver stiffness measurement (LSM) by TE in Cohort 2 (OR for each unit natural log increase in LSM of 2.42 (95% CI 1.13-5.19), p=0.023). In Cohort 1, in those with VPT<50V and complete data, those with higher NFS had greater odds of increasing VPT category after 2.2 (IQR 1.5-2.9) years. CONCLUSIONS: Higher VPT associates with markers of liver fibrosis due to NAFLD in diabetes mellitus.

Hepatocytes in liver injury: Victim, bystander, or accomplice in progressive fibrosis?

Chronic liver disease causes significant morbidity and mortality through progressive fibrosis, cirrhosis, and liver cancer. The classical theory of fibrogenesis has hepatic stellate cells (HSCs) as the principal and only significant source of abnormal extracellular matrix (ECM). Further, HSCs have the major role in abnormal ECM turnover. It is the death of hepatocytes, as the initial target of injury, that initiates a sequence of events including the recruitment of inflammatory cells and activation of HSCs. Following this initial response, the ongoing insult to hepatocytes is regarded as perpetuating injury, but otherwise, hepatocytes are regarded as "victims" and "bystanders" in progressive fibrosis. Recent developments, however, challenge this view and suggest the concept of the hepatocyte being an active participant in liver injury. It is clear now that hepatocytes undergo phenotypic changes, adapt to injury, and react to the altered microenvironment. In this review, we describe studies showing that hepatocytes contribute to progressive fibrosis by direct manipulation of the surrounding ECM and through signaling to effector cells, particularly HSCs and intrahepatic immune cells. Together, these findings suggest an active "accomplice" role for the hepatocyte in progressive liver fibrosis and highlight novel pathways that could be targeted for development of future anti-fibrotic therapies.

Conceptual models for the initiation of hepatitis B virus-associated hepatocellular carcinoma.

Although chronic hepatitis B virus (HBV) infection is a known risk factor for the development of hepatocellular carcinoma (HCC), the steps involved in the progression from normal liver to HCC are poorly understood. In this review, we apply five conceptual models, previously proposed by Vineis et al. to explain carcinogenesis in general, to explore the possible steps involved in the initiation and evolution of HBV-associated HCC. Available data suggest that the most suitable and inclusive model is based on evolution of hepatocyte subpopulations. In this evolutionary model, HCC-associated changes are driven by selection and subsequent clonal expansion of phenotypically altered hepatocyte subpopulations in the microenvironment of the HBV-infected liver. This model can incorporate the wide range of mechanisms proposed to play a role in the initiation of HCC including oncogenic HBV proteins, integration of HBV DNA and chronic inflammation of the liver. The model may assist in the early prevention, detection and treatment of HCC and may guide future studies of the initiation of HBV-associated HCC.

Analysis of Post-Liver Transplant Hepatitis C Virus Recurrence Using Serial Cluster of Differentiation Antibody Microarrays.

BACKGROUND: Hepatitis C virus (HCV) reinfection of the liver allograft after transplantation is universal, with some individuals suffering severe disease recurrence. Predictive markers of recurrent disease severity are urgently needed. In this study, we used a cluster of differentiation (CD) microarray to predict the severity of HCV recurrence after transplantation. METHODS: The CD antibody microarray assays of live leukocytes were performed on peripheral blood taken in the first year after transplantation. The results were grouped into phases defined as; Pre-transplant (day 0), Early (day 3 to week 2), Mid (week 4 to week 10), and Late (week 12 to week 26). Hepatitis C virus severity was based on fibrosis stages in the first 2 years (F0-1 mild and F2-4 severe). RESULTS: Serial blood samples from 16 patients were taken before and after liver transplantation. A total of 98 assays were performed. Follow-up was 3 years or longer. Comparing recurrence severity, significantly greater numbers of CD antigens were differentially expressed on the pretransplant samples compared to any posttransplant timepoints. Five differentially expressed CD antigens before transplantation (CD27 PH, CD182, CD260, CD41, and CD34) were significantly expressed comparing severe to mild recurrence, whereas expression of only CD152 was significant in the late phase after transplantation. No relationship was observed between the donor or recipient interleukin-28B genotypes and HCV recurrence severity. CONCLUSIONS: This study shows that circulating leukocyte CD antigen expression has utility in assessing recurrent HCV disease severity after liver transplantation and serves as a proof of principle. Importantly, pretransplant CD antigen expression is most predictive of disease outcome.

Circulating dipeptidyl peptidase-4 activity correlates with measures of hepatocyte apoptosis and fibrosis in non-alcoholic fatty liver disease in type 2 diabetes mellitus and obesity: A dual cohort cross-sectional study.

BACKGROUND: Intrahepatic expression of dipeptidyl peptidase-4 (DPP4), and circulating DPP4 (cDPP4) levels and its enzymatic activity, are increased in non-alcoholic fatty liver disease (NAFLD) and in type 2 diabetes mellitus and/or obesity. DPP4 has been implicated as a causative factor in NAFLD progression but few studies have examined associations between cDPP4 activity and NAFLD severity in humans. This study aimed to examine the relationship of cDPP4 activity with measures of liver disease severity in NAFLD in subjects with diabetes and/or obesity. METHODS: cDPP4 was measured in 106 individuals with type 2 diabetes who had transient elastography (Cohort 1) and 145 individuals with morbid obesity who had liver biopsy (Cohort 2). Both cohorts had caspase-cleaved keratin-18 (ccK18) measured as a marker of apoptosis. RESULTS: Natural log increases in cDPP4 activity were associated with increasing quartiles of ccK18 (Cohorts 1 and 2) and with median liver stiffness ≥10.3 kPa (Cohort 1) and significant fibrosis (F ≥ 2) on liver biopsy (Cohort 2). CONCLUSIONS: In diabetes and/or obesity, cDPP4 activity is associated with current apoptosis and liver fibrosis. Given the pathogenic mechanisms by which DPP4 may progress NAFLD, measurement of cDPP4 activity may have utility to predict disease progression and DPP4 inhibition may improve liver histology over time.