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The chimpanzee is the only animal model for investigating the pathogenesis of viral hepatitis types A through E in humans. Studies of the host response, including microarray analyses, have relied on the close relationship between these two primate species: chimpanzee samples are commonly tested with human-based reagents. In this study, the host responses to two dissimilar viruses, hepatitis E virus (HEV) and hepatitis C virus (HCV), were compared in multiple experimentally infected chimpanzees. Affymetrix U133 + 2.0 human microarray chips were used to assess the entire transcriptome in serial liver biopsies obtained over the course of the infections. Respecting the limitations of microarray probes designed for human target transcripts to effectively assay chimpanzee transcripts, we conducted probe-level analysis of the microarray data in conjunction with a custom mapping of the probe sequences to the most recent human and chimpanzee genome sequences. Time points for statistical comparison were chosen based on independently measured viremia levels. Regardless of the viral infection, the alignment of differentially expressed genes to the human genome sequence resulted in a larger number of genes being identified when compared with alignment to the chimpanzee genome sequence. This probably reflects the lesser refinement of gene annotation for chimpanzees. In general, the two viruses demonstrated very distinct temporal changes in host response genes, although both RNA viruses induced genes that were involved in many of the same biological systems, including interferon-induced genes. The host response to HCV infection was more robust in the magnitude and number of differentially expressed genes compared to HEV infection. [ABSTRACT FROM AUTHOR]

Chimpanzees represent the only animal model for studies of the natural history of hepatitis C virus (HCV). To generate virus stocks of important HCV variants, we infected chimpanzees with HCV strains of genotypes 1-6 and determined the infectivity titer of acute-phase plasma pools in additional animals. The courses of first- and second-passage infections were similar, with early appearance of viremia, HCV RNA titers of >104.7 IU/mL, and development of acute hepatitis; the chronicity rate was 56%. The challenge pools had titers of 10³-105 chimpanzee infectious doses/mL. Human liver-chimeric mice developed high-titer infections after inoculation with the challenge viruses of genotypes 1-6. Inoculation studies with different doses of the genotype 1b pool suggested that a relatively high virus dose is required to consistently infect chimeric mice. The challenge pools represent a unique resource for studies of HCV molecular virology and for studies of pathogenesis, protective immunity, and vaccine efficacy in vivo. [ABSTRACT FROM AUTHOR]

Alcohol synergistically enhances the progression of liver disease and the risk for liver cancer caused by hepatitis C virus (HCV). However, the molecular mechanism of this synergy remains unclear. Here, we provide the first evidence that Toll-like receptor 4 (TLR4) is induced by hepatocyte-specific transgenic (Tg) expression of the HCV nonstructural protein NS5A, and this induction mediates synergistic liver damage and tumor formation by alcohol-induced endotoxemia. We also identify Nanog, the stem/progenitor cell marker, as a novel downstream gene up-regulated by TLR4 activation and the presence of CD133/Nanog-positive cells in liver tumors of alcohol-fed NS5A Tg mice. Transplantation of p53-deficient hepatic progenitor cells transduced with TLR4 results in liver tumor development in mice following repetitive LPS injection, but concomitant transduction of Nanog short-hairpin RNA abrogates this outcome. Taken together, our study demonstrates a TLR4-dependent mechanism of synergistic liver disease by HCV and alcohol and an obligatory role for Nanog, a TLR4 downstream gene, in HCV-induced liver oncogenesis enhanced by alcohol. [ABSTRACT FROM AUTHOR]

Minagawa M, Kawamura H, Liu Z, Govindarajan S, Dennert G. Suppression of adenoviral gene expression in the liver: role of innate vs adaptive immunity and their cell lysis mechanisms.Liver International 2005: 25: 622–632.© Blackwell Munksgaard 2005Injection of adenoviral constructs causes liver infection prompting immunity, which suppress viral gene expression. Innate and adaptive immunity mediate these processes raising the question which pathways are the most prominent.Adenovirus expressing theβ-galactosidase (β-gal) gene was injected into normal and immunodeficient mice. Elimination ofβ-gal-expressing hepatocytes and increases in liver enzymes were assayed. Major histocompatibility complex (MHC) class I densities, perforin channel insertion and apoptosis by Fas and tumor necrosis factor (TNF)-α were assayed.At high virus doses, suppression of viral gene expression was as efficient in immunodeficient as in normal mice, while at low doses effects of cytotoxic T lymphocytes (CTL) were demonstrable. Despite CTL priming and elimination of infected hepatocytes no liver injury is detected. Hepatocyte MHC I densities were able to trigger CTL granule exocytosis and perforin lysisin vitrobut notin vivo. This is we show is because of decreased sensitivity of hepatocytes from infected mice to perforin and increased sensitivity to Fas and TNF-α lysis.Effector cells of the innate immune system are exceedingly effective in suppressing adenoviral gene expression. Perforin-independent pathways, those mediated by TNF-α and Fas are very efficient in hepatocytes from virus-infected livers. [ABSTRACT FROM AUTHOR]

GB virus B (GBV-B), the virus most closely related to hepatitis C virus (HCV), infects tamarins and causes acute hepatitis. The 3' untranslated region (UTR) of an infectious GBV-B clone (pGBB) has a proximal short sequence followed by a poly(U) tract and a 3' terminal sequence. Our investigators previously demonstrated that the 3' terminal sequence was critical for in vivo infectivity. Here, we tested the effect of deleting the short sequence and/or the poly(U) tract from pGBB; infectivity of each mutant was tested by intrahepatic transfection of two tamarins with transcribed RNA. A mutant lacking both regions was not viable. However, mutants lacking either the short sequence or the poly(U) tract were viable. All four tamarins had a wild-type-like acute infection and developed acute hepatitis. Whereas we found that five tamarins transfected with the wild-type clone pGBB had acute resolving infection, one tamarin transfected with the poly(U) deletion mutant became persistently infected. This animal had viremia and hepatitis until its death at week 90. The genomes recovered at weeks 2, 7, 15, 20, 60, and 90 lacked the poly(U) stretch. Eight amino acid changes were identified at week 90. One change, in the putative p7 protein, was dominant at week 15. Thus, persistence of GBV-B, like persistence of HCV, was associated with the emergence of virus variants. Four tamarins inoculated with serum collected at weeks 2 and 90 from the tamarin with persistent infection had an acute resolving infection. Nonetheless, the demonstration that GBV-B can persist in tamarins strengthens its relevance as a surrogate model for the study of HCV. [ABSTRACT FROM AUTHOR]

Discusses evidence that the p7 polypeptide of hepatitis C virus (HCV) is critical for infectivity and contains functionally important genotype-specific sequences. Construction of HCV expression vectors; Procession of HCV mutant proteins in mammalian cells; Finding that p7 mutants are processed in mammalian cells.

We have demonstrated that recombinant hepatitis E vaccine suitable for clinical evaluation was highly immunogenic and efficacious in preventing hepatitis E and even infection in rhesus macaques following intravenous challenge with three different genotypes of hepatitis E virus (HEV). Two doses of vaccine were essential for optimal protection; the two-dose regimen was more important than the formulation of the vaccine for achieving efficacy. The titers of anti-HEV that were protective in this study were quantified against a World Health Organization (WHO) standard. This permits direct comparison of the results with other studies. The results of this pre-clinical trial of a candidate hepatitis E vaccine strongly suggest that it will be highly efficacious for preventing hepatitis E in the field trial of this vaccine that is currently in progress in Nepal. [Copyright &y& Elsevier]

To define the early events that determine the outcome of acute hepatitis C virus (HCV) infection, we compared the course of viremia with the peripheral and intrahepatic T cell response and intrahepatic cytokine profile in six acutely infected chimpanzees. Three different outcomes were observed after peak viral titers were reached: sustained viral clearance, transient viral clearance followed by chronic infection, and chronic infection that persisted at initial peak titers. The results indicate that HCV spread outpaces the T cell response and that HCV rapidly induces but is not controlled by IFN-α/β; that viral clearance follows the entry and accumulation of HCV-specific IFN-γ-producing T cells in the liver; and that it may not require the destruction of infected cells. [ABSTRACT FROM AUTHOR]

Hepatitis E virus (HEV) is an enterically transmitted virus that causes acute hepatitis. A candidate vaccine containing recombinant HEV capsid protein (56 kDa) expressed in insect cells was shown previously to be highly immunogenic when administered in two doses to rhesus monkeys and to protect them from hepatitis E when challenged with a large intravenous dose of homologous or heterologous HEV. In the present study, the effect of a third dose of the same vaccine lot was evaluated and more importantly, the duration of protection following two doses was determined. Rhesus monkeys vaccinated twice with the 56 kDa capsid protein were challenged with homologous virus 6 or 12 months after the last vaccination: 3 of 4 monkeys challenged 6 or 12 months later, respectively were protected against viral hepatitis. Similarly, all four of the rhesus monkeys given a third dose of vaccine 1 month prior to challenge were protected against hepatitis. In contrast, all four monkeys given placebo developed hepatitis following challenge. In summary, two doses of HEV vaccine partially protected rhesus monkeys from hepatitis E following intravenous challenge 6 or 12 months after vaccination. [Copyright &y& Elsevier]

We describe the clinical course in 126 patients with delta hepatitis who have been evaluated in Los Angeles since 1967. In approximately two thirds of all patients, delta infection was associated with chronic hepatitis B. Most patients were members of two major risk groups: 65.9% were intravenous drug abusers, 11.9% were male homosexuals, and another 9.5% were both intravenous drug users and male homosexuals. The overall case fatality rate was 23%; fulminant hepatitis caused 17 of 29 (59%) deaths. Advanced liver disease occurred significantly more frequently in patients who had established chronic delta infections than in hepatitis B virus carriers with recent delta superinfections. Nonfatal infections with both hepatitis B virus and delta hepatitis virus resulted in clearance of both agents, whereas superinfection in carriers of chronic hepatitis B virus usually led to chronic delta hepatitis. Spontaneous loss of chronic delta infection was not observed. Delta hepatitis, a longstanding infection seen in patients in the Los Angeles area, has caused fulminant hepatitis and progressive liver disease in both intravenous drug users and male homosexuals. [ABSTRACT FROM AUTHOR]

This article describes the case of a patient who had several tests done on his hepatitis C virus (HCV)-associated fulminant hepatitis that offers an association between the two. A 68-year-old man was admitted to the hospital to have coronary-artery bypass surgery just a few months before blood supplies were checked for HCV. During the surgery he got 39 units of red-cell concentrate, 15 units of platelets, 21 units for fresh-frozen plasma and 2 units of plasma cryoprecipitate. He had no history of liver disease before the surgery but soon afterwards became ill and he died 7 weeks later from liver failure caused by fulminant hepatitis C. Tests showed that HCV caused his liver failure and the detection of HCV by PCR is the earliest marker for diagnosis.

Hepatitis B virus (HBV)-associated acute liver failure (ALF) is a dramatic clinical syndrome leading to death or liver transplantation in 80% of cases. Due to the extremely rapid clinical course, the difficulties in obtaining liver specimens, and the lack of an animal model, the pathogenesis of ALF remains largely unknown. Here, we performed a comprehensive genetic and functional characterization of the virus and the host in liver tissue from HBV-associated ALF and compared the results with those of classic acute hepatitis B in chimpanzees. In contrast with acute hepatitis B, HBV strains detected in ALF livers displayed highly mutated HBV core antigen (HBcAg), associated with increased HBcAg expression ex vivo, which was independent of viral replication levels. Combined gene and miRNA expression profiling revealed a dominant B cell disease signature, with extensive intrahepatic production of IgM and IgG in germline configuration exclusively targeting HBcAg with subnanomolar affinities, and complement deposition. Thus, HBV ALF appears to be an anomalous T cell-independent, HBV core-driven B cell disease, which results from the rare and unfortunate encounter between a host with an unusual B cell response and an infecting virus with a highly mutated core antigen., Competing Interests: The authors declare no conflict of interest.

There is limited data on the molecular mechanisms whereby hepatitis D virus (HDV) promotes liver cancer. Therefore, serum and liver specimens obtained at the time of liver transplantation from well-characterized patients with HDV-HCC ( n = 5) and with non-HCC HDV cirrhosis ( n = 7) were studied using an integrated genomic approach. Transcriptomic profiling was performed using laser capture-microdissected (LCM) malignant and nonmalignant hepatocytes, tumorous and nontumorous liver tissue from patients with HDV-HCC, and liver tissue from patients with non-HCC HDV cirrhosis. HDV-HCC was also compared with hepatitis B virus (HBV) HBV-HCC alone, and hepatitis C virus (HCV) HCV-HCC. HDV malignant hepatocytes were characterized by an enrichment of upregulated transcripts associated with pathways involved in cell-cycle/DNA replication, damage, and repair (Sonic Hedgehog, GADD45, DNA-damage-induced 14-3-3σ, cyclins and cell-cycle regulation, cell cycle: G 2 -M DNA-damage checkpoint regulation, and hereditary breast cancer). Moreover, a large network of genes identified functionally relate to DNA repair, cell cycle, mitotic apparatus, and cell division, including 4 cancer testis antigen genes, attesting to the critical role of genetic instability in this tumor. Besides being overexpressed, these genes were also strongly coregulated. Gene coregulation was high not only when compared with nonmalignant hepatocytes, but also to malignant hepatocytes from HBV-HCC alone or HCV-HCC. Activation and coregulation of genes critically associated with DNA replication, damage, and repair point to genetic instability as an important mechanism of HDV hepatocarcinogenesis. This specific HDV-HCC trait emerged also from the comparison of the molecular pathways identified for each hepatitis virus-associated HCC. Despite the dependence of HDV on HBV, these findings suggest that HDV and HBV promote carcinogenesis by distinct molecular mechanisms. Implications: This study identifies a molecular signature of HDV-associated hepatocellular carcinoma and suggests the potential for new biomarkers for early diagnostics. Mol Cancer Res; 16(9); 1406-19. ©2018 AACR ., (©2018 American Association for Cancer Research.)

The clinical presentation of alcoholic hepatitis (AH) can be mimicked by other alcoholic liver diseases. The aim of this study was to identify clinical features that predict AH on liver biopsy. Biopsies from patients hospitalized for presumed severe AH were used to identify a derivation cohort (101 patients) and validation cohort (71 patients). Using histologic scores for hepatocyte ballooning, Mallory-Denk bodies, and lobular inflammation, 95 patient biopsies (55%) were classified as definite AH, 55 (32%) as possible AH, and 22 (13%) as no AH. Survival was similar among the groups, but mortality was significantly increased for patients with fatty change ≤50% on initial liver biopsy. An analysis limited to uninfected patients with definite AH or no AH in the derivation cohort identified a greater leukocyte count at admission and radiographic evidence of liver surface nodularity as independent predictors of definite AH on biopsy ( P < 0.05). In the derivation cohort, the leukocyte count thresholds for ensuring 100% specificity for diagnosing definite AH were 10 × 10 9 /L if the liver surface was nodular and 14 × 10 9 /L if the liver surface was smooth, with a sensitivity of 76% and an area under the receiver operator characteristic curve of 0.88. In the validation cohort, these thresholds had a specificity of 86%, a sensitivity of 59%, and an area under the receiver operator characteristic curve of 0.72. Conclusion: The combination of an elevated leukocyte count and a nodular liver surface in the absence of active infection retrospectively identified patients with a high likelihood of histologic AH for whom liver biopsy may not be necessary. For patients with suspected severe AH who do not fulfill these criteria, liver biopsy is important to exclude other variants of alcoholic liver disease. ( Hepatology Communications 2017;1:1070-1084).

Obese animals and non-alcoholic fatty liver disease (NAFLD) patients exhibit elevated blood alcohol, suggesting potential contributions of alcohol metabolism to the development of NAFLD. Liver gene expression in patients with biopsy-proven mild (N = 40) and severe (N = 32) NAFLD were compared to that in healthy liver donors (N = 7) and alcoholic hepatitis (AH; N = 15) using microarrays. Principal components analyses (PCA) revealed similar gene expression patterns between mild and severe NAFLD which clustered with those of AH but were distinct from those of healthy livers. Differential gene expression between NAFLD and healthy livers was consistent with established NAFLD-associated genes and NAFLD pathophysiology. Alcohol-metabolizing enzymes including ADH, ALDH, CYP2E1, and CAT were up-regulated in NAFLD livers. The expression level of alcohol-metabolizing genes in severe NAFLD was similar to that in AH. The NAFLD gene expression profiles provide new directions for future investigations to identify disease markers and targets for prevention and treatment, as well as to foster our understanding of NAFLD pathogenesis and pathophysiology. Particularly, increased expression of alcohol-metabolizing genes in NAFLD livers supports a role for endogenous alcohol metabolism in NAFLD pathology and provides further support for gut microbiome therapy in NAFLD management. Copyright © 2015 Pathological Society of Great Britain and Ireland. Published by John Wiley © Sons, Ltd., (Copyright © 2015 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.)

Background: Cardiometabolic syndrome in individuals who are aging with spinal cord injury (SCI) increases the risk of cardiovascular disease and diabetes. Longitudinal research is needed on the natural progression of cardiometabolic syndrome in SCI., Objective: To identify the magnitude of changes in biomarkers of cardiometabolic syndrome and diabetes over time in people aging with SCI, and to discern how these biomarkers relate to demographics of race/ethnicity and sex., Methods: This cohort study was a follow-up of a convenience sample of 150 participants (mean age, 51.3; duration of SCI, 27.3 years) from a full cohort of 845 who participated in research in which physiologic and serologic data on cardiovascular disease had been prospectively collected (1993-1997). Inclusion criteria were adults with traumatic-onset SCI. Average years to follow-up were 15.7 ± 0.9. Assessments were age, race, level and completeness of injury, duration of injury, blood pressure, body mass index, waist circumference, serum lipids, fasting glucose, hemoglobin A1c, and medications used. Primary outcome was meeting at least 3 of the criteria for cardiometabolic syndrome., Results: The frequency of cardiometabolic syndrome increased significantly from 6.7% to 20.8% or 38.2% according to 2 definitions. It was significantly higher in Hispanics and apparently higher in women. Diabetes increased significantly by a factor of 6.7., Conclusion: Our data indicate clinically important increases in the frequency of cardiometabolic syndrome, especially among Hispanic and female participants, and a similar increase in diabetes among individuals aging with SCI. Clinical practice guidelines need to be customized for women and Hispanics with SCI.

Background: Rats fed diets deficient in choline develop hepatocellular carcinoma. Tumor DNA from these animals is characteristically hypomethylated, suggesting that disruption of the one-carbon metabolism pathway is an underlying mechanism for hepatocarcinogenesis. Prospective studies in humans on circulating choline and other one-carbon metabolites and hepatocellular carcinoma risk have been lacking., Methods: We prospectively examined the association between prediagnostic serum concentrations of one-carbon metabolites including betaine, choline, cystathionine, homocysteine, methionine, 5-methyltetrahydrofolate (5-MTHF), pyridoxal-5-phosphate (PLP, the bioactive form of vitamin B6) and S-adenosylmethionine (SAM), and risk of developing hepatocellular carcinoma based on a nested case-control study of 297 incident cases and 631 matched controls from a cohort of 18,244 men in Shanghai, China. Logistic regression methods were used to calculate ORs and 95% confidence intervals (CI) adjusted for established risk factors for hepatocellular carcinoma., Results: Serum choline and PLP were associated with statistically significant reduced risk of hepatocellular carcinoma, whereas serum cystathionine, methionine, and SAM were associated with increased hepatocellular carcinoma risk (all Ptrend < 0.05). The inverse associations for hepatocellular carcinoma risk with choline and PLP remained statistically significant after adjusting for all potential confounders. The multivariate-adjusted ORs (95% CIs) for the highest versus lowest quintiles of serum choline and PLP were 0.35 (0.16-0.78; P = 0.010) and 0.44 (0.25-0.78; P = 0.005), respectively. There were no associations for hepatocellular carcinoma risk with 5-MTHF, betaine, or homocysteine., Conclusion: The inverse associations between choline and vitamin B6 and the risk of hepatocellular carcinoma development are novel and warrant further investigation., Impact: Identifying new modifiable factors for hepatocellular carcinoma prevention is warranted.

Like the other hepatitis viruses, hepatitis E virus (HEV) has been difficult to study because of limitations in cell culture systems and small animal models. Much of what we know has come from epidemiological studies in developing countries and, more recently, in industrialized countries. However, the epidemiology is very different in these two settings: hepatitis E in developing countries is epidemic as well as sporadic, principally water-borne, most likely to cause disease in older children and young adults and relatively severe, especially in pregnant women; in industrialized countries the disease is sporadic, principally food-borne, most common in the elderly and probably associated with mostly inapparent infections. These differences are believed to be genotypically determined. To examine the biological parameters of hepatitis E, we have studied HEV infections in nonhuman primates, which are surrogates of man. Infections with HEV genotypes 1-3 were compared in rhesus and cynomolgus macaques and chimpanzees. In general, the biological characteristics of the different HEV genotypes mirrored their epidemiological characteristics.

Background: Earlier, we reported a highly statistically significant association between T-helper 1 (Th1) and Th2 cytokine genotypes and hepatocellular carcinoma (HCC) risk among natives of southern Guangxi, China, a hyperendemic region for HCC. Epidermal growth factor (EGF) plays a critical role in malignant transformation of hepatocytes and tumor progression. A polymorphism in the EGF gene (61A > G) results in elevation of EGF in liver tissues and blood. Epidemiological data are sparse on the possible association between EGF genetic polymorphism and HCC risk., Methods: The EGF 61A > G polymorphism, multiple Th1 and Th2 genotypes, and environmental risk factors for HCC were determined on 117 HCC cases and 225 healthy control subjects among non-Asians of Los Angeles County, California, a low-risk population for HCC, and 250 HCC cases and 245 controls of southern Guangxi, China., Results: Following adjustment for all known or suspected HCC risk factors, non-Asians in Los Angeles who possessed at least one copy of the high activity 61*G allele of the EGF gene showed a statistically non-significant, 78% increased risk of HCC compared with those possessing the EGF A/A genotype. This EGF-HCC risk association significantly strengthened among heavy users of alcohol [odds ratio (OR) = 3.44, 95% confidence interval (CI) = 0.93-12.76, P = 0.065)], and among individuals carrying the high-risk Th1/Th2 genotypes for HCC (OR = 3.34, 95% CI = 1.24-9.03, P = 0.017). No association between EGF genotype and HCC risk was observed among Chinese in southern Guangxi, China., Conclusion: Genetic polymorphism in the EGF gene resulting in elevated level of EGF, may contribute to HCC risk among low-risk non-Asians in Los Angeles.

Background: Coffee consumption has been associated with reduced markers of hepatic cell damage, reduced risk of chronic liver disease, and cirrhosis across a variety of populations. Data on the association between coffee consumption and risk of hepatocellular carcinoma (HCC), especially in high-risk populations, are sparse., Methods: This study examines the relationship between coffee and caffeine consumption, and the risk of developing HCC within the Singapore Chinese Health Study, a prospective cohort of 63,257 middle-aged and older Chinese men and women, a relatively high-risk population for HCC. Baseline data on coffee consumption and other dietary and lifestyle factors were collected through in-person interviews at enrollment between 1993 and 1998., Results: As of 31 December 2006, 362 cohort participants had developed HCC. High levels of coffee or caffeine consumption were associated with reduced risk of HCC (p for trend < 0.05). Compared with non-drinkers of coffee, individuals who consumed three or more cups of coffee per day experienced a statistically significant 44% reduction in risk of HCC (hazard ratio 0.56, 95% confidence interval, 0.31-1.00, p = .049) after adjustment for potential confounders and tea consumption., Conclusion: These data suggest that coffee consumption may reduce the risk of developing HCC in Chinese in Singapore.

Unlabelled: Patients with chronic hepatitis C with partial virologic response or nonresponse to interferon-based therapies can experience treatment-related improvements in liver histology. This retrospective analysis assessed the histologic response to treatment in patients with varying degrees of virologic response (sustained virologic response [SVR], breakthrough, relapse, or nonresponse), time to hepatitis C virus (HCV) RNA undetectability, and duration of viral suppression. Patients (HCV genotypes 1-6) with baseline and follow-up liver biopsies from eight phase 2 to phase 4 interferon-based trials were analyzed. Blinded biopsies were evaluated by a single pathologist. Improvements or worsening of METAVIR necroinflammatory activity and fibrosis were defined as increase or decrease of ≥1 grading category from baseline to 24 weeks after end of treatment. A majority of the 1571 patients with paired biopsy data were white, male, with HCV genotype 1/4, baseline HCV RNA levels >800,000 IU/mL, and baseline alanine aminotransferase levels ≤3 × upper limit of the normal range; mean baseline activity and fibrosis scores were 1.8 and 1.7, respectively. Overall, 80% of patients received peginterferon alfa-2a monotherapy or peginterferon alfa-2a/ribavirin combination therapy. Mean treatment duration was 46 weeks. There was a positive correlation between the degree of virologic response and improvements in METAVIR activity and fibrosis, and an inverse correlation with worsening activity and fibrosis (all comparisons, P < 0.0001). Patients with SVR had the greatest histologic benefit. As a combined group, relapsers and patients with breakthrough had significantly greater benefits than nonresponders (activity, P = 0.0001; fibrosis, P = 0.003). Consistent with these results, a better histologic response was correlated with a shorter time to undetectable HCV RNA and a longer duration of viral suppression (all comparisons, P < 0.0001)., Conclusion: In patients with chronic hepatitis C who were treated with interferon-based therapies, histologic benefits may be observed even in the absence of an SVR.

Unlabelled: Studies of the prognostic value of Ishak fibrosis stage are lacking. We used multi-year follow-up of the Hepatitis C Antiviral Long-Term Treatment Against Cirrhosis (HALT-C) Trial to determine whether individual Ishak fibrosis stages predicted clinical outcomes in patients with chronic hepatitis C. Baseline liver biopsy specimens from 1050 patients with compensated chronic hepatitis C who had failed combination peginterferon and ribavirin were reviewed by a panel of expert hepatopathologists. Fibrosis was staged with the Ishak scale (ranging from 0 = no fibrosis to 6 = cirrhosis). Biopsy fragmentation and length as well as number of portal tracts were recorded. We compared rates of prespecified clinical outcomes of hepatic decompensation and hepatocellular carcinoma across individual Ishak fibrosis stages. Of 1050 biopsy specimens, 25% were fragmented, 63% longer than 1.5 cm, 69% larger than 10 mm(2), and 75% had 10 or more portal tracts. Baseline laboratory markers of liver disease severity were worse and the frequency of esophageal varices higher with increasing Ishak stage (P < 0.0001). The 6-year cumulative incidence of first clinical outcome was 5.6% for stage 2, 16.1% for stage 3, 19.3% for stage 4, 37.8% for stage 5, and 49.3% for stage 6. Among nonfragmented biopsy specimens, the predictive ability of Ishak staging was enhanced; however, no association was observed between Ishak stage and outcomes for fragmented biopsy specimens because of high rates of outcomes for patients with noncirrhotic stages. Similar results were observed with liver transplantation or liver-related death as the outcome., Conclusion: Ishak fibrosis stage predicts clinical outcomes, need for liver transplantation, and liver-related death in patients with chronic hepatitis C. Patients with fragmented biopsy specimens with low Ishak stage may be understaged histologically.

Background: Hepatic steatosis is common in patients infected with hepatitis C virus (HCV). The effect of steatosis on anti-HCV therapy efficacy is unclear., Methods: We studied host and viral factors associated with steatosis and the effect of steatosis on treatment efficacy using the database of a large prospective trial in patients with HCV genotypes 2 and 3., Results: Out of 885 patients assessed for steatosis, a total of 614 patients or 69% had steatosis. Patients with genotype 3 were more likely to have steatosis than those with genotype 2 (79 vs. 59%, P<0.001). Using the logistic regression model, steatosis was associated with genotype 3 (P<0.0001), older age (P=0.0025), heavier weight (P<0.0001), higher HCV RNA (P<0.0001), and higher ALT levels (P=0.015). By univariate analysis, steatosis was associated with lower sustained virological response (SVR) in patients with genotype 3, but not in patients with genotype 2. When all factors associated with steatosis and SVR were evaluated by logistic regression analysis; genotype, age, bodyweight, histological diagnosis, ALT quotient, baseline HCV RNA and treatment duration were associated with the probability of SVR, but gender, race and steatosis were not. Further analysis showed that steatosis remained a non-significant factor while baseline viral load was significantly associated with the probability of an SVR., Conclusions: Steatosis did not influence the efficacy of treatment in our study population. Baseline viral load is a confounding factor, particularly in patients infected with genotype 3 and once baseline viral load was accounted for, the association between steatosis and SVR was not relevant.

GB virus-B (GBV-B) is the virus most closely related to hepatitis C virus (HCV). Thus, we have used GBV-B infection of tamarins, which develop acute hepatitis following experimental infection, as a surrogate model to study protective immunity. As challenge virus, we first produced a GBV-B pool from an infected tamarin, which was not infected with the related GBV-A viruses. Its infectivity titer was 10(6.6) tamarin 50% infectious doses per ml. Next, two tamarins that were convalescent from recombinant GBV-B infection were re-challenged. In the original infection viremia persisted for 8 and 12 weeks, respectively, and both animals developed moderately severe hepatitis. Each tamarin was re-challenged four times with 10(4.3) tamarin 50% infectious doses of the GBV-B challenge virus. In one animal, each re-challenge produced 1-2 weeks of viremia; hepatitis was observed following the first re-challenge. In the other animal, however, only the first re-challenge produced viremia, lasting 1 week. During the primary infection, peak GBV-B titers were about 10(8) genome equivalents/ml in both animals; following re-challenges, peak titers ranged from 10(3) to 10(6) genome equivalents/ml. Analysis of the polyprotein sequence of viruses recovered from both animals following the first re-challenge demonstrated that these did not represent immune escape variants since mutations were not detected. Neutralization studies suggested that the immunity was not humoral in nature. We also demonstrated that the immunity was long-lived: 1 year after the fourth challenge, the animal with sterilizing immunity had low titer viremia for only 1 week following an additional challenge., ((c) 2007 Wiley-Liss, Inc.)

Unlabelled: Methylenetetrahydrofolate reductase (MTHFR) and thymidylate synthase (TYMS) are known to play a role in DNA methylation, synthesis, and repair. The genetic mutations in MTHFR and TYMS genes may have influences on their respective enzyme activities. Data on the association studies of the MTHFR and TYMS genetic polymorphisms and risk of hepatocellular carcinoma (HCC) are sparse. MTHFR and TYMS genotypes were determined on 365 HCC cases and 457 healthy control subjects among Hispanic and non-Hispanic whites and African-Americans in Los Angeles County, California, and among Chinese in the city of Nanning, Guangxi, China. Relative to the high-activity genotype, each low-activity genotype of MTHFR was associated with a statistically nonsignificant 30% to 50% reduction in risk of HCC. Relative to the TYMS3'UTR +6/+6 genotype, individuals with 1 or 2 copies of the deletion allele had a statistically significant 50% reduction in risk of HCC. When we examined HCC risk by the total number of mutant alleles in the 3 polymorphic loci of MTHFR/TYMS (range, 0-4), there was a monotonic decrease in risk with increasing number of mutant alleles (P for trend = 0.003). Individuals possessing the maximum number of mutant alleles (i.e., 4) had an odds ratio of 0.46 (95% confidence interval = 0.23-0.93) for HCC compared with those with no or only 1 mutant allele., Conclusion: This study supports the hypothesis that reduced MTHFR activity and enhanced TYMS activity, both of which are essential elements in minimizing uracil misincorporation into DNA, may protect against the development of HCC.

Hepatitis C virus (HCV) infection causes acute and chronic liver disease often leading to liver cirrhosis and hepatocellular carcinoma. Numerous studies have shown that despite induction of virus specific immunity, a curative response is often not attained; this has led to the hypothesis that HCV genes modulate immunity, thereby enabling chronic infections. This study examined the effects on immune-mediated liver injury in transgenic mice expressing core protein throughout the body and bone marrow chimeras expressing core protein in either the lymphoid compartment or liver parenchyma. Presence of core protein in the liver parenchyma but not in lymphoid cells protects from autoimmune hepatitis induced by mitogen concanavalin A (ConA). Consistent with this observation, core transgenic hepatocytes are relatively resistant to death induced by anti-Fas antibody and tumor necrosis factor alpha (TNFalpha). This protective effect is associated with preferential activation of signal transducer and activation of transcription factor 3 (STAT3) versus STAT1 in livers of ConA-injected animals. In agreement with this effect of core protein on the Janus kinase (JAK)-STAT signaling pathway, transgenic mice accelerate liver regeneration after partial hepatectomy but are not protected from hepatocyte death. In conclusion, HCV core inhibits STAT1 and stimulates STAT3 activation, which protects infected hepatocytes from attack by the cell-mediated immune system and promotes their proliferation.

Background: In Southern Guangxi, China, chronic infection with the hepatitis B virus (HBV) acquired during the perinatal period from carrier mothers is a primary cause of hepatocellular carcinoma. However, only a minority of HBV carriers eventually develop hepatocellular carcinoma. The authors hypothesized that cytokine genotypes may be important codeterminants of the risk of HBV-related hepatocellular carcinoma., Methods: The authors examined the correlation between polymorphisms in T-helper 1 (Th1) and Th2 cytokine genes among a group of 250 patients with incident hepatocellular carcinoma (cases) and a group of 250 hospital controls who were matched individually to the index case by age, gender, ethnicity, residence, and month of hospital admission in the city of Nanning, Guangxi, China., Results: Relative to the putative high-activity genotypes, each individual low-activity genotype of interferon gamma, interleukin 12 (IL12), and IL18 was associated with a statistically nonsignificant increase (40-60%) in the risk of hepatocellular carcinoma. This risk increased with increasing numbers of low-activity Th1 genotypes after adjusting for potential confounders (2-sided P value for trend=0.04). Conversely, individual Th2 (IL4, IL10) low-activity genotypes were associated with a statistically nonsignificant reduced risk of hepatocellular carcinoma. This risk decreased with increasing number of low-activity Th2 genotypes after adjusting for potential confounders (2-sided P value for trend=0.01). Individuals who had the maximum number (i.e., 3) of low-activity Th1 genes and the minimum number (i.e., 0) of low-activity Th2 genes showed a relative risk of 20.0 (95% confidence interval, 1.7-235.0)., Conclusions: Diminished cell-mediated immune response, which is controlled genetically, appeared to be an important risk determinant of HBV-related hepatocellular carcinogenesis., (Copyright (c) 2005 American Cancer Society.)

Background: Heavy alcohol consumption, viral hepatitis, and diabetes are risk factors for hepatocellular carcinoma (HCC). However, to the authors' knowledge, the information concerning their interaction effect in patients with risk of HCC is sparse., Methods: A population-based, case-control study of HCC was conducted during 1984-2002. The study involved 295 HCC cases and 435 age-, gender-, and race-matched control subjects among Hispanic and non-Hispanic whites and blacks in Los Angeles County, California. Lifestyle risk factors were ascertained through in-person interviews. Infections with the hepatitis B and C (HCV) viruses were determined using their serologic markers., Results: Fourteen HCC cases but no control subjects tested positive for the hepatitis B surface antigen. Seropositivity for antibodies to HCV was associated with an odds ratio (OR) of 125 (95% confidence interval [95% CI], 17-909) for HCC, whereas seropositivity for antibodies to the hepatitis B core antigen was related to an OR of 2.9 (95% CI, 1.7-5.0). Heavy alcohol consumption and cigarette smoking were found to be independently associated with a statistically significant two to threefold increase in risk of HCC after adjustment for hepatitis B and C serology. Subjects with a history of diabetes had an OR of 2.7 (95% CI, 1.6-4.3) for HCC compared with nondiabetic subjects. A synergistic interaction on HCC risk was observed between heavy alcohol consumption and diabetes (OR = 4.2; 95% CI, 2.6-5.8), heavy alcohol consumption and viral hepatitis (OR = 5.5; 95% CI, 3.9-7.0), or between diabetes and viral hepatitis (OR = 4.8; 95% CI, 2.7-6.9)., Conclusions: Heavy alcohol consumption, diabetes, and viral hepatitis were found to exert independent and synergistic effects on risk of HCC in U.S. blacks and whites., (Copyright 2004 American Cancer Society.)

The development of a subgenomic replicon derived from the hepatitis C virus (HCV) strain Con1 enabled the study of viral RNA replication in Huh-7 cells. The level of replication of replicons, as well as full-length Con1 genomes, increased significantly by a combination of two adaptive mutations in NS3 (E1202G and T1280I) and a single mutation in NS5A (S2197P). However, these cell culture-adaptive mutations influenced in vivo infectivity. After intrahepatic transfection of chimpanzees, the wild-type Con1 genome was infectious and produced viral titers similar to those produced by other infectious HCV clones. Repeated independent transfections with RNA transcripts of a Con1 genome containing the three adaptive mutations failed to achieve active HCV infection. Furthermore, although a chimpanzee transfected with RNA transcripts of a Con1 genome with only the NS5A mutation became infected, this mutation was detected only in virus genomes recovered from serum at day 4; viruses recovered at day 7 had a reversion back to the original Con1 sequence. Our study demonstrates that mutations that are adaptive for replication of HCV in cell culture may be highly attenuating in vivo.