HBV whole-genome mutation profile in HIV-1/HBV coinfected patients in a long-term follow-up study.

PURPOSE: Human immunodeficiency virus (HIV-1)-infected patients frequently harbour hepatitis B and C viruses (HBV and HCV, respectively). Possible modifications of the natural history of hepatitis B may occur. The aim of this study was to characterise HBV diversity and evolutionary and mutational viral genome profiles in HIV-1/HBV coinfections. METHODS: HIV-1 and HBV markers determinations (Roche, FRG; Abbott, USA) and HBV genome-length retrospective analysis were performed in follow-up isolates from patients who were either stably HBsAg-negative with a low level of HBV DNA (occult hepatitis B infection, OBI) or HBsAg-positive with a high level of HBV DNA. Phylogenetic analysis (maximum likelihood method, MEGA5), statistical analysis and evolutionary rates calculation (d S/d N) were applied. RESULTS: Positive selection pressures in the PreS/S region and a significantly higher number of mutations in this region including the major hydrophilic region (MHR) and the "a" determinant were shown in HBsAg-negative (possibly OBI) compared to stably HBsAg-positive HIV-1/HBV subgenotypes D3/A2 coinfected patients. Mutants previously described in HIV-1/HBV coinfected patients were found. Known mutants Y100C, P127T and P120A associated to Y134H and S143T and new S mutants, which may potentially affect HBsAg expression and secretion and anti-HBs binding, were detected in baseline sera persisting up to the end of 9 years follow-up. Known mutations of BCP, Pre-C, C and X regions were also characterised. Natural mutants strictly known as being involved in diagnostic failure were not detected; however, numerous corresponding sites showed amino acid variations. CONCLUSIONS: Evolutionary and genotypic differences observed, particularly in the PreS/S region, between HBsAg-negative (OBI) and HBsAg-positive HIV-1/HBV coinfected patients, may contribute, in association with mutations of other genomic regions, to the HBsAg-negative phenotype.

Hepatitis E virus and hepatitis A virus exposures in an apparently healthy high-risk population in Italy.

PURPOSE: The prevalence of anti-hepatitis E virus (HEV) and anti-hepatitis A virus (HAV), as well as the possible links with socio-demographic and other viral risks factors, were evaluated in an inmates population. METHODS: The study population consisted of 973 consecutively recruited inmates of eight Italian prisons. RESULTS: The anti-HEV prevalence was 11.6 % (113/973). It increased significantly by age (χ(2) for linear trend: p = 0.001) and was significantly higher among non-Italian compared to Italian inmates (15.3 vs. 10.7 %, respectively). Age >40 years [odds ratio (OR) 2.1; 95 % confidence interval (CI) 1.4-3.1], non-Italian citizenship (OR 1.8; 95 % CI 1.1-2.9) and anti-HIV seropositivity (OR 2.2; 95 % CI 1.2-4.2) were the only factors independently associated to anti-HEV positivity by logistic regression analysis. The overall anti-HAV prevalence was 86.4 %, and was significantly higher in non-Italian compared to Italian prisoners (92.6 vs. 84.9 %, respectively; p = 0.02). Age older than 40 years (OR 3.6; 95 % CI 2.2-5.9), <5 years formal education (OR 2.1; 95 % CI 1.3-3.2) and non-Italian nationality (OR 2.7; 95 % CI 1.5-4.8) were factors independently associated to anti-HAV positivity by the logistic regression analysis. CONCLUSIONS: Compared to the general population, significantly higher anti-HEV and anti-HAV prevalences were observed in an inmates population in Italy. Old age and non-Italian nationality were factors independently related to both HEV and HAV exposures. This data suggest the important role of low socio-economic factors in the transmission of both infections in high-risk populations. The possible epidemiological and/or pathogenetic links between HEV and HIV exposures need to be studied further.

Virological and epitope evolution of HCV infection from acute hepatitis C to subsequent episodes of HCV-related acute liver cell necrosis.

AIM: To evaluate the virological and clinical events occurring during a 3-year follow-up in three patients who, after symptomatic acute hepatitis C (AHC), experienced subsequent episodes of HC virus (V)-related acute liver cell necrosis. PATIENTS AND METHODS: The three patients were investigated for viral variability in the core, E1/E2, and NS5b regions during different phases of infection, and a computer-assisted analysis of the variation of known predicted epitopes in the consensus sequence was performed. RESULTS: The first patient showed numerous genetic variations, which may be related to the maintenance of a chronic HCV infection state and to episodes of liver disease exacerbation. The second patient showed minimal viral variations associated with apparent resolution of the infection, but the same virus isolate, based on phylogenetic analysis, produced a second acute episode after the occult phase. The third patient, after the resolution of AHC, manifested a second episode of HCV infection by a different HCV sub-genotype. CONCLUSION: Episodes of HCV-related acute liver cell necrosis after AHC may be associated to different virological patterns, such as the establishment of a chronic HCV infection, a reactivation of an occult virus, or a reinfection by a different HCV genotype.

Kinetics of WHV-HDV replication in acute fatal course of woodchuck hepatitis.

The objective of this study was to evaluate, by developing one-step real-time PCR, the outcome of superinfection with hepatitis D virus (HDV) genotype I in woodchucks that were chronic carriers of woodchuck hepatitis virus (WHV) and did not show relevant signs of liver damage. Three woodchucks (Marmota monax) chronically infected with WHV were superinfected with a woodchuck HDV inoculum. The evolution of the WHV and HDV infections was monitored by quantifying HDV-RNA, WHV-DNA, and HDV-WHV antigens and antibodies. WHV and HDV sequencing was also performed and liver markers were evaluated. Liver damage was assessed using the Ishak method. All woodchucks showed a high HDV viral load, antigenemia and short survival after superinfection. Histopathological examination of autoptic liver samples showed massive liver necrosis compatible with an acute fatal course of hepatitis. The WHV sequencing showed that the virus population was not substituted by the WHV inoculum. The HDV sequencing performed during superinfection and at autopsy indicated amino acid changes in immune dominant regions of the HDV antigen. The strong correlation between acute infection with HDV genotype I and rapid and fatal liver failure indicates that HDV can be an important factor in the prognosis of HDV-WHV-superinfected woodchucks.

Epidemiological and virological characterization of a large community-wide outbreak of hepatitis A in southern Italy.

A large outbreak of hepatitis A virus (HAV) infection occurred in 2004 in Campania, a region of southern Italy, with 882 cases reported between 1 January and 1 August. The local public health authorities and the Italian National Institute of Health carried out investigations in order to characterize the agent, identify the source of infection and the route of transmission, and implement appropriate control measures. A web-based reporting system enhanced the flow of information between public health authorities, providing real-time epidemic curves and frequency distributions. The same 1B HAV genotype was found in 90% of sera from a subset of patients with acute disease, suggesting a local common source. A case-control study in the municipality with the highest attack rate showed that raw seafood consumption, in particular if illegally sold in water, was strongly associated with HAV illness. Samples of seafood systematically collected from retailers were found contaminated by HAV.

Hepatitis B virus infection in health care workers in Albania: a country still highly endemic for HBV infection.

BACKGROUND: Health care workers (HCW) have an elevated risk of acquiring and transmitting parenteral infections. The aim of this study was to evaluate the prevalence of hepatitis B virus (HBV) and hepatitis C virus (HCV) markers with the final goal to encourage HBV vaccination of the non-immune Albanian HCW. METHODS: Among 480 HCW enrolled, 92 were physicians, 246 were nurses/techniques, 120 were auxiliary workers and 22 were office workers. RESULTS: The HBsAg, anti-HBc and anti-HCV prevalence were 8.1%, 70% and 0.6%, respectively. The highest (11.4%) HBsAg prevalence was observed in the youngest age group (20-30 years of age). High HBsAg prevalence (7.2-7.5%) was detected also in age groups above 30 years. The highest HBsAg prevalence (12.6%) was found in the auxiliaries. The anti-HBc prevalence increased significantly with age from 59% in HCWs younger than 39 years to 87% among those older than 50 years. After adjustments for different job categories, age older than 40 years remained independently associated with anti-HBc positivity (OR = 2.9; 95% CI 1.9-4.6) and inversely associated with the lack of HBV immunity or infection markers (OR = 0.4; 95% CI 0.2-0.7). Of 142 HBsAg negative and/or anti-HBc Ab negative sera, 28 (20%) tested positive for anti-HBs. The 114 remaining individuals with no HBV infection or immunity markers were vaccinated against HBV infection. CONCLUSIONS: A high HBV infection rate and low HBV vaccination coverage were found in Albanian HCW. Albania is a Mediterranean country still highly endemic for HBV infection and new strategies to promote HBV vaccination are to be adopted.

Activation of the ER stress gene gadd153 by hepatitis C virus sensitizes cells to oxidant injury.

HCV induces endoplasmic reticulum (ER) stress which correlates with transcriptional induction of ER stress genes. Previously, we reported that expression of HCV structural proteins activates the ER stress and pro-apoptotic gene gadd153 which plays a relevant role in cell death induced by oxidative stress. In the present study, using human hepatic cell lines Huh7 carrying a full-length HCV replicon, we demonstrated that replication and expression of the complete set of HCV proteins were associated with elevated expression of gadd153. Analysis of gadd153 promoter activity revealed that both the ATF4 and the ATF6 pathways, which are typically induced during ER stress response, contribute to the induction of gadd153 in HCV replicon cells. Activation of the ATF4 pathway was confirmed by identification of increased levels of ATF4 protein in replicon cells. Importantly, we showed that, following H2O2 treatment, gadd153 gene reached higher levels of expression in replicon cells. Consistent with the marked induction of the pro-apoptotic gene gadd153, HCV replicon cells showed an increased vulnerability to oxidant injury. Treatment of replicon cells with a specific small interfering RNA, targeted to gadd153 gene, reduced basal expression of gadd153 and decreased cell death following H2O2. These findings suggest that gadd153 may play a major role in sensitivity of HCV replicon cell to oxidative stress.

Nosocomial transmission in simultaneous outbreaks of hepatitis C and B virus infections in a hemodialysis center.

Reported here are details of a simultaneous outbreak of hepatitis B virus (HBV) and hepatitis C virus (HCV) infections that occurred in a hemodialysis centre in northern Italy, with three patients seroconverting for HBsAg and four patients seroconverting for HCV antibodies. Phylogenetic analysis of the E2 region of the isolates from HCV-seroconverted patients showed the sequences were grouped in the same distinct branch as in a chronically HCV-infected patient, suggesting that the chronically infected patient was the index case. For the patients with HBV infection, phylogenetic analysis showed strong clustering among the sequences of the three patients who seroconverted to HBsAg and no relatedness between them and the sequences of patients chronically infected with HBV. For one of the patients who seroconverted to HBsAg, the last test with negative results for HBV markers had been performed 18 months prior to HBsAg seroconversion. This patient may have been previously infected with HBV and is presumed to be the source of the outbreak. This report emphasizes the importance of using universal precaution measures and HBV vaccination to prevent the transmission of viral hepatitis among chronic hemodialysis patients.

Seroprevalence of hepatitis E virus (HEV) antibody and the possible association with chronic liver disease: a case-control study in Albania.

A case-control study involving 109 in-patients with chronic liver disease and 190 in-patients with no apparent liver disease was conducted to evaluate the seroprevalence of anti-HEV antibodies and the possible association with chronic liver disease. Among cases, the anti-HEV prevalence was 36.6% which increased significantly by age; among controls, the prevalence was 12.1% (P<0.05) and was similar among age groups <60 years. Among cases, aged >50 years (OR 4.0, 95% CI 1.4-11) and the presence of end stage liver disease (ESLD) (OR 4.3, 95% CI 1.4-12.8) were associated independently with anti-HEV positivity. The mean optical density, determined by anti-HEV immunoenzymatic test, was significantly higher among patients with ESLD, compared to the other patients. These results indicate that there is a high seroprevalence of anti-HEV in patients with chronic liver disease and a possible association between HEV infection and/or anti-HEV production and advanced stage chronic liver disease.

Molecular epidemiology of hepatitis C virus genotype 4 isolates in Egypt and analysis of the variability of envelope proteins E1 and E2 in patients with chronic hepatitis.

We analyzed hepatitis C virus (HCV) genotype 4 isolates circulating in the Alexandria District (Egypt) in terms of genetic divergence and the presence of different subtypes. Hypervariable region 1 (HVR1) and the NH2 region of the E2 protein were characterized, and the heterogeneity of subtype 4a isolates was evaluated by analyzing epitope frequencies, immunoproteasome prediction, and possible glycosylation patterns. The heterogeneity of the nucleotide sequences was greater than that found in previous studies, which reported only subtype 4a. Subtype 4a was most common (78% of cases), yet four new subtypes were found, with subtype 4m representing 11% of the cases and the other three subtypes representing another 11%. Substantial heterogeneity was also found when the intrasubtype 4a sequences were analyzed. Differences in the probability of glycosylation and in the positions of the different sites were also observed. The analysis of the predicted cytotoxic-T-lymphocyte epitopes showed differences in both the potential proteosome cleavage and the prediction score. The Egyptian isolates in our study also showed high variability in terms of the HVR1 neutralization epitope. Five of these isolates showed amino acid substitutions never previously observed (a total of six positions). Four of these residues (in four different isolates) were in positions involved in anchoring to the E2 glycoprotein core and in maintaining the HVR1 conformation. The results of this study indicate that HCV genotype 4 in Egypt is extremely variable, not only in terms of sequence, but also in terms of functional and immunological determinants. These data should be taken into account in planning the development of vaccine trials in Egypt.

Activation of endoplasmic reticulum stress response by hepatitis C virus proteins.

Flaviviruses utilize the endoplasmic reticulum (ER) as the main site for replication and protein synthesis and cause some level of ER stress. In the present study, we evaluated the ability of HCV proteins to induce ER stress response by using a tetracycline-regulated cell line expressing a region of HCV genome containing the structural genes. In this system different levels of HCV protein expression could be obtained by varying the concentration of tetracycline in the medium. Real Time PCR and Western blotting assay demonstrated that HCV mRNA and protein levels reach a maximum value at 24-48 h and decrease at 72 h postinduction. Cell proliferation analysis indicated that HCV synthesis causes cell growth inhibition. The effect was also observed in cells expressing lower levels of HCV proteins. The expression profile of specific genes, which are markers of ER stress response, revealed the upregulation of the chaperone GRP78 and the transcription factor GADD153. Induction of GADD153 correlates with the downregulation of the antiapoptotic Bcl-2 gene suggesting that synthesis of HCV proteins may influence cell fate through the activation of ER stress signaling pathway.

Molecular characterisation of SENV and TTV infections in hepatopathic liver-transplant patients. Brief Report.

The presence of SENV and TTV infections among 50 patients who had undergone liver transplantation was evaluated. UTR amplification showed that 46 (92%) sera were positive. ORF-1 amplification showed that 25 (50%) patients were positive for either SENV (51.3%), TTV (10.8%), or both (37.8%) all confirmed by sequencing and phylogenetic analysis. SENV-D and SENV-H were the most prevalent viruses. The phylogenetic analysis of isolates showed that whereas SENV-D and SENV-G viruses showed sequence stability and strain persistence, SENV-H had cleared or mutated. Biological differences seem to exist among different genotypes in terms of viral replication and their persistence.

The transmembrane domain of hepatitis C virus E1 glycoprotein induces cell death.

The E1 protein of hepatitis C virus (HCV) shows the ability to induce cell lysis by the alteration of membrane permeability when expressed in Escherichia coli cells. This function seems to be an intrinsic property of a C-terminal hydrophobic region of E1 as permeability changes and cell lysis can be blocked by mutagenesis of specific amino acids in this domain. To establish whether the expression of E1 protein and its C-terminal domain was able to induce cell death also in eukaryotic cell, we cloned HCV sequences expressing the full-length E1 (E383), the C-terminal domain (SVP) and a mutant lacking the C-terminal region (E340) in the pRC/CMV expression vector. HepG2 cell line was co-transfected with empty vector or HCV expression plasmids and a reporter vector that expressed beta-galactosidase (beta-gal) to visualize co-transfected blue cells. At 60 h after transfection, the loss of blue cells, considered as a measure of cell death, was 31.5 and 64.3% for the E1 and SVP clones. On the contrary, the number of blue cells after transfection with E340 plasmid was similar to that observed with the control vector. The analysis by the terminal deoxynucleotidyltransferase-mediated dUTP nick end-labeling (TUNEL) assay revealed an increased number of apoptotic cells at 48 h after transfection with E1 and SVP clones. Furthermore, cells transfected with SVP revealed a typical internucleosomal DNA fragmentation and the activation of caspase-3-like proteases as the specific inhibitor Ac-DEVD-CHO peptide partially blocked SVP apoptosis. These data indicate that the intracellular expression of HCV E1 protein and its C-terminal domain induces an apoptotic response in human hepatoma cell line.

Cell cycle perturbation in a human hepatoblastoma cell line constitutively expressing Hepatitis C virus core protein.

Hepatitis C virus (HCV) is one of the major causes of chronic liver disease with the potential for development of hepatocellular carcinoma (HCC). The core protein of HCV has been shown to modulate expression of various cellular genes and to influence a number of cellular functions. We investigated the effect of constitutively expressed HCV core protein on cell cycle progression in HepG2 cell line, which is derived from a differentiated human hepatoblastoma and shows biosynthetic features similar to human hepatocytes. The results indicated that stable expression of the core protein in unsynchronized HepG2 cells induced a perturbation of the cell cycle with reduced cell doubling meantime and increased S phase fraction. Increase of c-myc protein above the basal expression level was demonstrated with a significant increase of c-myc stability, as revealed by its prolonged intracellular half-life, in HepG2 expressing HCV core protein. In contrast, p53 and p21 levels were unchanged. These results suggest that HCV core protein may promote cell cycle progression in HepG2 cells possibly through increasing stability of c-myc oncoprotein. These results are in support of important role played by HCV core protein in virus-mediated pathogenesis in persistently infected hosts and in hepatocarcinogenesis.

Induction of FAS ligand expression in a human hepatoblastoma cell line by HCV core protein.

Tumour cells and virus infected cells expressing Fas ligand (FasL) can evade immune surveillance by inducing apoptosis in T cells expressing Fas. In order to characterise a possible role of hepatitis C virus (HCV) core protein in similar mechanisms during HCV infection, we investigated Fas ligand expression and activity in a human hepatoblastoma cell line (HepG2) constitutively expressing this protein. Strong FasL induction was detected by immunoblotting and flow cytometry analysis in the core expressing cell lines Hep39. In contrast, vector transfected cells or cell lines expressing HCV E1-E2 proteins did not show FasL expression. Co-cultivation experiments of Hep39 cells with a Fas-sensitive T cell line indicated that FasL induced by the core protein had apoptotic activity toward target cells. Effect of the core protein on induction of FasL promoter was further examined by co-transfection of HepG2 cells with core-bearing plasmid and a vector in which luciferase gene expression is driven by human FasL promoter. Results of the luciferase assay indicated a positive regulation of FasL promoter by the core protein. In conclusion, HCV core protein plays a role in the induction of functional FasL in hepatoblastoma cell line and apoptosis in a target T cell line expressing Fas. Similar mechanisms may contribute, in vivo, to establishment of chronic infection and development of hepatocellular carcinoma (HCC).

Different levels of variability in subtypes 1b and 4a of hepatitis C viruses.

We performed genetic and phenic analyses to evaluate nucleotide and amino-acid sequences of the amino-terminus of the E1 protein of HCV genotype 1b (extracted from databank) and 4a (characterised in this study). The non-synonymous (ka) mutation analysis demonstrated that the genome of genotype 1b was not saturated by variations, with a rate of transition/transversion (s/v) of 1.5, which is similar to the expected ratio (i.e., 2.0). The s/v ratio in genotype 4a isolates was lower (0.98), indicating saturation due long-term variability. Moreover, the genotype 1b sequences showed a higher number of ka mutations (s+v) (mean of 2.8 per sequence) than genotype 4a (mean of 1.5). The introduction of ka mutations resulted in a higher degree of amino acid variability in genotype 4a. In the genome of genotype 1b, each nucleotide mutation introduced new amino acids, with a Granthan distance of 3.35-42.5, whereas for genotype 4a the distances ranged from 48.8 to 102.1. The phenic analysis also indicated different and complex patterns of amino-acid substitution. Finally, diverse isoelectric points and hydrophobicity were predicted for the two genotypes, with a higher acidity for genotype 4a E1 proteins.

Ultrasonography in the study of hepatocellular carcinoma in woodchucks chronically infected with WHV.

The woodchuck hepatitis virus (WHV)/woodchuck system is studied as animal model of human hepatocellular carcinoma (HCC) induced by chronic hepatitis B virus infection. The aim of the present study was the evaluation of ultrasound (US) liver examination in woodchuck as a routine method to detect HCC nodules and to follow their growth. Sixteen woodchucks were included in the study. US liver examination was carried out in all animals using a 5 MHz convex scanner. Macroscopic and microscopic examinations were performed to evaluate the US findings. The lower limit of nodule detection by US examination was a diameter of 5 mm. Macroscopic and microscopic examinations confirmed US findings in 14 of 16 animals (86.6%). No false negative results were obtained. Increase of nodule size was faster in the early phase of tumour growth. Small nodules (16 +/- 5 mm) appeared as hypoechoic lesions with well-defined margins and homogeneous structure. Large nodules (42 +/- 19 mm) appeared as hyperechoic lesions with irregular margins, heterogeneous or of mixed pattern; microscopical examination showed different degrees of necrosis, inflammation and fibrosis inside these latter neoplasms. The hepatitis reaction was conspicuously more severe around HCC nodules. No fibrosis and/or cirrhosis were found in normal liver parenchyma surrounding tumour nodules. On the whole, US appears to be helpful in the diagnosis of woodchuck HCC even at an early stage. Serial US evaluation can be used to study the growth rate of tumour nodules during natural history or experimental HCC treatments in woodchuck.

Scaffold attachment region located in a locus targeted by hepadnavirus integration in hepatocellular carcinomas.

The role of viral integration in HBV induced hepatocellular carcinoma (HCC) is still controversial. In the WHV/woodchuck animal model, WHV integration was found to activate the N-myc2 oncogene either by enhancer insertion in proximity of the gene, or by integration in a distantly located uncoding locus, win. In addition, we have reported that N-myc2 activation also results from WHV integration in the b3n locus, located several kilobases downstream of N-myc2. In this work we report the search for function(s) of the b3n locus that might be possibly affected by WHV integration and indirectly activate N-myc2. A 0.5 kb region of the sequence of this locus exhibited unusual features, typical of scaffold/matrix attachment regions (S/MAR). Standard in vitro binding assays are commonly used to assess if a DNA fragment is a S/MAR. DNA fragments cloned from the b3n locus were tested for in vitro binding affinity for both heterologous and autologous nuclear scaffold preparations. Only the fragment spanning the region rich of S/MAR motifs was found to bind specifically nuclear scaffolds, thus demonstrating that a S/MAR element is present in the b3n locus. Based on these findings, we speculate that WHV integration might deregulate the S/MAR element and indirectly affect the expression of the N-myc2 gene located upstream of the S/MAR. Our findings also suggest that the role of HBV integration should be reconsidered, because a similar mechanism has not been investigated to date in human HCC.

Prevalence of non-organ specific autoantibodies in HCV-infected subjects in the general population.

The significance of non-organ specific antibodies (NOSAs) in HCV-related chronic hepatitis is largely unclear. In this study we evaluated the prevalence of NOSAs in a non-selected population of HCV-infected subjects. One hundred and seventy anti-HCV positive and 192 anti-HCV negative sex and age-matched subjects (median age 64 years, range 7-91 years, female 68%) enrolled from the general population of a small Italian town were evaluated for NOSAs by indirect immunofluorescence on rat tissue sections and HEp-2 cells, and by counterimmunoelectrophoresis with thymus and spleen extracts as the antigen source. One hundred and sixty-three (96%) HCV-infected subjects had normal ALT serum levels and no evidence of liver disease. NOSAs were found in 31 out of 170 (18%) anti-HCV positive subjects and in 20 out of 192 (10%) controls (P = NS), with similar median titre (1:40) and range (1:40 to 1:160). Neither liver/kidney microsomal antibody type 1 nor antiactin reactivity were detected. No significant association between NOSAs and HCV genotypes was observed. In the general population, HCV-infected subjects and healthy controls have a similar prevalence of NOSAs. Without continuous liver damage HCV infection is unlikely to induce the appearance of NOSAs.