Use of NS-4 peptides to identify type-specific antibody to hepatitis C virus genotypes 1, 2, 3, 4, 5 and 6

Investigating the role of killer cell immunoglobulin-like receptors and human leukocyte antigen genetic variants in hepatitis C virus infection

The genetic diversity of killer cell immunoglobulin-like receptors (KIRs) and human leukocyte antigen (HLA) genes influences the host's immune response to viral pathogens. This study aims to explore the impact of five single nucleotide polymorphisms (SNPs) in KIR3DL2 and HLA-A genes on hepatitis C virus (HCV) infection. A total of 2251 individuals were included in the case-control study. SNPs including KIR3DL2 rs11672983, rs3745902, rs1654644, and HLA-A rs3869062, rs12202296 were genotyped. By controlling various confounding factors using a modified logistic regression model, as well as incorporating stratified analysis, joint effects analysis, and multidimensional bioinformatics analysis, we analyzed the relationship between SNPs and HCV infection. The logistic regression analysis showed a correlation between KIR3DL2 rs11672983 AA, KIR3DL2 rs3745902 TT, and increased HCV susceptibility (p < 0.01). Stratified analysis indicated that KIR3DL2 rs1654644 and HLA-A rs3869062 also heightened HCV susceptibility in certain subgroups. A linear trend of rising HCV infection rates was observed when combining KIR3DL2 rs11672983 AA and KIR3DL2 rs3745902 TT (ptrend = 0.007). Bioinformatics analysis suggested these SNPs' regulatory potential and their role in altering messenger RNA secondary structure, implying their functional relevance in HCV susceptibility. Our findings indicate that KIR3DL2 rs11672983 AA and KIR3DL2 rs3745902 TT are significantly associated with increased susceptibility to HCV infection.

Genetic mutations in NF-κB pathway genes were associated with the protection from hepatitis C virus infection among Chinese Han population

Host genetic polymorphism is one of major unalterable major factors for HCV infection. NF-κB proteins play multiple roles in immune response and involve in HCV infection and progression. This study was conducted to explore the relationship between single nucleotide polymorphisms (SNPs) in NF-κB pathway and the susceptibility as well as resolution of HCV infection. A total of 1642 Chinese subjects were enrolled in the study, including 963 uninfected control cases, 231 cases with spontaneous viral clearance and 448 cases with persistent HCV infection, and four SNPs (Rel rs842647, NF-κB2 rs12769316, RelA rs7101916, RelB rs28372683) were genotyped by TaqMan assay among them. Potentially functional polymorphisms were analyzed using online bioinformatics tools. The logistic analyses results indicated that RelA rs7101916 T allele (P_Bonferroni = 0.016) and RelB rs28372683 A allele (P_Bonferroni = 4.8e-5) were associated with an decreased risk of the susceptibility to HCV infection among Chinese Han population, which were consistent with the results of cumulative effects and haplotype analysis. The silico analysis of SNPs function suggested that the genetic variation of rs7101916 and rs28372683 could influence gene transcriptional regulation and expression, subsequently affecting NF-κB pathway activation and the susceptibility to HCV infection. This study firstly reported that the carriage of RelA rs7101916 T or RelB rs28372683 A was the potential protective factor against HCV infection among the Chinese population.

Association of HCV mutated proteins and host SNPs in the development of hepatocellular carcinoma

Hepatitis C virus plays a significant role in the development of hepatocellular carcinoma (HCC) globally. The pathogenic mechanisms of hepatocellular carcinoma with HCV infection are generally linked with inflammation, cytokines, fibrosis, cellular signaling pathways, and liver cell proliferation modulating pathways. HCV encoded proteins (Core, NS3, NS4, NS5A) interact with a broad range of hepatocytes derived factors to modulate an array of activities such as cell signaling, DNA repair, transcription and translational regulation, cell propagation, apoptosis, membrane topology. These four viral proteins are also implicated to show a strong conversion potential in tissue culture. Furthermore, Core and NS5A also trigger the accretion of the β-catenin pathway as a common target to contribute viral induced transformation. There is a strong association between HCV variants within Core, NS4, and NS5A and host single nucleotide polymorphisms (SNPs) with the HCC pathogenesis. Identification of such viral mutants and host SNPs is very critical to determine the risk of HCC and response to antiviral therapy. In this review, we highlight the association of key variants, mutated proteins, and host SNPs in development of HCV induced HCC. How such viral mutants may modulate the interaction with cellular host machinery is also discussed.

Genetic variations in NF-κB were associated with the susceptibility to hepatitis C virus infection among Chinese high-risk population

Polymorphisms within NF-κB pathway genes may be linked to hepatitis C virus (HCV) infection susceptibility and outcomes. We investigated the associations between single nucleotide polymorphisms (SNPs) in NF-κB and the susceptibility as well as resolution of HCV infection. A Chinese population, including 1125 uninfected control cases, 558 cases with spontaneous viral clearance and 898 cases with persistent HCV infection, was genotyped for four SNPs (rs11820062, rs230530, rs1056890 and rs3774963) using a TaqMan assay. Our logistic analyses indicate that the subjects carrying RelA rs11820062 A allele had a significantly increased risk of HCV susceptibility (P Bonferroni  < 0.003125 in a dominant or additive model). In stratified analysis, the increased risk associated with rs11820062 A allele on HCV susceptibility remained in some case subgroups. This study demonstrates that a genetic variant involved in the NF-κB pathway gene (rs11820062 A allele) is associated with an increased HCV susceptibility within a high-risk Chinese population.

Discrepancy between Hepatitis C Virus Genotypes and NS4-Based Serotypes: Association with Their Subgenomic Sequences

Determination of hepatitis C virus (HCV) genotypes plays an important role in the direct-acting agent era. Discrepancies between HCV genotyping and serotyping assays are occasionally observed. Eighteen samples with discrepant results between genotyping and serotyping methods were analyzed. HCV serotyping and genotyping were based on the HCV nonstructural 4 (NS4) region and 5'-untranslated region (5'-UTR), respectively. HCV core and NS4 regions were chosen to be sequenced and were compared with the genotyping and serotyping results. Deep sequencing was also performed for the corresponding HCV NS4 regions. Seventeen out of 18 discrepant samples could be sequenced by the Sanger method. Both HCV core and NS4 sequences were concordant with that of genotyping in the 5'-UTR in all 17 samples. In cloning analysis of the HCV NS4 region, there were several amino acid variations, but each sequence was much closer to the peptide with the same genotype. Deep sequencing revealed that minor clones with different subgenotypes existed in two of the 17 samples. Genotyping by genome amplification showed high consistency, while several false reactions were detected by serotyping. The deep sequencing method also provides accurate genotyping results and may be useful for analyzing discrepant cases. HCV genotyping should be correctly determined before antiviral treatment.

Single nucleotide polymorphisms of toll-like receptor 7 in hepatitis C virus infection patients from a high-risk chinese population

Hepatitis C virus (HCV) infection varies in the outcomes depending on both viral and host factors. This study aims to investigate the associations of three single nucleotide polymorphisms (SNPs) of Toll-like receptor 7 (TLR7), rs179016, rs5743733, and rs1634323, with susceptibility to HCV infection and clearance. The three SNPs were genotyped in a high-risk Chinese population, including 444 HCV spontaneous clearance cases, 732 persistent infection cases, and 1107 healthy controls. The G allele of rs1634323 was related to the protection from persistent infection among females (dominant model: odds ratio (OR) = 0.558, 95 % confidence interval (CI) = 0.348-0.894, P = 0.015). This protective effect was more evident in blood donation and HCV non-1 genotype-infected subgroups (all P < 0.05). The carriage of rs179016 C allele was more prone to develop persistent infection (OR = 1.444, 95 % CI = 1.096-1.903, P = 0.009) in males, and the risk effect remained significant among older (>50 years), hemodialysis (HD), and HCV-1 and HCV non-1 genotypes-infected subjects (all P < 0.05). Haplotype analyses showed that CCA haplotype among females was correlated with the elevated risk of HCV susceptibility while the carriage of GGA was more prone to be infected with HCV and CCA was more likely to develop persistent infection (all P < 0.05) among males. Our results first demonstrated that the carriage of rs179016 C allele had a negative effect on spontaneous clearance of HCV among males while rs1634323 G allele conferred a protective effect against persistent infection among female subjects.

Molecular Assay and Genotyping of Hepatitis C Virus among Infected Egyptian and Saudi Arabian Patients

Hepatitis C virus (HCV) infection is a major health problem recognized globally. HCV is a common cause of liver fibrosis that may lead to liver cirrhosis or hepatocellular carcinoma. The aim of this study was to estimate the prevalence of HCV infection and genotyping among Egyptian and Saudi Arabian chronic patients using different molecular techniques. HCV RNA viral load was assessed by real-time polymerase chain reaction (RT-PCR) technology. For HCV genotyping, RT-PCR hybridization fluorescence-based method and reverse hybridization line probe assay (INNO-LiPA) were used. A total of 40 anti-HCV-positive patients with chronic hepatitis C were examined for HCV RNA, genotyping, and different laboratory investigations. In the present study, HCV genotypes 4, mixed 4.1b, and 1 were detected in patients of both countries, while genotype 2 was only detected in Saudi Arabian patients. Genotyping methods for HCV showed no difference in the classification at the genotype level. With regard to HCV subtypes, INNO-LiPA assay was a reliable test in HCV genotyping for the detection of major genotypes and subtypes, while RT-PCR-based assay was a good test at the genotype level only. HCV genotype 4 was found to be the predominant genotype among Egyptian and Saudi Arabian chronic patients. In conclusion, data analysis for detecting and genotyping HCV was an important factor for understanding the epidemiology and treatment strategies of HCV among Egyptian and Saudi Arabian chronic patients.

Genetic variations in vitamin D receptor were associated with the outcomes of hepatitis C virus infection among Chinese population

Vitamin D has been considered as an immune modulator, and exerted the effect through the vitamin D receptor (VDR). This study investigated the associations of single-nucleotide polymorphisms (SNPs) of VDR with the outcomes of Hepatitis C virus (HCV) infection. Three SNPs (rs2228570, rs757343 and rs739837) were genotyped by TaqMan assay among Chinese population, including 538 HCV spontaneous clearance subjects, 834 persistent infection subjects and 1030 uninfected subjects. Binary logistic analyses were used to control the effects of confounding factors. The results showed that subjects with the rs757343 A allele and rs739837 A allele had the significantly reduced risk of HCV susceptibility (all PBonferroni<0.05 in dominant/additive model). In the stratified analysis, the protection of rs757343 A allele and rs739837 A allele against HCV infection remained effective in some subgroups. In addition, patients carrying rs739837 CA genotype were less prone to develop persistent infection (PBonferroni=0.033) and such effect still work in several subgroups in the stratified analysis. Furthermore, haplotype analysis indicated that when compared with the most frequent GC haplotype, the haplotype carrying AA (odds ratio (OR)=0.66, 95% confidence interval (CI)=0.56-0.78) and GA (OR=0.64, 95% CI=0.47-0.85) suggested a protective effect. Our findings indicated that the polymorphisms of VDR are associated with the outcomes of HCV infection among Chinese population.

Human Leukocyte Antigen Class II Alleles Are Associated with Hepatitis C Virus Natural Susceptibility in the Chinese Population

Human leukocyte antigen (HLA) class II molecule influences host antigen presentation and anti-viral immune response. The aim of this study was to investigate whether single nucleotide polymorphisms (SNPs) within HLA class II gene were associated with different clinical outcomes of hepatitis C virus (HCV) infection. Three HLA class II SNPs (rs3077, rs2395309 and rs2856718) were genotyped by TaqMan assay among Chinese population, including 350 persistent HCV infection patients, 194 spontaneous viral clearance subjects and 973 HCV-uninfected control subjects. After logistic regression analysis, the results indicated that the rs2856718 TC genotype was significantly associated with the protective effect of the HCV natural susceptibility (adjusted OR: 0.712, 95% CI: 0.554–0.914) when compared with reference TT genotype, and this remained significant after false discovery rate (FDR) correction (p = 0.024). Moreover, the protective effect of rs2856718 was observed in dominant genetic models (adjusted OR: 0.726, 95% CI: 0.574–0.920), and this remained significant after FDR correction (p = 0.024). In stratified analysis, a significant decreased risk was found in rs2856718C allele in the male subgroup (adjusted OR: 0.778, 95% CI: 0.627–0.966) and hemodialysis subgroup (adjusted OR: 0.713, 95% CI: 0.552–0.921). Our results indicated that the genetic variations of rs2856718 within the HLA-DQ gene are associated with the natural susceptibility to HCV infection among the Chinese population.

Toll-like receptor 7 variations are associated with the susceptibility to HCV infection among Chinese females

Toll-like receptors 7 (TLR7) play a crucial role in provoking an immune response in HCV infection. We aimed to investigate whether single nucleotide polymorphisms (SNPs) of TLR7, including rs179009, rs179010 and rs179012, affect the outcomes of HCV infection among the Chinese population. A total of 1767 Chinese Han individuals were enrolled. The distribution of SNP frequencies among three groups with different outcomes of HCV infection was assessed, including healthy controls, cases with spontaneous clearance and cases with viral persistence. Then TLR7 mRNA expression and the production of IFN-α and IL-6 after TLR7 agonist Imiquimod stimulation in vitro were determined. Our results suggested that rs179009 GG genotype was significantly associated with a higher risk of the susceptibility to HCV infection among female subjects (OR=2.42, 95% CI=1.24-4.71, P=0.01). Haplotype GCG was significantly associated with a high risk for HCV susceptibility (OR=1.50, 95% CI=1.11-2.03, P=0.01) as compared with the reference haplotype ACG among females. In the functional research of rs179009, a lower IFN-α level was observed in GG genotype than in AA genotype (P=0.032). Our data indicate that TLR7 rs179009 GG genotype and haplotype GCG were associated with an increased risk of the susceptibility to HCV infection among Chinese females, which may be due to the impaired IFN-α response.

Association of genetic variants in estrogen receptor α with HCV infection susceptibility and viral clearance in a high-risk Chinese population

The purpose of this study was to test the hypothesis that genetic variants of estrogen receptor α (ERα) are associated with the outcomes of hepatitis C virus (HCV) infection. We genotyped the seven single nucleotide polymorphisms (SNPs) (rs2077647, rs9340799, rs2234693, rs1801132, rs9322354, rs2228480 and rs3798577) of ERα and conducted a case-control study in a high-risk Chinese population, including 429 HCV spontaneous clearance cases, 880 persistent infection cases and 1,174 uninfected controls. The C allele of rs2234693 was significantly associated with increased susceptibility to HCV infection [dominant model: adjusted odds ratio (OR) = 1.377, 95% confidence interval (CI) =1.126-1.778], and the risk effect remained significant among the younger (≤55 years) and hemodialysis subjects (all P < 0.007). The other three SNPs variant genotypes also showed significant correlation with elevated risk of HCV infection in different strata (rs2077647 in males; rs9340799 in blood donors; rs1801132 in younger subjects; all P < 0.007). It was also discovered that carriage of rs2228480 A allele was more prone to develop persistent HCV infection (dominant model: adjusted OR = 1.203, 95% CI = 1.154-1.552), and the risk effect was more evident in females and blood donors (all P < 0.007). Haplotype analyses (rs2077647, rs9340799 and rs2234693) showed that, compared with the most frequent haplotype TAT, CAC played a risk effect in subgroups of younger (P = 3.24 × 10(-3)) and male (P = 5.51 × 10(-4)), whereas CAT expressed a protective effect in females (P = 2.27 × 10(-4)) for HCV infection susceptibility. We first report that these SNPs (rs2077647, rs9340799, rs2234693, rs1801132 and rs2228480) in ERα can influence the outcomes of HCV infection in a high-risk Chinese population.

Study of the hepatitis C virus in the republic of macedonia

Hepatitis C virus (HCV) is a major public health problem. It is a leading cause of chronic liver disease and the most common indication for liver transplantation. The therapy for eradication of HCV infection is successful in only 50.0–80.0% of patients and is highly dependent on the HCV genotype.

Molecular detection and characterization of HCV in the Republic of Macedonia started in 1990. Since then, more than 4000 samples have been analyzed at the Research Centre for Genetic Engineering and Biotechnology (RCGEB) “Georgi D. Efremov,” Skopje, Republic of Macedonia. The prevalence of HCV infections in the healthy population of the Republic of Macedonia was found to be 0.4%, while it varies between 23.0 and 43.0% in different at-risk groups of patients.

The prevalence of HCV genotypes, according to associated risk factors in HCV infected patients from the Republic of Macedonia, was analyzed. We found genotype 1 to be predominant in a group of hemodialysis patients, while genotype 3 was predominant in intravenous (IV) drug users.

Association of six polymorphisms in the Oligoadenylate synthetase (OASL)-like interferon-stimulated gene with a sustained virological response was also analyzed. Our preliminary results suggest that non ancestral alleles in four of the six studies polymorphisms in OASL gene are associated with sustained virological response among HCV infected patients in R. Macedonia.

Association of interleukin-18 gene polymorphisms with the outcomes of hepatitis C virus infection in high-risk Chinese Han population

Interleukin 18 (IL-18) gene polymorphisms have been reported to be associated with the outcomes of hepatitis C virus (HCV) infection in Americans, Indians and Europeans. We aimed to investigate whether the association can be replicated in Chinese Han population. Three IL-18 variants, -656G>T, -137G>C and +105A>C, were genotyped in three independent Han cohorts consisting of 552 cases and 784 controls. By using logistic regression analysis and multiple testing, haplotype GCC were associated with a protection from susceptibility to HCV. After stratified analysis, both the carriage of -137C allele in the older or hemodialysis subgroup and the carriage of +105C allele in the younger subgroup were found to be significantly associated with a decreased risk of HCV susceptibility. By using logistic regression analysis and multiple testing for the resolution of HCV infection, our study showed that +105C allele and haplotype GGC displayed a negative effect on HCV persistence. After stratified analysis, a significantly decreased risk for HCV persistence was found in +105C allele in the subgroups of young, male or female, drug user or hemodialysis and HCV-1 or HCV mixed genotype. No significant association was observed between -656G>T and the outcomes of HCV infection. Our results demonstrated that the carriage of -137C allele, +105C allele, haplotype -656G/-137C/+105C and haplotype -656G/-137G/+105C of IL-18 gene may contribute to better outcomes of HCV infection in high-risk Chinese Han population.

Hepatitis C virus-host interactions: Etiopathogenesis and therapeutic strategies

Hepatitis C virus (HCV) is a significant health problem facing the world. This virus infects more than 170 million people worldwide and is considered the major cause of both acute and chronic hepatitis. Persons become infected mainly through parenteral exposure to infected material by blood transfusions or injections with nonsterile needles. Although the sexual behavior is considered as a high risk factor for HCV infection, the transmission of HCV infection through sexual means, is less frequently. Currently, the available treatment for patients with chronic HCV infection is interferon based therapies alone or in combination with ribavirin and protease inhibitors. Although a sustained virological response of patients to the applied therapy, a great portion of patients did not show any response. HCV infection is mostly associated with progressive liver diseases including fibrosis, cirrhosis and hepatocellular carcinoma. Although the focus of many patients and clinicians is sometimes limited to that problem, the natural history of HCV infection (HCV) is also associated with the development of several extrahepatic manifestations including dermatologic, rheumatologic, neurologic, and nephrologic complications, diabetes, arterial hypertension, autoantibodies and cryglobulins. Despite the notion that HCV-mediated extrahepatic manifestations are credible, the mechanism of their modulation is not fully described in detail. Therefore, the understanding of the molecular mechanisms of HCV-induced alteration of intracellular signal transduction pathways, during the course of HCV infection, may offer novel therapeutic targets for HCV-associated both hepatic and extrahepatic manifestations. This review will elaborate the etiopathogenesis of HCV-host interactions and summarize the current knowledge of HCV-associated diseases and their possible therapeutic strategies.

Genetic variation in IL28RA is associated with the outcomes of HCV infection in a high-risk Chinese population

Hepatitis C virus (HCV) infection varies in the outcomes depending on both viral and host factors. This study aims to investigate the association of single-nucleotide polymorphisms (SNPs) of IFNAR2, IL10RB, and IL28RA genes with susceptibility to HCV infection and resolution. Genotyping of IFNAR2, IL10RB, and IL28RA gene polymorphisms were performed using TaqMan® method from 552 patients with sero-positive anti-HCV and 421 uninfected controls. The distribution of IFNAR2 and IL10RB genotypes among the control, persistent infection, and spontaneous clearance groups did not differ. However, IL28RA-rs10903035 A allele was over-represented in persistent infection group when compared with uninfected controls and spontaneous clearance group, respectively (OR=1.54, 95%CI=1.23-1.92, P=0.004; OR=1.42, 95%CI=1.12-1.81, P=0.016), and AA genotype had a significant increased risk of persistent infection in different strata except for the females subgroup (P<0.05). IL28RA-rs11249006 GG genotype showed reduced susceptibility to persistent HCV infection (OR=0.53, 95%CI=0.31-0.91, P=0.044), and the protective effect was significantly different among subgroups stratified by age and likely source of infection (P<0.05). Besides, AG genotype had a significant negative effect on spontaneous clearance of HCV among young subjects (aged ⩽40) and patients infected with viral genotype-1 (P<0.05). Stratified analysis also showed that IL10RB-rs2834167 AG genotype was associated with an increased risk of persistent HCV infection in females, and GG genotype was associated with an increased risk of persistent HCV infection in females and patients with viral genotype non-1 (P<0.05). Haplotype analysis showed that IL28RA rs10903035-rs11249006 haplotype GG played a protective effect for HCV infection (OR=0.21, 95%CI=0.13-0.36, P<0.001; OR=0.20, 95%CI=0.12-0.34, P<0.001). This study indicates that two SNPs in IL28RA are correlated with susceptibility to HCV infection and spontaneous viral clearance, which implicates a primary role of IL28RA in the outcomes of HCV infection.

Management of hepatitis C virus genotype 4: recommendations of an international expert panel

HCV has been classified into no fewer than six major genotypes and a series of subtypes. Each HCV genotype is unique with respect to its nucleotide sequence, geographic distribution, and response to therapy. Genotypes 1, 2, and 3 are common throughout North America and Europe. HCV genotype 4 (HCV-4) is common in the Middle East and in Africa, where it is responsible for more than 80% of HCV infections. It has recently spread to several European countries. HCV-4 is considered a major cause of chronic hepatitis, cirrhosis, hepatocellular carcinoma, and liver transplantation in these regions. Although HCV-4 is the cause of approximately 20% of the 170 million cases of chronic hepatitis C in the world, it has not been the subject of widespread research. Therefore, this document, drafted by a panel of international experts, aimed to review current knowledge on the epidemiology, natural history, clinical, histological features, and treatment of HCV-4 infections.

Oncogenic potential of hepatitis C virus proteins

Chronic hepatitis C virus (HCV) infection is a major risk factor for liver disease progression, and may lead to cirrhosis and hepatocellular carcinoma (HCC). The HCV genome contains a single-stranded positive sense RNA with a cytoplasmic lifecycle. HCV proteins interact with many host-cell factors and are involved in a wide range of activities, including cell cycle regulation, transcriptional regulation, cell proliferation, apoptosis, lipid metabolism, and cell growth promotion. Increasing experimental evidences suggest that HCV contributes to HCC by modulating pathways that may promote malignant transformation of hepatocytes. At least four of the 10 HCV gene products, namely core, NS3, NS5A and NS5B play roles in several potentially oncogenic pathways. Induction of both endoplasmic reticulum (ER) stress and oxidative stress by HCV proteins may also contribute to hepatocyte growth promotion. The current review identifies important functions of the viral proteins connecting HCV infections and potential for development of HCC. However, most of the putative transforming potentials of the HCV proteins have been defined in artificial cellular systems, and need to be established relevant to infection and disease models. The new insight into the mechanisms for HCV mediated disease progression may offer novel therapeutic targets for one of the most devastating human malignancies in the world today.

An overview about hepatitis C: a devastating virus

Hepatitis C (HCV) is the disease that has affected around 200 million people globally. HCV is a life threatening human pathogen, not only because of its high prevalence and worldwide burden but also because of the potentially serious complications of persistent HCV infection. Chronicity of the disease leads to cirrhosis, hepatocellular carcinoma and end-stage liver disease. HCV positive hepatocytes vary between less than 5% and up to 100%, indicating the high rate of replication of viral RNA. HCV has a very high mutational rate that enables it to escape the immune system. Viral diversity has two levels; the genotypes and Quasiaspecies. Major HCV genotypes constitute genotype 1, 2, 3, 4, 5 and 6 while more than 50 subtypes are known. All HCV genotypes have their particular patterns of geographical distribution and a slight drift in viral population has been observed in some parts of the globe.

Viral hepatitis a to e in South mediterranean countries

Viral hepatitis represents an important health problem in the South Mediterranean countries, Egypt, Libya, Tunisia, Algeria and Morocco. Emerging natural history and epidemiological information reveal differences in the overall epidemiology, risk factors and modes of transmission of viral hepatitis A, B, C, D, E infections in the South Mediterranean region. The differences in the in incidence and prevalence of viral hepatitis across North African countries is attributed to variations in health care and sanitation standards, risk factors and immunization strategies. The active continuous population movement through travel, tourism and migration from and to the South Mediterranean countries contribute to the spread of infections due to hepatitis viruses across borders leading to outbreaks and emergence of new patterns of infection or introduction of uncommon genotypes in other countries, particularly in Europe.

Predictors of a sustained virological response in patients with genotype 4 chronic hepatitis C

OBJECTIVES

To determine the clinical, biological, virological and histological predictive factors associated with a sustained virological response (SVR) to combined interferon therapy among Egyptian patients infected by genotype 4 hepatitis C virus (HCV).

PATIENTS AND METHODS

Individual data from 250 patients with genotype 4 chronic hepatitis C, treated with different regimens of combined interferon, were analysed. The primary end point was SVR defined as undetectable HCV RNA by polymerase chain reaction (PCR) 24 weeks after the end of treatment. Multivariate logistic regression analysis was performed to select the independent prognostic parameters associated with SVR.

RESULTS

A sustained virological response was achieved among 137/250 (54.8%) patients. Baseline factors independently and negatively associated with SVR were serum alpha-fetoprotein (AFP) level (above 0.3 upper limit of normal) [odds ratio (OR)=0.5, 95% confidence interval (CI): 0.2-0.8], severe fibrosis (Metavir score >F2) (OR=0.4, 95% CI: 0.2-0.8), presence of steatosis (OR=0.5, 95% CI: 0.3-0.97) and standard interferon treatment (OR=0.4, 95% CI: 0.2-0.8).

CONCLUSIONS

Among genotype 4 chronic hepatitis C patients, severe fibrosis, severe steatosis, treatment with standard interferon and a high serum AFP level were all negatively associated with SVR. Pretreatment serum AFP level should be considered in the routine assessment of factors predictive of a treatment response.

Hepatitis C genotype 4: What we know and what we don't yet know

Hepatitis C virus genotype 4 (HCV-4) is the most common variant of the hepatitis C virus (HCV) in the Middle East and Africa, particularly Egypt. This region has the highest prevelance of HCV worldwide, with more than 90% of infections due to genotype 4. HCV-4 has recently spread in several Western countries, particularly in Europe, due to variations in population structure, immigration, and routes of transmission. The features of HCV-4 infection and the appropriate therapeutic regimen have not been well characterized. This review discusses the virology, epidemiology, natural history, histology, clinical data, and treatment options for patients with HCV-4 infections. Early reports on the treatment of patients with chronic HCV-4 with conventional interferon (IFN)-alpha monotherapy indicated poor rates of sustained viral response (SVR), which improved slightly when combined with ribavirin. Pegylated IFN and ribavirin combination therapy has dramatically improved the response rates, with recent clinical trials showing rates that exceed 60%. These data can now be used as a platform for further research to define optimal treatment duration and predictors of SVR in patients with HCV-4 infection.

CONCLUSION

HCV-4 infection is spreading beyond its strongholds in Africa and the Middle East. Recent clinical trials show that HCV-4 is not difficult to treat, as the response to treatment may be at an intermediate level compared with genotype 1 and genotypes 2 or 3. Tailored treatment options that are comparable to the treatment approaches for genotype 1, 2, and 3 patients to optimize treatment for each patient are now being developed.

Spontaneous elimination of hepatitis C virus infection: A retrospective study on demographic, clinical, and serological correlates

AIM: To find correlates to spontaneous clearance of hepatitis C virus (HCV) infection, this study compared individuals with self-limited and chronic infection with regard to clinical, demographic, and serological parameters.

METHODS: Sixty-seven anti-HCV positive and repeatedly HCV RNA negative individuals were considered to have resolved HCV infection spontaneously. To determine the viral genotype these patients had been infected with HCV serotyping was performed. For comparison reasons, 62 consecutive patients with chronic hepatitis C were enrolled. Cases and controls were compared stratified for age and sex.

RESULTS: Retrospective analysis showed (1) a lower humoral reactivity to HCV in patients with self-limited compared to chronic HCV-infection and (2) that younger age, history of iv drug use, and acute/post-acute hepatitis A or B co-infections, but not viral genotypes, are independent correlates for spontaneous HCV clearance.

CONCLUSION: The stronger humoral reactivity to HCV in patients with persistent infections and in those with a history of iv drug use is supposed to be due to continuous or repeated contact(s) to the antigen. Metachronous hepatitis A or hepatitis B infections might favor HCV clearance.

Characterization of full-length hepatitis C virus genotype 4 sequences

Over 85% of the world's nearly 170 million hepatitis C virus (HCV)-infected subjects exist in regions of Africa, Southeast Asia and Middle Eastern countries where genotypes 4-6 are very common. In particular, HCV genotype 4 is highly prevalent in Egypt with more than 19% of the population infected and chronic HCV representing one of the top five leading causes of death, due in part to ineffective interferon alpha treatment against this genotype. Despite this, very little work has been carried out to characterize the sequence diversity of genotype 4, which will be critical to the development of effective vaccines and antiviral therapies against this genotype. As a result of the paucity of sequence data available for HCV genotype 4, for which only one full genome sequence is currently available, we were interested in characterizing additional genotype 4 sequences and to provide reagents for amplification of this genotype. Here we describe seven unique HCV genotype 4a full genomes, in addition to a single genotype 4d genome, and characterize their sequence diversity in relation to other more closely characterized HCV genotypes.

Interferon regulatory factor-1 promoter polymorphism and the outcome of hepatitis C virus infection

OBJECTIVE

Interferon-alpha (IFN-alpha), an important mediator for the host's innate antiviral defense system, has been approved for the treatment of persistent viral infections. We investigated whether two functional polymorphisms in genes involved in IFN-alpha signaling and effector functions are associated with the natural outcome of hepatitis C virus (HCV) infection and the responsiveness of chronic hepatitis C patients to IFN-alpha therapy.

METHODS

Forty-four individuals who had resolved HCV infection spontaneously and 147 patients who developed chronic hepatitis C were analyzed for functional single nucleotide polymorphisms in the promoter regions of the interferon regulatory factor-1 (IRF-1) and myxovirus resistance protein-1 (MxA) genes at positions -300 and -88, respectively.

RESULTS

With regard to -300 IRF-1 or -88 MxA genotype distributions or minor allele frequencies, individuals who spontaneously resolved the infection displayed no significant difference compared with those with chronic infections. Among patients with chronic infections, however, the -300AA IRF-1 genotype, associated with a higher IRF-1 transcriptional activity, was absent in patients with chronic HCV genotype 3a infections, with one exception. In contrast to expectations, -300AA IRF-1 individuals with HCV genotype 3a infection were not represented in higher numbers among those with self-limited infections. Regarding IFN-alpha therapy, -300AA IRF-1 chronic hepatitis C genotype 1 patients tend to respond more often than those with the other IRF-1 genotypes.

CONCLUSION

Our findings suggest the possibility that the -300AA IRF-1 genotype is associated with outcome in patients with HCV genotype 3 infection. In addition, in HCV genotype-1-infected patients, this genotype appears associated with response to therapy.

HCV virological assessment

Virological assessment of HCV infection relies on a series of assays that are essential for diagnostic purposes and to adopt therapeutic decisions. Diagnostic assays can be classified in three groups: assays that are designed to detect specific antibodies to HCV; techniques that detect and quantify viral load; and tests aimed at determining the infecting HCV type. In general, the use of these assays is similar in HCV infected patients as in those co-infected with HCV and HIV. Co-infected patients, however, have some inherent characteristics (deficient immune status, high HCV-RNA concentrations, particular genotype distribution, low response to antiviral therapy) that make the interpretation of such assays slightly different. Regarding assays to detect antibodies to HCV, last generation tests have a similar sensitivity in mono-infected and co-infected individuals. HCV-RNA testing might be helpful in anti-HCV negative individuals with clinical or analytical suspicion of liver disease. Genotype determination in patients co-infected with HCV and HIV should be performed by methods relying on sequence analysis, since serotyping assays have shown a lower sensitivity in co-infected cohorts. HCV-RNA concentration is a strong predictor of response to therapy. Due to the higher viral load of co-infected patients compared to HCV mono-infected individuals, those assays with a wide dynamic range seem more appropriate to monitor viral load during treatment.

Distribution of hepatitis C virus genotypes in the Middle East

It is well established that hepatitis C develops into cirrhosis of the liver and hepatocellular carcinoma (HCC) both of which are fatal diseases. The World Health Organization estimates that there are at least 21.3 million hepatitis C virus (HCV) carriers in the Eastern Mediterranean countries, which is close to the number of carriers estimated in the Americas and Europe combined. With such a high disease burden of HCV infection in this part of the world, and in light of the new evidence that genotypes may influence the outcome of antiviral therapy, the focus of this review is on the epidemiology and distribution of HCV genotypes in the Eastern Mediterranean countries. Accumulated data show that there are two main patterns for the distribution of HCV genotypes in the Middle East: in the first pattern, genotype 4 is prevalent in most of the Arab countries, and in the second pattern, genotype 1a or 1b predominates in the non-Arab countries. Results from the limited number of clinical trials on the treatment of chronic HCV genotype 4 using peginterferon alfa-2b in combination with ribavirin are encouraging. However, efforts to develop more effective antiviral therapies and the establishment of an effective HCV vaccine remain the largest challenges for the near future.

Genotyping of hepatitis C virus by Taqman real-time PCR

BACKGROUND

Genotype of hepatitis C virus (HCV) is of major importance for the outcome of treatment. The response rate is considerably lower for genotype 1, the predominant genotype in western countries.

OBJECTIVES

To develop and evaluate a new, simple method for genotyping of HCV based on real-time polymerase chain reaction (PCR) and Taqman probes targeting the 5' non-coding region.

STUDY DESIGN

The method was compared with Innolipa on 220 serum samples representing genotypes 1-4, and was applied on a further 614 clinical samples.

RESULTS

Taqman typing of the 220 samples showed genotype 1 in 69, genotype 2 in 58, genotype 3 in 57 and genotype 4 in 19, while 17 were non-reactive. There was a complete concordance with Innolipa with the exception of seven samples, which were of genotype 1 by Taqman, but genotype 4 by Innolipa. Sequencing of these samples showed a subtype 4 variant which differed at two positions compared with subtypes 4b/c/d, which are targeted by the probe. By adding a modified probe, these genotype 4 variants could also be identified. Out of 614 consecutive clinical samples, 524 could be typed by the Taqman assay; 45.2% were genotype 1, 19.3% genotype 2, 33.8% genotype 3 and 1.7%, genotype 4.

CONCLUSION

The method was overall accurate and provides an attractive alternative for genotyping because processing time and costs are significantly reduced. Inclusion of probes targeting genotypes 5 and 6 is required for the method to be useful in areas where these genotypes are present.

Discriminating between serological responses to European-genotype live vaccine and European-genotype field strains of porcine reproductive and respiratory syndrome virus (PRRSV) by peptide ELISA

A peptide ELISA was developed based on an immunodominant and hypervariable epitope in the ORF4 envelope glycoprotein of porcine reproductive and respiratory syndrome virus (PRRSV). The peptide sequence was derived from the Porcilis live-attenuated PRRSV vaccine strain (genotype 1, European). Antibodies induced by the field PRRSVs currently circulating in Poland were not detected by the Porcilis ORF4 peptide ELISA. In contrast, Porcilis-vaccinated animals seroconverted in the ORF4 peptide ELISA at 21 days post-vaccination. Maximal titers were seen 30-92 days post-vaccination; most sera had endpoint titers between 1:1000 and 1:100,000. In a paired format, where sera were assayed in two separate ELISAs using ORF4 peptides derived from the genetically very closely related Porcilis and Lelystad PRRSV strains, it was possible to differentiate between antibodies induced by these two viruses. The Porcilis and Lelystad ORF4 peptide ELISAs had sensitivities of 89 and 100%, respectively. Thus, ORF4 peptide ELISA afforded specific detection of antibodies induced by an European-genotype live-attenuated vaccine PRRSV strain (Porcilis). The results suggest that specific ORF4 peptide ELISAs can be custom-made for European-genotype PRRSV strains, using general peptide design criteria described in this work. Thus, ORF4 ELISAs may be generally useful, to monitor safety and operational aspects of European-genotype live-attenuated PRRSV vaccine virus use in populations with circulating field European-genotype PRRSVs.

Consensus proposals for a unified system of nomenclature of hepatitis C virus genotypes

International standardization and coordination of the nomenclature of variants of hepatitis C virus (HCV) is increasingly needed as more is discovered about the scale of HCV-related liver disease and important biological and antigenic differences that exist between variants. A group of scientists expert in the field of HCV genetic variability, and those involved in development of HCV sequence databases, the Hepatitis Virus Database (Japan), euHCVdb (France), and Los Alamos (United States), met to re-examine the status of HCV genotype nomenclature, resolve conflicting genotype or subtype names among described variants of HCV, and draw up revised criteria for the assignment of new genotypes as they are discovered in the future. A comprehensive listing of all currently classified variants of HCV incorporates a number of agreed genotype and subtype name re-assignments to create consistency in nomenclature. The paper also contains consensus proposals for the classification of new variants into genotypes and subtypes, which recognizes and incorporates new knowledge of HCV genetic diversity and epidemiology. A proposal was made that HCV variants be classified into 6 genotypes (representing the 6 genetic groups defined by phylogenetic analysis). Subtype name assignment will be either confirmed or provisional, depending on the availability of complete or partial nucleotide sequence data, or remain unassigned where fewer than 3 examples of a new subtype have been described. In conclusion, these proposals provide the framework by which the HCV databases store and provide access to data on HCV, which will internationally coordinate the assignment of new genotypes and subtypes in the future.

Serotyping of hepatitis C virus in hemodialysis patients: comparison with a standardized genotyping assay

The aims of this study were to investigate the prevalence of hepatitis C virus (HCV) genotypes and serotypes in anti-HCV-positive hemodialysis patients and determine the concordance between genotyping and serotyping methods. Sixty-two hemodialysis patients were included in this study. HCV RNA was determined using polymerase chain reaction assay and genotypes using a line probe assay. HCV serotyping was performed with competitive enzyme-linked immunosorbent assay. Genotype 4 (52 patients) was the most predominant genotype, followed by type 1 (10 patients). The most prevalent HCV serotype was type 4 (41 patients), followed by serotype 1 (6 patients). We detected multiple serotypes in 4 patients and untypeable strains in 11. The overall sensitivity of serotyping assay was 82% for the study patients. According to the genotyping results, the sensitivity of serotyping was 60% and 86.5% for HCV types 1 and 4, respectively. There was a 100% concordance between results of serotyping and genotyping in the identification of HCV type 1 and 91% concordance in HCV type 4. Serological typing method may be of great value in microbiology laboratories that require a simple assay for identification of HCV genotypes, although the sensitivity of this assay may be limited by the immunocompetence of infected hemodialysis patients.

Mix-infections with different genotypes of HCV and with HCV plus other hepatitis viruses in patients with hepatitis C in China

AIM

Clinical therapy and prognosis in HCV infections are not good, and mix-infections with different HCV genotypes or quasispecies and mix-infections with HCV plus other hepatitis viruses are important concerns worldwide. The present report describes the sequence diversity and genotying of the 5'NCR of HCV isolates from hepatitis patients mix-infected with different HCV genotypes or variants, and the conditions of mix-infections with HCV plus other hepatitis viruses, providing important diagnostic and prognostic information for more effective treatment of HCV infections.

METHODS

The 5' non-coding region (5'NCR) of HCV was isolated from the patients sera and sequenced, and sequence variability and genotypes of HCV were defined by nucleotide sequence alignment and phylogenetic analysis, and the patients mix-infected with HCV plus other hepatitis viruses were analyzed. The conditions and clinical significance of mix-infections with HCV plus other hepatitis viruses were further studied.

RESULTS

Twenty-four out of 43 patients with chronic hepatitis C were defined as mix-infected with different genotypes of HCV. Among these 24 patients, 9 were mix-infected with genotype 1 and 3, 7 with different variants of genotype 1, 2 with different variants of genotype 2, 6 with different variants of genotype 3. No patients were found mix-infected with genotype 1 and 2 or with genotype 2 and 3. The clinical virological analysis of 60 patients mix-infected with HCV plus other hepatitis viruses showed that 45.0 % of the patients were mix-infected with HCV plus HAV, 61.7 % with HCV plus HBV, 6.7 % with HCV plus HDV/HBV, 8.4 % with HCV plus HEV, 3.3 % with HCV plus HGV. Infections with HCV plus other hepatitis viruses may exacerbate the pathological lesion of the liver.

CONCLUSION

The findings in the present study imply that mix-infections with different HCV genotypes and mix-infections with HCV plus other hepatitis viruses were relatively high in Yunnan, China, providing important diagnostic and prognostic information for more effective treatment of HCV infections.

Evaluation of a new serotyping assay for detection of anti-hepatitis C virus type-specific antibodies in serum samples

The performance of a new version (HC03) of the hepatitis C virus (HCV) serotyping 1-6 assay (Abbott Murex Laboratories), a specific test for serological determination of HCV types, was evaluated using a selected panel of 180 HCV RNA-positive sera. HC03 was more sensitive than the current HC02 version, typing 53 (37.6%) of 141 samples which were not typable with HC02. Furthermore, the HC03 specificity was 94.1% as evaluated with a panel of 22 genotyped samples. This new version of the test improves the quality of the serological approach to HCV type determination.

A novel antigen detection immunoassay for field diagnosis of hepatitis C virus infection

The limitations of dominant methods-based on the detection of anti-HCV antibodies or HCV viremia currently used for the diagnosis of HCV infection enhance efforts to have a rapid, simple, sensitive, and specific alternative diagnostic approach to detect viral antigens. A highly reactive IgG antibody was raised to HCV-NS4 recombinant antigen. The produced antibody showed no cross-reactivity with the other HCV structural and nonstructural recombinant antigens (C1 + 2, C3 + 4, E2/NS1, NS3, NS5). The well established ELISA technique was adapted to detect the new target HCV-NS4 antigen in serum samples. Extremely high agreement was found between the results of ELISA and qualitative detection of HCV-RNA, using a RT-PCR test as a gold standard for the diagnosis of HCV infection. Based on these encouraging results, a novel enzyme immunoassay; dot-ELISA was developed for rapid (approximately 5 min) and simple qualitative detection of the target HCV antigen in serum. The developed method detected the HCV target antigen in 95% of serum samples from HCV infected individuals, with a specificity of 97% using sera of noninfected individuals in comparison with PCR test. The antigen detection method showed high predictive values of positive (99%) and negative (90%). Moreover, the dot-ELISA could detect the HCV target antigen in sera negative for anti-HCV Abs, but positive for HCV-RNA, and in sera of HCV infected individuals with low viremia, as well as those with high viremia, using quantitative RT-PCR. Accordingly, the developed highly sensitive and specific HCV antigen detection method could be applied for mass screening of HCV infection.

Characterization of monoclonal antibodies and epitope mapping of the NS4 protein of hepatitis C virus

Recombinant DNA containing sequences of HCV NS4 protein was expressed in Escherichia coli cells. Six hybridoma clones producing monoclonal antibodies (MAB) to recombinant NS4 protein (rNS4), aa 1677-1756, were developed. Mapping with a panel of 33 peptides and reciprocal competitive EIA have shown that MAB obtained revealed five antigen determinants, not described earlier: MAB 3F11 and 3F12-one genotype-independent epitope of NS4A (aa 1700-1707) common for genotypes 1, 2 and 3; MAB 1D11-genotype-independent epitope (aa 1713-1728) and MAB 1D3-genotype (subtype 1b)-specific epitope of NS4B (aa 1711-1731); MAB 6B11 and C1-two conformation-dependent determinants in 5-1-1 region. These data indicate that the 5-1-1 region of NS4 protein has a complex antigenic structure and contains at least eight epitopes, including five, revealed in the present work. MAB obtained recognized native viral protein in the cytoplasm of liver cells of patients with chronic hepatitis C. The positive rates of the immunostaining for NS4 antigen using MAB 6B11, 1D11 and 3F12 were 64, 59 and 50%, respectively. It was found that 6B11 MAB to a conformation-dependent epitope much more actively interacts with native NS4 than with the recombinant protein to which MAB was developed. The epitope recognized by 6B11 MAB is highly immunogenic since it induces the B-cell response in all patients investigated with identified anti-NS4 antibodies in blood serum. The MAB panel obtained in this study may become a useful tool for the diagnostic purposes, for the investigation of NS4B function and for the host-viral interactions at the cell level.

Factors related to the chronicity and evolution of hepatitis C infection in patients co-infected by the human immunodeficiency virus

OBJECTIVES

This work analyses the influence of immune status, serum human immunodeficiency virus (HIV) load and hepatitis C virus (HCV) genotypes on the probability of resolution of HCV infection in HIV-co-infected patients, as well as the evolution of HCV viremia after antiretroviral therapy.

PATIENTS AND METHODS

Forty-five patients with anti-HIV and anti-HCV antibodies were classified into two groups as a function of the positivity or persistent negativity of HCV RNA detection (active or recovered HCV infection, respectively). They were treated with highly active antiretroviral therapy (HAART). Serum HCV RNA was quantified by the reverse transcription-polymerase chain reaction. HCV genotypes were detected by line probe assay or by detection of type-specific antibodies.

RESULTS

HCV RNA was detectable in 30 (66.6%) out of 45 HIV-infected patients. CD4+ T-cell counts, HIV viremia, or HCV genotypes were similar in patients with active or recovered HCV infection. Patients with active HCV infection had a non-significant decrease of HCV viremia during a follow-up of 12 months (from 6.15 +/- 6.32 to 5.96 +/- 6.05 log copies/mL). This was not influenced by baseline HCV or HIV viral load, HCV genotype, or CD4+ T-cell count. The non-significant decrease was present in patients with or without an immunological response to HAART.

CONCLUSION

HCV genotypes, immune status, or serum HIV load did not influence the resolution or chronicity of HCV infection in HIV-co-infected individuals. A non-significant decrease of HCV viremia in these patients treated with combinations including antiproteases could be expected.

Immunopathogenesis of hepatitis C virus infection

Hepatitis C virus, a recently identified member of the family Flaviviridae, is an important cause of chronic viral hepatitis and cirrhosis. There are similarities in the nature of the immune response to this pathogen with immunity in other flavivirus and hepatotropic virus infections, such as hepatitis B. However, the high rate of viral persistence after primary hepatitis C infection, and the observation that neutralizing antibodies are not protective, would suggest that there are a number of important differences between hepatitis C, other flaviviruses, and hepatitis B. The phenomenon of quasispecies evolution and other viral factors have been proposed to contribute to immune evasion by hepatitis C virus. In the face of established persistent infection, virus-specific cytotoxic T lymphocytes may exert some control over viral replication. However, these same effectors may also be responsible for the progressive liver damage characteristic of chronic hepatitis C infection. The nature of protective immunity, including the role of innate immune responses early after hepatitis C exposure, remains to be defined.

Comparison of three HCV genotyping assays: a serological method as a reliable and inexpensive alternative to PCR based assays

BACKGROUND

Determination of hepatitis C virus (HCV) genotypes and subtypes is of rising clinical importance. In times where also an increasing need for cost effectiveness can be observed, the demand for fast and easy performable assays grows.

OBJECTIVES

To evaluate and compare different genotyping methods regarding their reliability, practicability, and expense in the daily routine.

METHODS

Sera of 39 patients infected with different HCV subtypes were examined by a serological genotyping assay (NS-4 IBA), by the widely used INNO-LiPA HCV II, and by a nucleotide sequencing method.

RESULTS

The tests performed equally well in terms of HCV subtyping and no different results were obtained. However, the serotyping assay provided the results in less than half the time needed by the other two assays. Significant differences were also observed regarding the 'hands on' times and the costs. The technical equipment which was necessary to perform the assays is significantly reduced using the serological assay.

CONCLUSION

Our study demonstrates that the serological test offers the opportunity to determine HCV genotypes and subtypes reliably, fast, easy, and cost effective.

Prevalence of antibodies against hepatitis C virus among blood donors in Lebanon, 1997-2000

Chronic hepatitis C virus (HCV) infection in many individuals is asymptomatic and the prevalence of antibodies to hepatitis C virus (anti-HCV) among blood donors in Lebanon is scarce. This study aimed to address the prevalence of anti-HCV in 8700 blood donors, the data obtained was compared to other world regions. Between 1997 and 2000, 8700 blood donors were screened for the presence of anti-HCV in their sera. Initially reactive specimens were retested in duplicate, and repeatedly positive samples were subsequently retested by a third generation microplate enzyme immunoassay. Of the 8700 blood donors screened, 51 were confirmed positive for anti-HCV, giving a prevalence rate of 0.6%. While there was no difference in anti-HCV prevalence in relation to age or gender, higher rates were seen in non-Lebanese compared to Lebanese subjects (6.17% vs. 0.48%, P < 0.001). None of the anti-HCV positive individuals had an identifiable risk factor for contracting HCV (intravenous drug user, prior transfusion, etc.), and their transaminases were comparable to anti-HCV-negative donors, suggesting that HCV-positive donors were asymptomatic. These results demonstrate low prevalence of anti-HCV among Lebanese blood donors, which was comparable to those established for Western countries.

Hepatitis C virus genotyping based on 5' noncoding sequence analysis (Trugene)

Hepatitis C virus (HCV) genotyping of samples from 184 patients with chronic HCV infection by the Trugene 5'NC genotyping kit, based on sequence analysis of the 5' noncoding region (5' NCR), and the InnoLiPA assay was evaluated. In addition to these methods, the 184 samples were also analyzed by sequencing of part of the NS5B of the HCV genome after in-house PCR amplification, as a means of validating results obtained with the 5' NCR. The distribution of the genotypes typed by NS5B sequence analysis was as follows: 1a, 41 samples; 1b, 58 samples; 1d, 1 sample; 2a, 5 samples; 2b, 2 samples; 2c, 7 samples; 3a, 46 samples; 4a, 7 samples; 4c, 1 samples; 4e, 9 samples; 5a, 6 samples; 6a, 1 sample. The Trugene and InnoLiPA assays gave concordant results within HCV types in 100% of cases. The ability to discriminate at the subtype level was 76 and 74% for the Trugene and the InnoLiPA assays, respectively.

Seroprevalence of hepatitis C virus (HCV) infection among blood donors: a hospital-based study

Insofar as chronic hepatitis C virus (HCV) infection in many individuals is asymptomatic, and as the prevalence of antibodies to hepatitis C virus (anti-HCV) among blood donors in Lebanon is scarce, this study addressed the prevalence of anti-HCV in 5,115 blood donors. Data obtained were compared to other world regions. Of the blood donors screened, 57 were initially tested positive or doubtful for anti-HCV Ab. Subsequent testing by two-third generation enzyme immunoassays confirmed that, of the 57 initially tested positive/doubtful, only 18 were positive for anti-HCV giving a prevalence rate of 0.4%. While there was no difference in HCV prevalence with respect to age or gender, a higher rate was seen in non-Lebanese compared to Lebanese subjects (3.4% vs 0.3%, P < 0.001). These results demonstrate a low prevalence of HCV infection among Lebanese blood donors, which was comparable to those established for western countries.

Hepatitis C prevalence among Australian injecting drug users in the 1970s and profiles of virus genotypes in the 1970s and 1990s

OBJECTIVES

To examine the seroprevalence of hepatitis C virus (HCV) in the Australian injecting drug-using community in the 1970s, and to compare the profile of HCV genotypes with that seen in the 1990s.

DESIGN

Investigation of stored sera that were collected from injecting drug users in the 1970s and comparison with sera collected in the 1990s.

SETTING

Inner Sydney, 1974-1975 and 1994-1996.

PATIENTS

The 1970s group comprised 141 consecutive injecting drug users who attended the Brisbane Street Methadone Clinic. The 1990s group comprised 88 consecutive, injecting drug users of European origin who were HCV antibody-positive and attended a primary healthcare facility (the Kirketon Road Centre).

MAIN OUTCOME MEASURES

HCV antibody prevalence (1970s); profile of HCV serotypes (1970s and 1990s); and serological evidence of hepatitis A and B.

RESULTS

84% of the 1970s group were HCV antibody-positive, of whom 92% were infected with HCV serotype 1 and 1% with serotype 3. In contrast, in the 1990s group, 69% were infected with HCV serotype 1 and 25% with serotype 3. The HCV-positive subjects from the early group were more likely than those from the recent group to have serological evidence of previous HBV infection.

CONCLUSIONS

The high prevalence of HCV among injecting drug users in the 1970s in Australia confirms an epidemic that has been present for at least 25 years. Over this period, the proportion of HCV genotype 1 infections has decreased and genotype 3 infections have emerged.

A novel hepatitis C virus (HCV) subtype from Somalia and its classification into HCV clade 3

Hepatitis C virus (HCV) sequences from throughout the world have been grouped into six clades, based on recently proposed criteria. Here, the partial sequences and clade assignment are reported for three HCV isolates from chronic hepatitis C patients from Somalia, for whom conventional assays failed to identify the genotype. Phylogenetic analysis of the sequences of the core, envelope 1 and part of the non- structural 5b regions suggests that all three isolates belong to a distinct HCV genetic group, tentatively classified as subtype 3h. This novel HCV subtype shows the highest sequence similarity with HCV isolates from Indonesia. Despite the fact that these patients were infected with HCV clade 3, none of them responded to standard interferon treatment.

HCV genotypes--role in pathogenesis of disease and response to therapy

Hepatitis C virus (HCV) shows considerable variation in its genomic structure, allowing classification into six main genotypes. Epidemiological studies have shown marked differences in genotype distribution by geographical region, and between patient groups. Improved understanding of the rate of nucleotide sequence mutation in HCV has allowed the approximate time of divergence of major genotypes to be estimated, and the origin and spread of the present epidemic of hepatitis C to be better defined. Improved methods of genotype definition over the last few years have enabled the importance of genotype in the progression of HCV-related disease and response to anti-viral therapy to be studied. Present data strongly indicates that HCV genotype is an important determinant of response to treatment, but the effect of genotype on disease progression has been harder to clarify. This is largely due to the absence of model systems of HCV infection, the epidemiological differences in patient groups infected with the different genotypes, and the lack of good prospective longitudinal clinical data. As a result of advances in methodology, and recent results of large clinical trials of combination therapy, a knowledge of HCV genotype is now central to the clinician in the management of patients with chronic hepatitis C.