Relationship between hepatocellular carcinoma and subtypes of hepatitis C virus: a nationwide analysis

Disease progression in Chinese patients with hepatitis C virus RNA-positive infection via blood transfusion

The majority of patients with hepatitis C virus (HCV) in China were infected via blood transfusion prior to the year 1996. In this systematic retrospective cohort study, disease progression in 804 consecutive patients with transfusion-acquired HCV is investigated. In addition, the occurrence of compensated cirrhosis, decompensated cirrhosis and hepatocellular carcinoma (HCC) is analyzed among these patients, along with the risk factors for disease progression. Patients with cirrhosis or HCC were classified as the serious development group (SD group) and the remaining patients with chronic hepatitis were classified as the hepatitis group (H group). Significant differences were found between the two groups in age at the time of infection, duration of infection and age at the time of observation. SD group patients were significantly older at the time of transfusion (33.73 vs. 23.56 years; P<0.001), with a significantly longer mean duration of HCV infection (21.88 vs. 21.15 years; P=0.029) compared with that in the H group. Male gender and age at the time of transfusion were significant risk factors for HCC (OR=2.48, P=0.031 and OR=1.07, P=0.002, respectively). Age was a significant risk factor for disease progression in older Chinese patients with transfusion-acquired HCV, and there were significant differences in the prevalence of compensated cirrhosis, decompensated cirrhosis and HCC between the age groups (P<0.001), suggesting that more patients with HCV may develop cirrhosis or HCC in their third and fourth decades of infection. Results of the present study will be helpful for predicting disease progression in Chinese patients with HCV infected via blood transfusion.

Hepatitis C virus genotype 1b increases cumulative lifetime risk of hepatocellular carcinoma

The association between subtypes of hepatitis C virus (HCV) and risk of hepatocellular carcinoma (HCC) remained inconclusive and evaluated in both case-control and cohort studies. In the case-control study, 397 HCC cases from medical centers were compared with 410 community-based non-HCC controls. All of them were anti-HCV-seropositive, HBsAg-seronegative with serum HCV RNA levels ≥1,000 IU/mL. Logistic regression models were used to estimate the odds ratio (OR) with 95% confidence interval (95% CI) of HCV subtype after controlling for other HCC risk factors. In the cohort study, 866 anti-HCV-seropositive individuals were followed from 1991 to 2008 to assess the long-term HCC predictability of HCV subtypes. Newly developed HCC cases were ascertained by follow-up health examinations and computerized linkage with national databases. The percentage of HCV 1b subtype was higher among HCC cases than controls (64 vs. 55%, p < 0.001). Participant infected with HCV 1b had a higher mean serum HCV RNA level (2.0 × 10(6) IU/mL) than those infected with HCV non-1b (1.2 × 10(6) IU/mL, p < 0.001). The multivariate-adjusted OR (95% CI) of developing HCC for HCV 1b comparing to non-1b was 1.43 (1.02-2.02). After the long-term follow-up, the cumulative lifetime (30-80 years old) HCC risk was 19.2 and 29.7% for patients infected with HCV non-1b and 1b, respectively (p < 0.001). The multivariate-adjusted hazard ratio (95% CI) was 1.85 (1.06-3.22) for HCV 1b compared to non-1b. HCV subtype 1b, the most prevalent subtype in Taiwan, was associated with an increased HCC risk and a proactive clinical management is suggested for patients with HCV 1b.

Identification of non-macrocyclic small molecule inhibitors against the NS3/4A serine protease of hepatitis C virus through in silico screening

Drug discovery and design for inhibition of the Hepatitis C Virus (HCV) NS3/4A serine protease is a major challenge. The broad, shallow, and generally featureless nature of the active site makes it a difficult target for "hit" selection especially using standard docking programs. There are several macrocyclic NS3/4A protease inhibitors that have been approved or are in clinical trials to treat chronic HCV (alone or as combination therapy), but most of the current therapies for HCV infection have untoward side effects, indicating a continuing medical need for the discovery of novel therapeutics with improved efficacy. In this study, we designed and implemented a two-tiered and progressive docking regime that successfully identified five non-macrocyclic small molecules that show inhibitory activity in the low micromolar range. Of these, four compounds show varying inhibition against HCV subgenotypes 1b, 1a, 2a, and 4d. The top inhibitor (3) has an IC(50) value of 15 μM against both subgenotypes 1b and 2a of the NS3/4A protease enzyme. Another inhibitor, 1, inhibits all four subgenotypes with moderate activity, showing highest activity for genotype 2a (24 μM). The five inhibitors presented in this study could be valuable candidates for future hit to lead optimization. Additionally, enzyme-inhibitor interaction models presented herein provide key information regarding structural differences between the active sites of the NS3/4A protease of the HCV subgenotype 1a and 1b that might explain the variable inhibitory activity between subgenotypes of the small molecule inhibitors identified here.

Comparison of envelope 2 CD81 binding regions in PBMC-derived versus serum-derived hepatitis C virus isolates: higher conservation of CD81 region 2 in PBMC isolates

The aim of the present study was to investigate the variability of hepatitis C virus (HCV) CD81 binding regions (CD81-1/2) in peripheral blood mononuclear cells (PBMC)-derived and serum-derived HCV-RNA samples. HCV-RNA was isolated from PBMC (10⁴ cells) and serum samples from 37 patients chronically infected with HCV genotype 1a/1b (n=21/16). The hypervariable regions 1/2 (amino acid 384-410, amino acid 474-482) and regions CD81-1/2 (amino acid 474-494, amino acid 522-551) were analysed. Mutational frequency of amino acid sequences was compared between PBMC-derived and serum-derived HCV variants as well as local accumulation of mutations. Furthermore, CD81 was quantified on PBMC. Mutational frequency was not different between PBMC-derived and serum-derived HCV variants. A trend to lower mutational frequency in genotype 1a PBMC variants compared with serum-derived variants was observed in region CD81-2 (5%vs 10%). Smoothed mutational frequency analysis showed a significantly lower variability within genotype 1a CD81-2 in PBMC-derived compared to serum-derived HCV-RNA (P=0.026). CD81 expression on PBMC was not correlated with the number of mutations within the CD81 binding regions.

CONCLUSION

A higher conservation was observed in region CD81-2 in PBMC-derived versus serum-derived HCV-RNA indicating selection of HCV variants on PBMC. The variability in the CD81 binding regions appeared to be independent from CD81 expression.

The global spread of hepatitis C virus 1a and 1b: a phylodynamic and phylogeographic analysis

BACKGROUND

Hepatitis C virus (HCV) is estimated to affect 130-180 million people worldwide. Although its origin is unknown, patterns of viral diversity suggest that HCV genotype 1 probably originated from West Africa. Previous attempts to estimate the spatiotemporal parameters of the virus, both globally and regionally, have suggested that epidemic HCV transmission began in 1900 and grew steadily until the late 1980s. However, epidemiological data suggest that the expansion of HCV may have occurred after the Second World War. The aim of our study was to elucidate the timescale and route of the global spread of HCV.

METHODS AND FINDINGS

We show that the rarely sequenced HCV region (E2P7NS2) is more informative for molecular epidemiology studies than the more commonly used NS5B region. We applied phylodynamic methods to a substantial set of new E2P7NS2 and NS5B sequences, together with all available global HCV sequences with information in both of these genomic regions, in order to estimate the timescale and nature of the global expansion of the most prevalent HCV subtypes, 1a and 1b. We showed that transmission of subtypes 1a and 1b "exploded" between 1940 and 1980, with the spread of 1b preceding that of 1a by at least 16 y (95% confidence interval 15-17). Phylogeographic analysis of all available NS5B sequences suggests that HCV subtypes 1a and 1b disseminated from the developed world to the developing countries.

CONCLUSIONS

The evolutionary rate of HCV appears faster than previously suggested. The global spread of HCV coincided with the widespread use of transfused blood and blood products and with the expansion of intravenous drug use but slowed prior to the wide implementation of anti-HCV screening. Differences in the transmission routes associated with subtypes 1a and 1b provide an explanation of the relatively earlier expansion of 1b. Our data show that the most plausible route of the HCV dispersal was from developed countries to the developing world. Please see later in the article for the Editors' Summary.

Characteristic mutations in hepatitis C virus core gene related to the occurrence of hepatocellular carcinoma

Chronic hepatitis C virus (HCV) infection often results in hepatocellular carcinoma (HCC). Previous studies have shown that there might be some characteristic mutations in the core region of HCV related to HCC. Thus, we downloaded and analyzed HCV genotype 1b core gene sequences from HCV databases online to identify them. Based on the information of the sequences, 63 from patients with HCC and 188 from non-HCC were enrolled into our analysis. Then, the nucleotides at each position were compared by chi(2)-test between the two groups, and 24 polymorphisms were found to be associated with HCC. Further analysis of these 24 polymorphisms by logistic regression indicated that eight were significantly related to the increased HCC risk: A028C, G209A, C219U/A, U264C, A271C/U, C378U/A, G435A/C, and G481A. Moreover, U303C/A was associated with the decreased HCC risk. These mutations could bring about four amino acid substitutions: K10Q, R70Q, M91L, and G161S. In conclusion, eight characteristic mutations in the HCV-1b core gene related to the occurrence of HCC were identified. The structural and functional alterations of core protein due to these mutations and the relationship with the occurrence of HCC need to be further studied.

Hepatitis C virus genotype 1b as a risk factor for hepatocellular carcinoma development: a meta-analysis

BACKGROUND/AIMS

Hepatitis C virus (HCV) is a known risk factor for hepatocellular carcinoma (HCC), but whether the risk varies among patients infected with different HCV genotypes is still controversial. We performed a meta-analysis to clarify whether the genotype 1b is associated with a higher risk of HCC than other genotypes.

METHODS

We identified 57 relevant papers through a literature search to December 2007 but, since age could represent a major confounder, we focused the meta-analysis on the 21 studies presenting age-adjusted risk estimates for HCV genotype 1b vs. other genotypes. We used random-effects models with the DerSimonian-Laird method and assessed heterogeneity between studies and publication bias.

RESULTS

Patients infected with HCV genotype 1b have almost double the risk to develop HCC than those infected with other genotypes (Relative Risk (95% Confidence Intervals) = 1.78(1.36-2.32)). The pooled risk estimate was somewhat lower when we restricted the analysis to the eight studies conducted in patients with liver cirrhosis (1.60;1.07-2.39) or considering the 36 studies presenting only crude data (1.63;1.30-2.06). In seven studies excluding patients with liver cirrhosis, the RR (95% CI) increased to 2.46(1.69-3.59).

CONCLUSIONS

This meta-analysis suggests that HCV genotype 1b plays an important role in HCC development, especially in patients with early stage liver disease.

Genetic diversity and models of viral evolution for the hepatitis C virus

In this review we discuss the application of theoretical frameworks to the interpretation of viral gene sequence data, with particular reference to the hepatitis C virus (HCV). The increasing availability of such data means that it is now possible (and necessary) to proceed from simple qualitative models of viral evolution, to more quantitative frameworks based on statistical inference, notably population genetics and molecular phylogenetics. We argue that these approaches are invaluable tools to the virologist and are essential for understanding the dynamics of viral infection and the outcome of therapeutic strategies. We use several recent HCV data-sets to illustrate the methods.

Genotyping of hepatitis C virus types 1, 2, 3, and 4 by a one-step LightCycler method using three different pairs of hybridization probes

Determination of hepatitis C virus (HCV) genotypes has become increasingly important during the last years for prediction of the clinical course and the outcome of antiviral therapy. Therefore, numerous different methods have been developed to enable HCV genotyping. However, many of them are very laborious and expensive, leading to limited usage in daily routine diagnostics. We have established a method which combines the speed of the new LightCycler technology with the use of amplification products generated for diagnostic quantitative HCV RNA determination. Differentiation of HCV genotypes is performed with these amplicons in a single step by using fluorophore-labeled hybridization probes. Although currently only two different acceptor fluorophores are available for the LightCycler, types 1, 2, 3, and 4, which are by far the prevailing HCV genotypes in Europe and the United States, can be distinguished. Genotypes of specimens from 190 chronically HCV-infected patients were determined by the LightCycler method and compared with the results of nucleotide sequencing. Concordant results were obtained for all samples. This new method offers a fast and convenient possibility to determine the quantitative HCV RNA load and the genotype in large-scale settings within about 4 h.

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.

Which patients with hepatitis C develop liver complications?

To identify variables that are independent predictors of adverse outcomes in chronic hepatitis C, we analyzed a cohort of 455 patients followed for a median of 4.7 years. Associations were sought between demographic and behavioral factors, hepatitis C virus (HCV) genotype, liver histology and liver tests at entry, and development of liver complications, hepatocellular carcinoma (HCC), hepatic transplantation and liver-related death. Independent predictors were identified by multivariate analysis. The following were associated with a significantly higher rate of liver complications: age; birth in Asia, Europe, Mediterranean region, or Egypt; transmission by blood transfusion or sporadic cases; HCV genotypes 1b and 4 (compared with 1/1a); fibrosis stage 3 or 4 (cirrhosis); serum albumin; bilirubin; prothrombin time; and alpha-fetoprotein. However, the only independent predictors of liver-related complications were sporadic transmission (P <.001), advanced fibrosis (P =.004), and low albumin (P <.001). The corresponding independent risk factors for HCC were male gender (P =. 07), sporadic transmission (P <.001), and albumin (P <.001); bilirubin (P =.02) was an additional predictor of transplantation or liver-related death. It is concluded that only patients with advanced hepatic fibrosis or cirrhosis, are at risk of developing hepatic complications of chronic hepatitis C during 5-year follow-up. Among such patients, abnormalities in serum albumin, bilirubin, or prothrombin time indicate a high probability of complications. Patients without definite risk factors for HCV (sporadic cases) are at higher risk of complications, possibly because of interaction between older age, duration of infection, country of birth, and HCV genotypes 1b and 4.

Correlation of clinicopathologic features of resected hepatocellular carcinoma with hepatitis C virus genotype

Clinicopathologic findings in patients with hepatocellular carcinoma complicating hepatitis C virus and outcomes after liver resection were compared between different viral genotypes. One hundred and forty-seven patients with both anti-hepatitis C virus antibody and hepatitis C virus RNA in their sera underwent curative resection for hepatocellular carcinoma in our department between 1991 and 1997. Of these patients, 115 were infected with hepatitis C virus genotype 1b (group 1), and 32 were infected with 2a or 2b (group 2). Clinicopathologic findings and outcomes after operation were compared between the two groups. Alanine aminotransferase activity was significantly higher in group 2 than in group 1. Genotypes did not differ concomitantly with histopathologic features of the carcinoma or adjacent hepatic tissue. Although the tumor-free survival rate did not differ significantly between the two groups, recurrence was not detected during the period beyond 3 years following operation in group 2, while recurrences arose during that period in 16 group 1 patients, most of whom continued to manifest active hepatitis. In 7 of these 16 patients, the recurrent tumors were histologically multicentric in origin. The cumulative survival rate was significantly lower in group 1 than 2. Multivariate analysis indicated that genotype 1b was an independent risk factor for short survival. Patients infected with genotype 1b may have a relatively high risk of ongoing hepatocarcinogenesis and more aggressive progression of associated liver dysfunction, resulting in a poorer outcome than with other genotypes.

Serological determination of hepatitis C virus subtypes 1a, 1b, 2a, 2b, 3a, and 4a by a recombinant immunoblot assay

Serological determination of hepatitis C virus (HCV) subtypes has been hampered by the lack of suitable assays. Therefore, a recombinant immunoblot assay has been established for serological differentiation of HCV subtypes 1a, 1b, 2a, 2b, 3a, and 4a. It consists of recombinant HCV proteins from the NS-4 region propagated in Escherichia coli. To confirm the serotyping assay results, the results were compared with those obtained by nucleotide sequencing of the NS-5 region. Sera from 157 patients with chronic HCV infection were examined by this assay, and specific antibodies could be detected in 86% (n = 135) of them. The HCV genotype was determined correctly in all but one sample, and the subtypes determined by the serotyping assay corresponded to the HCV subtypes detected by nucleotide sequencing for 95% (n = 128) of the samples. These data indicate that HCV subtypes can be distinguished serologically. The assay that is described provides an easier means of identification of infection with different HCV subtypes for wider clinical and epidemiological applications.

Immunological evaluation in oral lichen planus with chronic hepatitis C

Oral lichen planus (OLP) is frequently associated with hepatitis C virus (HCV) infection. We have previously reported that the pathogenesis of OLP arises from host rather than viral factors. In this study, we investigated the role of these factors in 41 patients with chronic hepatitis C: 22 with OLP (group 1) and 19 without OLP (group 2). All patients had antibodies to HCV (anti-HCV) and were serum HCV RNA-positive; none were HBsAg-positive. Immune abnormalities in serum were evaluated by testing for antinuclear antibody (ANA), rheumatoid factor (RF) activity, immunoglobulins (IgG, IgM, and IgA), and cryoglobulin. The rate for ANA positivity and IgM levels were significantly higher in group 1 than in group 2 (P < 0.05). Mean age in group 1 was significantly higher in group 2 (P = 0.0001). Of the factors tested, ANA, IgM, and age, logistic regression showed that age correlated independently with OLP (P = 0.003). In 5 patients in group 1, the infiltrating lymphocytic subsets of the OLP lesion were examined histopathologically. Predominant T cell infiltration was shown in all 5 patients. In addition to host factors, wer also examined viral factors in both groups of patients, measuring serum HCV RNA level and determining HCV genotype. There were no significant differences between the groups in these viral factors. This study suggested that host factors induced by the HCV infection are more important than viral factors in the pathogenesis of OLP associated with hepatitis C.

Response to interferon in chronic hepatitis C due to mixed genotype infection

We examined the response to interferon (IFN) in patients with chronic hepatitis C (CHC) due to two different genotypes of hepatitis C virus (HCV) infection. Among 64 CHC patients studied, one (2%) had HCV-RNA genotype I, 36 (56%) had genotype II, 19 (30%) had genotype III, 2 (3%) had genotype IV and 6 (9%) had both genotypes II and III. There was no significant difference in age, sex, history of blood transfusion and liver histology among patients with genotypes II, III and II + III. The HCV-RNA titre of genotype II patients was significantly higher than that of genotype III patients (P < 0.05). However, there was no significant difference in the HCV-RNA titre between genotype II + III and the other groups. The complete response rate achieved with IFN therapy was significantly higher in genotype III patients (74%) than in genotype II patients (17%; P < 0.01). Of the six patients with genotype II + III, a complete response to IFN was only achieved by two patients (33%), both of whom had a low HCV-RNA titre ( < or = 10(4.5) copies/mL) and HCV serotype 2. The remaining four patients had HCV serotype 1 and three of the patients had a high HCV-RNA titre ( > or = 10(5) copies/mL). The HCV genotype III was lost in two patients after IFN therapy. These data suggest that HCV-RNA titre and HCV serotype are important factors for predicting the efficacy of IFN therapy in patients with mixed genotype infection and show direct evidence of higher susceptibility towards CHC of patients with genotype III than genotype II.