Phylogenetic analysis of hepatitis C virus isolates and their correlation to viremia, liver function tests, and histology

Development of a Lateral Flow Assay for the Detection of the Hepatitis C Virus Core Antigen

BACKGROUND

Hepatitis C virus (HCV) infection remains a global health challenge, with millions of people affected annually. Current diagnostic methods, reliant on antibody screening and viral RNA detection, are complex, costly, and often inaccessible, particularly in resource-limited settings.

AIM

Development of a lateral flow immunochromatography-based assay for detecting the highly conserved hepatitis C core antigen (HCVcAg).

METHODS

The assay relies on the interaction of four highly specific and cross-reactive monoclonal antibodies with recombinant HCVcAg from five different genotypes in a double antibody sandwich format. Latex and colloidal gold were evaluated as detector nanoparticles.

RESULTS

Extensive evaluation of 32 antibody combinations led to identifying the most sensitive antibody pairs. The chosen assay, named LN17, demonstrated a target sensitivity of 10 ng/strip, with potential clinical implications for detecting HCV. Furthermore, the study examined matrix effects in serum samples, providing valuable insights for future clinical application.

CONCLUSIONS

The developed assay holds promise as a rapid, cost-effective, and user-friendly tool to enhance accessibility to hepatitis C screening, especially in high-risk populations and resource-limited environments.

Production and characterization of monoclonal antibodies for the detection of the hepatitis C core antigen

Background: Despite highly effective treatments to cure hepatitis C, almost 80% of chronically HCV-infected people are not treated, as they are unaware of their infection. Diagnostic rates and linkage to care must be substantially improved to reverse this situation. The HCV core antigen (HCVcAg) is a highly conserved protein that can be detected in the blood of HCV-infected patients and indicates active infection. Aim: To produce murine monoclonal antibodies against HCVcAg suitable for rapid and inexpensive tests to detect HCV infection. Methods: BALB/c mice were sequentially inoculated with purified recombinant HCVcAg from Gt1a, Gt3a, Gt4a, and Gt1b genotypes. Hybridomas producing the desired monoclonal antibodies were selected, and the reactivity of antibodies against HCVcAg from various genotypes was tested by Western blotting and dot blotting. The binding kinetics of the antibodies to purified HCVcAg was analyzed by surface plasmon resonance (SPR), and their ability to detect HCVcAg was tested by double antibody sandwich ELISA (DAS-ELISA). Results: Four specific monoclonal antibodies (1C, 2C, 4C, and 8C) were obtained. 1C, 2C, and 4C recognized HCVcAg of all genotypes tested (Gt1a, Gt1b, Gt2a, Gt3a, and Gt4a), while 8C did not recognize the Gt2a and Gt3a genotypes. Based on SPR data, the antibody-HCVcAg complexes formed are stable, with 2C having the strongest binding properties. DAS-ELISA with different antibody combinations easily detected HCVcAg in culture supernatants from HCV-infected cells. Conclusion: Specific and cross-reactive anti-HCVcAg monoclonal antibodies with strong binding properties were obtained that may be useful for detecting HCVcAg in HCV-infected samples.

Very Low Hepatitis C Viral Loads in Treatment-naive Persons: Do They Compromise Hepatitis C Virus Antigen Testing?

BACKGROUND

Hepatitis C virus (HCV) antigen testing is less expensive than quantitative reverse-transcription polymerase chain reaction but has lower sensitivity for very low viral load (VLVL; HCV RNA ≤3000 IU/mL). Currently the benefits of antigen testing for screening are discussed, but data on prevalence and outcomes of persons with VLVL are scarce.

METHODS

We assessed prevalence and predictors of VLVL by logistic regression in treatment-naive participants in the Swiss Hepatitis C Cohort Study. We analyzed if the last viral load after VLVL was low, compared cirrhosis and mortality in persons with and without VLVL, and evaluated the number of samples with VLVL that were reactive by antigen testing.

RESULTS

We included 2533 treatment-naive persons with available quantitative HCV RNA testing results. Overall, 133 persons (5.3%) had a VLVL. Age 18-40 years, female sex, and human immunodeficiency virus coinfection were associated with VLVL. Of 72 persons with a viral load available after VLVL, 14% had a VLVL and 17% had spontaneous viral clearance. The prevalence and incidence of cirrhosis and mortality were comparable in persons with and without VLVL; all 24 persons with VLVL and cirrhosis had excessive alcohol consumption or immunosuppression. Overall, 33% of samples with VLVL were reactive by antigen testing.

CONCLUSIONS

The frequency of VLVL was low. Among the persons who would probably be missed by antigen screening, some had a favorable disease course, but some had immunosuppression and liver cirrhosis. The benefit of HCV antigen testing for screening may be limited by the risk of missing patients with severe liver disease.

Impact of Different Sources of Infection on Therapy Response in Chronic Hepatitis C

Introduction:

Prior to the 1990s, the most common sources of HCV infections were blood transfusions, unsafe injections and I.V drug use. Screening of blood products for HCV has eradicated transfusion-transmitted hepatitis C in most countries since 1992–in Bosnia and Herzegovina, however, since 1995, due to the war.

Aim:

To investigate the impact of the source of HCV infection on the therapeutic response in patients treated for chronic HCV infection with dual combined therapy.

Methods:

We diagnosed chronic HCV infections amongst 246 patients over a period of five years and selected them according to the reported source of infection. Pegylated interferon alfa 2a or alfa 2b with ribavirin was administered during the time that was genotype-dependent. HCV RNA levels in sera were measured by real time PCR. Liver histology was evaluated in accordance with the level of necroinflammation activity and the stadium of fibrosis.

Results:

Regardless of the genotype of the virus and the source of infection, SVR was achieved in 67% of the patients. Therapeutic response (ETR) was not achieved in 25% of the patients who were infected with an untested blood transfusion and 6% of the patients who had had wartime surgery. Amongst the different sources of infections, patients with a war-surgery source of infection responded better to therapy than those with a blood transfusion source of infection (p = 0.023). A blood transfusion source of infection implies a larger fibrosis stage than in blood donors; (g = 1.177; s² = 0.577). A blood transfusion source of infection implies a significantly larger necroinflammatory activity than in blood donors; (g = 1.456; s² = 0.618).

Conclusions:

An untested blood transfusion was a significant risk factor for more advanced liver diseases in regards to necroinflammatory activity and the fibrosis stage. This source of infection was also a risk factor for low responses to antiviral therapy. At the same time, I.V. drug users had more progressive necroinflammatory activity, but a high therapeutic response to antiviral therapy.

[Impact of antiviral therapy on the natural history of hepatitis C virus]

Chronic hepatitis C virus infection affects around 150 million persons, and 350,000 persons worldwide die of this disease each year. Although the data on its natural history are incomplete, after the acute infection, most patients develop chronic forms of hepatitis C with variable stages of fibrosis. In these patients, continual inflammatory activity can cause significant fibrosis, cirrhosis, decompensation of the liver disease, or hepatocarcinoma. In the next few years, it is expected that hepatitis C virus infection and its complications will significantly increase, as will the incidence of hepatocarcinoma in Spain. This review presents the data on the natural history of hepatitis C virus infection and discusses the potential impact of antiviral therapy on the distinct stages of the disease.

Correlation of biochemical markers and HCV RNA titers with fibrosis stages and grades in chronic HCV-3a patients

INTRODUCTION

Hepatitis C virus (HCV) is one of the most important causes of chronic liver diseases, which include inflammation, fibrosis, cirrhosis and hepatocellular carcinoma. Several factors have been proposed to determine the clinical outcome of HCV infection. The accurate mechanism by which HCV damages the liver remains poorly understood. In chronic hepatitis C patients, the relation between serum biochemical markers, HCV RNA titers and histological liver injury remain controversial.

OBJECTIVES

The aim of this study was to investigate the relation between serum biochemical markers, HCV RNA titers and the degree of liver damage in patients with chronic HCV.

MATERIALS AND METHODS

Liver biopsies were performed on 79 of a total of 100 enrolled patients. The histological activity was evaluated by the METAVER scoring system. HCV RNA quantification was performed by quantitative real-time PCR, and HCV genotyping was performed by nested PCR. Biochemical markers were measured with biochemical instruments.

RESULTS

HCV RNA titers were significantly correlated with aspartate aminotransferase (AST) (P=0.004), alkaline phosphatase (ALP) (P=0.001) and total bilirubin (P=0.012) levels. HCV RNA titers were also significantly correlated with a progression of the fibrosis stage (P=0.000), but no correlation was observed with the change in inflammatory grades. It was observed that bilirubin levels were higher in later fibrosis stages as compared with the initial stage (P=0.000). Results revealed that in different fibrosis stages, the levels of AST (P=0.000), ALP (P=0.000) and alanine aminotransferase (ALT) (P=0.008), the age at diagnosis (P=0.000), the present age (P=0.000) and the BMI (P=0.009) were statistically significant. In the case of the inflammatory grade, levels of bilirubin (P=0.000), ALP (P=0.000), AST (P=0.016) and ALT (P=0.000) were statistically different between the inflammatory grades.

CONCLUSION

Serum HCV RNA titers were correlated with AST, ALP and total bilirubin. Levels of ALT, AST, ALP and bilirubin had significant relation with the liver fibrosis stage and the inflammatory grade in genotype 3a. Hence, our study suggests that AST, ALP and ALT may correlate with liver damage.

IFNL4/IL-28B haplotype structure and its impact on susceptibility to hepatitis C virus and treatment response in the Japanese population

A new type III interferon, IFN lambda 4 (IFNL4), and its single-nucleotide polymorphism (SNP) ss469415590 causing a frame shift have been recently reported strongly to affect antiviral therapy for chronic hepatitis C virus (HCV) infection in African and Caucasian populations compared to previously reported IL-28B SNPs rs12979860 and rs8099917. To compare the predictability for treatment outcome among those polymorphisms, we estimated haplotype structure of IFNL4/IL-28B consisting of the three SNPs in 4630 Japanese chronic hepatitis C patients and 1122 healthy controls and then compared their impact on response to pegylated-IFN (PEG-IFN) plus ribavirin (RBV) combined therapy in 903 HCV-1b-infected patients. A total of five haplotypes were identified, although two major haplotypes accounted for >99 % of the variation. The SNPs were tightly linked but not in absolute linkage disequilibrium. We could not find any difference in the predictive impact of any of these three SNPs with regard to susceptibility to HCV and treatment response. However, patients with favourable rs8099917 TT, linked to unfavourable genotypes of ss469415590 and rs12979860, showed poor initial viral response compared with those with all favourable genotypes (P = 0.0022). These findings suggest that, in part, ss469415590 and rs12979860 may have better predictive impact on response to PEG-IFN plus RBV therapy in the Japanese population, especially in patients with any of the minor haplotypes consisting of these SNPs.

Hepatic decompensation in antiretroviral-treated patients co-infected with HIV and hepatitis C virus compared with hepatitis C virus-monoinfected patients: a cohort study

BACKGROUND

The incidence and determinants of hepatic decompensation have been incompletely examined among patients co-infected with HIV and hepatitis C virus (HCV) in the antiretroviral therapy (ART) era, and few studies have compared outcome rates with those of patients with chronic HCV alone.

OBJECTIVE

To compare the incidence of hepatic decompensation between antiretroviral-treated patients co-infected with HIV and HCV and HCV-monoinfected patients and to evaluate factors associated with decompensation among co-infected patients receiving ART.

DESIGN

Retrospective cohort study.

SETTING

Veterans Health Administration.

PATIENTS

4280 co-infected patients who initiated ART and 6079 HCV-monoinfected patients receiving care between 1997 and 2010. All patients had detectable HCV RNA and were HCV treatment-naive.

MEASUREMENTS

Incident hepatic decompensation, determined by diagnoses of ascites, spontaneous bacterial peritonitis, or esophageal variceal hemorrhage.

RESULTS

The incidence of hepatic decompensation was greater among co-infected than monoinfected patients (7.4% vs. 4.8% at 10 years; P < 0.001). Compared with HCV-monoinfected patients, co-infected patients had a higher rate of hepatic decompensation (hazard ratio [HR] accounting for competing risks, 1.56 [95% CI, 1.31 to 1.86]). Co-infected patients who maintained HIV RNA levels less than 1000 copies/mL still had higher rates of decompensation than HCV-monoinfected patients (HR, 1.44 [CI, 1.05 to 1.99]). Baseline advanced hepatic fibrosis (FIB-4 score >3.25) (HR, 5.45 [CI, 3.79 to 7.84]), baseline hemoglobin level less than 100 g/L (HR, 2.24 [CI, 1.20 to 4.20]), diabetes mellitus (HR, 1.88 [CI, 1.38 to 2.56]), and nonblack race (HR, 2.12 [CI, 1.65 to 2.72]) were each associated with higher rates of decompensation among co-infected patients.

LIMITATION

Observational study of predominantly male patients.

CONCLUSION

Despite receiving ART, patients co-infected with HIV and HCV had higher rates of hepatic decompensation than HCV-monoinfected patients. Rates of decompensation were higher for co-infected patients with advanced liver fibrosis, severe anemia, diabetes, and nonblack race.

PRIMARY FUNDING SOURCE

National Institutes of Health.

Association between TGFB1 915G/C polymorphism and susceptibility to chronic hepatitis C virus infection: A meta-analysis

The human transforming growth factor-β1 (TGF-β1) gene, namely TGFB1, contains several single-nucleotide polymorphisms (SNPs) and some of the polymorphic variants were shown to affect the TGF-β1 protein levels. A number of studies reported the association between 915G/C polymorphism and susceptibility to chronic hepatitis C virus (HCV) infection. However, the results were inconsistent. This meta-analysis was conducted to assess the association of TGFB1 915G/C polymorphism with susceptibility to chronic HCV infection. PubMed, ISI Web of Knowledge, ScienceDirect and Google Scholar databases were systematically searched up to August, 2013 to identify relevant studies. The pooled odds ratios (ORs) with their corresponding 95% confidence intervals (95% CIs) were calculated in 5 genetic comparison models (C vs. G, CC vs. GG, GC vs. GG, CC vs. GG+GC and CC+GC vs. GG). The Galbraith plot and subgroup analyses based on ethnicity, genotyping methods, sample size and fibrosis were performed to investigate possible sources of heterogeneity. A sensitivity analysis and assessment of publication bias were also conducted. Finally, 8 eligible case-control studies on TGFB1 915G/C polymorphism, including a total of 910 cases and 632 controls, were included in this meta-analysis. Overall, there was no evidence of any gene-disease association obtained from the subgroup analyses. Therefore, this meta-analysis demonstrated that there is no association between TGFB1 915G/C polymorphisms and susceptibility to chronic HCV infection.

Non-structural 3 protein expression is associated with T cell protein tyrosine phosphatase and viral RNA levels in chronic hepatitis C patients

The hepatitis C virus (HCV) non-structural 3 (NS3) protein plays key roles in both the viral life cycle and in the modulation of intrahepatic signaling and immunity. We recently showed that NS3 cleaves the T cell protein tyrosine phosphatase (TCPTP). To better understand the inactivation of TCPTP in HCV-infected humans, we investigated whether there is an association between TCPTP cleavage, NS3 protein levels and clinical parameters in hepatitis C patients. Liver biopsies were obtained from 69 HCV RNA positive patients with confirmed chronic HCV infection and 16 control patients. Hepatic NS3 and TCPTP protein levels were determined and correlated to viral load or clinical parameters for the severity of liver disease. We found a positive correlation between the viral load and the intrahepatic NS3 protein levels in patients infected with HCV. HCV-infected patients had significantly lower intrahepatic TCPTP levels than non-infected control patients. In HCV-infected patients both intrahepatic NS3 expression and the viral load were inversely correlated with the intrahepatic TCPTP protein levels. Detection of NS3 did not associate with any other clinical parameters such as liver damage, the grade of liver inflammation or fibrosis stage. This is the first study reporting a detailed analysis of HCV NS3 and TCPTP protein levels in the liver. It demonstrates a clear link between HCV viral load, NS3 expression in the liver and intrahepatic TCPTP levels. Thus, the association between TCPTP cleavage and viral replication may have important consequences for the HCV life cycle and HCV-induced liver diseases.

Treatment of chronic hepatitis C virus infection in Japan: update on therapy and guidelines

Hepatitis C virus (HCV) infection is a serious health problem leading to cirrhosis, liver failure and hepatocellular carcinoma. The recent introduction of telaprevir, which was approved in November 2011, in combination with peg-interferon and ribavirin is expected to markedly improve the eradication rate of the virus. However, side effects of triple therapy may be severe. In a phase three III clinical trial, 2250 mg of telaprevir, which is the same dosage used in clinical trials in Western countries, was given to Japanese patients. As this dosage is considered to be relatively high for Japanese patients, who typically have lower weight than patients in Western countries, reduction of telaprevir is recommended in the 2012 revision of the guidelines established by the Study Group for the Standardization of Treatment of Viral Hepatitis Including Cirrhosis published by the Ministry of Health, Labour and Welfare of Japan. Other protease inhibitors with fewer side effects are now in clinical trials in Japan. Alternatively, treatment of patients with combination of direct acting antivirals without interferon has been reported. In this review we summarize current treatment options in Japan and discuss how we treat patients with chronic HCV infection.

Toward the establishment of a prediction system for the personalized treatment of chronic hepatitis C

BACKGROUND

Although several direct-acting antivirals (DAAs) are now available, the therapy regimen for chronic hepatitis C will continue to include pegylated interferon and ribavirin for the foreseeable future. Despite their improved rate of sustained virological response (SVR), DAAs pose increased risks of side effects and selection for antiviral resistance. Not all patients require DAA to achieve SVR, whereas others are unlikely to respond even to triple therapy. Therefore, a personalized approach to candidate selection is necessary.

METHODS

In this retrospective study, data from 640 Japanese patients who were treated for chronic hepatitis C genotype 1, 2, or 3 with pegylated interferon plus ribavirin combination therapy was compiled to identify robust pretreatment predictive factors for SVR.

RESULTS

A logistic regression model for personalized therapy was developed based on age, viral genotype, initial viral load, aspartate aminotransferase/alanine aminotransferase ratio, α-fetoprotein levels, and IL28B single-nucleotide polymorphism genotype. The area under the receiver-operating characteristic curve (AUC) was 0.85. The mean AUC following 10 rounds of 10-fold cross validation was 0.82, with a true positive rate of 78.2%.

CONCLUSIONS

A personalized approach to therapy may better inform treatment decisions and reduce incidence of side effects and antiviral resistance.

IL28B but not ITPA polymorphism is predictive of response to pegylated interferon, ribavirin, and telaprevir triple therapy in patients with genotype 1 hepatitis C

BACKGROUND

Pegylated interferon, ribavirin, and telaprevir triple therapy is a new strategy expected to eradicate the hepatitis C virus (HCV) even in patients infected with difficult-to-treat genotype 1 strains, although adverse effects, such as anemia and rash, are frequent.

METHODS

We assessed efficacy and predictive factors for sustained virological response (SVR) for triple therapy in 94 Japanese patients with HCV genotype 1. We included recently identified predictive factors, such as IL28B and ITPA polymorphism, and substitutions in the HCV core and NS5A proteins.

RESULTS

Patients treated with triple therapy achieved comparatively high SVR rates (73%), especially among treatment-naive patients (80%). Of note, however, patients who experienced relapse during prior pegylated interferon plus ribavirin combination therapy were highly likely to achieve SVR while receiving triple therapy (93%); conversely, prior nonresponders were much less likely to respond to triple therapy (32%). In addition to prior treatment response, IL28B SNP genotype and rapid viral response were significant independent predictors for SVR. Patients with the anemia-susceptible ITPA SNP rs1127354 genotype typically required ribavirin dose reduction earlier than did patients with other genotypes.

CONCLUSIONS

Analysis of predictive factors identified IL28B SNP, rapid viral response, and transient response to previous therapy as significant independent predictors of SVR after triple therapy.

Common genetic polymorphism of ITPA gene affects ribavirin-induced anemia and effect of peg-interferon plus ribavirin therapy

An association between a single nucleotide polymorphism (SNP) in the inosine triphosphate pyrophosphatase (ITPA) gene and reduction of hemoglobin during peg-interferon plus ribavirin combination therapy for patients with chronic hepatitis C virus (HCV) infection has been reported. However, the effect of the SNP on outcome of therapy has not been fully elucidated. Factors associated with anemia during combination therapy, including rs1127354 genotype, were analyzed in 1,002 treated patients. The effect of the SNP on outcome of therapy was analyzed in a subset of 830 patients with genotype 1. A rapid initial decrease in hemoglobin levels was observed in patients with rs1127354 genotype CC compared with a slow decrease in non-CC patients. Cumulative reduction of ribavirin was significantly more frequent in genotype CC patients than non-CC patients (odds ratio 1.928, P = 8.6 × 10(-8) ). The frequency of patients who received at least the recommended 80% of scheduled ribavirin was significantly lower among genotype CC patients, especially among those who had pretreatment hemoglobin levels between 13.5 and 15 g/dl (P < 0.03), and the sustained viral response rate was significantly lower in this group of patients. Independent predictive factors for sustained virological response included a SNP in the IL28B locus (rs809991), age, fibrosis, ITPA SNP rs1127354 as well as pretreatment hemoglobin levels. Our data suggests that measures to prevent anemia should be considered for patients who have pretreatment hemoglobin levels less than 13.5 g/dl or who have rs1127354 genotype CC and pretreatment hemoglobin levels between 13.5 and 15 g/dl.

Fibrosis in chronic viral hepatitis

In the last years, several studies have been performed with the aim to evaluate the real impact of antiviral treatments on fibrosis progression in patients with chronic viral hepatitis. The main goal of therapy in patients with chronic hepatitis B is viral suppression. This outcome leads to an important improvement in both hepatic inflammation and fibrosis and reduces the HCC occurrence. An histological improvement has been largely demonstrated in patient treated with oral nucleoside and nucleotide analogs achieving the rate of 72% with entecavir and tenofovir. Similarly, in patients with chronic hepatitis C, sustained virologic response to interferon therapy is associated with regression of fibrosis and lower liver decompensation and HCC occurrence. In the next future further studies will assess the real impact of the new directly anti-viral agents on liver necroinflammation and fibrosis in chronic hepatitis C.

Gas exchanges and pulmonary vascular abnormalities at different stages of chronic liver disease

BACKGROUND

It is unclear whether and to which extent respiratory function abnormalities may complicate the earliest stages of chronic liver disease (CLD). Aim of this study was to compare pulmonary capillary volumes and gas exchange efficiency of CLD patients with and without cirrhosis.

METHODS

Sixty-seven participants (mean age 56.5 years; women 22.4%) were divided into three groups (matched by age, sex, smoking) according to the baseline CLD stage as follows: (a) healthy controls (Group A, n=20); (b) non-cirrhotic CLD patients (Group B; n=23); (c) cirrhotic CLD patients (Group C; n=24). All participants underwent clinical assessment, respiratory function tests, gas exchange estimation by the alveolar diffusion of carbon monoxide (TLCO) measurement and 6-min walking test. Groups were compared by chi-square and one-way anova tests.

RESULTS

Chronic liver disease patients had significantly lower levels of TLCO (Group B=17.7 ml/min mmHg, and Group C=14.2 ml/min mmHg) compared with healthy controls (Group A=24.4 ml/min mmHg). Consistent results were obtained when analyses were performed using TLCO expressed as percentage of the predicted value. TLCO adjusted for the alveolar volume was lower in cirrhotic patients compared with both controls and non-cirrhotic CLD patients (P<0.001 and P=0.035 respectively). Group C participants presented blood gas parameters tending to a compensated chronic respiratory alkalosis status compared with the other groups.

CONCLUSIONS

Pulmonary microvascular and gas exchange modifications are present at early stages of CLD. Future studies should be focused at evaluating the pathophysiological mechanisms underlying this relationship.

Predictive value of the IL28B polymorphism on the effect of interferon therapy in chronic hepatitis C patients with genotypes 2a and 2b

BACKGROUND & AIMS

Common IL28B locus polymorphisms (SNPs rs8099917 and rs12979860) have been reported to affect peg-interferon plus ribavirin combination therapy (PEG-RBV) for hepatitis C virus (HCV) genotype 1b, but few reports have examined their effect on other two common genotypes, 2a and 2b.

METHODS

We analyzed predictive factors for sustained virological response (SVR) in a retrospective study of 719 patients with either genotype 2a (530) or 2b (189). Of these patients, 160 were treated with PEG-RBV and 559 were treated with interferon monotherapy. We evaluated predictive factors including HCV RNA, histological findings, IL28B SNP genotypes (rs8099917, rs12979860, and rs12980275), and the effect of treatment regimen and prior treatment history.

RESULTS

HCV RNA viral load, treatment regimen, and rs8099917 genotypes independently contributed to the effect of the therapy. For patients treated with PEG-RBV, rs8099917 and viral load were independent predictive factors for SVR in genotype 2b but not in genotype 2a. Conversely, in patients treated with interferon monotherapy, viral load and rs8099917 were independent predictive factors for SVR in genotype 2a but not in genotype 2b. The favorable rs8099917 genotype is also associated with a steep decline in viral load by the second week of treatment.

CONCLUSIONS

Initial viral load and rs8099917 genotype are significant independent predictors of SVR in genotype 2 patients.

Comparative study of patients with chronic hepatitis C virus infection due to genotypes 1 and 3 referred for treatment in southeast Brazil

BACKGROUND

The progression of liver disease in patients with chronic hepatitis C virus (HCV) infection is influenced by host and viral factors. Distinct clinical outcomes in patients infected with different HCV genotypes have been described in the literature. However, the association between specific HCV genotype and clinical outcome remains unclear. We set out to study the natural history of HCV genotype 1 and 3 infections in Campinas, São Paulo state, Brazil, focusing on epidemiological, clinical, biochemical, and histological characteristics.

METHODS

Patients with HCV infection referred for treatment between January 2003 and December 2006 were included in this study. We collected epidemiological, clinical, and laboratorial data using standard forms.

RESULTS

A total of 283 patients were included; genotype 1 was identified in 163 (57.6%) patients, genotype 3 in 112 (39.6%), genotype 2 in 7 (2.5%), and genotype 4 in 1 (0.35%). Patients with genotype 2 and 4 were excluded from analysis. Multivariate analysis showed that intravenous energetic drug, positive cryoglobulin, and cirrhosis were independently and significantly associated with HCV genotype 3 (p < 0.05).

CONCLUSION

Genotype 3 currently seems to be associated with intravenous energetic drug, high frequency of cryoglobulinemia, and advanced liver disease in our region. Understanding the distribution of the different HCV genotypes can elucidate transmission of HCV and support optimal prevention strategies.

Natural history of chronic hepatitis C virus infection

The natural history of chronic Hepatitis C Virus (HCV) infection is still poorly understood. The main reason is the asymptomatic onset and course in the majority of infected subjects. Moreover, in the presence of the very effective therapies now available it is impossible to follow people untreated in order to analyse the events and their timing and type of evolution. For these reasons, most studies are mainly retrospective, although studies on post-transfusion hepatitis could help in understanding the natural course of the infection. Another important phenomenon that makes this issue problematic is that chronic HCV infection is not linear in time, probably because many co-factors can change the speed of development of fibrosis, cirrhosis and hepatocellular carcinoma. Data now available show that this disease can persist for about two decades with limited morbidity and mortality; problems may arise between the third and fourth decade after infection. Alcohol consumption is a very important factor of additional risk of progression, but there are several other factors (iron, steatosis, metabolic problems, etc.) that must be better analysed. In conclusion, only in a small group (no more than 15%) of all HCV-infected patients does the disease reduce quality and/or quantity of life.

Translation efficiencies of the 5'-untranslated region of genotypes 1a and 3a in hepatitis C infected patients

Differences between the translation efficiencies mediated by the 5'-untranslated regions (5'-UTR) of genotypes (gt) 1 and 3 of hepatitis C virus (HCV) have been reported but it is unknown if such differences are biologically significant. The 5'-UTR was sequenced from paired serum and liver samples from 26 patients with chronic HCV hepatitis (11 gt 1a, 15 gt 3a). To determine whether there is a consistent difference between gts 1a and 3a translation efficiency, 5'-UTR (nt 1-356) and 5'-UTR plus core (nt 1-914) sequences were cloned into bicistronic, luciferase-encoding constructs and relative translation efficiencies (RTE) measured in Huh7 cells and BHK cells. The relationships between viral load, liver biopsy Ishak scores, degree of steatosis and translational activity of the patient-derived nucleotide sequence were examined. There were no differences in 5'-UTR sequence between serum and corresponding liver samples. The mean RTE of 5'-UTR sequences from gt 3a isolates was not significantly different from gt 1a whether or not the core encoding sequence was included, although inclusion of core led to a reduction in RTE by 93-97% for both genotypes. No correlation was found between RTE and serum HCV RNA levels, liver steatosis, inflammation, or fibrosis. However, a significant correlation was found between the presence of steatosis and infection with HCV gt 3a. It is concluded that there was no difference in translation efficiencies of 5'-UTRs from patients infected with gts 1a and 3a, and translation activity measured in vitro does not correlate with viral load or severity of liver disease.

Influence of iron on the severity of hepatic fibrosis in patients with chronic hepatitis C

AIM: To evaluate the association among hepatic fibrosis, serum iron indices, and hepatic iron stores in patients with Chronic Hepatitis C (CHC).

METHODS: Thirty-two CHC patients were included in our study. The histological degree of fibrosis and inflammation activity was assessed according to the Metavir system. The serum iron indices including ferritin, iron and transferrin saturation were measured. Hepatic iron deposition was graded by Perls’ stain.

RESULTS: The CHC patients with severe hepatic fibrosis (n = 16) were significantly older than CHC patients with mild fibrosis (n = 16) (P = 0.024). The serum iron indices, increased serum iron store and positive hepatic iron stain were not significantly different between the two groups. In multivariate logistic regression analysis, the age at biopsy was an independent predictor of severe hepatic fibrosis (Odds ratio = 1.312; P = 0.035). The positive hepatic iron stain was significantly associated with the values of alanine aminotransferase (ALT) (P = 0.017), ferritin (P = 0.008), serum iron (P = 0.019) and transferrin saturation (P = 0.003). The ferritin level showed significant correlation with the value of ALT (r = 0.531; P = 0.003), iron (r = 0.467; P = 0.011) and transferrin saturation (r = 0.556; P = 0.002).

CONCLUSION: Our findings suggest that the severity of hepatitis C virus (HCV)-related liver injury is associated with patient age at biopsy. Both serum iron indices and hepatic iron deposition show correlation with serum indices of chronic liver disease but are not related to grade and stage of liver histology.

Distribution of HCV genotypes in patients with end-stage renal disease according to type of dialysis treatment

The objective of this study was to investigate the effects of types of dialysis treatments on hepatitis C virus infection and the epidemiologic properties of hepatitis C virus (HCV) infection at three Baskent University hospitals, in Ankara, Adana, and Izmir, Turkey, in 655, 326, and 118 patients with end-stage renal disease, respectively. One hundred thirty patients with HCV viremia among 271 patients with end-stage renal disease seropositive for HCV were included in this cross-sectional study. HCV RNA-positive patients were classified according to the renal replacement therapies (hemodialysis or continuous ambulatory peritoneal dialysis), and viral load, transaminase levels, and distribution of genotypes were compared between these subgroups. In the continuous ambulatory peritoneal dialysis group, 26 of 165 patients (16%) were serum anti-HCV positive, and 11 of 26 patients (42%) were serum HCV RNA positive. Twenty-six percent of the patients undergoing hemodialysis were anti-HCV positive, and 49% were HCV RNA positive. The prevalence of genotype 1b was 68% and 73% for patients in the continuous ambulatory peritoneal dialysis and hemodialysis groups, respectively. No significant differences were found between the genotype 1b and the non-1b groups or between different dialysis types with regard to age and sex and serum aspartate transaminase, alanine aminotransferase, and HCV RNA levels. We conclude that HCV seropositivity may differ between different types of dialysis treatments, although viral load and genotypes may be similar in persons with end-stage renal disease and those without.

Hepatitis C virus infection in renal transplant patients: a comparative study with immunocompetent patients

The behavior of hepatitis C in states of immunodeficiency is poorly understood and it is still unclear whether the characteristics of hepatitis C virus (HCV) infection in renal transplant patients differ from those observed in immunocompetent subjects. The aim of this study was to compare the biochemical and histologic characteristics of chronic HCV infection between renal transplant and immunocompetent patients. Forty-one HCV-RNA-positive renal transplant patients and 41 immunocompetent controls matched for gender, age at infection and time of infection were included in the study. The groups were compared regarding laboratory and histologic variables. Renal transplant patients showed lower alanine aminotransferase (ALT) levels (p = 0.005) and higher levels of gamma-glutamyltransferase (p = 0.003), alkaline phosphatase (p < 0.001), and direct bilirubin (p < 0.001) when compared with controls. Histologic analysis revealed less intense portal (p < 0.001) and periportal (p = 0.046) inflammatory infiltrate in renal transplant patients but a larger proportion of cases with confluent necrosis (p = 0.043). No difference in the presence of septal fibrosis, hepatic steatosis, bile duct injury and siderosis was observed. However, there was a difference in the presence of lymphoid aggregates, which were less frequent in the renal transplant group (p < 0.001). In conclusion, the characteristics of hepatitis C in renal transplant patients differ from that observed in immunocompetent patients. In renal transplant patients, HCV infection is biochemically characterized by lower ALT levels and higher frequency of cholestasis. Regarding histology, despite lower frequency of lymphoid aggregates and less intense portal/periportal inflammatory infiltrate, a greater lobular damage was observed. The impact of these differences on the progression of fibrosis remains to be established.

Peginterferon Alpha/Ribavirin Combination Therapy for the Treatment of Hepatitis C Infection

Chronic infection with the hepatitis C virus is widespread in the United States. This disease is associated with a progression of fibrosis of the liver leading to liver cirrhosis in as many as 20% of cases. The current standard of care for the treatment of chronic hepatitis C infection is combination therapy with pegylated interferon alpha plus ribavirin. In more than 50% of patients, this regimen has been shown to induce a sustained viral response, defined as undetectable hepatitis C viral ribonucleic acid (RNA) for 6 months after the end of treatment. Typically, patients are treated for 24 or 48 weeks. A number of possible adverse events are associated with combination therapy, and patient empowerment through supportive nursing care is critical to facilitating patient adherence to treatment. This article provides an update on information concerning the diagnosis and treatment of chronic hepatitis C infection. This information can be tailored to provide patient-focused assessment, education, and treatment.

Assessment of correlation between serum titers of hepatitis c virus and severity of liver disease

AIM: The significance of hepatitis C virus (HCV) serum titers has been examined in several clinical situations. There is much evidence that patients with a lower viral load have better response rates to anti-viral therapy compared to those with higher levels. Moreover, a direct association has been observed between serum titers of HCV and transmission rates of the virus. The aim of the present study was to determine if there was any correlation between HCV viral load and the severity of liver disease.

METHODS: Fifty patients with HCV infection were included in the study. These comprised of 34 subjects with a history of alcohol use and 16 non-alcoholics. Quantitative serum HCV RNA assay was carried out using the branched DNA (bDNA) technique. Linear regression analysis was performed between serum viral titers and liver tests. In addition, for the purpose of comparison, the subjects were divided into two groups: those with low viral titers ( < / = 50 genome mEq/ mL) and high titers ( > 50 mEq/mL).

RESULTS: All subjects were men, with a mean ± SD age of 47 ± 7.8 years. The mean HCV RNA level in the blood was 76.3 × 10⁵± 109.1 genome equivalents/mL. There was no correlation between HCV RNA levels and age of the patients (r = 0.181), and the history or amount (g/d) of alcohol consumption (r = 0.07). Furthermore, no correlation was observed between serum HCV RNA levels and the severity of liver disease as judged by the values of serum albumin (r = 0.175), bilirubin (r = 0.217), ALT (r = 0.06) and AST (r = 0.004) levels. Similarly, no significant difference was observed between patients with low viral titers and high titers with respect to any of the parameters.

CONCLUSION: Our results indicate that the severity of liver disease is independent of serum levels of hepatitis C virus. These findings are important since they have a direct impact on the current debate regarding the role of direct cytopathic effect of hepatitis C virus versus immune-mediated injury in the pathogenesis of HCV-related liver damage.

Neither hepatitis C virus genotype nor virus load affects survival of patients with hepatocellular carcinoma

OBJECTIVE

Hepatitis C virus (HCV) genotype and virus load, the strongest determinants of the efficacy of interferon therapy, have been presumed to be associated with risk for hepatocellular carcinoma (HCC). This study was conducted to elucidate whether these two factors are capable of predicting the prognosis of patients with HCC.

METHODS

A total of 371 patients with HCV infection (258 men and 113 women; median age, 66 years; range, 37-88 years) who developed HCC between January 1993 and December 1999 were enrolled. Overall survival and recurrence-free survival were analysed with the Cox proportional hazard regression according to HCV genotype (type 1 versus type 2) and virus load (above versus below 100 kIU/ml).

RESULTS

Of the 371 patients, 346 received locoregional treatments (ethanol injection, microwave, radiofrequency, or surgery), and 307 achieved complete response as determined by subsequent imaging studies. The remaining 25 patients underwent arterial embolization or chemotherapy. Cox proportional hazard regression showed that neither genotype (P = 0.814) nor virus load (P = 0.958) were significant predictors for survival (P = 0.814 and 0.958, respectively) and recurrence (P = 0.505 and 0.736, respectively).

CONCLUSIONS

Neither genotype nor virus load of HCV affected prognosis of HCC patients.

Management of patients with hepatitis C in a community population: diagnosis, discussions, and decisions to treat

BACKGROUND

Chronic hepatitis C, a treatable condition caused by the hepatitis C virus (HCV), can be found in almost all primary care and community practices. The rate of hepatitis C treatment is low, however. This study explores the frequency of hepatitis C treatment, documented discussions of treatment consideration, and the reasons treatment may not be offered in a community population.

METHODS

This study is a retrospective medical record review of care provided to all patients in Olmsted County, Minn, who had a confirmed diagnosis of hepatitis C. Using all records from all health care providers in Olmsted County, the rates of documented discussions regarding hepatitis C treatment and the treatment rates by specialty of diagnosing physician were assessed. In addition, comorbidities listed as reasons not to treat and or comorbid conditions in patients without a documented treatment discussion were assessed.

RESULTS

Of the 366 patients with hepatitis C, 62% were men. Hepatitis C was more commonly diagnosed by generalist physicians (41% of cases). Treatment discussions were documented for 77% of patients with hepatitis C diagnosed by either a generalist or a gastrointestinal specialist (gastroenterologist or hepatologist) compared with 46% of patients with hepatitis C diagnosed by other physicians. Generalists' patients were more likely to have documented contraindications to treatment and were only one half as likely to receive hepatitis C treatment compared with patients with hepatitis C diagnosed by gastrointestinal specialists (16% vs 33%). Documented attempts to treat or reassess after resolution of potentially reversible contraindications to hepatitis C therapy were infrequent.

CONCLUSIONS

In this community population, hepatitis C treatment was discussed with the majority of patients with a diagnosis of hepatitis C; however, the actual treatment rate was low. Many opportunities exist for treating more patients for HCV infection, particularly those found during emergency care and chemical dependency treatment. In addition, generalists' recognition and treatment of potentially reversible contraindications to hepatitis C therapy could greatly increase the number of treatment candidates.

Impact of moderate alcohol consumption on histological activity and fibrosis in patients with chronic hepatitis C, and specific influence of steatosis: a prospective study

AIM

To evaluate the effects of minimal to moderate alcohol consumption on the severity of histological lesions in patients with chronic hepatitis C.

METHODS

Daily alcohol intake (none, 1-20, 21-30, 31-50 g/day) and histological activity and fibrosis were recorded in 260 patients with chronic hepatitis C.

RESULTS

The proportion of patients with moderate (A2) or marked (A3) activity increased gradually from 53.8% in abstinent patients to 86.5% for an intake between 31 and 50 g/day (P = 0.003). In multivariate analysis, age > 40 years, alcohol intake between 31 and 50 g/day and moderate or severe steatosis were independently related to histological activity. The proportion of patients with moderate (F2) or marked (F3) fibrosis or cirrhosis (F4) gradually increased from 29.0% in abstinent patients to 67.6% for an intake between 31 and 50 g/day (P < 0.001). Multivariate analysis also showed that alcohol intake between 31 and 50 g/day, moderate or severe steatosis and histological activity were independently related to fibrosis. The deleterious effect of alcohol intake on histological lesions differed according to gender.

CONCLUSIONS

This study demonstrates that both activity and fibrosis gradually increase according to the amount of alcohol ingested, and that even moderate alcohol consumption, as low as 31-50 g/day in men and 21-50 g/day in women, may aggravate histological lesions in patients with chronic hepatitis C.

Fibrosis and disease progression in hepatitis C

The progression of fibrosis in chronic hepatitis C determines the ultimate prognosis and thus the need and urgency of therapy. Fibrogenesis is a complex dynamic process, which is mediated by necroinflammation and activation of stellate cells. The liver biopsy remains the gold standard to assess fibrosis. Scoring systems allow a semiquantitative assessment and are useful for cross-sectional and cohort studies and in treatment trials. The rate at which fibrosis progresses varies markedly between patients. The major factors known to be associated with fibrosis progression are older age at infection, male gender, and excessive alcohol consumption. Viral load and genotype do not seem to influence significantly the progression rate. Progression of fibrosis is more rapid in immunocompromised patients. Hepatic steatosis, obesity, and diabetes may also contribute to more rapid progression of fibrosis. There are no tests that reliably predict the rate of progression of fibrosis in an individual patient. High serum alanine aminotransferase (ALT) levels are associated with a higher risk of fibrosis progression, and worsening of fibrosis is uncommon in patients with persistently normal serum aminotransferase levels. Serum markers for fibrosis are not reliable and need to be improved and validated. Liver biopsy provides the most accurate information on the stage of fibrosis and grade of necroinflammation, both of which have prognostic significance. Repeating the liver biopsy, 3 to 5 years after an initial biopsy is the most accurate means of assessing the progression of fibrosis.

Fibrosis and disease progression in hepatitis C

The progression of fibrosis in chronic hepatitis C determines the ultimate prognosis and thus the need and urgency of therapy. Fibrogenesis is a complex dynamic process, which is mediated by necroinflammation and activation of stellate cells. The liver biopsy remains the gold standard to assess fibrosis. Scoring systems allow a semiquantitative assessment and are useful for cross-sectional and cohort studies and in treatment trials. The rate at which fibrosis progresses varies markedly between patients. The major factors known to be associated with fibrosis progression are older age at infection, male gender, and excessive alcohol consumption. Viral load and genotype do not seem to influence significantly the progression rate. Progression of fibrosis is more rapid in immunocompromised patients. Hepatic steatosis, obesity, and diabetes may also contribute to more rapid progression of fibrosis. There are no tests that reliably predict the rate of progression of fibrosis in an individual patient. High serum alanine aminotransferase (ALT) levels are associated with a higher risk of fibrosis progression, and worsening of fibrosis is uncommon in patients with persistently normal serum aminotransferase levels. Serum markers for fibrosis are not reliable and need to be improved and validated. Liver biopsy provides the most accurate information on the stage of fibrosis and grade of necroinflammation, both of which have prognostic significance. Repeating the liver biopsy, 3 to 5 years after an initial biopsy is the most accurate means of assessing the progression of fibrosis.

Pulmonary dysfunction in non-cirrhotic patients with chronic viral hepatitis

Background: Hepatopulmonary syndrome (HPS), defined as hypoxemia and functional intrapulmonary right-to-left shunts in the presence of chronic liver disease, is a frequent complication of end-stage liver disease. The aim of this study was to determine the extent of pulmonary dysfunction and the prevalence of HPS in non-cirrhotic patients with chronic viral hepatitis. Methods: Lung function tests were carried out in 178 patients with chronic viral hepatitis (mean age 43.2 years, 95 smokers). To demonstrate intrapulmonary shunting, contrast echocardiography was performed in all patients with hypoxemia (paO(2)<70 mmHg) or a reduced diffusion capacity (DLCO<70% predicted). Results: The median results of lung function parameters (FVC, FEV(1), FEV(1)/FVC, TLC, DLCO, and blood gas analysis) were normal. Despite normal lung function, hypoxemia and/or DLCO reduction were observed in 17 of 178 patients (9.6%). A correlation with inflammatory activity, extent of fibrosis, or etiology was not found. Intrapulmonary shunting was observed in three of 17 patients. Two of these patients fulfilled the diagnostic criteria of HPS. Conclusions: Impaired gas exchange is a common finding even in non-cirrhotic patients with chronic viral hepatitis. HPS, however, was present in 1.1% of patients with chronic viral hepatitis and is thus not restricted to patients with liver cirrhosis, portal hypertension, or acute liver failure.

Chronic hepatitis C infection: influence of the viral load, genotypes, and GBV-C/HGV coinfection on the severity of the disease in a Brazilian population

The distributions of the different genotypes of the hepatitis C virus (HCV) and GBV-C virus (GBV-C/HGV) vary geographically and information worldwide is still incomplete. In particular, there are few data on the distribution of genotypes (and their relationship to the severity of liver disease) in South America. Findings are described in 114 consecutive patients from Northeast Brazil (median age 52 years, range 18-72 years) who had abnormal levels of serum aminotransferases and seropositivity for HCV RNA. The patients were recruited from an outpatient clinic between November 1997 and April 1998. Quantitative HCV RNA and GBV-C/HGV RNA estimations were carried out by double-nested polymerase chain reaction (PCR) using primers from the 5'-untranslated regions (UTRs) of the genomes. HCV genotypes were determined by restriction fragment length polymorphism (RFLP) analysis with 5'-UTR primers and by PCR with type-specific 5'-UTR primers. GBV-C/HGV-RNA genotypes were determined by RFLP with specific 5'-UTR primers and phylogenetic trees were constructed using the Neighbour-Joining and Drawtree programs. Histological features were graded and staged according to international criteria. Of the 114 patients, 35 (30.7%) patients had cirrhosis and 22 (27.8%) had mild, 51 (64.6%) had moderate, and 6 (7.6%) had severe chronic hepatitis. Median HCV viral load was 10(6) genome equivalents per millilitre (range 10(4)-10(9)/ml). Frequencies of genotypes were 5.3% type 1a, 44.7% type 1b, 3.5% type 2, 41.2% type 3, and 5.3% mixed types. GBV-C/HGV-RNA was detected in the sera of 12 (10.5%) patients and was distributed among three phylogenetic groups. There were no significant differences between patients with the predominant HCV genotypes (1b and 3) with respect to gender, age group, viral load, severity of liver disease, or coinfection with GBV-C/HGV.

Hypervariable region 1 quasispecies in hepatitis C virus genotypes 1b and 3 infected patients with normal and abnormal alanine aminotransferase levels

The role of hepatitis C virus (HCV) heterogeneity in the severity of chronic hepatitis C infection remains unclear. Our aim was to study the hypervariable region 1 (HVR1) heterogeneity in patients with chronic hepatitis C infected with genotype 1b or 3 and with normal or abnormal alanine aminotransferase (ALT). HVR1 quasispecies were assessed by single strand conformational polymorphism (SSCP) in 67 patients with chronic hepatitis C, including 35 with persistently normal ALT and 32 with abnormal ALT. Sixty-two patients underwent a liver biopsy. Among the 67 patients, 40 were infected with genotype 1b and 27 with genotype 3. In univariate analysis, low heterogeneity (<or= 3 bands at SSCP) was significantly associated with normal ALT (P < 0.001), milder histological lesions (activity, P=0.02; fibrosis, P=0.04), and at the limit of significance for genotype 1b (P=0.07). In multivariate analysis, low heterogeneity was significantly and independently associated with normal ALT (P=0.09) and genotype 1b (P=0.03). In patients with chronic hepatitis C, a low viral heterogeneity is significantly and independently associated with normal ALT and genotype 1b. These results are consistent with the view that patients with normal ALT have a different immune response against HCV resulting in a low HCV heterogeneity.

Tissue viral load variability in chronic hepatitis C

OBJECTIVE

Liver biopsy is regarded as the gold standard for assessing disease activity in chronic hepatitis C, but sampling error is a potential limitation. Whether sampling variability applies equally to viral load assessment as it does to histology is uncertain. To examine this, we compared viral load between right- and left-lobe biopsy specimens from patients infected with hepatitis C virus (HCV).

METHODS

Bilobe biopsies were taken from 16 patients who were serum positive for HCV RNA by reverse transcription-polymerase chain reaction. Genotype was identified by reverse line probe hybridization. There was an absence of competing risk factors for infectious and other liver diseases in this patient group. Histology and hepatic viral load were assessed blindly. None of the patients had received antiviral therapy at the time of study.

RESULTS

Detection of HCV in right and left lobes was concordant with serum positivity in all cases. The viral load between lobes was highly correlated (p = 0.0003, r = 0.79). In contrast, the histological activity indices of inflammation and fibrosis/cirrhosis were poorly correlated between lobes (p = 0.038, r = 0.60, and p = 0.098, r = 0.50, respectively).

CONCLUSION

Hepatic viral load variability does not suffer from the same degree of heterogeneity of sampling variability as does histology.

Genetic clustering of hepatitis C virus strains and severity of recurrent hepatitis after liver transplantation

The influence of viral factors on the severity of hepatitis C virus (HCV)-related liver disease is controversial. We studied 68 liver transplant patients with recurrent hepatitis C, of whom 53 were infected by genotype 1 strains. Relationships between core sequences, serum HCV RNA levels, and fibrosis scores for each patient were analyzed in pairwise fashion 5 years after transplantation. We used Mantel's test, a matrix correlation method, to evaluate the correspondence between measured genetic distances and observed phenotypic differences. No clear relationship was found when all 68 patients were analyzed. In contrast, when the 53 patients infected by genotype 1 strains were analyzed, a strong positive relationship was found between genetic distance and differences in 5-year fibrosis scores (P = 0.001) and differences in virus load (P = 0.009). In other words, the smaller the genetic distance between two patients' viral core sequences, the smaller the difference between the two patients' fibrosis scores and viral replication levels. No relationship was found between genetic distance and differences in age, sex, or immunosuppression. In multivariate analysis, the degree of fibrosis was negatively related to the virus load (r = -0.68; P = 0.003). In the particular setting of liver transplantation, and among strains with closely related phylogenetic backgrounds (genotype 1), this study points to a correlation between the HCV genetic sequence and the variability of disease expression.

The kinetics of hepatitis C virus infection

Mathematical modeling of viral dynamics reveals high turnover rates of pretreatment viral production and clearance (10(11)-10(13) virions/day) and permits the estimation of in-vivo half-lives of a few hours for HCV free virions. The balance between virus production and clearance in untreated patients with chronic hepatitis C virus results in a decline of viremia when active antiviral treatment is initiated. During the first phase of IFN-alpha therapy, the kinetics of the viral load is characterized by a rapid, dose-dependent decline. After about 24 to 48 hours, the viral decline enters a second phase of a relatively slow exponential decay during the following weeks of therapy which may reflect the death rate of infected hepatocytes. The second-phase decay is predictive for the virologic end-of-treatment status and, even more so, for the likelihood of sustained response. Nonresponding patients typically show constant viremia or even a rebound during this second phase.

Influence of the genetic heterogeneity of the ISDR and PePHD regions of hepatitis C virus on the response to interferon therapy in chronic hepatitis C

Two genomic regions of hepatitis C virus (HCV), the interferon sensitivity-determining region (ISDR) of the non-structural 5A gene (NS5A) and the protein kinase-RNA activated (PKR)-eukariotic transcription factor (eIF2-alpha) phosphorylation homology domain (PePHD) of the structural E2 gene, interact in vitro with the interferon-inducible cellular PKR protein kinase. Mutations within these regions might, therefore, influence the response to interferon therapy. Viral load at baseline and sequence heterogeneity of HCV in NS5A and E2 regions was studied in 74 HCV-1b and in 12 HCV-3a infected patients with chronic hepatitis C who were treated with interferon. As previously reported by us, in a smaller series of patients in which the ISDR region was analyzed [Saiz et al. (1998) Journal Infectious Diseases 177:839-847], in the present study a low viral load and a high number of amino acid mutations within the ISDR, but not within the PePHD region, were significantly associated with long-term response to interferon among HCV-1b infected patients. No relationship between these viral features and response to therapy was disclosed in patients infected with HCV-3a.

Serum HCV RNA levels correlate with histological liver damage and concur with steatosis in progression of chronic hepatitis C

The role of HCV RNA levels and host factors in the severity of liver injury was studied. Enrolled were 298 consecutive liver biopsy-proven chronic hepatitis (CH) C patients (179 men; median age: 52 years, range 19-68; CH, 198; cirrhosis, 100) and 18 chronic hepatitis C with normal ALT. HCV genotypes were: 1a, 4.3%; 1b, 53%; 2a/c, 28%; 3a, 7%; 4, 1.3%, and mixed 6.4%. Serum HCV RNA levels were similar for all genotypes (median: 2.8 x 10(6) eq/ml; range <0.2-69). In patients with chronic hepatitis without cirrhosis, the serum HCV RNA levels reflected the grade of liver necroinflammatory activity (R = 0.45; P < 0.001) and the stage of fibrosis (R = 0.51; P < 0.001), regardless of age, gender, HCV genotype, hepatic steatosis, and hepatic iron overload. Patients with high serum HCV RNA levels (> or =3 x 10(6) eq/ml) had higher ALT values (P < 0.002) than those with lower HCV RNA levels. Patients with normal ALT showed low HCV RNA levels (median: 0.82 x 10(6) eq/ml) and histological features of minimal or mild chronic hepatitis. Cirrhotic patients showed significantly lower levels of viremia than those with chronic hepatitis with a similar HAI. The data of a subgroup of 62 patients with an established time of infection showed that for a similar duration of disease, patients with serum HCV RNA levels > or =3 x 10(6) eq/ml had a significantly higher fibrosis score than those with lower levels. HAI and fibrosis score were significantly higher in patients with HCV RNA levels > or =3 x 10(6) eq/ml and grade 3-4 steatosis than those with lower HCV RNA levels and steatosis grades. The data indicate that the liver damage is correlated with the HCV RNA levels and that a high viral load acts together with steatosis in accelerating the progression of liver injury.

Hepatitis C virus infection: 10 years after the discovery of the virus

The hepatitis C virus (HCV) causes an acute but very often chronic liver disease. An estimated 3% of the world population is chronically infected with HCV. Chronic hepatitis C is the major cause of cirrhosis and hepatocellular carcinoma (HCC), which most often lead to liver transplantation. HCV is a single-stranded enveloped RNA virus; it belongs to the flaviviridae family. The virus has been classified into six genotypes, some of which are distributed worldwide, others of which are confined to more restricted areas. The genotype is an independent predictor of response to antiviral treatment. Blood transfusion was a major risk factor for acquiring HCV infection before donor screening for surrogate marker testing for non-A, non-B (NANB) hepatitis began in the mid-1980s, followed by screening for antibody to HCV in 1990. Today, intravenous drug use and high-risk sexual activity are the most frequently identified risk factors associated with HCV infection. The prevalence of people with unknown HCV infection worldwide is high, so it is necessary to screen people with risk factors. The treatment of patients with chronic HCV infection who have not been treated previously should consist of interferon alpha (IFN-alpha) and ribavirin.