Treatment decisions and contemporary versus pending treatments for hepatitis C

A bioinformatics investigation into the pharmacological mechanisms of the effect of the Yinchenhao decoction on hepatitis C based on network pharmacology

Background

Globally, more than 170 million people are infected with hepatitis C virus, a major cause of cirrhosis and hepatocellular carcinoma. The Yinchenhao Decoction (YCHD) is a classic formula comprising three herbal medicines. This decoction have long been used in China for clinically treating acute and chronic infectious hepatitis and other liver and gallbladder damp heat-accumulation disorders.

Methods

In this study, we identified 32 active ingredients and 200 hepatitis C proteins and established a compound-predicted target network and a hepatitis C protein–protein interaction network by using Cytoscape 3.6.1. Then, we systematically analyzed the potential targets of the YCHD for the treatment of hepatitis C. Finally, molecular docking was applied to verify the key targets. In addition, we analyzed the mechanism of action of the predicted targets by the Kyoto Encyclopedia of Genes and Genomes and gene ontology analyses.

Results

This study adopted a network pharmacology approach, mainly comprising target prediction, network construction, module detection, functional enrichment analysis, and molecular docking to systematically investigate the mechanisms of action of the YCHD in hepatitis C. The targets of the YCHD in the treatment of hepatitis C mainly involved PIK3CG, CASP3, BCL2, CASP8, and MMP1. The module and pathway enrichment analyses showed that the YCHD had the potential to influence varieties of biological pathways, including the TNF signaling pathway, Ras signaling pathway, PI3K-Akt signaling pathway, FoxO signaling pathway, and pathways in cancer, that play an important role in the pathogenesis of hepatitis C.

Conclusion

The results of this study preliminarily verified the basic pharmacological effects and related mechanisms of the YCHD in the treatment of hepatitis C.

Alphavirus-based hepatitis C virus therapeutic vaccines: can universal helper epitopes enhance HCV-specific cytotoxic T lymphocyte responses?

Background:

Antigen-specific T cell immune responses play a pivotal role in resolving acute and chronic hepatitis C virus (HCV) infections. Currently, no prophylactic or therapeutic vaccines against HCV are available. We previously demonstrated the preclinical potency of therapeutic HCV vaccines based on recombinant Semliki Forest virus (SFV) replicon particles. However, clinical trials do not always meet the high expectations of preclinical studies, thus, optimization of vaccine strategies is crucial. In efforts to further increase the frequency of HCV-specific immune responses in the candidate SFV-based vaccines, the authors assessed whether inclusion of three strong, so-called universal helper T cell epitopes, and an endoplasmic reticulum localization, and retention signal (collectively termed sigHELP-KDEL cassette) could enhance HCV-specific immune responses.

Methods:

We included the sigHELP-KDEL cassette in two of the candidate SFV-based HCV vaccines, targeting NS3/4A and NS5A/B proteins. We characterized the new constructs in vitro for the expression and stability of the transgene-encoded proteins. Their immune efficacy with respect to HCV-specific immune responses in vivo was compared with the parental SFV vaccine expressing the corresponding HCV antigen. Further characterization of the functionality of the HCV-specific CD8⁺ T cells was assessed by surface and intracellular cytokine staining and flow cytometry analysis.

Results:

Moderate, but significantly, enhanced frequencies of antigen-specific immune responses were achieved upon lower/suboptimal dosage immunization. In optimal dosage immunization, the inclusion of the cassette did not further increase the frequencies of HCV-specific CD8⁺ T cells when compared with the parental vaccines and the frequencies of effector and memory populations were identical.

Conclusion:

We hypothesize that the additional effect of the sigHELP-KDEL cassette in SFV-based vaccines depends on the immunogenicity, nature, and stability of the target antigen expressed by the vaccine.

Cost-effectiveness of novel regimens for Chinese patients with chronic hepatitis C

OBJECTIVE

Direct-acting antiviral agents (DAAs) have been approved for treating hepatitis C virus (HCV) infection in China. However, they are substantially more expensive. The current analysis will investigate the cost-effectiveness of novel regimens compared with pegylated interferon and ribavirin (PR) therapies for informing Chinese decision-makers.

METHODS

A Markov model was developed to measure economic and health outcomes of novel regimens for genotype 1b, 2, 3, and 6 HCV infections compared with PR treatment. Clinical, cost, and utility inputs were gathered from published sources. Discounted quality-adjusted life-years (QALYs), costs, and incremental cost-effectiveness ratios (ICERs) are shown. The uncertainty was facilitated by one-way and probabilistic sensitivity analyses.

RESULTS

For genotype 1b HCV infection, the combination of paritaprevir, ritonavir, ombitasvir and dasabuvir was cost-saving compared with four competing alternatives. The ICERs of sofosbuvir plus ribavirin for genotypes 2 and 3 were lower than the threshold ($18,234/QALY). Among available strategies for patients with genotype 6, sofosbuvir in combination with ribavirin was the cost-saving alternative compared with PR. The results were robust to sensitivity analyses.

CONCLUSIONS

For both genotype 1b and 6 HCV infections in the context of Chinese patients, there were combinations of DAAs that were cost-saving compared with the usual PR treatment, and cost-effective for genotypes 2 and 3.

Cost Effectiveness of Daclatasvir Plus Asunaprevir Therapy for Chinese Patients with Chronic Hepatitis C Virus Genotype 1b

BACKGROUND AND OBJECTIVES

Daclatasvir plus asunaprevir has shown superior efficacy and safety for treating hepatitis C virus genotype 1b infection in comparison with pegylated interferon and ribavirin. The objective of this analysis is to investigate the cost effectiveness of daclatasvir plus asunaprevir compared with interferon-α-based therapies from the perspective of the Chinese healthcare system.

METHODS

A Markov model was established to measure economic and health outcomes of daclatasvir plus asunaprevir compared with general interferon-α plus ribavirin and pegylated interferon plus ribavirin for hepatitis C virus genotype 1b infection. We also considered the two following scenarios: 24 weeks of daclatasvir plus asunaprevir used as a second-line treatment for ineligible/intolerant and non-responding patients with HCV during 48 weeks of first-line interferon-α plus ribavirin (interferon-α plus ribavirin and daclatasvir plus asunaprevir) or pegylated interferon plus ribavirin (pegylated interferon plus ribavirin and daclatasvir plus asunaprevir) treatment. Clinical costs and utility inputs were derived from the published literature. The incremental cost-effectiveness ratio was shown as costs in US dollars per quality-adjusted life-years gained. Uncertainty was examined by one-way and probabilistic sensitivity analyses.

RESULTS

Compared with interferon-α plus ribavirin, pegylated interferon and ribavirin, interferon-α plus ribavirin plus daclatasvir plus asunaprevir, and pegylated interferon plus ribavirin plus daclatasvir plus asunaprevir strategies, daclatasvir plus asunaprevir gained an additional 0.62, 0.32, 0.20, and 0.15 quality-adjusted life-year with increasing costs of US$11,950, US$671, US$8366, and -$3783, respectively. The incremental cost-effectiveness ratios of pegylated interferon and ribavirin, daclatasvir plus asunaprevir, interferon-α plus ribavirin and daclatasvir plus asunaprevir, and pegylated interferon plus ribavirin and daclatasvir plus asunaprevir against the baseline interferon-α plus ribavirin strategy were US$37,930, US$19,233, US$8495, and US$33,031 per quality-adjusted life-year gained. Daclatasvir plus asunaprevir and interferon-α plus ribavirin plus daclatasvir plus asunaprevir were presented as the cost-effective alternatives, and pegylated interferon plus ribavirin and pegylated interferon plus ribavirin and daclatasvir plus asunaprevir strategies dominated. The model outputs were sensitive to a patient's age, discount rate, and the risk ratio between pegylated interferon plus ribavirin and interferon-α plus ribavirin.

CONCLUSIONS

Daclatasvir plus asunaprevir in the Chinese setting is likely to be cost effective for treating hepatitis C virus genotype 1b infection.

Discovery of Novel Nucleotide Prodrugs with Improved Potency Against HCV Variants Carrying NS5B S282T Mutation

Resistant HCV variants carrying NS5B S282T mutation confer reduced sensitivity to sofosbuvir, the sole marketed NS5B polymerase inhibitor. On the basis of the finding that 2'-α-F-2'-β-C-methylcytidine 5'-triphosphate (8) was more potent than sofosbuvir's active metabolite on inhibition of both wild-type and S282T mutant polymerase, a dual-prodrug approach has been established. Twenty-nine phosphoramidates with N⁴-modified cytosine were designed, synthesized, and evaluated for anti-HCV activity. The results showed that compounds 4c-4e and 4m (EC₅₀ = 0.19-0.25 μM) exhibited comparable potency to that of sofosbuvir (EC₅₀ = 0.15 μM) on inhibition of wild-type replicons. Notably, 4c (EC₅₀ = 0.366 μM) was 1.5-fold more potent than sofosbuvir (EC₅₀ = 0.589 μM) on inhibition of S282T mutant replicons. In vitro metabolic studies disclosed the possible metabolic pathways of 4c. The toxicity study results indicated a good safety profile of 4c. Together, 4c-4e and 4m hold promise for drug development for the treatment of HCV infection, especially the resistant variants with NS5B S282T mutation.

Network meta-analysis of first- and second-generation protease inhibitors for chronic hepatitis C genotype 1: efficacy based on RVR and SVR 24

PURPOSE

This study aimed to compare the efficacy among direct-acting antiviral agents (first and second-generation direct-acting antiviral agents (DAAs)) with placebo and with standard dual therapy (pegylated interferon + ribavirin (Peg-IFN + RBV)) in terms of rapid virologic response (RVR) and sustained virologic response (SVR) in chronic hepatitis C genotype 1 treatment.

METHODS

We performed a systematic review of randomized controlled trials (RCTs) in MEDLINE, International Pharmaceutical Abstracts, Cochrane Library, SCIELO, and Scopus and conducted a network meta-analysis to compare the efficacy of boceprevir (BOC), daclatasvir (DCV), grazoprevir, simeprevir (SMV) and telaprevir (TVR), in treatment-naive and treatment-experienced patients.

RESULTS

Sixteen studies encompassing 7171 patients were analysed. Associations between DAAs therapies (IFN-free regimens) could not be addressed since no common comparator was found in the RCTs among these associations and the other agents included in the present analysis. All agents were more efficacious than placebo or Peg-IFN + RBV in terms of RVR, while only BOC and SMV showed statistically significant superiority for the SVR outcome when compared to placebo or standard dual therapy. No significant differences between the DAAs were observed. The analysis prioritized treatment with DCV for both efficacy outcomes. Node-splitting analysis showed that our networks are robust (p > 0.05).

CONCLUSIONS

The superiority of DAAs over placebo or standard dual therapy with Peg-IFN + RBV was confirmed, indicating the greater efficacy of DCV. This study is the first network meta-analysis that included RVR as an outcome in the evaluation of these agents via indirect comparison. Further investigation should be carried out addressing safety and tolerability outcomes.

Chronic hepatitis C: This and the new era of treatment

Over the last years it has started a real revolution in the treatment of chronic hepatitis C. This occurred for the availability of direct-acting antiviral agents that allow to reach sustained virologic response in approximately 90% of cases. In the near future further progress will be achieved with the use of pan-genotypic drugs with high efficacy but without side effects.

Polymorphisms near the IFNL3 Gene Associated with HCV RNA Spontaneous Clearance and Hepatocellular Carcinoma Risk

The aims of this study were to investigate associations between single nucleotide polymorphisms (SNPs) near the genes IFNL2, IFNL3, and IFNL4 and spontaneous clearance of hepatitis C virus (HCV) and to evaluate variants for their risk of hepatocellular carcinoma (HCC) among subjects in whom spontaneous HCV RNA clearance did not occur. In the first study, 889 untreated anti-HCV-seropositive patients without HCC symptoms were followed from 1991 to 2005. The spontaneous HCV clearance rate was found to be 33.1%. The TT variant of rs8099917 near IFNL3 was associated with increased spontaneous HCV RNA clearance, with an adjusted odds ratio (95% CI) of 2.78 (1.43-5.39), as was the newly-identified TT/TT dinucleotide variant rs368234815 near IFNL4 (adjusted odds ratio 2.68, 95% CI: 1.42-5.05). In the second study, associations between SNPs and HCC risk were examined in 483 HCC cases with detectable HCV RNA and 516 controls. In participants with HCV genotype 1, unfavorable genotypes for HCV clearance near IFNL3 were associated with increased HCC risk, the adjusted odds ratio (95% CI) for rs12979860 and rs8099917 being 1.73 (1.00-2.99) and 1.84 (1.02-3.33), respectively. Host characteristics should be considered to identify high-risk patients to prioritize the use of new antiviral agents and intensive screening.

Toward a more complete understanding of the association between a hepatitis C sustained viral response and cause-specific outcomes

Sustained viral response (SVR) is the optimal outcome of hepatitis C virus (HCV) therapy, yet more detailed data are required to confirm its clinical value. Individuals receiving treatment in 1996-2011 were identified using the Scottish HCV clinical database. We sourced data on 10 clinical events: liver, nonliver, and all-cause mortality; first hospitalisation for severe liver morbidity (SLM); cardiovascular disease (CVD); respiratory disorders; neoplasms; alcohol-intoxication; drug intoxication; and violence-related injury (note: the latter three events were selected a priori to gauge ongoing chaotic lifestyle behaviours). We determined the association between SVR attainment and each outcome event, in terms of the relative hazard reduction and absolute risk reduction (ARR). We tested for an interaction between SVR and liver disease severity (mild vs. nonmild), defining mild disease as an aspartate aminotransferase-to-platelet ratio index (APRI) <0.7. Our cohort comprised 3,385 patients (mean age: 41.6 years), followed-up for a median 5.3 years (interquartile range: 3.3-8.2). SVR was associated with a reduced risk of liver mortality (adjusted hazard ratio [AHR]: 0.24; P < 0.001), nonliver mortality (AHR, 0.68; P = 0.026), all-cause mortality (AHR, 0.49; P < 0.001), SLM (AHR, 0.21; P < 0.001), CVD (AHR, 0.70; P = 0.001), alcohol intoxication (AHR, 0.52; P = 0.003), and violence-related injury (AHR, 0.51; P = 0.002). After 7.5 years, SVR was associated with significant ARRs for liver mortality, all-cause mortality, SLM, and CVD (each 3.0%-4.7%). However, we detected a strong interaction, in that ARRs were considerably higher for individuals with nonmild disease than for individuals with mild disease.

CONCLUSIONS

The conclusions are 3-fold: (1) Overall, SVR is associated with reduced hazard for a range of hepatic and nonhepatic events; (2) an association between SVR and behavioral events is consistent with SVR patients leading healthier lives; and (3) the short-term value of SVR is greatest for those with nonmild disease.

Impaired interferon signaling in chronic hepatitis C patients with advanced fibrosis via the transforming growth factor beta signaling pathway

Malnutrition in the advanced fibrosis stage of chronic hepatitis C (CH-C) impairs interferon (IFN) signaling by inhibiting mammalian target of rapamycin complex 1 (mTORC1) signaling. However, the effect of profibrotic signaling on IFN signaling is not known. Here, the effect of transforming growth factor (TGF)-β signaling on IFN signaling and hepatitis C virus (HCV) replication was examined in Huh-7.5 cells by evaluating the expression of forkhead box O3A (Foxo3a), suppressor of cytokine signaling 3 (Socs3), c-Jun, activating transcription factor 2, ras homolog enriched in brain, and mTORC1. The findings were confirmed in liver tissue samples obtained from 91 patients who received pegylated-IFN and ribavirin combination therapy. TGF-β signaling was significantly up-regulated in the advanced fibrosis stage of CH-C. A significant positive correlation was observed between the expression of TGF-β2 and mothers against decapentaplegic homolog 2 (Smad2), Smad2 and Foxo3a, and Foxo3a and Socs3 in the liver of CH-C patients. In Huh-7.5 cells, TGF-β1 activated the Foxo3a promoter through an AP1 binding site; the transcription factor c-Jun was involved in this activation. Foxo3a activated the Socs3 promoter and increased HCV replication. TGF-β1 also inhibited mTORC1 and IFN signaling. Interestingly, c-Jun and TGF-β signaling was up-regulated in treatment-resistant IL28B minor genotype patients (TG/GG at rs8099917), especially in the early fibrosis stage. Branched chain amino acids or a TGF-β receptor inhibitor canceled these effects and showed an additive effect on the anti-HCV activity of direct-acting antiviral drugs (DAAs).

CONCLUSION

Blocking TGF-β signaling could potentiate the antiviral efficacy of IFN- and/ or DAA-based treatment regimens and would be useful for the treatment of difficult-to-cure CH-C patients.

The dynamic relationship between innate immune biomarkers and interferon-based treatment effects and outcome in hepatitis C virus infection is altered by telaprevir

Soluble CD14 (sCD14) and IL-18 are markers and mediators of the innate immune response, and their plasma levels candidate biomarkers of HCV treatment effects and outcome. Here, we retrospectively studied sCD14 and IL-18 over the course of interferon-based treatment of HCV genotype 1 infection, with the aim to investigate the impact of direct-acting antivirals (DAAs) on the dynamics and relationships between these biomarkers and treatment effects and outcome. Two cohorts were followed longitudinally; one treated with standard dual therapy of pegylated IFNα and ribavirin, and one cohort receiving triple therapy including Telaprevir. sCD14 and IL-18 were measured before and during treatment and analyzed in relation to treatment effects. The initial analysis confirmed two patterns previously observed in patients with HCV/HIV-1 co-infection: Baseline levels of sCD14 were significantly lower in patients that went on to clear HCV infection in response to IFNα and ribavirin, and sCD14 levels were strongly induced during the course of this treatment. Interestingly, baseline levels of sCD14 and IL-18 in combination predicted treatment outcome in dual therapy better than either marker alone. Notably, these associations were weaker with the addition of Telaprevir to the treatment regimen, suggesting that the relationships between innate immune activation and outcome were altered and diminished by inclusion of a DAA in the treatment. In triple therapy, the dynamic increase of sCD14 in response to treatment was higher in patients clearing the virus, suggesting that the innate response to interferon is still significantly associated with outcome in patients treated with DAA-containing regimens. These results support the notion that levels of innate immune activation before and during treatment are associated with interferon-based treatment outcome. Furthermore, the addition of Telaprevir significantly alters the dynamics and relationships between innate immune biomarkers and treatment effects and outcome.

Patient-important benefits of clearing the hepatitis C virus through treatment: a simulation model

BACKGROUND & AIMS

Given an appreciable risk of adverse-effects, current therapies for chronic hepatitis C virus (HCV) infection pose a dilemma to patients. We explored, via simulation modelling, patient-important benefits of attaining a sustained viral response (SVR).

METHODS

We created the HCV Individualised Treatment-decision model (the HIT-model) to simulate, on a per patient basis, the lifetime course of HCV-related liver disease according to two distinct scenarios: (i) SVR attained, and (ii) SVR not attained. Then, for each model subject, the course of liver disease under these alternative scenarios was compared. The benefit of SVR was considered in terms of two patient-important outcomes: (1) the percent-probability that SVR confers additional life-years, and (2) the percent-probability that SVR confers additional healthy life-years, where "healthy" refers to years spent in compensated disease states (i.e., the avoidance of liver failure).

RESULTS

The benefit of SVR varied strikingly. It was lowest for patients aged 60 years with initially mild fibrosis; 1.6% (95% CI: 0.8-2.7) and 2.9% (95% CI: 1.5-4.7) probability of gaining life-years and healthy life-years, respectively. Whereas it was highest for patients with initially compensated cirrhosis aged 30 years; 57.9% (95% CI: 46.0-69.0) and 67.1% (95% CI: 54.1-78.2) probability of gaining life-years and healthy life-years, respectively.

CONCLUSIONS

For older patients with less advanced liver fibrosis, SVR is less likely to confer benefit when measured in terms of averting liver failure and premature death. These data have important implications. Foremost, it may inform the contemporary patient dilemma of immediate treatment with existing therapies (that have poor adverse effect profiles) vs. awaiting future regimens that promise better tolerability.

Hepatitis C virus cell-cell transmission and resistance to direct-acting antiviral agents

Hepatitis C virus (HCV) is transmitted between hepatocytes via classical cell entry but also uses direct cell-cell transfer to infect neighboring hepatocytes. Viral cell-cell transmission has been shown to play an important role in viral persistence allowing evasion from neutralizing antibodies. In contrast, the role of HCV cell-cell transmission for antiviral resistance is unknown. Aiming to address this question we investigated the phenotype of HCV strains exhibiting resistance to direct-acting antivirals (DAAs) in state-of-the-art model systems for cell-cell transmission and spread. Using HCV genotype 2 as a model virus, we show that cell-cell transmission is the main route of viral spread of DAA-resistant HCV. Cell-cell transmission of DAA-resistant viruses results in viral persistence and thus hampers viral eradication. We also show that blocking cell-cell transmission using host-targeting entry inhibitors (HTEIs) was highly effective in inhibiting viral dissemination of resistant genotype 2 viruses. Combining HTEIs with DAAs prevented antiviral resistance and led to rapid elimination of the virus in cell culture model. In conclusion, our work provides evidence that cell-cell transmission plays an important role in dissemination and maintenance of resistant variants in cell culture models. Blocking virus cell-cell transmission prevents emergence of drug resistance in persistent viral infection including resistance to HCV DAAs.

In spite of the rapid development of antiviral agents, antiviral resistance remains a challenge for the treatment of viral infections including hepatitis B and C virus (HBV, HCV), human immunodeficiency virus (HIV) and influenza. Virus spreads from infected cells to surrounding uninfected host cells to develop infection through cell-free and cell-cell transmission routes. Understanding the spread of resistant virus is important for the development of novel antiviral strategies to prevent and treat antiviral resistance. Here, we characterize the spread of resistant viruses and its impact for emergence and prevention of resistance using HCV as a model system. Our results show that cell-cell transmission is the main transmission route for antiviral resistant HCV strains and is crucial for the maintenance of infection. Monoclonal antibodies or small molecules targeting HCV entry factors are effective in inhibiting the spread of resistant HCV in cell culture models and thus should be evaluated clinically for prevention and treatment of HCV resistance. Combination of inhibitors targeting viral entry and clinically used direct-acting antivirals (DAAs) prevents antiviral resistance and leads to viral eradication in cell culture models. Collectively, the investigation provides a new strategy for prevention of viral resistance to antiviral agents.

Anti-CD20 monoclonal antibodies and associated viral hepatitis in hematological diseases

Over the past decade, the administration of anti-CD20 monoclonal antibodies such as rituximab has demonstrated various degrees of effectiveness and has improved patients’ outcomes during the treatment of autoimmune hematological disorders and hematological malignancies. However, the depletion of B-cells, the distribution of T-cell populations, and the reconstruction of host immunity resulting from the use of anti-CD20 monoclonal antibodies potentially lead to severe viral infections, such as hepatitis B virus (HBV), hepatitis C virus (HCV), parvovirus B19, and herpes viruses, in patients who are undergoing immune therapy or immunochemotherapy. Of these infections, HBV- and HCV-related hepatitis are a great concern in endemic areas because of the high morbidity and mortality rates in untreated patients. As a result, prophylaxis against HBV infection is becoming a standard of care in these areas. Parvovirus B19, a widespread pathogen that causes red blood cell aplasia in immunocompromised hosts, also causes hepatitis in healthy individuals. Recently, its association with hepatitis was recognized in a patient treated with rituximab. In addition, adenovirus, varicella-zoster virus, hepatitis E virus, and rituximab itself have been linked to the occurrence of hepatitis during or after rituximab treatments. The epidemiologies and pathogeneses of these etiologies remain unknown. Because of the increasing use of anti-CD20 monoclonal antibodies for the treatment of hematological malignancies or autoimmune hematological disorders, it is imperative that physicians understand and balance the risks of hepatotropic virus-associated hepatitis against the benefits of using anti-CD20 monoclonal antibodies.

Interferon alpha induced intrahepatic pSTAT1 inversely correlate with serum HCV RNA levels in chronic HCV infection

BACKGROUND

The Jak-STAT signaling of hepatitis C virus (HCV) infected hepatocyte is critical for the antiviral action of endogenously produced interferon (IFN) as well as exogenously administered interferon alpha (IFN-α). The activation of cellular Jak-STAT signaling by IFN-α results in the phosphorylation and nuclear translocation of pSTAT1 and pSTAT2 proteins to induce antiviral gene transcription. Clinical studies show that chronic HCV patients with high viral load show poor response to interferon alpha and ribavirin combination therapy.

AIM

We seek to determine whether the IFN-α induced activation of pSTAT1 and pSTAT2 in hepatocytes isolated from liver biopsy of patients chronically infected with hepatitis C virus could be related to the viral load.

METHOD

Hepatocytes were isolated from liver biopsies of 18 chronic HCV patients using the collagen digestion method. Induction of pSTAT1 protein in the isolated hepatocyte was measured after IFN-α treatment. The fold change in the levels of pStat1 in the cell lysates due to IFN-treatment was measured by Western blot analysis followed by densitometry analysis.

RESULTS

Results of our study indicate that IFN-α induced pSTAT1 levels vary in chronically infected hepatocytes from chronic HCV patients. Semi-quantitative analysis of the pSTAT1 bands revealed a median induction of 7.4-fold in non-infected primary hepatocytes and 2.3-fold in chronic hepatitis C patients (p < 0.001). Total STAT1 levels were not significantly different between treated and untreated primary hepatocytes. We also found a significantly inverse correlation between the intrahepatic pSTAT1 inductions with the serum HCV RNA levels.

CONCLUSION

We have developed an antibody based Western blot detection method to measure intrahepatic pStat1 and pStat2 levels to assess the cellular response to exogenous IFN-alpha. Our results indicate that pStat1 activation is a good indicator to assess the level of HCV replication in chronic HCV patients.