Genotype and viral load as prognostic indicators in the treatment of hepatitis C

Hepatitis C virus (HCV) genotype 1b displays higher genetic variability of hypervariable region 1 (HVR1) than genotype 3

Hepatitis C virus (HCV) is characterized by high genetic variability, which is manifested both at the inter-host and intra-host levels. However, its role in the clinical course of infection is less obvious. The aim of the present study was to determine the genetic variability of HCV HVR1 (hypervariable region 1) of genotype 1b and 3 in plasma of blood donors in the early seronegative stage of infection (HCV-RNA+, anti-HCV−) and in samples from chronically infected patients using next-generation sequencing. Sequencing errors were corrected, and haplotypes inferred using the ShoRAH software. Genetic diversity parameters (intra-host number of variants, number of nucleotide substitutions and diversity per site) were assessed by DNA SP and MEGA. During the early infection, the number of variants were significantly lower in subjects infected with genotype 3 than with genotype 1b (p < 0.02). Similarly, intra-host number of variants, number of nucleotide substitutions and diversity per site were lower in genotype 3 chronic infection (p < 0.0005). In addition, early infection was characterized by significantly lower HVR1 variability values (p < 0.04) when compared to chronic infection for both genotypes. It seems that the observed differences in HVR1 variability represent an inherent property of particular viral genotypes.

Recent trends in molecular epidemiology of Hepatitis C virus in Mardan, KPK Pakistan

To determine the genotypic distribution of HCV, frequency of risk factors involved in its transmission, and correlation of genotype with viral load in Mardan population which is the second largest city of Khyber Pakhtunkhwa (KPK), Pakistan. Blood samples of 1140 were collected from different regions of Mardan and major proportion of recruited patients were internally displaced people (IDPs), refugees, and slum dwellers. Complete patient's history was analyzed to assess the possible risks involved in HCV transmission. Viral genotype was determined by PCR (polymerase chain reaction) whereas, HCV RNA was measured by qRT-PCR. Data was analyzed using SPSS statistical software. Our results indicate 3a as the most abundant subtype in Mardan population followed by 3b, 2a, 2b, 4a, untypeable, mixed, 1a, and 1b. In contrast to previous findings, genotype 1 was the least prevalent genotype and the overall prevalence of HCV in Mardan population was significantly higher in females (n = 687, 60.2%) than males (n = 453, 39.7%). Significant difference between-genotypes and gender was observed in genotype 1 (p < .034) and genotype 3 (p < .004). The mean age was 44 (SD ± 9.51). The most frequently found mixed genotype was 3a + 1b and mixed genotype was more prevalent in males. The proportion of middle-aged people (41-49 years) was higher whereas, older and younger people were least infected with HCV. This is the first study that showed substantial correlation of genotype 3 with low and intermediate viral load in Mardan population. Moreover, high and extremely high viral load was associated with other genotypes. Our findings showed that most of the patients who experienced high and extremely high viremia in their blood were males and belonged to Takhat Bhai and Mardaan regions. There were significant difference in the prevalence of HCV genotype 3a (p = .001) and genotype 3b (p = .005) in different regions of Mardan. Pre-treatment viral load is significantly high (p 0.001) in tehsil Mardan patients infected with HCV genotype 3 as compared to other genotypes. Unsafe medical practices such as medical and dental surgeries, intravenous drug use, and blood transfusions were the main risk factors for HCV transmission in Mardan, KPK Pakistan. This study gives clear insights into the epidemiological status of HCV in Mardan population. Genotype 3 is correlated with low and intermediate viral load whereas high viral loads were revealed among patients infected with genotypes other than genotype 3. In the absence of better data and robust epidemiological information, this detailed analysis of HCV genotypes with special reference to risk factors, pretreatment viral load, gender, and age will provide the baseline data for development of optimal HCV eradication and preventive strategies.

Clinical Features and Outcomes of Patients With Genotype 3 Hepatitis C Virus Infection in Korea: A Retrospective Observational Study

Hepatitis C virus (HCV) genotype 3 infection is very rare in high-income Asia Pacific. The aim of our retrospective observational study was to evaluate the incidence, clinical features, and treatment outcomes of patients with a genotype 3 HCV infection in the Gyeongnam Province of Korea. Ninety-eight consecutive patients diagnosed with a genotype 3 HCV infection at Gyeongsang National University Hospital, between January 2005 and December 2014, were enrolled into the study. Relevant characteristics of the study group included: 80.6% men, mean age of 41.8 years, and including 69 patients with chronic hepatitis, 25 with liver cirrhosis, and 4 with hepatocellular carcinoma (HCC). Risk factors for HCV infection, sustained virologic response rate, development of HCC, and mortality in patients with genotype 3 were retrospectively analyzed.Among all patients diagnosed with a HCV infection during the study period, the prevalence of genotype 3 was 7.3%. The incidence of genotype 3 was higher in young patients with a risk factor of IVDU (54.0%) and tattooing (62.3%). Among 45 treatment-naive genotype 3 patients, sustained virologic response was achieved with a combination of pegylated-interferon alpha and ribavirin in 75.6%. The cumulative 5-year incidence of HCC was 13.6%, and 8.9% for overall mortality. Liver cirrhosis at enrollment was an independent risk factor for HCC development.This is the first study to elucidate the clinical features and outcomes among the patients with HCV genotype 3 infection in Korea. Further prospective studies are needed to investigate transmission routes and outcomes for HCV genotype 3 infections.

Clinical Applications of Quantitative Real-Time PCR in Virology

Since the invention of the polymerase chain reaction (PCR) and discovery of Taq polymerase, PCR has become a staple in both research and clinical molecular laboratories. As clinical and diagnostic needs have evolved over the last few decades, demanding greater levels of sensitivity and accuracy, so too has PCR performance. Through optimisation, the present-day uses of real-time PCR and quantitative real-time PCR are enumerable. The technique, combined with adoption of automated processes and reduced sample volume requirements, makes it an ideal method in a broad range of clinical applications, especially in virology. Complementing serologic testing by detecting infections within the pre-seroconversion window period and infections with immunovariant viruses, real-time PCR provides a highly valuable tool for screening, diagnosing, or monitoring diseases, as well as evaluating medical and therapeutic decision points that allows for more timely predictions of therapeutic failures than traditional methods and, lastly, assessing cure rates following targeted therapies. All of these serve vital roles in the continuum of care to enhance patient management. Beyond this, quantitative real-time PCR facilitates advancements in the quality of diagnostics by driving consensus management guidelines following standardisation to improve patient outcomes, pushing for disease eradication with assays offering progressively lower limits of detection, and rapidly meeting medical needs in cases of emerging epidemic crises involving new pathogens that may result in significant health threats.

Estrogen receptor alpha expression and liver fibrosis in chronic hepatitis C virus genotype 1b: a clinicopathological study

BACKGROUND

Hepatic damage due to chronic hepatitis C virus (HCV) genotype 1b infection varies widely.

OBJECTIVES

We aimed to investigate whether estrogen receptor alpha (ERα) plays a role in liver fibrosis in patients infected with HCV genotype 1b.

PATIENTS AND METHODS

All the consecutive patients who received the same standard treatment protocol for HCV genotype 1b were subdivided into two subgroups according to their fibrosis scores as fibrotic stages < 2 in mild fibrosis group and fibrotic stages ≥ 2 in advanced fibrosis group, depending on the presence of septal fibrosis. ERα was stained in liver biopsy specimens. Demographics and clinical properties were compared between the groups. Multivariate logistic regression analysis was performed to predict advanced fibrosis.

RESULTS

There were 66 patients in the mild fibrosis group and 24 in the advanced fibrosis group. Among the mild and advanced fibrosis groups, 65.1% and 50%were female, respectively (P = 0.19). There was an inverse correlation between ERα and fibrotic stage (r: -0.413; P < 0.001). Age, platelet counts, neutrophil counts, Alanine aminotransferase (ALT), Aspartate aminotransferase (AST), Gamma glutamyl transferase (GGT) and ERα were statistically significant in the univariate analysis. In multivariate logistic regression analyses, ERα expression continued to be an independent predicting factor of liver fibrosis in patients infected with chronic HCV genotype 1b (OR: 0.10; 95% CI: 0.018-0.586; P < 0.001).

CONCLUSIONS

ERα expression in liver was inversely correlated with liver fibrosis among patients infected with chronic HCV genotype 1b.

Treatment of chronic hepatitis C in a Canadian Aboriginal population: results from the PRAIRIE study

BACKGROUND

The Aboriginal population of Canada is at increased risk of exposure to the hepatitis C virus (HCV). Previous data indicate that spontaneous clearance of HCV occurs more often in Aboriginals than Caucasians. Whether this enhanced response extends to antiviral therapy for chronic HCV remains to be determined.

OBJECTIVES

To document and compare the biochemical and virological responses to antiviral therapy in HCV-infected Canadian Aboriginals and Caucasians.

METHODS

A total of 101 treatment-naive adult patients (46 Aboriginal, 55 Caucasian) with chronic HCV genotype 1 infections were prospectively treated with pegylated-interferon and ribavirin and followed as per national guidelines.

RESULTS

Aboriginals had higher HCV-RNA loads at baseline (6.42log(10) versus 5.98log(10); P<0.03). Although normalization of serum aminotransferase levels, decreases in viral loads, and rapid, early and end-of-treatment virological responses were similar in the two cohorts, sustained virological responses were significantly lower in Aboriginals (35% versus 55%; P=0.047). Premature discontinuation of treatment and⁄or loss of patients to follow-up was common (Aboriginals 37%, Caucasians 27%). Treatment-related side effects were similar in the two cohorts.

CONCLUSION

Despite higher rates of spontaneous HCV clearance, the response to antiviral therapy was similar, if not lower, in Aboriginals compared with Caucasians with chronic HCV genotype 1 infections. Compliance with treatment is an issue that needs to be addressed in the management of these patients.

The Role of Interferon Gamma Gene Polymorphism (+874A/T, +2109A/G, and -183G/T) in Response to Treatment Among Hepatitis C Infected Patients in Fars Province, Southern Iran

BACKGROUND

Hepatitis C virus (HCV) infection as a worldwide health problem is associated with cirrhosis and hepatocellular carcinoma. With current treatment regimen, pegylated interferon (PEG-IFN) plus ribavirin, sustain virological response (SVR) is achieved in only 50% of infected individuals. In HCV infection, an inappropriate ratio of cytokines may affect the benefit of antiviral therapy. Given the polymorphisms in regulatory regions of cytokines genes may influence cytokines production.

OBJECTIVES

We aimed to investigate both the frequency of genotypes and alleles of interferon gamma (IFN-γ) gene at +874A/T, +2109A/G, and -183G/T loci in HCV-infected patients and their associations with response to therapy.

PATIENTS AND METHODS

A total of 158 patients were included and treated with PEG-IFN plus ribavirin. The presence of HCV infection in patients was confirmed by reverse transcription polymerase chain reaction, and genomic DNA was extracted from peripheral leukocytes using salting out method. IFN-γ gene polymorphisms were identified by polymerase chain reaction using sequence specific primers and restriction fragment length polymorphism analysis on genomic DNA.

RESULTS

Of 158 patients, 110 (69.5%) subjects achieved SVR and 48 (30.5%) subjects did not respond to therapy. The frequency of AA genotype (P = 0.001; OR: 11.2; CI: 2.26-63.21) and A allele (P = 0.01; OR: 3.23; CI: 1.23 8.56) of IFN-γ gene at +2109 locus were significantly different between the responder and non-responder subjects infected with genotype 1. Regardless of HCV genotype, the frequency of AG genotype was also higher in responder group than those who did not respond to therapy (P = 0.041; OR: 05.05; CI: 1.05-33.25)). In case of IFN-γ gene at +874 locus, there was no difference in genotypes and alleles frequencies between the responder and non-responder subjects infected with HCV genotypes 1 and 3. Haplotype analysis showed no association between haplotypes and response to therapy. All participants had G/T genotype at -183 locus.

CONCLUSIONS

Our findings indicate that heterogeneity at +2109 locus of IFN-γ gene but not at +874 locus could interfere with successful therapy in patients infected with HCV genotype 1.

Determination of HCV genotypes and viral loads in chronic HCV infected patients of Hazara Pakistan

Hepatitis C Virus (HCV) genotype and viral load are two significant predictive variables knowledge of which might persuade treatment decisions. The objective of the present study was to identify the distribution of different HCV genotypes circulating in the study area and to estimate viral load in chronically HCV infected patients. Out of total 305 HCV positive patients, 177 (58%) were males and 128 (42%) were females. Frequency breakup of the HCV positive patients was 169, 69, 38 and 29 from Abbottabad, Mansehra, Haripur and Battagram districts respectively. Out of the total 305 tested serum samples, 255 (83.06%) were successfully genotyped whereas 50 (16.4%) samples were found with unclassified genotypes. Among typable genotypes, 1a accounted for 21 (6.8%) 1b for 14 (4.6%), 2a for 4 (1.31%) 3a for 166 (54.42%) and genotype 3b for (8.19%). Twenty five (8.19%) patients were infected with mixed HCV genotypes. Viral load distribution was classified into three categories based on its viral load levels such as low (< 60, 0000 IU/mL), intermediate (60,0000-80,0000 IU/mL) and high (> 80,0000 IU/mL). The baseline HCV RNA Viral load in HCV genotype 3 infected patients was 50 (26.17%), 46 (24.08%) and 95 (49.73%) for low, intermediate and high categories respectively. For genotypes other than 3, these values for low, intermediate and high viral load categories were 50 (43.85), 35 (30.70) and 29 (25.43) respectively. Pre-treatment viral load in patients with untypable genotype was 19 (38.00%), 5 (20.00%) and 11 (44.00%) for low, intermediate and high viral load categories. Viral load distribution was also categorized sex wise; for males it was 58 (32.76%), 26 (14.68%) and 93 (52.54%) whereas for females it was 40 (31.25%), 34 (26.56%) and 54 (42.18%) for low, intermediate and high viral load respectively. In conclusion HCV genotype 3a is the most prevalent genotype circulating in Hazara Division like other parts of pakistan. Pre-treatment viral load is significantly high (p 0.014) in patients infected with HCV genotype 3 as compared to other genotypes.

Association of genetic variation in IL28B with hepatitis C treatment-induced viral clearance in the Chinese Han population

BACKGROUND

Genome-wide association studies have recently shown that the rs12979860 polymorphism in IL28B is associated with the response to chronic hepatitis C treatment. The aim of this study was to investigate whether rs12979860 could be used as a predictive marker for end-of-treatment response (ETR) or sustained virological response (SVR) in the Chinese Han population.

METHODS

The rs12979860 genotype was detected in 259 individuals infected with HCV by DNA sequencing. Among them, 120 patients were administered complete pegylated interferon-α and ribavirin combination therapy and 92 patients were followed for 24 weeks after the cessation of treatment and were divided into different groups according to outcomes of treatment.

RESULTS

The rs12979860 genotype CC was the primary genotype (87.64%, 227/259) and genotype TT was found in only one individual within this cohort. The patients with the rs12979860 genotype CC had higher rates of ETR (P=0.0044) and SVR (P=0.0046) than the patients with N-CC (CT or TT). In multivariate analyses, the rs12979860 genotype CC was associated with a substantial difference in rates of achieving ETR (odds ratio [OR] 8.983, 95% confidence interval [CI] 2.173-37.145; P=0.0024) and SVR (OR 24.298, 95% CI 2.27-259.90; P=0.0083).

CONCLUSIONS

This study demonstrated for the first time that the rs12979860 variation in IL28B could be a predictor of ETR and SVR in Chinese Han patients infected with HCV. The high frequency of the rs12979860 genotype CC might explain why the SVR rate is higher than that of the average global population.

Intracellular expression of IRF9 Stat fusion protein overcomes the defective Jak-Stat signaling and inhibits HCV RNA replication

Interferon alpha (IFN-α) binds to a cell surface receptor that activates the Jak-Stat signaling pathway. A critical component of this pathway is the translocation of interferon stimulated gene factor 3 (a complex of three proteins Stat1, Stat2 and IRF9) to the nucleus to activate antiviral genes. A stable sub-genomic replicon cell line resistant to IFN-α was developed in which the nuclear translocation of Stat1 and Stat2 proteins was prevented due to the lack of phosphorylation; whereas the nuclear translocation of IRF9 protein was not affected. In this study, we sought to overcome defective Jak-Stat signaling and to induce an antiviral state in the IFN-α resistant replicon cell line by developing a chimera IRF9 protein fused with the trans activating domain (TAD) of either a Stat1 (IRF9-S1C) or Stat2 (IRF9-S2C) protein. We show here that intracellular expression of fusion proteins using the plasmid constructs of either IRF9-S1C or IRF9-S2C, in the IFN-α resistant cells, resulted in an increase in Interferon Stimulated Response Element (ISRE) luciferase promoter activity and significantly induced HLA-1 surface expression. Moreover, we show that transient transfection of IRF9-S1C or IRF9-S2C plasmid constructs into IFN-α resistant replicon cells containing sub-genomic HCV1b and HCV2a viruses resulted in an inhibition of viral replication and viral protein expression independent of IFN-α treatment. The results of this study indicate that the recombinant fusion proteins of IRF9-S1C, IRF9-S2C alone, or in combination, have potent antiviral properties against the HCV in an IFN-α resistant cell line with a defective Jak-Stat signaling.

SH2 modified STAT1 induces HLA-I expression and improves IFN-γ signaling in IFN-α resistant HCV replicon cells

Background

We have developed multiple stable cell lines containing subgenomic HCV RNA that are resistant to treatment with interferon alpha (IFN-α. Characterization of these IFN-α resistant replicon cells showed defects in the phosphorylation and nuclear translocation of STAT1 and STAT2 proteins due to a defective Jak-STAT pathway.

Methodology/Principal Findings

In this study, we have developed an alternative strategy to overcome interferon resistance in a cell culture model by improving intracellular STAT1 signaling. An engineered STAT1-CC molecule with double cysteine substitutions in the Src-homology 2 (SH2) domains of STAT1 (at Ala-656 and Asn-658) efficiently phosphorylates and translocates to the nucleus of IFN-resistant cells in an IFN-γ dependent manner. Transfection of a plasmid clone containing STAT1-CC significantly activated the GAS promoter compared to wild type STAT1 and STAT3. The activity of the engineered STAT1-CC is dependent upon the phosphorylation of tyrosine residue 701, since the construct with a substituted phenylalanine residue at position 701 (STAT1-CC-Y701F) failed to activate GAS promoter in the replicon cells. Intracellular expression of STAT1-CC protein showed phosphorylation and nuclear translocation in the resistant cell line after IFN-γ treatment. Transient transfection of STAT1-CC plasmid clone into an interferon resistant cell line resulted in inhibition of viral replication and viral clearance in an IFN-γ dependent manner. Furthermore, the resistant replicon cells transfected with STAT1-CC constructs significantly up regulated surface HLA-1 expression when compared to the wild type and Y to F mutant controls.

Conclusions

These results suggest that modification of the SH2 domain of the STAT1 molecule allows for improved IFN-γ signaling through increased STAT1 phosphorylation, nuclear translocation, HLA-1 surface expression, and prolonged interferon antiviral gene activation.

[Mutations within the interferon sensitivity determining region in Korean patients infected with hepatitis C virus genotype 1b]

BACKGROUND/AIMS

The treatment response to interferon could differ with mutations in the interferon-sensitivity-determining region (ISDR) in patients infected with hepatitis C virus (HCV) genotype-1b (HCV-Ib). We examined the pattern of ISDR mutations and analyzed whether the number of amino acid substitutions influences the treatment response to peginterferon plus ribavirin in chronic hepatitis or cirrhotic patients infected with HCV-Ib.

METHODS

The study population comprised 52 patients who visited Seoul Asan Medical Center and Seoul National University Bundang Hospital from January 2006 to December 2008 and who received peginterferon alpha-2a (n=37) or -2b (n=15) plus ribavirin, and whose serum was stored. We analyzed the early virologic response, end-of-treatment response, and sustained virologic response (SVR), and examined the ISDR using direct sequencing.

RESULTS

The proportions of patients with ISDR mutation types of wild (0 mutations), intermediate (1-3 mutations), and mutant (> or =4 mutations) were 50.0%, 42.3%, and 7.7%, respectively, and the corresponding SVR rates were 63%, 50%, and 67% (p>0.05). The SVR rates were 59.4% and 50.0% in patients with <2 and > or =2 mutations, respectively (p>0.05). On univariate analysis, age was the only predictive factor for SVR (p=0.016). The pretreatment HCV RNA titer tended to be lower in those with SVR, but without statistical significance (p=0.069).

CONCLUSIONS

The frequency of ISDR mutations was low in our cohort of Korean patients infected with HCV-Ib. Therefore, ISDR mutations might not contribute to the response to treatment with peginterferon plus ribavirin.

[Efficacy of combined antiviral therapy with pegylated interferon alpha-2a and ribavirin for chronic hepatitis C infection in intravenous drug users]

INTRODUCTION

Hepatitis C Virus infection represents not just a medical, but also a socio-economic problem. It is estimated that among 170 million infected, 60% belongs to the category of intravenous drug users (IDUs).

OBJECTIVE

The aim of this paper was to compare the response to the combined therapy of pegylated interferon alfa 2a and ribavirin, in the group of patients with HCV infection who were intravenous drug users (IDUs) and in patients who were identified in the other way of transmission of HCV. Also to identify the influence of the therapy on diseases of addiction, during the course of HCV infection and on the effects of the combined therapy of pegylated interferon alfa 2a and ribavirin.

METHODS

We conducted a retrospective-prospective study, on 60 patients, treated with combined antiviral therapy--pegylated interferon alfa 2a and ribavirin. 30 patients were from the group of IDUs, and 30 patients from other epidemiological groups.

RESULTS

There were significant differences between the age of the patients (30.2 +/- 7.1 vs. 39.3 +/- 11.2 years; p = 0.002), but no significant difference in the duration of the HCV infection between the two groups of patients (8.9 +/- 7.4 vs. 13.1 +/- 7.0 years; p > 0.05). A large number of the patients in the group of IDUs had a problem with the abstinence of the drug abuse. In this group, there was the influence of alcohol (30%) and other substances with potential hepatotoxicity: marihuana (23.3%) and psychoactive drugs (73.6%). Staging of the liver fibrosis was not influenced by those two parameters and was similar in both groups (p > 0.05). The genotype 3a was dominant in intravenous drug users (50.0%) and genotype 1b in the control group of the patients (76.6%). In both groups, SVR was achieved at a higher percentage (86% vs. 70.00%; p > 0.05), but among the intravenous drug users the relapses of HCV infection were at a lower percentage (3.3% vs. 20.0%; p = 0.044). Side effects were noticed in solitary cases in both of the examined groups, but severe side effects were found only in the control group of the patients. Relapse of drug abuse was noticed in 6.66% of cases.

CONCLUSION

We have registered that the group of intravenous drug users has the same or even better response to the antiviral therapy than other epidemiological groups and that the use of drugs does not change the course of HCV infection.

Significance of changes in serum IL-18 and IL-1β levels in patients with chronic hepatitis C

AIM: To investigate the roles of serum IL-18 and IL-1β in the progression of chronic hepatitis C and explore the correlation between serum IL-18 and IL-1β levels and the efficacy of interferon (IFN) therapy.

METHODS: The levels of IL-18 and IL-1β in the serum of 30 chronic hepatitis C patients were determined before and after they received IFN therapy to observe changes in the serum levels of the two cytokines in different periods after HCV infection. Moreover, the correlations of serum IL-18 and IL-1β levels with ALT level, HCV genotype, IL-2 and IL-6 levels were analyzed. The differences in the serum levels of the two cytokines were also compared between patients with response and nonresponse to interferon treatment. The levels of serum cytokines were determined by ELISA. HCV genotypes were classified by direct sequencing. HCV RNA loads were determined by fluorescence quantitative PCR.

RESULTS: The level of IL-18 in the serum of chronic hepatitis C patients was higher than that of healthy controls (1077.44 ± 657.58 ng/L vs 259.92 ± 328.47 ng/L, P < 0.001). No significant difference in the level of serum IL-1β was noted between chronic hepatitis C patients and healthy controls though it had an upward trend over time (in contrast to a downward trend for IL-18). Severe patients had higher serum IL-1β level than mild ones (4.99 ± 1.44 ng/L vs 3.68 ± 0.76 ng/L, P < 0.05). The levels of the two cytokines were not significantly different among patients with different genotypes or subtypes of HCV. The level of IL-18 was positively correlated with that of IL-2 (r = 0.434, P < 0.05) rather than IL-6. The level of IL-1β was not correlated with those of IL-2 and IL-6. No significant differences were noted in the serum levels of IL-18 and IL-1β between patients with response and nonresponse to IFN therapy.

CONCLUSION: Serum IL-18 and IL-1β levels may be correlated with the chronicity and severity of hepatitis C but can not be used for prediction of the efficacy of IFN therapy.

Poor response to pegylated interferon and ribavirin in older women infected with hepatitis C virus of genotype 1b in high viral loads

BACKGROUND

Response to treatment in patients with chronic hepatitis C, with reference to age and gender, has not been examined fully.

AIM

The influence of gender and age on treatment with pegylated interferon (PEG-IFN) and ribavirin was evaluated in a retrospective study.

METHODS

PEG-IFN and ribavirin were given for 48 weeks to 179 men and 121 women infected with hepatitis C virus (HCV) of genotype 1b in high viral loads (>100 kIU/ml).

RESULTS

Sustained virological response at 24 weeks after treatment was poorer in women than men who were aged >or=50 years (22% vs 53%, P < 0.001). Among the patients aged >or=50 years who had received >or=80% of the doses of PEG-IFN, ribavirin, or both, women responded less often than men (26% vs 64%, P < 0.001; 33% vs 61%, P = 0.022; and 32% vs 63%, P = 0.016; respectively). In multivariate analysis, male gender, retention of indocyanine green, ribavirin dose and compliance with therapy increased sustained virological response.

CONCLUSIONS

Response to combined PEG-IFN and ribavirin is poorer in female than male patients with hepatitis C who are aged >or=50 years, irrespective of compliance with treatment. Low estrogen levels in older women could be responsible for their impaired response to PEG-IFN and ribavirin.

Association of genetic polymorphisms with interferon-induced haematologic adverse effects in chronic hepatitis C patients

Interferon (IFN)-based combination therapy with ribavirin has become the gold standard for the treatment of chronic hepatitis C virus infection. Haematologic toxicities, such as neutropenia, thrombocytopenia, and anaemia, however, frequently cause poor treatment tolerance, resulting in poor therapeutic efficacy. The aim of this study was to identify host genetic polymorphisms associated with the efficacy or haematologic toxicity of IFN-based combination therapy in chronic hepatitis C patients. We performed comprehensive single nucleotide polymorphism detection in all exonic regions of the 12 genes involved in the IFN signalling pathway in 32 healthy Japanese volunteers. Of 167 identified polymorphisms, 35 were genotyped and tested for an association with the efficacy or toxicity of IFN plus ribavirin therapy in 240 chronic hepatitis C patients. Multiple logistic regression analysis revealed that low viral load, viral genotypes 2 and 3, and a lower degree of liver fibrosis, but none of the genetic polymorphisms, were significantly associated with a sustained virologic response. In contrast to efficacy, multiple linear regression analyses demonstrated that two polymorphisms (IFNAR1 10848-A/G and STAT2 4757-G/T) were significantly associated with IFN-induced neutropenia (P = 0.013 and P = 0.011, respectively). Thrombocytopenia was associated with the IRF7 789-G/A (P = 0.031). In conclusion, genetic polymorphisms in IFN signalling pathway-related genes were associated with IFN-induced neutropenia and thrombocytopenia in chronic hepatitis C patients. In contrast to toxicity, the efficacy of IFN-based therapy was largely dependent on viral factors and degree of liver fibrosis.

Low-density lipoprotein receptor variants are associated with spontaneous and treatment-induced recovery from hepatitis C virus infection

Low-density lipoprotein receptor (LDLR) is involved in the entry of hepatitis C virus (HCV) in host cells. We investigated whether three single-nucleotide alterations within LDLR might be associated with the course of hepatitis C infection and response to antiviral therapy. We enrolled 651 individuals with chronic HCV infection who had received interferon-based combination therapy, 174 individuals with self-limited HCV infection, and 516 healthy controls. LDLR c.1171G>A, c.1413G>A, and c.*52G>A genotyping was performed by real-time PCR-based assays. HCV genotype 1-infected individuals who were homozygous for 3'UTR c.*52G were at increased risk for virologic non-response to antiviral therapy compared to virologic responders (66.3% vs. 51.0%, p=0.001). Furthermore, compared to healthy controls, self-limited HCV genotype 1 infection was significantly associated with c.1171A (15.1% vs. 6.6%, p=0.006) and negatively associated with c.1413G>A heterozygosity (33.0% vs. 46.1%, p=0.023). The data indicate that LDLR alterations are correlated with response to interferon-based combination therapy and with self-limitation of HCV 1 infection.

A polymorphism in MAPKAPK3 affects response to interferon therapy for chronic hepatitis C

BACKGROUND & AIMS

This study aimed to identify host single nucleotide polymorphisms (SNPs) that are associated with the efficacy of interferon (IFN) therapy in patients with chronic hepatitis C.

METHODS

We examined whether 116 tagging-SNPs from 13 genes that are involved in type I IFN signaling associate with the outcome of IFN therapy in Japanese case-control groups; the study included 468 sustained responders and 587 nonresponders.

RESULTS

We identified 2 SNPs (rs3792323 [A/T] and rs616589 [G/A]), located in intron 2 of mitogen-activated protein kinase-activated protein kinase 3 (MAPKAPK3) that were associated with the outcome of IFN therapy in patients infected with hepatitis C virus (HCV) genotype 1b (P = 4.6 x 10(-5) and 4.8 x 10(-5), respectively). The 2 SNPs were in strong linkage disequilibrium and multivariate logistic regression analysis showed that rs3792323 is an independent factor associated with the IFN efficacy (genotype 1b; P = .0011). MAPKAPK3 is a kinase involved in the mitogen and stress responses, but the biological significance of MAPKAPK3 in IFN responses is poorly understood. By using an allele-specific transcript quantification assay in liver biopsy, we showed that allele-specific expression of MAPKAPK3 messenger RNA, corresponding to the risk allele for nonresponse, was significantly higher than that of the other allele. Luciferase reporter assay data indicated that overexpression of MAPKAPK3 inhibits IFN-alfa-induced gene transcription via IFN-stimulated response element and IFN-gamma-activated site.

CONCLUSIONS

The SNP rs3792323 in MAPKAPK3 associates with the outcome of IFN therapy in patients with HCV genotype 1b. Our functional analyses indicate that MAPKAPK3 inhibits IFN-alfa-induced antiviral activity.

Predictors of sustained virological response to a 48-week course of pegylated interferon alfa-2a and ribavirin in patients infected with hepatitis C virus genotype 4

BACKGROUND AND OBJECTIVES

Knowledge of the predictors of sustained viral response (SVR) to pegylated interferon (PEG-INF) alfa-2a and ribavirin (RBV) therapy in patients with hepatitis C genotype-4 (HCV-4) is crucial for selecting patients who would benefit most from therapy. We assessed the predictors of SVR to this combination therapy in Saudi patients with chronic HCV-4 infection.

PATIENTS AND METHODS

This retrospective study included 148 patients with HCV-4 infection who underwent clinical, biochemical and virological assessments before treatment and at 12, 24, 48 and 72 weeks post-treatment.

RESULTS

Of the 148 patients, 90 (60.8%) were males. Mean (SD) for age was 48.5 (12.7) years and BMI was 27.9 (7.5) kg/m(2). Seventy-nine of 148 (60.1%) patients were treatment naïve and 110 (74.3%) underwent pre-treatment liver biopsy. Eighteen (12.2%) patients did not complete therapy because of side effects or they were lost to follow up. Early virological response was achieved in 84 of 91 (92.3%) patients. In the 130 (87.8%) patients who completed therapy, 34 (26.2%) were non-responders and 96 (63.8%) achieved end-of-treatment virological response (ETVR). SVR and virological relapse (24 weeks after ETVR) occurred in 66/130 (50.7%) and 30/130 (31.2%) patients, respectively. Compared to relapsers, sustained responders were significantly younger (P=.005), non-diabetic (P=.005), had higher serum albumin (P=.028), lower alpha-fetoprotein level (P=.026), lower aspartate aminotransferase (AST) (P=.04) levels, and were treatment-naïve (P=.008). In a multivariate regression analysis, the independent predictors of SVR were younger age (P=.016), lower serum AST (P=.012), and being treatment naïve (P=.021).

CONCLUSION

Approximately half of HCV-4 patients who complete the course of combination therapy achieve an SVR, especially if they are young, treatment naA ve and have lower AST levels.

A globally occurring indel polymorphism in the promoter of the IFNA2 gene is not associated with severity of malaria but with the positivity rate of HCV

BACKGROUND

Type I Interferons (IFNs) are well known cytokines which exert antiviral activity, antitumor activity and immunomodulatory effects. Single-nucleotide polymorphisms (SNP) and deletions in the gene coding for IFNA2 have been shown to influence the level of expression in vitro. The indel polymorphism -305_-300delAACTTT showed the strongest effect in vitro. To analyse the worldwide distribution of this polymorphism we analyzed five different populations (586 Vietnamese, 199 Central Africans, 265 Brazilians, 108 Kaingang and 98 Guarani). To investigate a possible association with susceptibility to infectious diseases we determined the polymorphism in malaria patients suffering either mild or severe malaria and in a cohort of hepatitis C virus infected individuals.

RESULTS

We could detect the indel polymorphism in all populations analysed. There was no association with this polymorphism and the outcome of malaria but we found an increase of this indel polymorphism in hepatitis C virus positive individuals compared to healthy controls (p = 0.014).

CONCLUSION

Polymorphisms in genes involved in the interferon pathway have been implicated in the resistance or susceptibility against cerebral malaria and HBV. Here we show that an indel polymorphism, which mediates a disadvantageous effect in HBV patients, may also play a disadvantageous role in HCV infections stressing the importance of a fully functional interferon pathway.

Seroprevalence of hepatitis B and C genotypes among young apparently healthy females of karachi-pakistan

INTRODUCTION

Although the prevalence of hepatitis virus infections in Pakistan is still unknown, limited data indicate that the exposure rate to HBV is 35-38% with 4% being carriers and 32% having anti-HBV surface antibodies through natural conversion [1, 2, 3]. Studies in Pakistan have shown that the prevalence rate of HCV is 4.8-14% for, and that it is continuously increasing. Hence there is an urgent need to create awareness about the prevalence of both hepatitis B and C, and to develop preventive measures aimed at minimizing the prevalence of these diseases in the country.

STUDY DESIGN

Prospective, descriptive study. The study took place from March 2002 till October 2006 at two university campuses in Karachi.

MATERIALS AND METHODS

A total of 4000 healthy female students were screened for HBs Ag, anti-HBs antibodies and anti-HCV antibodies by rapid immunochromatography, ELISA and PCR.

RESULTS

A total of 3820 volunteers (95.5%) were negative by all three methods, 181 (4.5%) tested positive for HB surface antigen and 20 (0.5%) were positive for anti HB surface antibodies; 208 volunteers (5.2%) were positive for HCV. Double infection with HBV and HCV was found in only one patient (0.025%). Out of 180 HBs antigen positive samples 151 (83.89%) were genotype D, 28 (15.56%) showed mixed infection with genotypes B and D, and one patient (0.56%) showed mixed infection with genotypes C and D. Out of 208 samples positive for HCV antibodies, 107 (51.44%) were genotype 3a, 50 (24.04%) were mix of genotype 3a and 3b, 33 (15.87%) were genotype 3b, 10 (4.81%) were genotype 1b while, 8 (3.84%) samples could not be typed.

CONCLUSION

Although the presence of these pathogenic viruses was not very high in our young healthy female population, it is still a matter of concern to control the unregulated spread of these deadly infections by promoting increased awareness and regular immunization programs in the community. Local manufacturing of vaccines and related products may reduce these infections.

Baseline cholesterol is associated with the response to antiviral therapy in chronic hepatitis C

BACKGROUND

Hepatitis C virus (HCV) partially interacts with low-density lipoprotein (LDL) receptors, suggesting a role for lipids in regulating HCV clearance. Our aim was to study if baseline lipids can discriminate responders from non-responders among patients with HCV infection.

METHODS

A total of 109 HCV patients were studied. Laboratory measurements included serum lipids, aminotransferases and viral load, as well as HCV genotype determinations.

RESULTS

Responders (n = 53) had significantly higher serum baseline levels of total cholesterol, LDL cholesterol and apolipoprotein B compared to non-responders (n = 56). Multivariate logistic regression analysis showed that a 10 mg/dL increase in total cholesterol was associated with 3.02 higher odds of responding to treatment (95% CI 1.74-5.32, P < 0.001), while a 10 mg/dL increase in apolipoprotein B levels was associated with 1.81 higher odds of responding to treatment (95% CI 1.37-2.54, P < 0.001), after adjustment for age, sex, body mass index (BMI), smoking habits, baseline viral load, liver histology and administration of pegylated interferon. An inverse association between BMI and response to treatment was also evident (adjusted odds ratio 0.73, 95% CI 0.55-0.96; P = 0.03).

CONCLUSION

Baseline serum total cholesterol levels and BMI could be helpful in discriminating responders to antiviral therapy among patients with HCV infection.

The use of different Peg-interferon alpha-2b regimens plus ribavirin in HCV-1b-infected patients after rapid virological response does not affect the achievement of sustained virological response

In patients with chronic hepatitis C, rapid virological response (RVR) at week 4 of treatment seems to be strongly associated with a high probability of achieving a sustained virological response (SVR). The aim of this study was to investigate the outcome of different pegylated interferon-alpha2b (Peg-IFN-alpha2b) dosages plus ribavirin (RBV) in patients with RVR. Forty-five naïve patients chronically infected with hepatitis C virus (HCV)-1b started Peg-IFN-alpha2b (1.5 microg/kg/week) in combination with weight-based RBV doses (800-1200 mg/day). Thirty-one patients (68.9%) attained RVR at week 4 of therapy, while four further patients showed negative HCV-RNA values for the first time at week 12 and were considered early virological responders (EVR). The 31 RVR patients were randomized to receive either RBV plus 1.5 microg/kg/week (17 pts) or 1.0 microg/kg/week (14 pts) of Peg-IFN-alpha2b for the remaining 44 weeks. The two groups were matched for age, sex, baseline alanine aminotransferase levels, viral load and fibrosis score. After 6 months of post-treatment follow-up, the prevalence of SVR was 94.1% (16/17) among RVR patients treated with 1.5 microg/kg/week and 92.8% (13/14) in RVR patients treated with 1.0 microg/kg/week (P = not significant). A high-baseline viral load (P = 0.01) and bridging fibrosis/cirrhosis (P = 0.02) negatively influenced the likelihood of achieving RVR. On the contrary, the ability of RVR patients to achieve SVR did not correlate with these baseline characteristics in either of the treatment group. Finally, the SVR rate among EVR patients who responded after more than 4 weeks of treatment was significantly lower than among RVR patients (1/4 = 25%vs 29/31 = 93.5%; P = 0.0058), because of a high prevalence of post-treatment relapse among patients with EVR.

Sustained virologic response to peginterferon alpha-2a and ribavirin in 335 patients with chronic hepatitis C: a tertiary care center experience

BACKGROUND/AIM

This retrospective study assessed the efficacy, safety, and the predictors of sustained viral response (SVR) to a 48-week-course of peginterferon alpha-2a (Pegasys) and ribavirin combination therapy in 335 consecutive Saudi patients with chronic hepatitis C virus (HCV) infection.

MATERIALS AND METHODS

Clinical, biochemical, and virological parameters were collected at time 0 (pretreatment) and at 12, 24, 48, and 72 weeks posttreatment. The mean +/- SD age was 49.1 +/- 13.0 years; 229 (68.4%) were males, mean +/- SD body mass index was 27.8 +/- 7.4, 85 (25.4%) were diabetic, 25 (7.5%) had renal impairment, 136 (40.6%) had previously received interferon +/- ribavirin therapy, and 247 (73.7%) underwent pretreatment liver biopsy. Patients with genotypes 1, 2 or 3, 4 and mixed genotype were 60 (22.15%), 30 (11.0%), 148 (54.4%), and 34 (12.5%), respectively.

RESULTS

Early viral response (>or=2-log10 HCV-RNA decline 12 weeks posttreatment) was achieved in 253 (75.3%). Patients who completed 48 weeks of treatment were 292 (87.1%); of these, 121 (75.6%) achieved ETVR, 161 (55.1%) continued to have SVR and 60 (20.5%) had a viral relapse following end-of-treatment response, that is 48.1 and 17.9% of all patients (n = 335), respectively. Nonresponders (NR) were 71 (24.3%) patients and 43 (12.8%) were unable to complete treatment (due to side effects or loss to follow up). Compared to the relapsers, patients with SVR were significantly younger (P = 0.000), nondiabetics (P = 0.015), had higher serum albumin (P = 0.007), had less pretreatment inflammatory grade (P = 0.011), infected with genotypes 2 or 3 (P = 0.014), and treatment-naïve patients (P = 0.001). However, in stepwise multivariate logistic regression analysis, only treatment naiveté and low pretreatment inflammatory score were the independent predictors of SVR (P = 0.005 and P = 0.018, respectively).

CONCLUSION

Combination therapy, if tolerated and completed, is effective in treating chronic HCV patients, especially those with no previous interferon therapy and lower pretreatment inflammatory grade.

Hepatitis C virus genotype 3 predominates in North and Central India and is associated with significant histopathologic liver disease

Hepatitis C virus (HCV) genotypes help to tailor the treatment response, but their influence on the disease severity and association with hepatic steatosis is not well understood. The prevalence of HCV genotypes and their correlation with the histopathological severity of liver disease and steatosis in Indian patients were studied. HCV-RNA and genotyping was carried out in 398 patients with chronic hepatitis C. Liver biopsy was available in 292 (73.4%) patients. The severity of liver disease was graded on the basis of the histological activity index and the stage of hepatic fibrosis. The patients were categorized as having mild (histological activity index < or =5 and/or fibrosis < or =2) or severe (histological activity index > or =6 and/or fibrosis > or =3) liver disease. Steatosis was graded in 106 patients as 0 (no steatosis), 1 (<33% of hepatocytes affected), 2 (33%-66% of hepatocytes affected), or 3 (>66% of hepatocytes affected). HCV genotype 3 was detected in 80.2% patients (3a:24.4%, 3b:3.3%, 3c:0.5%, 3a/3b:36.7%, and un-subtypable 3:15.3%), genotype 1 in 13.1% (1a:3%, 1b:5.5%, 1a/1b:0.3%, and un-subtypable 1:4.3%), genotype 4 in 3% patients (4a:1.5%, 4b:0.3%, 4a/4c:0.5%, and un-subtypable 4:0.8%), 2 in 2.5% and mixed genotypes (more than one genotype) in 1.3% of patients. The median histological activity index and fibrosis scores were: 5 and 2 in genotype 1; 4 and 2 in genotype 2; 5 and 2 in genotype 3; 7 and 3 in genotype 4; and 5 and 2 in mixed genotypes, respectively. Severe liver disease was present in 17 of 38 (45%) with genotype 1; in 1 of 3 (33%) with genotype 2; in 128 of 236 (54%) with genotype 3; 7 of 10 (70%) with genotype 4; and in 1 of 4 (25%) with mixed genotype. Hepatic steatosis grade > or =2 was found in 28.1% of genotype 3; 23.5% of genotype 1; 20% of genotype 4; and in none of genotype 2 and mixed genotypes. In conclusion, genotype 3 is the most prevalent genotype in patients with chronic hepatitis C in North and Central India and this is associated with significant hepatic steatosis and fibrosis.

Chronic hepatitis C virus infection: Is there a correlation between HCV genotypes and the level of viremia?

Introduction. Hepatitis C virus (HCV) RNA status and HCV genotypes have become extremely important for exact diagnosis, prognosis, duration of treatment and monitoring of antiviral therapy of chronic HCV infection. Material and methods. For the purpose of precise and objective assessment of virologic analyses, such as the determination of the number of virus copies and virus genotypes, 110 patients with chronic HCV infection were tested. Genotyping of HCV isolates and HCV RNA quantification were performed by using the PCR method. Genotype lb infection was verified in 49.1% of patients, genotype 3a infection was found in 28.2%, genotype 4 in 9.1%, genotype 2 in 4.5%, while mixed genotype infections were diagnosed in 9.1% of cases. Results. Patients infected by genotype lb had significantly higher serum HCV RNA level in relation to patients infected by other genotypes (p<0.05). Over 70% of patients infected by genotype lb had more than 2xl06 virus copies in 1 ml of blood, while in genotypes 2, 3a and 4, the percentage was 40%, 38.5% and 30%, respectively. Male patients had approximately 7.7x10.6 virus copies in 1 ml of blood, which was significantly higher in comparison with female patients (2.3xl06 copies/ml; p<0.05). Conclusion. Our results are in concordance with the results of other authors reporting that genotype lb is predominant in Europe, as well as significantly higher incidence of viremia in patients with genotype lb infection in relation to other HCV genotypes. Based on these results, we can conclude that our patients, most commonly, present with severe clinical course of chronic HCV infection and require longer treatment (48 weeks), which causes economic problems. .

Pegylated interferon-alpha 2b-ribavirin combination in Egyptian patients with genotype 4 chronic hepatitis

Egypt has a high prevalence rate of hepatitis C (HCV) infection and as much as 90% is genotype 4. Response to interferon (IFN) varies with viral genotype and degree of fibrosis. Genotype 4 is poorly sensitive to standard IFN and IFN-ribavirin combination. We evaluated pegylated interferon (PEG-IFN)-alpha2b in our patients. Sixty-one patients with compensated chronic HCV genotype 4 were enrolled in two groups: group A (31 patients) received IFN-alpha2b 3 MU three times per week and group B (30 patients) received 1.5 mug/kg PEG-IFN-alpha2b once weekly. Ribavirin was added to each regimen in a dose of 800-1200 mg based on body weight. Patients were followed up for 24 weeks to assess the sustained response (SR). End-of-treatment response (ETR) was achieved in 11 of 31 patients (35.48%) in group A, and 13 of 30 patients (43.33%) in group B (P < 0.05). Only eight patients in group A and 10 in group (B) achieved a sustained virological response (25.8 and 33.3%, respectively) (P < 0.05). By computing ETR, SR or relapse and pretreatment baseline data (pretreatment, viral load, alanine transaminases, necroinflammatory and hepatic fibrosis), both inter- and intragroup, no significant correlations could be detected. In terms of safety and tolerability, PEG-IFN-alpha2b and IFN-alpha2b were comparable. In spite of mild insignificant increase in ETR and SR with the pegylated form, the poor response of genotype 4 in Egypt (genotype 4a) to different forms of IFNs may be related to an intrinsic resistance to the direct antiviral effect of IFN.

Differential transcriptional expresión of the polymorphic myxovirus resistance protein A in response to interferon-alpha treatment

Levels of myxovirus resistance protein A (MxA) mRNA were studied for a single nucleotide polymorphism in the promoter region at nucleotide position -88 of the gene to identify individual-specific responses to interferon (IFN)-alpha2 that might predict responsiveness to IFN-alpha therapy. We quantified MxA expression by reverse transcription and real-time polymerase chain reaction in peripheral blood mononuclear cells (PBMC) in vitro, induced by IFN-alpha2, from 22 healthy donors, in relation with G/T polymorphism located in the promoter of the MxA. MxA mRNA was significantly upregulated in all subjects (mean of 53-fold) in response to IFN-alpha2 in vitro (P < 0.01). Comparison of the inducibility of MxA mRNA expression in relation with G/T polymorphism showed a 4.26-fold higher induction of MxA mRNA levels in PBMC from carriers of the mutant allele (GT or TT) than homozygotes with the wild-type allele (GG) (P < 0.001). We propose that expression of the IFN-inducible MxA is affected by a single nucleotide polymorphism in the MxA promoter which can identify an individual response to IFN-alpha2.

Amantadine therapy for chronic hepatitis C

OBJECTIVE

Although treatment of hepatitis C has improved, up to 50% do not respond to standard therapy with interferon regimes or cannot tolerate the treatment due to side effects. The purpose of the present investigation was to evaluate the safety and effectiveness of the antiviral drug amantadine for the treatment of hepatitis C in those who had either previously failed interferon therapy or were not candidates for interferon.

DESIGN

A prospective double-blind randomized placebo-controlled trial.

SETTING

Outpatient research clinic of a teaching hospital.

PATIENTS/PARTICIPANTS

One hundred fifty-two patients with confirmed hepatitis C with abnormal liver enzymes, detectable hepatitis C RNA in the blood, and abnormal liver histology by biopsy were randomized to receive treatment or placebo.

MEASUREMENTS AND MAIN RESULTS

Patients received either amantadine 100 mg twice daily by mouth or placebo for 6 months. After 6 months, placebo-treated patients were crossed over and treated with amantadine for 6 months and amantadine-treated subjects received 6 additional months of therapy. Amantadine therapy resulted in a significant decline in serum alanine aminotransferase compared to placebo (P =.03). Nine percent cleared the virus at the end of therapy and 6.8% had a sustained virologic response 6 months after discontinuation of amantadine, but this was not statistically significant. Side effects were minimal, and the social quality of life survey improved with 12 months of amantadine (P =.02).

CONCLUSIONS

Oral amantadine may provide a safe alternative treatment for those patients who are intolerant or unresponsive to interferon.

Host factors and failure of interferon-alpha treatment in hepatitis C virus

Failure of interferon-alpha (IFN-alpha) treatment in patients with chronic hepatitis C virus (HCV) infection is a challenging obstacle for clinical and experimental hepatology. Both viral and host factors have been implicated in reducing responsiveness to IFN-alpha therapy. The role of viral factors has been studied extensively and has been summarized in several review articles; however, much less attention has been paid to host factors. In this paper, we review evidence of host factor involvement in IFN-alpha treatment failure. We discuss possible underlying mechanisms responsible for these effects. Potential therapeutic strategies to enhance the effectiveness of IFN-alpha therapy for HCV are also proposed.

Effects of interferon, ribavirin, and iminosugar derivatives on cells persistently infected with noncytopathic bovine viral diarrhea virus

Persistent infection with hepatitis C virus (HCV) is a major cause of chronic hepatitis in humans. In chronic carriers, the viral infection induces liver damage that predisposes the patient for cirrhosis and can lead to hepatocellular carcinoma. Current chemotherapies are limited to alpha interferon (IFN-alpha) used either alone or in combination with ribavirin (RBV). In addition to its limited efficacy, this treatment is frequently poorly tolerated because of its side effects. The urgently needed development of new drugs is made difficult by the lack of an in vitro or in vivo infectivity model, and no cell line has been found so far to reliably and reproducibly support HCV infection. For this reason, the closely related pestivirus bovine viral diarrhea virus (BVDV) has sometimes been used as a surrogate in vitro infectivity model. In this study we used an MDBK cell line persistently infected with noncytopathic BVDV to assess the antiviral effect of IFN-alpha and RBV, the two drugs currently in clinical use against HCV. The same system was then used to evaluate the potential of two classes of iminosugar derivates to clear noncytopathic BVDV infection from MDBK cells. We show that treatment with long-alkyl-chain deoxynojirimycin derivatives, which are inhibitors of the endoplasmic reticulum (ER)-resident alpha-glucosidases, can greatly reduce the amount of secreted enveloped viral RNA. Long-alkyl-chain deoxygalactonojirimycin derivatives, which do not inhibit ER alpha-glucosidases, were less potent but still more effective in this system than IFN-alpha or ribavirin.

Comparative study of the efficacy of an induction dose of interferon-alpha2b with ribavirin compared with standard combined treatment in naive patients with chronic hepatitis C

The efficacy and secondary effects of an induction dose of interferon-alpha2b (IFN-alpha2b) with ribavirin compared with standard combined treatment in naive patients with chronic hepatitis C infection were compared. A prospective study was undertaken between March 1998 and November 2001 in which 84 Spanish hospitals took part. Six hundred and fourteen naive patients (age range 18-65 years) diagnosed with chronic hepatitis C virus (HCV) infection and without cirrhosis or co-infection by other viruses, were included. Patients were divided into two groups. Group A (n = 304) received induction treatment with a daily dose of 5 MU of IFN-alpha2b for 4 weeks, followed by 5 MU three times a week with ribavirin (1000-1200 mg/day, according to weight) until completing 1 year of treatment. Group B (n = 310) received the standard dose of IFN-alpha2b of 3 MU three times per week for 48 weeks together with ribavirin (1000-1200 mg/day, according to weight). Both groups were completely comparable according to age, gender, body weight, transaminase levels, genotype, viral load and hepatic inflammatory activity (Knodell Index). No control group was included for ethical reasons. Pegylated interferon was not available at the time of the study. Serum baseline samples were collected for the determination of genotype. Samples were also collected at baseline, weeks 4, 12, 24, 48 and 72, in order to detect and quantify HCV-RNA. The efficacy of treatment was evaluated by means of sustained viral response (SVR) characterized by persistent negativity of HCV-RNA at the end of the follow-up period. At week 4, the response to treatment was greater in group A (49.6%) compared with group B (34.5%) (P = 0.0002), and was maintained until week 12 (64.1% compared with 55.8% respectively) (P = 0.03). These differences disappeared at week 24, when group A (69%) was compared with group B (65%) (NS). At week 48, the response rate for group A was 50.6% compared with group B 47.4% (NS), and at week 72, the SVR in group A was 46% compared with 40.3% for group B (NS). The global SVR was 43.1%. On analysing the response to treatment according to genotype and viral load, we found that the induction treatment was slightly superior in patients with genotype 1 and an elevated viral load (>2 x 10(6) copies/ml). They achieved a SVR in group A of 39.1% compared with 25.5% in group B (P < 0.05). However, this slight improvement obtained in group A, was achieved at the expense of a greater percentage of dropouts compared with group B (6.4% vs 2.2%, P < 0.01); a greater rate of side effects (58.5 vs 36.7%, P < 0.05) and also a greater percentage of neutropenia (3.1% vs 0.9%, P < 0.05). The induction treatment presented a better initial response, but this was not maintained at the end of treatment, and did not improve the results obtained with the standard treatment. Although the patients with genotype 1 and elevated viral load had a better response with the induction treatment, this was accompanied by a greater percentage of dropouts and secondary effects. It would be interesting to repeat this type of study in the future, using pegylated interferon.

Hepatitis C virus-related cryoglobulinemic glomerulonephritis: long-term remission after antiviral therapy

BACKGROUND

Renal involvement in patients with hepatitis C virus (HCV) infection commonly manifests as cryoglobulinemic glomerulonephritis (CGN). The combination of interferon-alpha (IFN-alpha) and ribavirin, which is currently considered the standard antiviral therapy in chronic hepatitis C, could be difficult to carry out in cryoglobulinemic patients who are frequently anemic, even in the absence of renal failure. Clinical and histologic long-term results of this therapeutic regimen have not been so far reported in patients with CGN.

METHODS

Three patients with HCV-related CGN and slightly impaired kidney function were treated with IFN-alpha and ribavirin for 12 months, and subsequently were followed up for 24 to 36 months. Two of these patients who were anemic were pretreated with erythropoietin (EPO). In each patient renal biopsy was performed before starting therapy and repeated 14 to 26 months after the end of treatment.

RESULTS

In all three patients, antiviral therapy induced sustained virologic response, which was followed by clear improvement in clinical, biochemical, immunologic, and histologic features. Clinical and biochemical improvement steadily progressed in all three patients, achieving normal or nearly normal results at the end of follow-up. In contrast, some immunologic features, such as serum levels of C4 and rheumatoid factor activity, did not normalize in two and three patients, respectively. Posttreatment renal biopsies showed mildly active histologic lesions.

CONCLUSION

Antiviral therapy with IFN-alpha and ribavirin may be considerably beneficial in patients with HCV-related CGN who obtain sustained virologic response.

Hepatitis C virus infection in a Brazilian population with sickle-cell anemia

Patients with sickle-cell anemia submitted to frequent blood transfusions are at risk of contamination with hepatitis C virus (HCV). Determination of HCV RNA and genotype characterization are parameters that are relevant for the treatment of the viral infection. The objective of the present study was to determine the frequency of HCV infection and the positivity for HCV RNA and to identify the HCV genotype in patients with sickle-cell anemia with a history of blood transfusion who had been treated at the Hospital of the HEMOPE Foundation. Sera from 291 patients were tested for anti-HCV antibodies by ELISA 3.0 and RIBA 3.0 Chiron and for the presence of HCV RNA by RT-PCR. HCV genotyping was performed in 19 serum samples. Forty-one of 291 patients (14.1%) were anti-HCV positive by ELISA and RIBA. Both univariate and multivariate analysis showed a greater risk of anti-HCV positivity in those who had started a transfusion regime before 1992 and received more than 10 units of blood. Thirty-four of the anti-HCV-positive patients (34/41, 82.9%) were also HCV RNA positive. Univariate analysis, used to compare HCV RNA-negative and -positive patients, did not indicate a higher risk of HCV RNA positivity for any of the variables evaluated. The genotypes identified were 1b (63%), 1a (21%) and 3a (16%). A high prevalence of HCV infection was observed in our patients with sickle-cell anemia (14.1%) compared to the population in general (3%). In the literature, the frequency of HCV infection in sickle-cell anemia ranges from 2 to 30%. The serological screening for anti-HCV at blood banks after 1992 has contributed to a better control of the dissemination of HCV infection. Because of the predominance of genotype 1, these patients belong to a group requiring special treatment, with a probable indication of new therapeutic options against HCV.

Dynamic changes of HVR1 quasispecies in chronic hepatitis C after IFN therapy

AIM: To evaluate the correlation between the complexity of HCV HVR1 quasi-species and their response to IFN therapy in patients with chronic hepatitis C.

METHODS: Twenty patients with chronic hepatitis C received IFN therapy (3 mu/d, three times/week for 24 wk). Serum quasispecies complexity of HVR1 was analyzed by polymerase chain reaction mediated singl-strand conformation polymorphism (SSCP) before and 3 mo, 6 mo post-therapy, respectively.

RESULTS: Of 20 patients, 7 had low level of complexity (SSCP bands ≤ 3), 13 had high level of complexity (SSCP bands > 3). The rate of HCV RNA negative in low level complexity group was higher than that in high level complexity group. Patients with low level of complexity prior to therapy had good responsive to IFN; Serum HCV RNA in some patients did not convert to negative after IFN therapy, however, the number of SSCP bands decreased gradually.

CONCLUSION: HCV HVR1 quasi-species complexity is a predictive factor in response to IFN therapy, a statistically significant correlation between high level of complexity of HCV HVR1 quasi-species and lacking of response to IFN therapy in patients with chronic hepatitis C was found.

Treatment of chronic hepatitis C with pegylated-interferon

Introduction Since the discovery of the hepatitis C virus, the etiology of chronic liver diseases has been revealed in great number of patients. However, the treatment of hepatitis C viral infection still hasn?t been completely resolved. Antiviral and immunomodulatory effects of interferon, and antiviral effect on the nucleoside analogs were efficient only in small number of patients. Discovery of pegylated interferon brings progress in therapeutic success rates. Material and methods Combined therapy with peginterferon alfa-2a (Pegasys) 180mg once a week plus Ribavirin 800mg a day during a 24-week period was conducted in 20 patients (13 were previously treated with standard antiviral therapy). The aim of this study was to determine the safety and the efficacy of therapy in our patients. Results and discussion Analysis of safety of the combined therapy was conduced in all 20 patients, and analysis of efficiency in 18 patients. Efficacy of the combined therapy was assessed regarding to biochemical response (normalization of aminotransferase activity at the end of therapy and at the end of 6-month follow-up) and virologic response (disappearance of RNA HCV in serum at the end of 6-month follow-up). 30% of treated patients experienced no troubles during treatment. Influenza-like symptoms, weight loss, depression, hair loss and reaction at the site of injection were mild and did not exclude patients from their usual activities in family, society and work place. Neutropenia, thrombocytopenia and anemia as well as elevated aminotransferase activity demanded periodical dose modification in 20% of patients. Unexpected unwanted effect emerged in one patient after cessation of therapy (pulmonary sarcoidosis). Good effects of combined therapy at the end of follow-up period showed biochemical and virologic response in 66% of patients. Conclusion Combined therapy with Pegasys 180mg/week and Ribavirin 80mg/day is safe and well tolerated. Sustained biochemical and virologic response was achieved in 66% of patients.

Management issues in chronic viral hepatitis: hepatitis C

The natural history of chronic hepatitis C virus (HCV) infection and intervention with antiviral therapy are closely linked issues that cause the greatest controversy and concern for the person infected with HCV, as well as for the clinician involved in the assessment and treatment of people with chronic HCV infection. The outstanding challenge of natural history is to identify the person who is likely to develop serious liver disease, and to make that determination early in the course of chronic HCV infection when treatment is likely to be of the greatest benefit. Significant advances in the therapy of chronic HCV infection have occurred over the past decade. A sustained virological response (SVR), defined as undetectable HCV-RNA in blood 6 months after completing antiviral treatment, is the best indicator of a beneficial treatment effect. Relapse, breakthrough or non-response should all be regarded as unsuccessful outcomes of therapy. Interferons are still the mainstay of antiviral therapy for chronic HCV infection. The combination of interferon and ribavirin has improved SVR by decreasing the relapse rate. Treatment responses vary according to host factors such as age and gender, fibrotic severity and to viral factors like genotype and viral load. Patients with genotype 1 HCV and a high viral load require 12 months of treatment to achieve a SVR in approximately 30%, compared to those with genotypes 2 or 3 who achieve a SVR in approximately 65% after 6 months. Patients who relapse after an end-of-treatment response to interferon monotherapy have a good chance of responding to combination interferon and ribavirin given for 6 months, but a longer treatment course should be considered in less optimal cases. At present, the treatment of those with non-response is less clear, but there is interest in more intense forms of interferon therapy, such as induction dosing or pegylated interferon in combination with ribavirin. Clinicians need to be aware of the common side-effects of interferon and ribavirin so that appropriate counseling and testing can be instituted before and during therapy. The combination of pegylated interferon and ribavirin will be the new standard of therapy for hepatitis C and pegylated interferon monotherapy provides quite acceptable efficacy for those patients intolerant of ribavirin. Current data strongly support the concept that SVR in HCV infection (or treatment-induced latency) provides a cure in terms of its beneficial effects on quality of life and sustained amelioration of liver injury.

Molecular testing in the diagnosis and management of hepatitis C virus infection

OBJECTIVES

To review hepatitis C virus (HCV), describe the types of molecular-based tests available for the diagnosis and management of HCV infection, and discuss the appropriate utilization of these tests.

DATA SOURCES

Current information is presented from the published literature, as well as new information where available.

STUDY SELECTION

A major cause of posttransfusion and community-acquired non-A, non-B hepatitis worldwide is HCV. Approximately 4 million people in the United States are infected with HCV, resulting in 8000 to 10,000 deaths annually. Because HCV is not readily cultured, in vitro molecular-based tests have been developed for use in the diagnosis and treatment of HCV-infected patients. Molecular tests include qualitative and quantitative nucleic acid amplification tests, branched DNA tests, and HCV genotyping assays. Qualitative HCV nucleic acid amplification tests are used routinely in association with serologic tests to help make a diagnosis of infection with HCV. Quantitative HCV testing and genotyping methods have been found to be valuable tools in the treatment of infected patients. A patient's pretreatment HCV viral load and the rate of virus decline during therapy have been shown to correlate with the likelihood of long-term response to antiviral therapy. Information pertaining to the genotype of HCV infecting patients has been shown to be helpful in making recommendations regarding treatment. Certain genotypes of HCV are much more responsive to therapy, allowing a shorter course of treatment.

CONCLUSIONS

Molecular tests are valuable tools for use in the diagnosis and treatment of patients infected with HCV.

Interferon-alpha inhibits hepatitis C virus subgenomic RNA replication by an MxA-independent pathway

Hepatitis C virus (HCV) persists in the majority of infected individuals and is a major cause of chronic hepatitis, liver cirrhosis and hepatocellular carcinoma. Chronic hepatitis C is currently treated with interferon (IFN)-alpha or with a combination of IFN-alpha and ribavirin. The availability of an HCV replicon system (Lohmann et al., SCIENCE: 285, 110-113, 1999) allowed the investigation of the effects of IFN on genuine HCV replication in cultured cells. It is shown here that IFN-alpha inhibits subgenomic HCV RNA replication in HuH-7 human hepatoma cells. Immunofluorescence, Western blot and Northern blot analysis revealed that levels of both HCV protein and replicon RNA were reduced after treatment with IFN-alpha in a dose-dependent manner. In further experiments, it was investigated whether MxA plays a role in the inhibition of HCV. The human MxA protein is an IFN-induced GTPase that has antiviral activity against various RNA viruses. However, HCV RNA replication was not affected in transfected HuH-7 cells that transiently overexpressed MxA. Moreover, a dominant-negative mutant of MxA did not interfere with the antiviral activity of IFN-alpha against HCV RNA replication. Taken together, these results demonstrate that IFN-alpha inhibits HCV replicons via an MxA-independent pathway.