Detection of hepatitis C virus by polymerase chain reaction and response to interferon-alpha therapy: relationship to genotypes of hepatitis C virus

Rapid Detection of SARS-CoV-2 RNA Using Reverse Transcription Recombinase Polymerase Amplification (RT-RPA) with Lateral Flow for N-Protein Gene and Variant-Specific Deletion-Insertion Mutation in S-Protein Gene

Rapid molecular testing for severe acute respiratory coronavirus 2 (SARS-CoV-2) variants may contribute to the development of public health measures, particularly in resource-limited areas. Reverse transcription recombinase polymerase amplification using a lateral flow assay (RT-RPA-LF) allows rapid RNA detection without thermal cyclers. In this study, we developed two assays to detect SARS-CoV-2 nucleocapsid (N) gene and Omicron BA.1 spike (S) gene-specific deletion-insertion mutations (del211/ins214). Both tests had a detection limit of 10 copies/µL in vitro and the detection time was approximately 35 min from incubation to detection. The sensitivities of SARS-CoV-2 (N) RT-RPA-LF by viral load categories were 100% for clinical samples with high (>9015.7 copies/µL, cycle quantification (Cq): < 25) and moderate (385.5-9015.7 copies/µL, Cq: 25-29.9) viral load, 83.3% for low (16.5-385.5 copies/µL, Cq: 30-34.9), and 14.3% for very low (<16.5 copies/µL, Cq: 35-40). The sensitivities of the Omicron BA.1 (S) RT-RPA-LF were 94.9%, 78%, 23.8%, and 0%, respectively, and the specificity against non-BA.1 SARS-CoV-2-positive samples was 96%. The assays seemed more sensitive than rapid antigen detection in moderate viral load samples. Although implementation in resource-limited settings requires additional improvements, deletion-insertion mutations were successfully detected by the RT-RPA-LF technique.

Association of Toll-Like Receptor 3 and Toll-Like Receptor 9 Single Nucleotide Polymorphisms with Hepatitis C Virus Infection and Hepatic Fibrosis in Egyptian Patients

Toll-like receptors (TLRs) are recognized as fundamental contributors to the immune system function against infections. Hepatitis C virus (HCV) infection represents a global health problem especially in Egypt having the highest HCV prevalence worldwide where HCV infection is a continuing epidemic. The aim of the present study was to investigate the possible association between genetic variation in TLR-3 and TLR-9 and HCV infection and hepatic fibrosis in chronic HCV-positive Egyptian patients. The present study included 100 naïve chronic HCV-positive patients and 100 age- and sex-matched healthy controls. Genotyping of TLR-3 (_7 C/A [rs3775296]), TLR-3 (c.1377C/T [rs3775290]) and TLR-9 (1237T/C [rs5743836]) were done by polymerase chain reaction restriction fragment length polymorphism technique. Frequency of polymorphic genotypes in TLR-3 (_7 C/A), TLR-3 (c.1377C/T) and TLR-9 (1237T/C) were not significantly different between studied HCV-positive patients and controls with P values 0.121, 0.112, and 0.683, respectively. TLR-3 c.1377 T-allele was associated with advanced stage of hepatic fibrosis (P = 0.003).

Discrepant diagnostic results using two genotyping methods in a chronic hepatitis C patient in serogroup 1

We present the case of a chronic hepatitis C (CHC) patient who was originally diagnosed with genotype 2a on serogroup 1 CHC genotype testing, but who was subsequently confirmed to have genotype 1b when using the hepatitis C virus (HCV) monitor genotype assay. The genotype 2a diagnosis was attributed to the fact that the type 2a-specific primer used in Okamoto et al.'s method (HCV genotype primer kit) has relatively high homology, which caused the amplification reaction to proceed, rendering a HCV RNA genotype test result of 2a. Genotype testing is important in determining whether a patient is indicated for concomitant dual oral therapy; however, the potential for different diagnoses such as described in this report highlights the importance of serogroup confirmation.

Evaluation of Interferon Resistance in Newly Established Genotype 1b Hepatitis C Virus Cell Culture System

BACKGROUND AND AIMS

The hepatitis C virus (HCV) genotype 1b is known to exhibit treatment resistance with respect to interferon (IFN) therapy. Substitution of amino acids 70 and 91 in the core region of the 1b genotype is a significant predictor of liver carcinogenesis and poor response to pegylated-IFN-α and ribavirin therapy. However, the molecular mechanism has not yet been clearly elucidated because of limitations of the HCV genotype 1b infectious model. Recently, the TPF1-M170T HCV genotype 1b cell culture system was established, in which the clone successfully replicates and infects Huh-7-derived Huh7-ALS32.50 cells. Therefore, the purpose of this study was to compare IFN resistance in various HCV clones using this system.

METHODS

HCV core amino acid substitutions R70Q and L91M were introduced to the TPF1-M170T clone and then transfected into Huh7-ALS32.50 cells. To evaluate the production of each virus, intracellular HCV core antigens were measured. RESULTS were confirmed with Western blot analysis using anti-NS5A antibodies, and IFN sensitivity was subsequently measured.

RESULTS

Each clone was transfected successfully compared with JFH-1, with a significant difference in intracellular HCV core antigen (p < 0.05), an indicator of continuous HCV replication. Among all clones, L91M showed the highest increase in the HCV core antigen and HCV protein. There was no significant resistance against IFN treatment in core substitutions; however, IFN sensitivity was significantly different between the wildtype core and JFH-1 (p < 0.05).

CONCLUSIONS

A novel genotype 1b HCV cell culture was constructed with core amino acid substitutions, which demonstrated IFN resistance of genotype 1b. This system will be useful for future analyses into the mechanisms of HCV genotype 1b treatment.

Optimum predictors of therapeutic outcome in HCV patients in Pakistan

Hepatitis C virus (HCV) constitutes a major public health issue in Pakistan. Interferon α and ribavirin is used widely in routine practice in HCV infected patients in Pakistan.Treatment prediction is an important tool in therapy management. The present study aims to evaluate trends of predictive variables of treatment outcome in patients with different genotypes. The analysis comprised of 921 patients infected with different HCV genotypes. All the patients received IFN α-2b combined with ribavirin for 24 weeks. Overall, 60.2% patients achieved Sustained virologic response (SVR). In females sustained virologic response (SVR) was higher in age group <40 years (77.2%) than ≥40-50 years (60%) but in male SVR was almost equal in both age groups. We also found higher SVR with low pretreatment viral load (72.4%, P < 0.0001). Sustained Virologic Response in genotype 3a was 63.1%, 3b was 55%, 1a was 36.3% and 1b was 35% 3a +3b was 55.0% and 1a+3a was 42.9%. According to multivariable logistic regression analysis age < 40 years (2.0; 95%CI, 1.49-2.84; P = 0.0001), low pretreatment RNA level<800,000 IU/ml (4.0; 95%CI, 2.64-6.17; P = 0.0001), early virologic response at week 12 (12.3; 95%CI, 8.18-18.58; P < 0.0001) and non-fatty liver (2.5; 95%CI, 3.6-6.2; P = 0.005) showed significance for SVR. Nucleotide substitution in 5'UTR before treatment failed to show any characteristic pattern that has correlation with sustained response. Subtype 3a showed 95% presence among patients with age <40 years while older patients showed 79.9%.

Occurrence of genetic modifications in core, 5'UTR and NS5b of HCV associated with viral response to treatment

Background

It is becoming progressively more understandable that genetic variability of viruses is a major challenge in translating the laboratory findings to clinic. Genetic variability is the underlying cause of variant viral proteins which are not targetable by host immunological machinery.

Methods

500 patients were enrolled in study and amongst them, 451 patients were followed and categorized into two groups on the basis of their treatment response. Group 1 consisting of the 376 patients exhibited SVR while group 2 comprised 75 patients who were non-responders on the basis of viral load as evidenced by Real-Time PCR. Comparative sequence analysis was done between 75 non-responders and 75 responders (randomly picked from 376) by targeting three genomic regions, 5′UTR, core and NS5B and amplified products were directly sequenced and obtained sequences were cleaned, aligned and submitted to GenBank. Maximum Parsimony (MP) method was used for phylogenetic analysis and dendrograms were dragged using MEGA 5. Heterogeneity at nucleotide and amino acid level was determined using software BioEdit and DNAman while phosphorylation and N-linked glycosylation sites were determined using NetPhos 2.0 and SignalP-NN.

Results

Genotype 3 was prevalent in group 1 whereas non-responders indicated rare genotypes of Pakistan i.e. 4 and 5, genotype 6q and 6v were reported first time from Pakistan in this study. At nucleotide and amino acid level, the genetic distance and mutation, number of predicted N-phosphorylation and N-glycosylation sites was higher in group 2 as compared to group 1. Difference in percentage composition of individual amino acids was noted to be different between the two groups.

Conclusions

It can be concluded that heterogeneity both at nucleotide and amino acid level contributed in developing drug resistant phenotype. Moreover, occurrence of rare genotypes might hurdle the way to positive response of conventional treatment. Furthermore, prediction of phosphorylation and glycosylation sites could help in targeting the proper sites for drug designing.

HCV NS3 Blocking Effect on IFN Induced ISGs Like Viperin and IL28 With and Without NS4A

BACKGROUND

Hepatitis C virus (HCV) is able to down-regulate innate immune response. It is important to know the immune pathways that this virus interacts with. HCV non-structural protein 3 (NS3) plays an important role in this viral feature. HCV NS3 protein could affect the expression of antiviral protein such as viperin, and interleukin 28whichare important proteins in antiviral response.

OBJECTIVES

HCV has developed different mechanisms to maintain a persistent infection, especially by disrupting type I interferon response and subsequent suppression of expression of Interferon stimulatory genes (ISGs). Viperin, a member of ISGs, is considered as a host antiviral protein, which interferes with viral replication. Since it is a good target for some viruses to evade host responses, it is interesting to study if HCV has evolved a mechanism to interfere with this member of ISGs.

MATERIALS AND METHODS

We evaluated the impact of NS3, NS3/4A and a mutated nonfunctional NS3 on ISGs expression such as viperin and IL-28 after the induction of IFN signaling Jak-STAT pathway using IFN-.

RESULTS

NS3 protein disrupted the expressions of viperin gene and IL-28, an inducer for the expression of ISGs and viperin itself. By comparing the roles of NS3 and NS3/4A protease activities in suppressing the innate immune responses, we also showed that NS3 (without NS4A) has the ability to down-regulate ISGs expression, similar to that of NS3/4A.

CONCLUSIONS

ISGs expression is impeded by NS3 protease activity and its interaction with Jak-STAT pathway proteins. In addition, the NS3/4A substrates spectrum seems to be similar to those of NS3.

Association between hepatic steatosis and hepatic expression of genes involved in innate immunity in patients with chronic hepatitis C

BACKGROUNDS/AIMS

We investigated the association between hepatic steatosis and hepatic expression of genes involved in innate immunity, both of which are reportedly associated with resistance to peginterferon (PEG-IFN) and ribavirin combination therapy for hepatitis C virus (HCV) infection.

METHODS

A total of 122 patients infected with HCV genotype 1b who underwent and completed PEG-IFN and ribavirin combination therapy were studied. Hepatic steatosis was evaluated on the basis of the liver specimen biopsied prior to antiviral therapy. The levels of mRNA of innate immunity genes (RIG-I, MDA5, LGP2, Cardif, RNF125, ISG15, and USP18) were measured by real-time polymerase chain reaction in RNA extracted from biopsied liver tissue and compared between patients with and without hepatic steatosis.

RESULTS

The proportion of patients with hepatic steatosis, the hepatic expression levels of RIG-I gene, and RIG-I/Cardif and RIG-I/RNF125 ratios were significantly higher in patients in whom serum HCV RNA did not disappear throughout the treatment period. Hepatic expression of RIG-I and the ratios of RIG-I/Cardif and RIG-I/RNF125 were significantly higher in patients with steatosis than those without.

CONCLUSIONS

Changes in hepatic expression of some genes involved in innate immunity were observed along with hepatic steatosis, possibly playing a mechanistic role in resistance to IFN-based therapy in patients with hepatic steatosis.

Distribution of hepatitis C virus genotypes in Canada: Results from the LCDC Sentinel Health Unit Surveillance System

In a sentinel hepatitis surveillance study conducted by sentinel health units, 1469 patients were enrolled, and 959 (65.3%) were positive for antibody to hepatitis C virus (HCV). Samples from 387 patients (40.4%) were tested for HCV RNA, and 289 (74.7%) were positive for RNA. The major risk factor for HCV infection was injection drug use, reported in 71% of cases. The genotyping of HCV isolates showed that subtype 1a (48%) was predominant in Canada. The other subtypes detected were 1b (19%), 2a (6%), 2b (3%), 3a (22%) and 4a (1%). In Winnipeg, Manitoba, subtype 3a (47%) was more prevalent than subtype 1a (37%), and, in Guelph, Ontario, both subtypes 1a and 3a had equal (40%) distribution. The prevalence of subtype 3a was significantly higher in injection drug users (27%) than in nonusers (10%) (P<0.005). In Canada, injection drug use is the major risk factor for HCV infections, and subtype 1a is more prevalent.

Hepatitis C viral heterogeneity based on core gene and an attempt to design small interfering RNA against strains resistant to interferon in rawalpindi, pakistan

BACKGROUND

Global prevalence of Hepatitis C Virus (HCV) infection corresponds to about 130 million HCV positive patients worldwide. The only drug that effectively reduces viral load is interferon-α (IFN-α) and currently combination of IFN and ribavirin is the choice for treatment.

OBJECTIVES

The present study is aimed to resolve the genotypes based on core gene that might affect the response to interferon therapy. Furthermore an attempt was made to propose a powerful therapeutic approach by designing the siRNA from sequences of the same patients who remain resistant to IFN in this study.

PATIENTS AND METHODS

To achieve the objectives, a sequence analysis was performed in five HCV ELISA positive subjects who have completed IFN treatment. Neighbor Joining (NJ) method was used to study the evolutionary relationship. Atomic models were predicted using online software PROCHECK and i- TASSER.

RESULTS

Two new genotypes were reported for the first time namely 4a from suburban region of Rawalpindi and 6e from all over the Pakistan. According to Ramachandran plot, satisfactory atomic model was considered useful for further studies, i.e. to calculate HCV genotypes conservation at structural level, to find out critical binding sites for drug designing, or to silence those binding sites by using appropriate siRNA. Single siRNA can be used to inhibit HCV RNA synthesis against genotype 3 and 4, as the predicted siRNA were originated from the same domain in studied HCV core region in both genotypes.

CONCLUSIONS

We can conclude that any change or mutation in core region might be the cause of HCV strains to resist against IFN therapy. Therefore, further understanding of the complex mechanism involved in disrupting viral response to therapy would facilitate the development of more effective therapeutic regimens. Additionally, a single designed siRNA can be used as an alternative for current therapy against more than one resistant HCV genotypes.

Replication and infectivity of a novel genotype 1b hepatitis C virus clone

Hepatitis C virus infection is a major public health problem because of an estimated 170 million carriers worldwide. Genotype 1b is the major subtype of HCV in many countries and is resistant to interferon therapy. Study of the viral life cycle is important for understanding the mechanisms of interferon resistance of genotype 1b HCV strains. For such studies, genotype 1b HCV strains that can replicate and produce infectious virus particles in cultured cells are required. In the present study, we isolated HCV cDNA, which we named the NC1 strain, from a patient with acute severe hepatitis. Subgenomic replicon experiments revealed that several mutations enhanced the colony-formation efficiency of the NC1 replicon. The full-length NC1 genome with these adaptive mutations could replicate in cultured cells and produce infectious virus particles. The density gradient profile and morphology of the secreted virus particles were similar to those reported for the JFH-1 virus. Further introduction of a combination of mutations of the NS3 and NS5a regions into the NC1 mutants further enhanced secreted core protein levels and infectious virus titers in the culture medium of HCV-RNA-transfected cells. However, the virus infection efficiency was not sufficient for autonomous virus propagation in cultured cells. In conclusion, we established a novel cell culture-adapted genotype 1b HCV strain, termed NC1, which can produce infectious virus when the viral RNA is transfected into cells. This system provides an important opportunity for studying the life cycle of the genotype 1b HCV.

Impact of HCV genetic differences on pathobiology of disease

Multiple HCV genotypes have been isolated worldwide. Genotype seems to be involved in the main pathological aspects of HCV infection. Insulin resistance, steatosis and progression toward cirrhosis, fibrosis and hepatocellular carcinoma establish and develop following genotype-specific mechanisms. Moreover genotype influences pharmacological treatment in term of dose and duration. Pathways involved in cell proliferation, apoptosis, lipid metabolism, insulin and interferon signaling are impaired to a different extent among genotypes, leading to distinct pathological settings. Genotype 1 is associated with a more aggressive disease with increased insulin resistance, worst response to therapy, higher risk of cirrhosis and hepatocellular carcinoma development, while genotype 3 is associated with increased steatosis and fibrosis. The identification and characterization of HCV types and subtypes provides insight into the different outcome of HCV infection and responsiveness to therapy. In the present article, we focused on the pathogenicity of HCV genotypes and their effect on disease progression and treatment.

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.

Development of recombinant hepatitis C virus with NS5A from strains of genotypes 1 and 2

Nonstructural protein 5A (NS5A) of hepatitis C virus (HCV) plays multiple and diverse roles in the viral lifecycle, and is currently recognized as a novel target for anti-viral therapy. To establish an HCV cell culture system with NS5A of various strains, recombinant viruses were generated by replacing NS5A of strain JFH-1 with those of strains of genotypes 1 (H77; 1a and Con1; 1b) and 2 (J6CF; 2a and MA; 2b). All these recombinant viruses were capable of replication and infectious virus production. The replacement of JFH-1 NS5A with those of genotype 1 strains resulted in similar or slightly reduced virus production, whereas replacement with those of genotype 2 strains enhanced virus production as compared with JFH-1 wild-type. A single cycle virus production assay with a CD81-negative cell line revealed that the efficient virus production elicited by replacement with genotype 2 strains depended on enhanced viral assembly, and that substitutions in the C-terminus of NS5A were responsible for this phenotype. Pulse-chase assays revealed that these substitutions in the C-terminus of NS5A were possibly associated with accelerated cleavage kinetics at the NS5A-NS5B site. Using this cell culture system with NS5A-substituted recombinant viruses, the anti-viral effects of an NS5A inhibitor were then examined. A 300- to 1000-fold difference in susceptibility to the inhibitor was found between strains of genotypes 1 and 2. This system will facilitate not only a better understanding of strain-specific roles of NS5A in the HCV lifecycle, but also enable the evaluation of genotype and strain dependency of NS5A inhibitors.

Prevalence of hepatitis C virus (HCV) genotypes among positive UAE patients

A molecular study was conducted to investigate the prevalence of Hepatitis C virus genotypes in HCV infected population of UAE. 67 HCV seropositive samples were collected from different health care centres. Quantitative analysis of these samples using PCR resulted in 67 positive samples. The PCR positive samples were subjected to genotyping using the method described by Simmonds et al. (J Gen Virol 74: 2391-2399, 1993). HCV genotype 4 was the predominant genotype (46.2%) followed by genotype 3a (23.8%) and 1a (15%). The predominant genotype among the female patients was genotype 4 (65.6%), while genotype 3a was the predominant among the male patients (42.8%). The predominance of HCV genotype 4 in our population confirms the predominance of HCV genotype 4 in UAE and most of the Arab countries in the Middle East. Implications of genotyping for clinical outcome of HCV infection, response to treatment as well as for vaccine development are discussed.

Peginterferon and ribavirin treatment for hepatitis C virus infection

Pegylated interferon α (IFNα) in combination with ribavirin is currently recommended as a standard-of-care treatment for chronic hepatitis C virus (HCV) infection. This combination therapy has drastically improved the rate of sustained virological response, specifically in difficult-to-treat patients. Recently, individualized treatment, such as response-guided therapy, is being developed based on host-, HCV- and treatment-related factors. Furthermore, modified regimens with currently available medications, novel modified IFNα and ribavirin or combinations with specifically targeted antiviral therapy for HCV agents, are currently being investigated. The purpose of this review is to address some issues and epoch-making topics in the treatment of chronic HCV infection, and to discuss more optimal and highly individualized therapeutic strategies for HCV-infected patients.

Hepatitis C virus: How genetic variability affects pathobiology of disease

As an RNA virus, hepatitis C virus (HCV) shows a characteristically high level of nucleotide diversity. Accumulation of nucleotide substitutions in the virus has resulted in diversification into quasispecies, subtypes and distinct genotypes. Pathobiological studies linking nucleotide and amino acid sequences with clinical findings have identified relationships between certain genotypes and characteristic biological properties. Genotype 3 HCV infection was found to be associated with a high level of liver steatosis. Genotypes 1 and 4 were found to be more resistant to interferon (IFN) based therapies than genotypes 2 and 3. Studies of genotype 1 sequences obtained from patients treated with IFN have identified a relationship between favorable response to interferon therapy and amino acid substitutions in the NS5A region (interferon response determining region; ISDR). Further studies have identified a relationship between the effect of IFN therapy and other regions of the NS5A protein. More recently, a relationship has been found between poor response to peg-IFN plus ribavirin combination therapy and substitutions at amino acid 70 and 91 in the core protein. Furthermore, a correlation between human genetic variation in the IL28B (IFN-lamda 3) locus and core amino acid substitutions has been characterized. In this review we briefly summarize the discovery, classification and nomenclature of HCV genotypes and subtypes. We also discuss amino acid substitutions within specific regions that have been reported to be associated with outcome of IFN and peg-IFN plus ribavirin combination therapy.

Distribution of hepatitis C virus genotypes, hepatic steatosis and their correlation with clinical and virological factors in Pakistan

Background: Due to the inherently unstable nature of HCV, various genotypes have been identified. Steatosis is a histological feature in the progression of HCV-associated liver disease and has been shown to alter the host lipid metabolism. Objective: Assess the distribution of HCV genotypes in the two provinces of Pakistan, and determine the association of hepatic steatosis with altered clinical and virological factors in chronic HCV patients. Methods: One hundred twenty six chronic HCV patients (steatosis in 49 patients) were enrolled for qualitative analysis by PCR. Out of 126 ELISA and PCR positive samples, 119 (48 with hepatic steatosis) chronic HCV patients (mean age 42.0±13.3 years, mean body mass index (BMI) 24.2±4.1) were proved positive after PCR-based detection. Biochemical and virological factors such as HCV genotype, or glucose, in 119 CHC patients were determined and compared between patients with and without hepatic steatosis. Results: Out of 126 samples, 119 were HCV positive, where 58 (48.7%) were genotype 3a, 24 (20.2%) were 3b, 12 (10.1%) were 1a, eight (6.7%) were 2a, six (5.0%) were 1b, and one (0.8%) was 4. Furthermore, seven (5.9%) had a co-infection and three (2.5%) were untypable. BMI (p=0.004), genotype 3a (p<0.001), and triglycerides (p=0.002) were significantly associated with steatosis. It is noteworthy that cholesterol (p=0.281), glucose (p=0.305), lowdensity lipoprotein (p=0.101), high-density lipoprotein (p=0.129), alanine amino transferase (p=0.099), aspartate transaminase (p=0.177), bilirubin (p= 0.882), and age (p=0.846) showed non-significant association. Conclusion: Genotype 3a is the predominant genotype in Pakistan. Hepatic steatosis is quite frequent feature in HCV patients and strongly correlates with BMI, genotype 3a, and triglyceride contents in patients infected with HCV.

Immediate virological response predicts the success of short-term peg-interferon monotherapy for chronic hepatitis C

AIM: To investigate the efficacy of short-term peg-interferon (PEG-IFN) monotherapy for chronic hepatitis C patients who achieved an immediate virological response.

METHODS: Defining an “immediate virological response (IVR)” as the loss of serum hepatitis C virus (HCV) RNA 7 d after the first administration of PEG-IFN α, we conducted a 12-wk course of PEG-IFN α2a monotherapy without the addition of ribavirin for 38 patients who had low pretreatment HCV RNA load and exhibited IVR. The patients included 21 men and 17 women, whose ages ranged from 22 to 77 years (mean ± SD: 52.0 ± 17.8 years). There were 4 patients with HCV genotype 1b, 23 patients with genotype 2a and 4 patients with genotype 2b. HCV genotype was not determined for the remaining 7 patients. Patients were categorized into a sustained virological response (SVR) group, if serum HCV RNA remained negative for 24 wk after the end of treatment, or into a relapse group.

RESULTS: Based on the intention-to-treat analysis, 35 patients (92.1%) achieved SVR. One patient (2.6%) relapsed with serum HCV RNA 12 wk after the end of treatment. Two patients (5.3%) withdrew from the study during the 24-wk follow-up period. With regard to the HCV RNA genotype, the SVR rates were 100% (4/4) for genotype 1b, 95.7% (22/23) for genotype 2a and 100% (4/4) for genotype 2b. The SVR rate in 7 patients, whose HCV RNA genotypes were not determined, was 71.4% (5/7).

CONCLUSION: Short-term PEG-IFN α2a monotherapy is highly effective for chronic hepatitis C patients who have low pretreatment HCV RNA load and exhibit IVR.

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

BACKGROUND/AIMS

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Phylogeography and molecular epidemiology of hepatitis C virus genotype 2 in Africa

Understanding the origin and nature of hepatitis C virus (HCV) genetic diversity is critical for improving treatment and vaccine design, and such diversity is the sole source of information about the virus' epidemic history prior to its identification 20 years ago. In this paper, we study the molecular epidemiology of HCV genotype 2 in its region of endemic origin, west and central Africa. Our analysis includes 56 new and highly diverse HCV isolates sampled from infected individuals in Guinea-Bissau. By combining phylogenetic, geographical and epidemiological information, we find a previously unappreciated geographical structure in the diversity of HCV genotype 2, pointing to a history of eastwards spatial spread from the west African coast to Cameroon that took place over several centuries. Molecular clock analysis dates the common ancestor of HCV in Guinea-Bissau to 1470 (1414-1582). The phylogenetic position of isolates from Madagascar and Martinique suggests a role for the historical slave trade in the global dissemination of HCV and of the epidemic subtypes 2a and 2c. Coalescent-based estimates of epidemic growth indicate a rapid 20th-century spread of HCV genotype 2 in Cameroon that is absent in Guinea-Bissau. We discuss this contrast in the context of possible parenteral HCV exposure during public-health campaigns undertaken during the colonial era.

Four-week pegylated interferon α-2a monotherapy for chronic hepatitis C with genotype 2 and low viral load: A pilot, randomized study

AIM: To assess the efficacy and advantages of 4-wk pegylated interferon α-2a (peg-IFN-α2a) monotherapy for chronic hepatitis C patients with strong predictors of sustained virologic response (SVR).

METHODS: Patients (n = 33) with genotype 2 and low viral load (< 100 KIU/mL), who became HCV RNA negative after 1 wk of IFN treatment, were randomly allocated to receive a 4- or 12-wk treatment course at a ratio of 2:1, respectively, with a subsequent 24-wk follow-up period. Peg-IFN-α2a was administered subcutaneously at a dose of 180 μg or 90 μg once weekly. SVR was defined as absence of serum HCV RNA at the end of the follow-up period.

RESULTS: All patients completed the treatment schedule, and more than half were symptom-free during the treatment. In the 4-wk treatment group, 20 of 22 (91%) patients achieved SVR. Two patients relapsed, but achieved SVR following re-treatment with peg-IFN-α2a alone. In the 12-wk treatment group, 11 of 11 (100%) patients attained SVR.

CONCLUSION: Our results show that a 4-wk course of peg-IFN-α2a monotherapy can achieve a high SVR rate in “IFN-sensitive” patients, without negatively affecting outcome.

Prevalence of hepatitis C virus (HCV) genotypes in Balochistan

A molecular study was conducted to investigate the prevalence of Hepatitis C virus genotypes in HCV infected population of Balochistan. Forty HCV seropositive samples belonging to seven different locations of Balochistan were collected from different health care centres. Qualitative analysis of these samples using PCR resulted in 28 positive samples. The PCR positive samples were subjected to genotyping using the method described by Ohno et al (J Clin Microbiol 35:201-202, 1997) with minor modifications. Genotyping of 28 samples revealed three different genotypes including 3a, 3b and 1a. The most prevalent genotype was 3a with rate of 50% followed by genotype 3b and 1a, respectively. Nine samples remained untyped, suggesting the need of further investigation of genotypes in this region. It has been proposed that sequencing of these samples may be helpful to unreveal these genotypes and further epidemiology of HCV genotypes. Further more, extensive and large scale studies are needed to understand the epidemiology of HCV genotypes, as no such study has been carried in this province.

Genotyping of Hepatitis C virus (HCV) in infected patients from South India

Hepatitis C virus shows substantial nucleotide sequence diversity distributed throughout the viral genome. In the present study genotyping for Hepatitis C virus (HCV) infected patients was based on RFLP analysis of 5' UTR and using type specific primers of NS5B regions. It was observed that 60% of the patients (30 patients with chronic hepatitis) were infected with variants of genotype 1 and 40% of the patients (4 chronic hepatitis patients, 12 patients with chronic renal failure and 4 cirrhosis) were infected with variants of type 3 of HCV. None of the cirrhotic patients and patients with chronic renal failure, in the present study, were infected with type 1 of HCV. While PCR-RFLP, typing was rapid in conjunction with the primers used for RT-PCR, NS5 typing was helpful in determining the subtype. There was good correlation between the two typing methods and this method can be used as a cost-effective method for studying large number of samples. The study shows that predominant genotypes of HCV in South India include type 1 and 3. Type 3 seems to be transmitted nosocomially as suggested by the results in patients with chronic renal failure, as these patients are exposed to multiple medical interventions.

Efficacy of interferon treatment for chronic hepatitis C predicted by feature subset selection and support vector machine

Chronic hepatitis C is a disease that is difficult to treat. At present, interferon might be the only drug, which can cure this kind of disease, but its efficacy is limited and patients face the risk of side effects and high expense, so doctors considering interferon must make a serious choice. The purpose of this study is to establish a simple model and use the clinical data to predict the interferon efficacy. This model is a combination of Feature Subset Selection and the Classifier using a Support Vector Machine (SVM). The study indicates that when five features have been selected, the identification by the SVM is as follows: the identification rate for the effective group is 85%, and the ineffective group 83%. Analysis of selected features show that HCV-RNA level, hepatobiopsy, HCV genotype, ALP and CHE are the most significant features. The results thus serve for the doctors' reference when they make decisions regarding interferon treatment.

Prolonged Negative HCV-RNA Status Led to a Good Outcome in Chronic Hepatitis C Patients with Genotype 1b and Super-High Viral Load

OBJECTIVE

We examined whether a sustained negative HCV-RNA status for 48 weeks affects the outcome in patients with genotype 1b and super-high viral load, and also investigated whether the outcome is affected by the induction therapy of twice-daily pre-administrated interferon (IFN)-beta.

METHODS

78 eligible patients were divided into four groups. 40 were patients assigned to the short treatment protocol. 13 patients received 3 MU IFN-beta twice daily for 2 weeks followed by IFN-alpha2b+ribavirin for 22 weeks (beta-induction group: group 1). 27 patients received IFN-alpha2b+ribavirin for 24 weeks (standard combination group: group 2). 38 patients were assigned to the maintenance treatment protocol. All of the 13 in the beta-induction group (group 3) and 21 of 25 patients in the standard combination group (group 4) who were negative HCV-RNA PCR at week 24 had IFN monotherapy to maintain a negative HCV-RNA result for 48 weeks.

RESULTS

An HCV-RNA-negative status at week 24 was observed in 96% (25/26) of groups 1 and 3 versus in 79% (41/52) of groups 2 and 4 (p<0.01). The sustained virological response (SVR) was 38% (5/13) in group 1 and 11% (3/27) in group 2 (p<0.05). In the maintenance treatment, SVR was observed in 46% (6/13) of group 3 and 32% (8/25) of group 4 (NS).

CONCLUSIONS

A sustained negative HCV-RNA status for 48 weeks might be associated with viral elimination in patients with genotype 1 and super-high viral load.

Distribution of hepatitis C virus genotypes in patients infected by different sources and its correlation with clinical and virological parameters: a preliminary study

BACKGROUND

Information about genotypes and associated risk factors in hepatitis C virus (HCV) infected patients in Iran is limited. The aim of this study was to identify the HCV genotypes and associated risk factors in a group of HCV infected patients from Iran.

RESULTS

Genotyping analysis was performed in 156 patients with positive anti-HCV and HCV-RNA. Patients were questioned concerning documented risk factors. Genotypes 1 and 3 were found in 87 (55.8%) and 45 (28.8%) patients, respectively. The most frequent HCV subtype was 1a (37.8), followed by 3a (28.9%) and 1b (16.7%). There was no statistically significant difference between the risk factors analyzed and the acquisition of HCV infection. We further found that 18 (40%) and 17 (37.8%) patients that were intravenous drug users (IVDU) had genotype 1a and 3a respectively.

CONCLUSION

Genotypes 3a and 1a in Iran are less prevalent in IVDU than in Europe and USA, but there is a high similarity between the pattern of genotype in IVDU in both Europe and United States, and Iran. However, in this case it can not be due to people migration among countries since history of travel abroad existed only in 6 cases (13.3%).

Selective inhibitors of hepatitis C virus replication

Worldwide over 170 million people are chronically infected with the hepatitis C virus and hence at high risk to develop fatal liver disease. There is no vaccine available and the standard therapy [(pegylated) interferon alfa plus ribavirin] is only effective in 50-60% of patients and is associated with important side-effects. The discovery of novel antiviral strategies to selectively inhibit HCV replication has long been hindered by the lack of convenient cell culture models for the propagation of HCV. This hurdle has been overcome first with the establishment of the HCV replicon system in 1999 and, in 2005, with the development of robust HCV cell culture models. In recent years also mouse models have been elaborated that will be instrumental in assessing the in vivo efficacy of novel drugs. The viral serine protease and the viral RNA dependent RNA polymerase have shown to be excellent targets for selective anti-HCV therapy. Clinical studies with a limited number of HCV protease and polymerase inhibitors resulted in encouraging results. However, and not unexpected, preclinical evidence suggest that the virus may become rapidly resistant to such inhibitors. Combination therapy of drugs with different mode of action and resistance profiles may thus be required. Alternative strategies, such as the use of non-immunosuppressive cyclosporin A analogues with potent anti-HCV activity, may prove important, in particular since such compounds may have a resistance profile that is very different from that of protease or polymerase inhibitors.

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

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

Morphology of hepatitis C and hepatitis B virus particles as detected by immunogold electron microscopy

We performed indirect immunogold electron microscopy (EM) for immunological identification and characterization of hepatitis C virus (HCV). To clarify the morphology of HCV, an indirect immunogold EM of two plasma samples from patients with high HCV RNA titers was carried out using antibodies specific for the putative HCV envelope protein (E) 1. Spherical virus particles 55-65 nm in diameter with delicate spike projections were detected in the 1.14-1.16 g/ml fractions after sucrose density gradient centrifugation. Polyclonal and monoclonal antibodies to the putative HCV E1 specifically recognized these particles. In addition, immunogold EM of the samples was also performed to uncover the morphology of HCV core particles. Spherical particles 33-40 nm in diameter (average, 37 nm) were detected in the 1.22- to 1.25-g/ml fractions by conventional EM after sucrose density gradient centrifugation. Immunogold EM using rabbit polyclonal antibody (RR8) specific for the putative HCV core protein and colloidal gold-labeled goat antirabbit IgG showed binding of the gold particles with RR8. Some of the HCV core particles showed icosahedric morphology. Optical rotation technique showed that the HCV core particles exhibit sixfold symmetry and that the length of the regular hexagon side is approximately 20 nm, suggesting that they have an icosahedric structure. Further, the detection limit of the indirect immunogold EM was evaluated in 11 plasma samples from chronic hepatitis B patients with different degrees of hepatitis B virus (HBV) DNA titers using antihepatitis B surface antigen antibody. The study showed that the detection limit of virus using this method is 10(7) virions/ml.

Mutations in carboxy-terminal part of E2 including PKR/eIF2alpha phosphorylation homology domain and interferon sensitivity determining region of nonstructural 5A of hepatitis C virus 1b: their correlation with response to interferon monotherapy and viral load

AIM

To study the amino acid substitutions in the carboxy (C)-terminal part of E2 protein and in the interferon (IFN) sensitivity determining region (ISDR) and their correlation with response to IFN and viral load in 85 hepatitis C virus (HCV)-1b-infected patients treated with IFN.

METHODS

The C-terminal part of E2 (codons 617-711) including PKR/eIF2alpha phosphorylation homology domain (PePHD) and ISDR was sequenced in 85 HCV-1b-infected patients treated by IFN monotherapy.

RESULTS

The amino acid substitutions in PePHD detected only in 4 of 85 patients were not correlated either with response to IFN or with viral load. The presence of substitutions in a N-terminal variable region (codons 617-641) in the C-terminal part of E2 was significantly correlated with both small viral load (33.9% vs 13.8%, P = 0.0394) and sustained response to IFN (25.0% vs 6.9%, P = 0.0429). Four or more substitutions in ISDR were significantly correlated with both small viral load (78.6% vs 16.2%, P < 0.0001) and sustained response to IFN (85.7% vs 2.9%, P < 0.0001). In multivariate analysis, ISDR in nonstructural (NS) 5A (OR = 0.39, P < 0.0001) and N-terminal variable region (OR = 0.51, P = 0.039) was selected as the independent predictors for small viral load, and ISDR (OR = 39.0, P < 0.0001) was selected as the only independent predictor for sustained response.

CONCLUSION

The N-terminal variable region in the C-terminal part of E2 correlates with both response to IFN monotherapy and viral load and is one of the factors independently associated with a small viral load.

Efficacy of interferon therapy in elderly patients with chronic hepatitis C

OBJECTIVE

We assessed the efficacy and safety of interferon (IFN) monotherapy in 84 elderly patients aged > or =65 years with chronic hepatitis C in a retrospective cohort study.

METHODS

Twenty-two of the 84 elderly patients were treated with IFN at a dose of 6 million units daily for 6-8 weeks, 18 patients were treated 2-3 times a week for 24 weeks and 44 patients were treated daily for 2-8 weeks and 2-3 times a week for 16-24 weeks.

RESULTS

A sustained virological response (SVR) occurred in 35.7% (30/84) of the patients by intention-to-treat analysis. Multivariate analysis showed that patients achieved a significant SVR when: (1) serum HCV-RNA level before IFN therapy was <100 KIU/ml (p < 0.0001) and (2) staging of liver fibrosis was mild (p = 0.040). Eleven (13.1%) patients discontinued the IFN regimen due to adverse events. Regarding factors predicting discontinuation of IFN, univariate analysis showed that patients aged >70 years were prone to drop out of therapy due to adverse events in IFN therapy (p = 0.009).

CONCLUSION

Our results suggest that IFN administration is suitable for 65- to 70-year-old patients with chronic hepatitis C without genotype 1b and high virus load.

Pretreatment prediction of interferon-alfa efficacy in chronic hepatitis C patients

BACKGROUND & AIMS

Interferon has been used widely to treat patients with chronic hepatitis C infections. Prediction of interferon efficacy before treatment has been performed mainly by using viral information, such as viral load and genotype. This information has allowed the successful prediction of sustained responders (SR) and non-SRs, which includes transient responders (TR) and nonresponders (NR). In the current study we examined whether liver messenger RNA expression profiles also can be used to predict interferon efficacy.

METHODS

RNA was isolated from 69 liver biopsy samples from patients receiving interferon monotherapy and was analyzed on a complementary DNA microarray. Of these 69 samples, 31 were used to develop an algorithm for predicting interferon efficacy, and 38 were used to validate the precision of the algorithm. We also applied our methodology to the prediction of the efficacy of interferon/ribavirin combination therapy using an additional 56 biopsy samples.

RESULTS

Our microarray analysis combined with the algorithm was 94% successful at predicting SR/TR and NR patients. A validation study confirmed that this algorithm can predict interferon efficacy with 95% accuracy and a P value of less than .00001. Similarly, we obtained a 93% prediction efficacy and a P value of less than .0001 for patients receiving combination therapy.

CONCLUSIONS

By using only host data from the complementary DNA microarray we are able to successfully predict SR/TR and NR patients for interferon therapy. Therefore, this technique can help determine the appropriate treatment for hepatitis C patients.

Treatment of chronic hepatitis C with interferon alone or combined with ribavirin in Japan

We treated 665 patients with chronic hepatitis C with interferon (IFN) monotherapy and 288 with combined IFN and ribavirin. At the baseline, age (53.8 +/- 11.1 vs. 49.7 +/- 10.5 years, p < 0.0001) and activity (p = 0.0207) as well as fibrosis (p = 0.0270) were higher in patients who received combination therapy than in those receiving monotherapy. Compliance to treatment (64.2 vs. 62.1%, p < 0.0001) and discontinuation were more frequent (18.1 vs. 14.5%, p < 0.0001) in patients with combination therapy than in those with monotherapy. Patients with combination therapy with genotype 2 infection achieved sustained viral response (SVR) at a rate of 77.0%, regardless of viral loads, in contrast to those with genotype 1 infection, of whom only 24.4% gained SVR. Of patients with combination therapy, reduction (42.6 vs. 29.0%, p = 0.0453) and discontinuation (34.0 vs. 21.6%, p = 0.0414) of ribavirin were more frequently required in the 47 patients > or =65 years than in the 241 patients <65 years. Although a trend for higher SVR to combination therapy was observed in patients aged < 65 than in those aged > or =65 years (39.4 vs. 25.2%), the difference was not significant (p = 0.0819). In patients with genotype 1 infection, IFN monotherapy in addition to the 24-week combination therapy increased the SVR rate (18.3 vs. 42.6%, p = 0.0003). A decrease in SVR was observed with an increased body mass index in patients who received combination therapy.

Comparison between subgenomic replicons of hepatitis C virus genotypes 2a (JFH-1) and 1b (Con1 NK5.1)

Although replicon systems for hepatitis C virus (HCV) recently developed have enabled the replication of HCV in cultured cells, limited genotypes are available for them. We have isolated HCV cDNA of genotype 2a (JFH-1 strain) from serum of a patient with fulminant hepatitis. A subgenomic replicon of JFH-1 was constructed and compared with the HCV replicon of genotype 1b (Con1 NK5.1) which possessed adaptive mutations. Huh7 cells transfected with replicon RNAs that had been transcribed in vitro were cultured in the presence of neomycin sulfate (G418), and selected colonies were isolated and expanded. Then, growth rates and replication of HCV RNA were evaluated on isolated cells hosting replicons. Saturation densities were lower for cells propagating JFH-1 than Con1 NK5.1 or untransfected Huh7 cells, and the mean doubling time was longer for JFH-1 than for Huh7 cells. Levels of HCV RNA replication in isolated clones were similar between JFH-1 and Con1 NK5.1 cells. Replication of RNA decreased reciprocally with cell densities in both JFH-1 and Con1 NK5.1 cells. The replication of HCV RNA was more resistant to interferon-alpha in JFH-1 than in Con1 NK5.1 cells based on the comparison of an inhibitory concentration of 50%. In conclusion, we found differences between HCV replicon clones of genotypes 1b and 2a. However, these differences may result from strain-specific characteristics, such as the source of HCV, rather than characteristics of distinct genotypes. Therefore, further investigation may be needed on more HCV isolates of diverse genotypes.

Risk factors and medical follow-up of drug users tested for hepatitis C--can the risk of transmission be reduced?

Of 1728 patients attending a regional drug and alcohol clinic, 202 were considered at risk of hepatitis C virus (HCV). Forty-nine per cent (99/202) agreed to testing-67% (67) were HCV antibody positive. Age and a history of needle sharing was the significant factor associated with positive HCV status. Patients on methadone maintenance medication were more-likely to have been HCV positive, but significantly (p = 0.005) less likely to have shared needles in the previous year. Seventy-three per cent (49/67) attended for follow-up at a "liver clinic". Fifty per cent were infected with genotype 1a. Eighteen patients were biopsied and all were abnormal, ranging from mild hepatitis to severe fibrotic hepatitis. Attendance for medical follow-up was poor, which emphasizes the importance of preventative measures such as methadone maintenance programmes for reducing the spread of HCV.

Role of nitric oxide (NO) in interferon-alpha therapy for hepatitis C

BACKGROUND AND AIM

The role of nitric oxide in infectious disease is gaining increased attention because antiviral effects of nitric oxide. In addition, there is evidence that nitric oxide synthase-2 expression was noted in chronic hepatitis C found within mononuclear cells.

METHODS

We studied serum levels of nitrite and nitrate before and during interferon alpha therapy in 66 patients with chronic hepatitis C.

RESULTS

There was no significant difference of their levels between the healthy control subjects and the patients before the treatment with interferon (55.9+/-21.8 microM vs. 60.9+/-30.0 microM). Their levels were determined at 2 weeks after the initiation of treatment with interferon and compared with those before the treatment in the patients with chronic hepatitis C. In the total patients treated, there was no significant difference between their levels before and at 2 weeks after the treatment (60.9+/-30.0 microM vs. 65.5+/-30.0 microM, P=0.14). However, when the levels were compared between sustained responders, in whom hepatitis C virus was eradicated, and non-responders, in whom the virus was not eradicated, the former had significantly higher levels of nitrite and nitrate than the latter at 2 weeks after the initiation of treatment (83.7+/-40.9 microM vs. 57.6+/-19.5 microM, P<0.01). The multivariate logistic regression analysis showed that the rise of nitrite and nitrate was an independent predictive factor for efficacy of interferon treatment.

CONCLUSIONS

Nitric oxide may be an important factor for antiviral therapy by interferon treatment for chronic hepatitis C, which suggests an additional therapeutic pathway for further study.

Interactions between helper T-cell epitopes of hepatitis C virus

The premise of this work is that within a given hepatitis C virus (HCV) protein there exists an array of Th1 and Th2 epitopes, each of which can provide synergistic (positive or negative) effects upon other epitopes by intramolecular, cytokine-mediated immunoregulation of helper T-cell responses. To address this question, we constructed minigene plasmids pHCVTh1, pHCVTh1X3 and pHCVThR, and HCV NS3 full-length plasmid pHCVNS3. 293T cells were transfected with these plasmids and cell lysates from the transfected cells were used to stimulate PBMC from a patient with chronic HCV infection. IL-2 and IFN-gamma in the supernatant of the cultured PBMC were tested and proliferation of the PBMC was measured. The results demonstrate that interactions exist among helper T-cell epitopes; the synergistic effects of suppressive Th2 epitopes upon Th1 epitopes will inhibit the responses induced by Th1 epitopes, which may contribute to chronic infection by HCV; synergistic effects among Th1 epitopes induce higher levels of IFN-gamma, which may suggest a new strategy for HCV vaccine development. Further, stimulation of an HCV NS3 specific clone with cell lysates from 293T cells transfected with different constructs shows that the HCV NS3 clone could respond to all suggesting that the epitope-specific suppression may be due to an imbalance of Type 1 and Type 2 cytokines or regulatory T-cells.

Anti-hepatitis C virus effect of citrus unshiu peel and its active ingredient nobiletin

We investigated the effects of water and ethyl acetate extracts of Citrus unshiu peel (Aurantii Nobilis pericarpium) on hepatitis C virus (HCV) absorption in MOLT-4 cells (a human lymphoblastoid leukemia cell line). By reverse transcription polymerase chain reaction (RT-PCR), we showed that both the ethyl acetate layer of Citrus unshiu peel extract and fraction 7 decreased HCV absorption in MOLT-4 cells. Furthermore, we demonstrated that 3',4',5,6,7,8-hexamethoxyflavone (nobiletin) is the active ingredient that markedly inhibited HCV infection in MOLT-4 cells.

Efficacy of short-term interferon therapy for patients infected with hepatitis C virus genotype 2a

BACKGROUND AND AIMS

The efficacy of interferon (IFN)-based antiviral therapy for chronic hepatitis C (CHC) varies depending on predictive factors such as hepatitis C virus (HCV) genotype and viral load. For patients with good predictive factors, a low dose and short course of IFN-based therapy may be adequate. However, there is no evidence about the optimal duration of IFN-based therapy for these patients. The aim of this study was to clarify whether the duration of IFN therapy could be shortened to less than the conventional treatment period for patients with good predictive factors.

METHODS

A total of 25 treatment-naive CHC patients with genotype 2a were randomized to receive either IFN monotherapy for 24 wks (group A: long-term IFN therapy, n = 13) or for 6 wks (group B: short-term IFN therapy, n = 12). Patients were monitored for HCV RNA and routine liver function tests during and following treatment, and data were examined according to intention-to-treat analysis.

RESULTS

Eleven of 13 patients in group A and all patients in group B completed IFN therapy according to the original planned schedule. At the end of the treatment, viral clearance occurred in all patients. However, 4 patients in group A and 5 in group B relapsed within 6 months of follow-up. There was no significant difference of sustained response rate between group A (53.8%) and group B (58.3%). Among patients who had HCV viral load of <100 kIU/ml, the sustained response rate was 83.3% (5/6) in group A and 100% (5/5) in group B.

CONCLUSIONS

In this study, our results suggest that the duration of IFN therapy can be shortened to less than 24 wks in patients with good predictive factors. Further studies, however, should examine the optimal regimen of IFN therapy based on the backgrounds of patients.

High sustained virologic response rate after interferon monotherapy in Japanese hepatitis C patients with a low HCV RNA titer and/or HCV genotype 2. A prospective study

OBJECTIVE

Hepatitis C virus (HCV) RNA titer and HCV genotype are considered to be major determinants of the outcome of interferon monotherapy. To clarify whether interferon monotherapy is really effective in patients with the appropriate viral parameters, we prospectively examined these parameters and treated the patients with interferon monotherapy.

METHODS

Sixty-four patients with an HCV RNA titer <100 kIU/ml and/or HCV genotype 2 were enrolled in the study. Eighteen patients with an HCV RNA titer >100 kIU/ml and genotype 1 were also enrolled as controls. All patients were treated with 10 megaunits of interferon-alpha2b every day for 2 weeks and then 3 times a week for 24 weeks.

RESULTS

Of the 64 patients with either HCV RNA <100 kIU/ml and/or genotype 2, seven dropped out from the study. Of the remaining 57 who completed the treatment, 48 (84%) showed a virologic sustained response. In contrast, only 4 of the 18 patients (22%) with HCV RNA >100 kIU/ml and genotype 1 were virologic sustained responders (p < 0.001).

CONCLUSION

Our current study showed that the patients with HCV RNA <100 kIU/ml and/or HCV genotype 2 are good candidates for interferon monotherapy.

New combination test for hepatitis C virus genotype and viral load determination using Amplicor GT HCV MONITOR test v2.0

AIM

To develop a new sensitive and inexpensive hepatitis C virus (HCV) combination test (HCV Guideline test) that enables the determination of HCV genotypes 1, 2 and 3, and simultaneous determination of HCV viral load using commercial Amplicor GT HCV MONITOR test v2.0 (microwell version).

METHODS

The HCV Guideline test used the PCR product generated in commercial Amplicor GT HCV Monitor test v2.0 for viral load measurement using microwell plate version of Amplicor HCV Monitor and also captured on separate plates containing capture probes and competitive oligonucleotide probes specific for HCV genotypes 1, 2 and 3, The HCV genotype was subsequently determined using the biotin-labeled PCR product and five biotin-labeled HCV-specific probes.

RESULTS

The sensitivity of the HCV Guideline test was 0.5 KIU/mL. Specificity of the HCV Guideline test was confirmed by direct sequencing of HCV core region and molecular evolutionary analyses based on a panel of 31 samples. The comparison of the HCV Guideline test and an in-house HCV core genotyping assay using 252 samples from chronic hepatitis C patients indicated concordant results for 97.2% of samples (59.5% genotype 1, 33.7% genotype 2, 6.0% genotype 3, and 0.8% mixed genotypes). Similarly, the HCV Guideline test showed concordance with a serological test, and the serological test failed to assign any serotype in 12.7% of the samples, indicating a better sensitivity of the HCV Guideline test.

CONCLUSION

Clinically, both viral load and genotypes (1, 2 and 3) have been found to be major predictors of antiviral therapy outcome regarding chronic hepatitis C based on guidelines and they are, in normal circumstances, performed as separate stand-alone assays. The HCV Guideline test is a useful method for screening large cohorts in a routine clinical setting for determining the treatment regimen and for predicting the outcome of antiviral therapy of chronic hepatitis C.