Lichen planus and hepatitis C virus in the Northern Kyushu region of Japan

Abstract. Oral lichen planus (OLP) is a common oral disorder that manifests a mucosal reaction to a variety of aetiological factors, including liver disorder. This study investigated the relationship between OLP and hepatitis C virus (HCV) infection by studying the prevalence of hepatitis B and C virus infection or liver disease in 45 patients with OLP in the Northern Kyushu region of Japan where the prevalence of HCV infection is the highest in the country. Serum hepatitis B virus surface antigen (HBsAg) was positive in only four patients. Serum anti-HCV or serum HCV RNA was positive in 28 (62%) and 27 (60%) of 45 OLP patients, respectively. The majority (35 of 45, 78%) of OLP patients suffered from liver disease, including chronic hepatitis C (22/45, 49%), HCV-related liver cirrhosis (two), and HCV-related hepatocellular carcinoma (two). These results suggest that HCV is a major cause of OLP.     

Genotype does not affect pattern of HCV RNA decrease among responders during interferon treatment of chronic hepatitis C. Consensus Interferon Study Group

We assessed differences in the pattern of HCV RNA decrease for HCV genotypes 1, 2, and 3 during interferon treatment to determine if the lower response rates observed among genotype 1 patients were related to a slower decrease in HCV clearance. Serum HCV RNA values of 472 chronic hepatitis C patients treated with either consensus interferon (CIFN) or interferon alfa-2b (IFN alfa-2b) were evaluated. Neither virological sustained responders nor relapsers differed in the pattern of serum HCV RNA decrease based on genotype. Virological sustained responders infected with genotype 1 cleared HCV RNA as rapidly as sustained responders who were infected with genotype 2 or 3. Relapsers had a slower rate of serum HCV RNA decrease than did virological sustained responders. Nonresponders differed in the pattern of serum HCV RNA decrease based on genotype: HCV genotype 3 patients had the greatest decrease in serum HCV RNA; genotype 2 patients had an intermediate decrease; and genotype 1 patients had the least serum HCV RNA decrease. HCV genotype 1 patients treated with CIFN had a greater decrease in serum HCV RNA during therapy than did patients treated with IFN alfa-2b. However, there was no difference in the magnitude of serum HCV RNA decrease between the two interferon treatments for patients infected with genotype 2 or 3. In summary, both genotype and ultimate response to treatment are determinants of the pattern and rate of serum HCV RNA change during interferon therapy of chronic hepatitis C.     

丙型肝炎患者基因分型与干扰素治疗疗效分析

目的讨本地区丙型肝炎病毒基因型与干扰素疗效的关系。方法156例慢性丙型肝炎（CHC）患者,HCVRNA采用荧光定量PCR试剂盒,RFLP分析进行HCV基因分型,57例慢性丙型肝炎患者采用IFN—alb治疗,疗程24周。全自动生化分析仪检测血清ALT。结果156例抗HCV阳性患者HCVRNA检出率82．05％（128／156）,HCVⅠ型、Ⅱ型、Ⅲ型、Ⅳ型、Ⅱ＋Ⅲ型分别为0、21．15％、55．13％、0,5．78％。干扰素治疗病例中,HCVⅡ型、Ⅲ型、Ⅱ＋Ⅲ型感染的应答率分别为28．95％、53．33％、25．00％,有显著性差异（P〈0．05）。HCV基因型与血清ALT水平无相关性。结论鲁北地区HCV感染以Ⅱ、Ⅲ型感染为主,干扰素对HCVⅢ型感染的疗效优于HCVⅡ型,ALT与HCVRNA水平可作为干扰素疗效的参考指标,HCV基因分型有预测干扰素疗效的意义。     

一种竞争性RT-PCR测定HCV RNA方法的建立及其应用

目的　建立检测丙型肝炎病人血清HCVRNA水平的竞争性逆转录 聚合酶链式反应定量方法。方法　采用含HCV 5 非编码区 ( 5 NCR)缺失突变的重组质粒 5T1d ,将其目的基因亚克隆到体外转录载体pCDNAⅠ多克隆位点上 ,获得转录重组体 5T1d 。将其线性化后用SP6RNA聚合酶体外转录竞争性缺失突变模板RNA ,该模板定量后与血清HCVRNA一起作逆转录 聚合酶链式反应 (RT PCR) ,建立检测血清HCVRNA水平的竞争性定量方法。结果　检测 15例丙肝病人 2 0份血清 ,滴度为 6.6× 10 2 ～ 6.6× 10 6copies/ml。 结论　各类丙型肝炎患者血清病毒滴度均较高 ,经干扰素治疗后病毒水平下降 1～ 5个Log ,年龄小于 2 0岁者干扰素治疗效果较好。     

Long-term follow-up of HIV-infected patients with chronic hepatitis C virus infection treated with interferon-based therapies

BACKGROUND: Chronic hepatitis C virus (HCV) infection is frequent among HIV-infected patients. Clearance of serum HCV RNA 6 months after discontinuing HCV therapy is generally interpreted as a cure of HCV infection in HIV-negative subjects. However, the occurrence of liver complications (including hepatocellular carcinoma) and/or HCV relapses in coinfected patients when followed for long periods of time after HCV therapy is not well known. METHODS: All HIV-infected patients who had been treated for chronic hepatitis C at our institution and had a minimum follow-up of 6 months after discontinuing therapy were retrospectively analysed. They had received one of three HCV treatment modalities: IFN monotherapy, IFN plus ribavirin (RBV) or pegylated interferon (PEG-IFN) plus RBV. RESULTS: A total of 351 patients were retrospectively analysed. Sustained virological response (SVR) to HCV therapy had been reached by 77 (22%) of them: 22/119 (18.5%) with IFN monotherapy, 17/106 (16%) with IFN plus RBV and 38/126 (30.2%) with PEG-IFN plus RBV. Considering the HCV genotypes, SVR had been reached by 19/184 (10.3%) of patients with genotype 1, 54/138 (39.1%) with genotypes 2 or 3, and 4/29 (13.8%) of those with genotype 4. Within a total of 4466 patient-months follow-up (mean of 58 months), none of the 77 patients with SVR showed HCV-RNA rebounds, elevations in liver enzymes potentially linked to HCV, development of hepatocellular carcinoma or episodes of decompensated cirrhosis. In contrast, all 274 patients who did not reach SVR with HCV therapy showed evidence of persistent serum HCV RNA and 90% of them showed liver enzyme elevations during a total of 15344 patient-months follow-up (mean of 56 months). Moreover, 11 (4%) developed clinical complications of liver cirrhosis and two of them died of end-stage liver disease. CONCLUSIONS: HCV replication and HCV-related liver disease seem to be permanently halted in HIV/HCV-coinfected patients showing HCV-RNA clearance 6 months after completing any kind of IFN-based therapy. In contrast, complications of liver disease due to persistent HCV infection continue to occur in non-responders. The role of maintenance HCV therapy should be explored in HIV/HCV-coinfected patients.     

Viral dynamics and pharmacokinetics in combined interferon alfa-2b and ribavirin therapy for patients infected with hepatitis C virus of genotype 1b and high pretreatment viral load

OBJECTIVE: The aim of this study was to clarify the viral dynamics and single- and multiple-dose pharmacokinetics of ribavirin and interferon (IFN) alfa-2b in the virologic response to combination therapy with both compounds in patients infected with hepatitis C virus (HCV) genotype 1b and high viral load. METHODS: Fourteen patients received high-dose daily induction therapy followed by intermittent maintenance therapy with IFN alfa-2b and daily oral ribavirin for 24 weeks, and followed up for 24 weeks after treatment. Single- and multiple-dose pharmacokinetic studies and viral dynamics were assessed by serial measurements of serum concentrations of both compounds and HCV RNA, respectively, at weeks 1 and 24. RESULTS: During treatment, all 14 patients showed biochemical response (i.e., normalization of serum alanine transaminase activity), while 11 showed virologic response (i.e., undetectable serum HCV RNA level by qualitative polymerase chain reaction assay). Sustained biochemical and virologic response after cessation of treatment was noted in 8 and 2 patients, respectively. Serum ribavirin concentrations asymptoted by 4 weeks of treatment. Serum ribavirin concentrations in steady state, and maximum concentration and accumulation rate of ribavirin after multiple dosing were significantly higher in the presence of sustained virologic response. HCV-related parameters were not significantly associated with sustained virologic response. CONCLUSIONS: Continuous exposure and tissue accumulation of ribavirin may be necessary for sustained virologic response to combination therapy in chronic hepatitis C with genotype 1b and high viral load. Pharmacokinetic analysis of ribavirin provides information on its mechanism of action and for developing more rational treatment for IFN-resistant HCV.     

Anticarcinogenic impact of interferon on patients with chronic hepatitis C: a large-scale long-term study in a single center

BACKGROUND: The anticarcinogenic capacity of interferon (IFN) was assessed in a cohort of Japanese patients with chronic hepatitis C en masse. PATIENTS AND METHODS: The rate of hepatocarcinogenesis was analyzed in 2,166 patients with chronic hepatitis C, of whom 1,654 had received IFN therapy while 512 had not. RESULTS: Crude rates of hepatocarcinogenesis in treated and untreated patients were 2.6 and 4.6% at the end of the 5th year, 5.8 and 12.7% at the 10th year and 13.9 and 23.9% at the 15th year (after completion of IFN therapy for those treated) (p < 0.001). IFN decreased the hazard ratio of carcinogenesis to 0.42 (p < 0.001) in multivariate analysis with adjustments for significant covariates including fibrotic stage, gamma-glutamyl transpeptidase level, gender, platelet count and age. Among the 1,654 patients treated with IFN, 606 (36.6%) achieved persistent loss of hepatitis C virus (HCV) RNA and an additional 266 (16.1%) gained normal levels of alanine aminotransferase without loss of HCV RNA for 6 months or longer after the completion of IFN therapy. Cumulative rates of hepatocarcinogenesis in sustained virological responders and biochemical responders were 1.4 and 2.0% at the end of the 5th year, 1.9 and 3.6% at the 10th year and 1.9 and 7.5% at the 15th year, respectively. The hazard ratio of sustained virological response was 0.10 (p < 0.001), and that of biochemical response was 0.12 (p < 0.001). Normalization of aminotransferase levels after IFN therapy without loss of serum HCV RNA decreased hepatocarcinogenesis. CONCLUSION: IFN significantly decreased the rate of hepatocarcinogenesis in patients with chronic hepatitis C as a whole in Japan, even in those who fail to clear HCV RNA from serum.     

Retinol Supplements Antiviral Action of Interferon in Patients with Chronic Hepatitis C: A Prospective Pilot Study

Sustained virologic response with peg-interferon and ribavirin combination therapy for 48 weeks is still inadequate. Our study examined whether short-term administration of retinol clinically influences the anti-viral activity of interferon early during interferon and ribavirin combination therapy. The control group received 6 MIU of interferon α-2b every day for two weeks and then 3 times a week for 22 weeks intramuscularly plus 600 mg or 800 mg per day of ribavirin orally for 24 weeks. The retinol group, in addition to above treatment, received retinol 30,000 units per day orally for 3 weeks from one week before the start of interferon α-2b plus ribavirin combination therapy. The hepatitis C virus (HCV) RNA negativity rate at 1 week after the end of interferon α-2b and ribavirin combination therapy was 46.7% (28/60) for the retinol group and 31.7% (19/60) for the control group, which was significantly higher for the retinol group. The level of serum HCV RNA in the retinol group was significantly lower at 1 week after beginning treatment as compared to the control group (p<0.01). Furthermore, serum 2,5''AS protein at 1 week after beginning treatment was significantly higher in the retinol group (p = 0.0002). The results suggest that retinol supplement increases the antiviral effect of interferon α-2b plus ribavirin only during the administration of IFN α-2b, ribavirin and retinol in patients with chronic hepatitis C.     

Interferon therapy of chronic hepatitis]

The current state of interferon (IFN) therapy for chronic hepatitis B and C in Japan is reviewed. The administration of IFN results in induction of 2'-5' oligoadenylate synthetase (2-5AS). 2-5AS produces 2-5A capable of activating a latent RNAase that degrades viral RNA. In patient with chronic hepatitis B, prominent reduction of HBV DNA, HBe antigen and HBs antigens is observed, when IFN is administered. However, the replication of HBV starts again after stopping of IFN administration, because the effects of IFN do not affect HBV DNA which is the origin of replication. On the other hand, HCV is a RNA virus IFN not only suppresses the production of HCV proteins and its pregenome, but also eradicate HCV RNA that is the origin of replication. In around 40% of the patients with chronic hepatitis C, sustained normalization of ALT and negativity of HCV RNA was obtained after IFN therapy under the most satisfactory regimen.     

Utility of hepatitis C virus serotypes in predicting response to treatment of chronic hepatitis C. Consensus Interferon Study Group

Hepatitis C virus (HCV) genotyping has been shown to predict response to interferon, but is expensive. HCV serotyping is less expensive and simpler, and may be similarly useful. Using data from a large, randomized trial comparing consensus interferon (CIFN) and interferon alfa-2b (IFN alfa-2b) in patients with chronic HCV, we evaluated response rates based on HCV serotypes versus genotypes. Patients included in this analysis received subcutaneous injection of 9 microg CIFN (n = 232) or 3 MU IFN alfa-2b (n = 240) three times weekly for 24 weeks followed by 24 weeks of observation. Serum HCV RNA concentrations were measured regularly during treatment and at the end of both the treatment and post-treatment periods. Response to interferon was similar for HCV antibody types and their corresponding genotypes. The end-of-treatment HCV RNA rate of response (defined as undetectable serum on two consecutive assessments) was 29% for serotype 1 versus 24% for genotype 1 after CIFN; and 14% versus 15%, respectively, after IFN alfa-2b. Independently of treatment, patients infected with serotype or genotype 2 or 3 had a better therapeutic response than those infected with serotype or genotype 1. Similar results were obtained based on HCV antibody typing and genotyping, suggesting the potential of the former for predicting response to interferon.     

Efficacy and Tolerability of Combination Therapy with Interferon-Alfa Plus Ribavirin in Patients with Chronic Hepatitis C Virus Infection: A Single-Center Study in Relapsers and Nonresponders to Previous Treatment with High-Dose Interferon-Alfa Monotherapy

Background: In chronic hepatitis C virus (HCV) infection, interferon (IFN) monotherapy usually is carried out at doses of 3 to 6 million units (MU) 3 times per week, but treatment efficacy is low.Objective: The aim of our study was to assess the efficacy and tolerability of IFN-alfa_2b in combination with ribavirin in relapsers and nonresponders to high-dose IFN treatment (5 to 6 MU 3 times per week). We measured the biochemical and virologic responses to treatment and the risk for relapse during the 24 weeks following the end of treatment.Methods: Patients with chronic HCV infection (relapsers and nonresponders to a previous treatment with high-dose IFN) received IFN-alfa_2b, 3 MU 3 times per week, and ribavirin, 1000 or 1200 mg/d for 24 or 48 weeks. The patients were then followed up for an additional 24 weeks. Sustained response was defined as normal serum alanine aminotransferase (ALT) level and undetectable HCV RNA 24 weeks after treatment was stopped.Results: Forty-three patients (32 men, 11 women; mean [SD] age, 45 [2] years; 10 relapsers, 33 nonresponders) were included in the study. Four patients were withdrawn from the study at week 4 of treatment because of treatment-related adverse events, and 1 dropped out. At the end of the treatment period, normalization of serum ALT levels and undetectable HCV RNA levels were seen in 58.1% and 30.2% of patients, respectively. No significant difference in virologic response at the end of treatment was found between nonresponders (10/33 [30.3%]) to previous IFN therapy and relapsers (3/10 [30.0%]). At the end of follow-up, 3 (7.0%) treated patients had sustained response (2 nonresponders to the first IFN course and 1 relapser). All of the patients with sustained response were treated for 24 weeks.Conclusion: Based on the results of our study, combination therapy with IFN-alfa and ribavirin may be of value in a limited number of patients with chronic HCV infection who do not respond to, or relapse after, a first course of treatment with high-dose IFN monotherapy.     

Therapy for treatment-refractory chronic hepatitis C virus genotype 1b infection: A retrospective analysis

Background:

The most effective current therapy for hepatitis C virus (HCV) infection is the combination of pegylated interferon (peg-IFN) plus ribavirin (RBV).

Objective:

The aim of this retrospective analysis was to determine the rateof response to this therapy, and the factors affecting outcome, in patients with treatment-refractory chronic HCV genotype l b.

Methods:

The records of patients with chronic HCV infection and HCV geno-type1b who failed (nonresponse or relapse) previous treatment with standard interferon (IFN) + RSV were retrospectively analyzed for demographic data, virologic load, liver histology, biochemistry, treatment-related adverse effects (AEs), and the effects of dose reduction during treatment with peg-IFN + RBV for 48 weeks. Early virologic response (EVR) was defined as ≥2-log (copies/mL) decrease from baseline in serum HCV RNA concentration or the absence of detectable serum HCV RNA at treatment week 12. End-of-treatment response (ETR) was defined as the absence of detectable serum HCV RNA at treatment week 48. Sustained virologic response (SVR) was defined as the absence of detectable serum HCV RNA 24 weeks after treatment was discontinued. Factors affecting treatment outcome were determined using correlation analyses.

Results:

Data from the files of 17 patients (12 men, 5 women; mean [SD] age, 48 [2] years) were analyzed. EVR was achieved in 7 patients; however, viral breakthrough occurred in 2 of these patients during the treatment period, and 5 of these patients discontinued treatment because of severe treatment-related AEs (depression [1 patient] and neutropenia [4]). Seven patients achieved ETR, but HCV infection relapsed during the follow-up period. Three (18%) patients achieved SVR. Data concerning previous patterns of response to IFN + RBV therapy were available in 10 patients. Of these, 3 of 6 patients who had experienced relapse with the previous treatment achieved SVR with peg-IFN + RBV; neither of the 2 patients with nonresponse to the previous treatment achieved SVR. Major determinants of failure to reach SVR in these patients included previous nonresponder pattern, noncompliance with the therapy, and advanced-stage liver fibrosis. Tolerability was similar to that with the previous treatment.

Conclusions:

In this study in patients with chronic HCV genotype lb infectionand a history of relapse or nonresponse to standard IFN + RSV treatment, treatment with peg-IFN + RBV achieved an SVR rate of 18%. Further research is needed to determine the role of peg-IFN + RBV in the re-treatment of HCV infection.     

Accurate prediction of response to interferon therapy by repeated measurement of hepatitis C virus core protein in patients with chronic hepatitis C

OBJECTIVE AND METHODS: Serum levels of hepatitis C virus (HCV), a predictor of the response to interferon (IFN) therapy, can fluctuate widely in patients with chronic hepatitis C, even without antiviral therapy. In order to increase the accuracy of predicting the response to therapy, serum samples from 134 patients with chronic hepatitis C were collected twice: 1.0-4.5 months before and just before the start of IFN therapy, and were tested for HCV core protein by a fluorescent enzyme immunoassay. RESULTS: Forty-one (31%) patients had a complete response to IFN and 93 (69%) had no response. The most useful cutoff value between high and low viral loads for predicting the response to therapy was 40 pg/ml of HCV core protein. A complete response was obtained more frequently in 32 of 45 patients with persistently low viral loads than in those with persistently high viral loads (7 of 71) (p < 0.0001). In 2 of 18 patients with a low viral load at one time point but a high viral load at another, the rate of complete response was similar to that in patients with persistently high viral loads. CONCLUSION: Prediction of the response to IFN therapy based on HCV core protein measurement at two time points before therapy is more reliable than that based on HCV core protein measurement at only one time point.     

Interferon therapy for 2 years or longer reduces the incidence of hepatocarcinogenesis in patients with chronic hepatitis C viral infection

OBJECTIVE: The purpose of this clinical study was to determine the effect of long-term interferon (IFN) administration on the incidence of hepatocellular carcinomas (HCC) in chronic hepatitis C patients, without eradication of hepatitis C virus (HCV) by IFN therapy. METHODS: The number of patients with biopsy-proven chronic hepatitis with moderate or severe staging, HCV genotype 1b, a high viral load exceeding 1 MEq/ml (mega equivalents per milliliter), who received 6 MU of natural IFN-alpha daily for 2-8 weeks, followed by three times/week for 16-22 weeks, as initial IFN therapy, and positivity for HCV RNA during IFN administration was 131. 47 of the 131 patients continued to be treated with IFN (long-term IFN group, dose 3 or 6 MU twice or three times weekly for 1.5-10.5 years, median 4.0 years) after initial IFN therapy, while 84 patients did not receive any IFN therapy apart from the initial 6-month course (no-add-IFN group). The patients were prospectively monitored, and the cumulative incidence of HCC and risk factors for HCC were examined. RESULTS: The 5- and 10-year cumulative rates of HCC were 1.9 and 6.4% and 1.9 and 26.8% for long-term IFN and no-add-IFN groups, respectively. Cox regression analysis indicated that the relative risk of HCC in the patients of the no-add-IFN group was 8.72 times of that in patients of the long-term IFN group. CONCLUSION: Long-term IFN therapy in patients with chronic HCV infection is effective in preventing hepatocarcinogenesis.     

Antiviral treatment of hepatitis C: present status and future prospects

Hepatitis C virus (HCV) infection is a major cause of chronic hepatitis. A substantial proportion of patients with chronic hepatitis C eventually develop hepatocellular carcinoma (HCC), which is one of the leading causes of death worldwide. Therefore, efficient antiviral treatments for HCV have long been needed. A recently developed combination therapy of pegylated interferon and ribavirin has dramatically improved the outcome of antiviral therapy for HCV infection. In genotype 1b HCV infection, 48 weeks of the combination therapy achieved eradication of the virus in 50% of patients, and in genotype 2 HCV infection, 24 weeks of the therapy resulted in viral eradication in 80%–90% of patients. By this eradication, an improvement in the hepatic fibrosis, an inhibition of HCC development, and an improvement in life expectancy were attained. Patients who did not respond to the combination therapy may be treated with long-term interferon monotherapy, which is not intended to eradicate HCV, but will lower the serum alanine aminotransferase (ALT) level. Thus, the treatment for HCV infection has progressed significantly, but therapies with new modalities, such as inhibitors of viral protease or RNA polymerase, are still being awaited.     

Response to interferon-based therapies in HIV-infected patients with chronic hepatitis C due to genotype 4

BACKGROUND: The hepatitis C virus (HCV) genotype is the main predictor of response to interferon (IFN)-based therapies. HCV genotype 4 is spreading among European intravenous drug users, who are frequently coinfected with HIV. Information about treatment response in this subset of patients is scarce and conflicting results have been reported. METHODS: All HIV-infected patients treated for chronic hepatitis C at our institution with a minimum follow-up of 6 months after discontinuing therapy were retrospectively analysed. They had received one of three HCV treatment modalities: IFN monotherapy, IFN plus ribavirin (RBV) or pegylated interferon (PEG-IFN) plus RBV. Treatment responses were stratified according to HCV genotype. RESULTS: A total of 390 patients were analysed. Sustained virological response (SVR) to HCV therapy had been reached by 90 (23.1%): 22/119 (18.5%) with IFN monotherapy; 17/106 (16%) with IFN plus RBV; and 51/165 (30.9%) with PEG-IFN plus RBV. SVR was significantly higher among those with HCV genotypes 2 or 3 (40.4%; 61/151) than in patients with either HCV genotype 1 (11.2%; 22/197) or HCV genotype 4 (16.7%; 7/42) (P<0.0001). In contrast, there were no significant differences in the response rate comparing HCV genotypes 1 and 4 (P=0.53). CONCLUSIONS: Response to IFN-based therapies in HIV-positive patients with hepatitis C due to HCV genotype 4 is poor, similar to that obtained for HCV genotype 1 and much lower than for HCV genotypes 2 and 3. Therefore, HIV-infected patients with hepatitis C due to genotype 4 should be considered as a particular subset of difficult-to-treat patients. New treatment strategies and drugs for these patients are eagerly awaited.     

Interferon-alpha therapy exerts selective pressure on hepatitis C virus quasispecies equilibrium

Two patients with chronic hepatitis C virus (HCV) genotype 2b infection were studied. They responded biochemically to interferon (IFN) but had early virological and later biochemical relapse. The HCV quasispecies equilibrium in these patients was studied by a combination of cloning, sequencing and construction of phylogenetic trees. Another patient with chronic HCV genotype 2b infection was followed every 6 months for 30 months (including one episode of biochemical exacerbation) to serve as the control. Quasispecies equilibrium drifted during IFN therapy but moved back in the direction of the original equilibrium during biochemical relapse. In the control patient, there was no significant drifting throughout the follow-up period. These data suggest that IFN therapy exerts selective pressure on HCV quasispecies equilibrium.     

Therapeutic DNA Vaccination Using In Vivo Electroporation Followed by Standard of Care Therapy in Patients With Genotype 1 Chronic Hepatitis C

Clearance of infections caused by the hepatitis C virus (HCV) correlates with HCV-specific T cell function. We therefore evaluated therapeutic vaccination in 12 patients with chronic HCV infection. Eight patients also underwent a subsequent standard-of-care (SOC) therapy with pegylated interferon (IFN) and ribavirin. The phase I/IIa clinical trial was performed in treatment naive HCV genotype 1 patients, receiving four monthly vaccinations in the deltoid muscles with 167, 500, or 1,500 μg codon-optimized HCV nonstructural (NS) 3/4A-expressing DNA vaccine delivered by in vivo electroporation (EP). Enrollment was done with 2 weeks interval between patients for safety reasons. Treatment was safe and well tolerated. The vaccinations significantly improved IFN-γ–producing responses to HCV NS3 during the first 6 weeks of therapy. Five patients experienced 2–10 weeks 0.6–2.4 log₁₀ reduction in serum HCV RNA. Six out of eight patients starting SOC therapy within 1–30 months after the last vaccine dose were cured. This first-in-man therapeutic HCV DNA vaccine study with the vaccine delivered by in vivo EP shows transient effects in patients with chronic HCV genotype 1 infection. The interesting result noted after SOC therapy suggests that therapeutic vaccination can be explored in a combination with SOC treatment.     

Effect of ribavirin on the hepatitis C virus (JFH-1) and its correlation with interferon sensitivity

BACKGROUND: The consensus therapy for chronic hepatitis C infection is based on a synergistic combination of pegylated interferon and ribavirin. The therapy leads to a sustained virological response in around 60% of infected patients. The mechanism by which this synergy occurs has not yet been elucidated. Several mechanisms of action have been proposed; one suggests that ribavirin, which is a nucleoside analogue, is incorporated into the RNA strand and generates an increase in the error rate. Such an accumulation of mutations would threaten the integrity of the virus's genetic information. METHODS: The effects of ribavirin on the new infectious hepatitis C virus cell culture (HCVcc) system were investigated using Huh-7 cells. Cells were cultured for 1 month in either 0 microM, 20 microM or 50 microM ribavirin. The HCV interferon sensitivity and the NS5A quasispecies were analysed. RESULTS: An increase in the mutation rate in the HCV NS5A gene was observed when the infected cells were treated with 50 microM ribavirin for 1 month. Amino acid sequence analysis revealed that ribavirin exerts an increase in G to A transition events as predicted by its mutagenic effect and a selective pressure on the HCV NS5A sequence. Furthermore, ribavirin treatment modified the efficacy of interferon (IFN) treatment. The IFN half-inhibition concentration (IC50) was significantly lower for viruses obtained after 1 month's exposure to 50 microM ribavirin than for viruses cultured in the absence of ribavirin. CONCLUSIONS: Ribavirin's mutagenic effect could explain in part its synergistic action with interferon.