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.     

Hepatic interferon receptor mRNA expression: clinical relevance and its relationship with effectiveness of interferon plus ribavirin therapy in patients with genotype 1b hepatitis C virus infection

BACKGROUND/AIMS: Hepatic expression of interferon (IFN) receptor mRNA has been shown to correlate with the effectiveness of IFN monotherapy in patients with chronic hepatitis C virus (HCV) infection. We investigated the expression of hepatic IFN receptor alpha/beta (IFNAR2c) mRNA and its association with the effectiveness of IFN plus ribavirin (RBV) therapy and with the clinical features in patients with HCV genotype 1b (HCV-1b) infection. METHODS: A total of 42 naive patients who had chronic HCV-1b infection were treated with IFN alpha-2b 3 MU or 5 MU three times weekly plus RBV for 24 weeks. Hepatic IFNAR2c mRNA was quantified by real-time RT-PCR. RESULTS: There was no significant difference in the mean expression level of IFNAR2c mRNA between patients with sustained virological response (SVR) and non-SVR (0.069 +/-0.042 versus 0.053 +/-0.033, P=0.182). Multiple linear regression analysis showed that lower fibrosis scores (P=0.006) and younger age (P=0.03) were associated with hepatic IFNAR2c mRNA expression with r2=0.34. CONCLUSIONS: Hepatic IFNAR2c mRNA expression may not be useful for predicting the response to IFN plus RBV therapy in patients with HCV-1b infection, but appeared to correlate inversely with the fibrosis stage and age.     

Virological profiles in hepatitis B virus/hepatitis C virus coinfected patients under interferon plus ribavirin therapy

BACKGROUND: Hepatitis C virus (HCV) is believed to exert a suppressive effect on hepatitis B virus (HBV) in most HBV/HCV-coinfected patients; once HCV is cured by interferon-based therapy, these patients may show HBV reactivation. However, recent evidence revealed that the virological status in HBV/HCV-untreated individuals may vary over time and may show fluctuating profiles. METHODS: To evaluate the behaviour of apparently inactive HBV infection in patients under treatment for a concurrent HCV infection, we performed a prospective study that evaluated nine consecutive patients (eight males with a median age of 45.9 years, and one female aged 62 years) longitudinally followed-up with bi-monthly evaluation of HBV/HCV viraemia levels and liver biochemistry during a 1-year treatment with interferon plus ribavirin. RESULTS: In seven cases the HBV infection maintained its inactive status independently of the HCV response to therapy. By contrast, two non-responder cases with persistently high HCV RNA levels showed HBV DNA flairs during the follow-up, indicating a status of active HBV infection with fluctuating virological profiles. CONCLUSIONS: This study suggests that the HBV behaviour may be independent of the HCV activity during anti-HCV therapy in HBV/HCV-coinfected patients, and that the HBV virological profile should be monitored to recognize possible reactivations that might lead to more proper therapeutic choices or adjustments.     

Evolution of hepatitis C virus quasispecies during therapy with IL2 combinated to alpha interferon and ribavirin

This study analyses the impact of interleukin 2 (IL2) combined with alpha interferon (IFN-alpha) and ribavirin on the heterogeneity of hepatitis C virus (HCV). We studied 10 patients who took part in a clinical trial that assessed the effects of retreatment with IL2, IFN-alpha and ribavirin in patients who failed to clear the virus after a previous bitherapy. The heterogeneity of HCV quasispecies was assessed by cloning and sequencing the hypervariable region 1 (HVR1) in samples obtained at baseline (W0), after 12 weeks of treatment with IFN-alpha and ribavirin (W12), after a cycle of administration of IL2 in combination with the classical bitherapy (W21 and W24) in the eight patients who failed to clear the virus under treatment. The mean viral load at W21 and at W24 was not different from that at W12. The heterogeneity of HVR1 quasispecies after the administration of IL2 was not different from that at baseline or after 12 weeks of bitherapy. Furthermore, the proportion of nonsynonymous substitutions was unchanged after the IL2 cycles. Thus, the efficacy of the tritherapy with IL2, IFN-alpha and ribavirin is similar to that of the classical bitherapy. Treatment with IL2 in combination with IFN-alpha and ribavirin had no effect on the selective pressure on HCV quasispecies. IL2 is not the best option to treat hepatitis C.     

Chronic cough associated with interferon/ribavirin therapy for hepatitis C

What is known and Objective: The combination of pegylated interferon and ribavirin has become standard therapy for chronic hepatitis C infection. The occurrence of chronic cough associated with this treatment regimen has been reported, but the mechanism by which cough occurs has not previously been investigated. We measured cough reflex sensitivity, during and after completion of therapy, in four patients who developed chronic cough associated with interferon/ribavirin therapy. Case summary: Four patients without history of respiratory symptoms developed chronic cough temporally related to initiation of therapy with pegylated interferon and ribavirin for chronic hepatitis C infection. Cough resolved within 2–6 weeks after completion of a 48‐week course of therapy. To measure cough reflex sensitivity, capsaicin cough challenge testing was performed 1 month prior to cessation of therapy, and 1 and 2 months after completion of treatment. In all patients, cough reflex sensitivity, as measured by C₅, the concentration of capsaicin inducing 5 or more coughs, was significantly enhanced during treatment compared to 1 month after completion of therapy (P = 0·016). What is new and Conclusion: Previous studies have observed that cough occurs more commonly in patients receiving the combination of interferon and ribavirin compared to interferon alone, thus implicating ribavirin as the causal agent. Our data demonstrate that it does so by reversible enhancement of cough reflex sensitivity. Clinicians should be aware of this potential treatment‐related effect, so as to avoid unnecessary and costly diagnostic evaluations seeking an alternative aetiology of cough.     

Using pegylated interferon and ribavirin to treat patients with chronic hepatitis C

Hepatitis C virus is the most common chronic blood-borne infection in the United States. The advent of new treatment regimens using pegylated interferons in combination with ribavirin has led to improved sustained viral response rates for some genotypes in large multicenter trials. Advances in the management of side effects and toxicities have expanded the pool of treatable patients. A recent National Institutes of Health consensus conference recommended that all patients who have bridging hepatic fibrosis and moderate inflammation together with detectable viremia should receive treatment with pegylated interferon and ribavirin. Unfortunately, these medications are very expensive and have significant side effects. Hematologic toxicities include anemia and leukopenia. These can be managed with close monitoring, use of growth factors, or dose reductions. Depression also can be caused or exacerbated by these medicines and may require treatment with a selective serotonin reuptake inhibitor, comanagement with psychiatry, or cessation of pegylated interferon and ribavirin treatment. Contraception is imperative because ribavirin is highly teratogenic. Influenza-like symptoms of fatigue, nausea, and mild fevers can be helped by quality patient education and support including frequent office visits. Data from randomized controlled trials demonstrating improvements in long-term survival as a result of treatment are not yet available, but it appears that patients who have no detectable virus six months after treatment have a good chance of remaining virus free for at least five years.     

Combination therapy with interferon and ribavirin in the treatment of chronic hepatitis C infection

OBJECTIVE: To review and critique the medical literature regarding the combination of interferon and ribavirin in the initial treatment of chronic hepatitis C virus (HCV) infection. DATA SOURCES: A MEDLINE search (January 1966-June 1999) was conducted to identify human clinical trials regarding the combination of interferon and ribavirin therapy for the initial treatment of chronic HCV. Bibliographies were reviewed for relevant literature. STUDY SELECTION: Clinical trials of combination interferon and ribavirin for the treatment of chronic HCV in interferon-na?ve adults were reviewed. DATA SYNTHESIS: The combination of ribavirin and interferon in the treatment of chronic HCV has been beneficial in patients who are interferon-na?ve. Patients with predictors of poor response, such as baseline cirrhosis, male gender, age >40 years, high baseline viral loads (>2 x 10(6) copies/mL), and genotype 1 respond better to combination treatment when compared with those who receive interferon monotherapy. Patients with genotype 1 and/or high viral loads may benefit most from 48 weeks of combination therapy; however, adverse effects are of greater concern in these patients. Monitoring can limit these complications. CONCLUSIONS: Combination therapy is effective in the treatment of interferon-naive patients with chronic HCV infection. Patients should be evaluated for duration of treatment with combination therapy by determination of predictors of response. Further trials are needed to more closely evaluate the duration of treatment and to determine the best patient population to receive combination therapy.     

Combined interferon and ribavirin therapy for chronic hepatitis C in Taiwan

Chronic hepatitis C virus (HCV) infection, including its sequelae, is an important healthcare problem in Taiwan. The seroprevalence of HCV infection in first-time blood donors in Taiwan is 1.2% and an estimated 2-5% in the general population, with a great geographic variation. Genotype 1b is the most prevalent HCV genotype in Taiwan, with a prevalence rate of 50-70%. An increasing incidence of hepatocellular carcinoma (HCC) is mainly attributed to HCV infection, while the declining role of HBV is observed in Taiwan. The seroprevalence of hepatitis B surface antigen among patients with HCC was 90% three decades ago, while recently, chronic HCV infection accounts for more than 30% of HCC patients in the National Taiwan University Hospital. With the advent of a combined conventional interferon (IFN)-alpha and ribavirin therapy, to which Taiwan has contributed in the early study phase, the sustained virological response rate has been greatly improved compared with IFN monotherapy. The sustained virological response rate in Taiwanese patients treated with the combination therapy for 6 months has reached up to 50-60%, which is higher than that reported in patients from the Western countries receiving a 12-month regimen. It is necessary to search for the underlying mechanisms for the better treatment outcome with IFN plus ribavirin combination therapy in Taiwanese patients. Whether long-term effects of IFN plus ribavirin therapy can reduce the incidence of HCC needs to be established.     

Retreatment of patients with chronic hepatitis C not responding to interferon/ribavirin combination therapy with daily interferon plus ribavirin plus amantadine

There is currently no accepted therapeutic regimen for patients with chronic hepatitis C who failed to respond to standard combination treatment with interferon-alpha plus ribavirin. We investigated triple combination treatment with induction dosing of interferon-alpha plus ribavirin plus amantadine in these difficult-to-treat patients. Nonresponders (n = 67), breakthroughs (n = 16) and relapsers (n = 19) to previous interferon/ribavirin combination treatment of at least 6 months were included. For the first 16 weeks, patients received interferon-alpha2a 6 MU daily, ribavirin 800-1200 mg/d, and amantadine 200 mg/d. In cases of undetectable HCV RNA at week 12, treatment was continued with interferon-alpha2a 6 MU every other day and the same doses of ribavirin and amantadine until week 48. In cases of HCV RNA positivity at week 12, treatment was stopped. A total of 102 patients were enrolled (80%: genotype 1, 19%: cirrhosis). HCV RNA was negative in 35/102 patients (34%) at week 12 and in 27/ 102 patients (26%) at the end of treatment. Virological response was sustained in 15/102 patients (15%). On-treatment virological response was higher in previous relapsers/breakthroughs than in previous nonresponders (week 12: 49% vs. 27%, p < 0.05; week 48: 46% vs. 16%, p < 0.01) but no such difference was found for sustained virological response (20% vs. 12%, NS). In conclusion, triple combination treatment with daily interferon-alpha plus ribavirin plus amantadine for 3 months can induce virological response in a considerable number of nonresponders/relapsers to previous dual combination treatment, but the sustained virological response rate remains low.     

Sustained suppression of hepatitis C virus by high doses of interferon and ribavirin in adult hemophilic patients

BACKGROUND: In a recent randomized controlled study, only a minority (15%) of adult hemophiliacs with chronic HCV achieved a sustained virologic response to treatment with interferon (IFN) and ribavirin given at standard doses. STUDY DESIGN AND METHODS: Whether the therapeutic response might be improved in these patients by increasing the doses of IFN was evaluated. Thirty-four previously untreated, adult hemophiliacs with chronic HCV but negative for HIV were investigated. There were 33 men and 1 woman, aged 21 to 60 years (mean, 36). Twenty-three patients (68%) had genotype 1, and median serum HCV-RNA was 473 x 10(3) IU per L (range, 3.6-2145). Patients were treated with IFN at 5 million units (MU) thrice weekly for 6 months, followed by 3 mol/L for 6 additional months in combination with daily oral doses of 1 or 1.2 g of ribavirin. RESULTS: A total of 33 patients (97%) completed the study; one patient withdrew because of treatment-related symptoms. Treatment dosage had to be reduced in 20 patients (59%). By intention-to-treat analysis, 14 patients (41%) had a sustained virologic response, particularly those infected by HCV genotype 2 or 3 (70% vs. 29% with genotype 1 or 4, p < 0.05). Sustained response rates were similar in the 13 compliant patients and the 20 patients who had to reduce IFN and/or ribavirin doses (54% vs. 35%). CONCLUSIONS: High-dose IFN therapy plus ribavirin provided high rates of sustained virologic responses in adult hemophiliacs with chronic HCV, even if side-effects led to dose reduction in half of these patients.     

The effect of zinc supplementation on the treatment of chronic hepatitis C patients with interferon and ribavirin

OBJECTIVES: To evaluate the effects of zinc supplementation on serum zinc and copper levels, and the severity of adverse reactions and virologic responses in chronic hepatitis C patients undergoing interferon (IFN)/ribavirin therapy. DESIGN AND METHODS: Forty subjects were randomly assigned to receive IFN-alpha-2a/ribavirin with or without zinc gluconate for 24 weeks, then a period of 6 months for follow-up. Twenty healthy controls were also enrolled in the study. Blood samples were collected at different time points during therapy and at 6 months after the completion of therapy and were analyzed for zinc and copper levels. The adverse reactions and the virologic responses were also examined accordingly. RESULTS: Serum zinc levels were significantly lower in chronic hepatitis C patients than in healthy controls and further depressed by IFN/ribavirin treatment. However, serum zinc levels in patients were remediable by zinc supplements. No apparent difference was seen in virologic responses between subjects with or without zinc supplements, but certain adverse side effects associated with the zinc therapy were significantly decreased. CONCLUSIONS: Zinc supplementation may be a complementary therapy in chronic hepatitis C patients to increase the tolerance to IFN-alpha-2a and ribavirin.     

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.     

Significance of serum ribavirin concentration in combination therapy of interferon and ribavirin for chronic hepatitis C

OBJECTIVE: The purpose of this clinical retrospective cohort study was to determine the most suitable ribavirin concentration on combination therapy of interferon (IFN)-ribavirin. METHODS: Entry criteria were serum HCV-RNA level >/=100 KIU/ml, HCV-genotype 1b, chronic hepatitis, and initial combination treatment of IFN-alpha-2b (6 million units daily for 2 weeks and then 3 times weekly for 6 weeks) and ribavirin (600-800 mg/day) for 8 weeks without stopping or decreasing the dosage of IFN and/or ribavirin. Sixty-eight consecutive patients who satisfied the above criteria were given maintenance therapy for another 16 weeks. RESULTS: A sustained virological response (SVR) rate of 25.0% (17/68) was seen in all subjects. The SVR rate was 44.0% (11/25) in the high ribavirin group with a serum ribavirin concentration of >/=3,000 ng/ml at 8 weeks after initiation of combination therapy. SVR was significantly dependent at a serum ribavirin level of >/=3,000 ng/ml (p = 0.005). The incidence of discontinuations and dose modifications for combination therapy in patients having a serum ribavirin concentration of >/=3,500 ng/ml 8 weeks after initiation of therapy was 57.1% (4/7). This value was statistically higher than that in patents with <3,500 ng/ml (p = 0.033). CONCLUSION: Our results showed that the most suitable serum ribavirin concentrations are from 3,000 to 3,500 ng/ml 8 weeks after initiation of combination therapy.     

Response to combined interferon and ribavirin is better in patients infected with hepatitis C virus genotype 6 than genotype 1 in Hong Kong

Data on the treatment efficacy of interferon (IFN)-alpha and ribavirin in patients with chronic hepatitis infected with hepatitis C virus (HCV) of genotype 6 are lacking. A study has been reported from Hong Kong which compared the treatment efficacy of IFN-alpha and ribavirin in the treatment of chronic HCV infection with genotypes 1 and 6. Twenty-four patients with HCV genotype 1 and 16 patients with HCV genotype 6 were studied. The baseline demographic data including median age, gender ratio, alanine aminotransferase levels, bilirubin levels, HCV RNA levels and histological scores were comparable between the two groups of patients. All patients received IFN-alpha 5 million units three times per week and ribavirin (1,000 mg for those weighing 75 kg) for 1 year. Patients infected with HCV genotype 6 achieved virological response significantly higher than those with HCV genotype 1 (67 vs. 33% at week 24, p = 0.02; 75 vs. 42% at the end of treatment, p = 0.05; 63 vs. 29% at 6 months after completion of treatment, p = 0.04). Histological improvement in inflammatory activity and fibrosis in the liver were observed in 25% and 25% of patients infected with HCV genotype 6 in contrast to only 13 and 8% in patients infected with HCV genotype 1; however, the differences were not statistically significant. In conclusion, patients with HCV genotype 6 gain a better response to combined treatment with IFN-alpha and ribavirin than those with HCV genotype 1 and achieve a significantly higher rate of sustained virological response.     

Neurocognitive changes in patients with hepatitis C receiving interferon alfa-2b and ribavirin

BACKGROUND: During antiviral therapy of chronic hepatitis C, patients frequently report impairment of concentration or memory. Therefore we prospectively investigated neurocognitive performance in patients receiving interferon alfa and ribavirin. METHODS: Repeated computer-based testing of neurocognitive function was performed in 70 patients with chronic hepatitis C receiving interferon alfa-2b (pegylated or conventional) and ribavirin. In addition, depression scores were obtained (Hospital Anxiety and Depression Scale). RESULTS: Reaction times were significantly increased during treatment (mean reaction time increase after 3 months of therapy: alertness, 46.76 ms [95% confidence interval (CI)], 26.86-66.66 ms), P < .001; divided attention, 47.04 ms [95% CI, 26.44-67.64 ms], P < .001; vigilance, 60.78 ms [95% CI, 29.24-92.32 ms], P < .001; and working memory, 38.53 ms [95% CI, 1.22-75.83], P = .34). Accuracy measures (number of false reactions) were affected for the working-memory task exclusively. Cognitive performance returned to pretreatment values after the end of therapy. Cognitive impairment was not significantly correlated with the degree of concomitant depression (0.04 < r [absolute value] < 0.10, P > .390). CONCLUSIONS: Interferon-based combination therapy of chronic hepatitis C causes significant but reversible impairment of neurocognitive performance. Consequences for the requirements of an active life in patients with chronic hepatitis C receiving antiviral therapy need to be assessed.     

Combination therapy with pegylated interferon plus ribavirin in the treatment of hepatitis C virus-related thrombocytopenia

Background:

Isolated thrombocytopenia is a common manifestation of hepatitis C virus (HCV) infection. There is no established treatment modality for this condition. The efficacy of standard interferon (IFN) monotherapy has been reported in some studies. The major disadvantage of this treatment is the high rate of recurrence due to viral breakthrough during the first 12 weeks of treatment. Pegylated IFNs are now the standard regimen for chronic hepatic disease due to HCV infection. However, due to a lack of evidence, pegylated IFNs are not widely used for HCV-related isolated thrombocytopenia.

Objective:

The aim of this report was to present the case of a male patientwith severe symptomatic thrombocytopenia due to HCV infection.

Methods:

Thrombocytopenia was treated with pegylated IFN plus ribavirin.

Results:

Although standard IFN monotherapy failed to achieve virologic and hematologic improvement, therapy with pegylated IFN alfa-2a plus ribavirin was associated with both virologic and hematologic improvement without any significant adverse effects.

Conclusions:

Pegylated IFN plus ribavirin was effective in this patient for thetreatment of HCV-related thrombocytopenia. However, further research is needed to define the response rate in different patient populations.