Short-term therapy for patients with hepatitis C virus genotype 2 or 3 infection

Evaluation of antiviral effect of type I, II, and III interferons on direct-acting antiviral-resistant hepatitis C virus

Treatment of hepatitis C virus (HCV) infection has greatly improved in the last 5 years because of the identification of direct-acting antivirals (DAAs). However, concerns exist regarding the emergence of drug resistance-associated substitutions (RASs). In this study, we evaluated the in vivo antiviral effect of three classes of interferons (IFNs), namely, types I, II, and III IFNs, on DAA-resistant HCVs. IFN-α₂, IFN-γ, and IFN-λ₁ were selected as typical types I, II, and III IFNs, respectively. Human hepatocyte-transplanted chimeric mice were infected with NS3-D168, NS5A-L31-, and NS5A-Y93-mutated HCVs, and the antiviral effect of IFN-α₂, IFN-γ, and IFN-λ₁ on these HCV RASs was examined. Chimeric mice infected with NS3- and NS5A-mutated HCVs were hydrodynamically injected with IFN-expressing plasmids to evaluate the antiviral effect of IFNs. Serum concentrations of IFNs were maintained for at least 42 days. We found that serum HCV level significantly decreased and serum and hepatic HCV levels reached below detection limit in 5/5 and 3/5 chimeric mice injected with IFN-γ- and IFN-λ₁-expressing plasmids, respectively. The antiviral effect of IFN-α₂ on DAA-resistant HCVs was weaker than that of IFN-γ and IFN-λ₁. Serum ALT levels showed a small and transient increase in mice injected with the IFN-γ-expressing plasmid but not in mice injected with the IFN-λ₁-expressing plasmid. However, no apparent histological damage was observed in the liver sections of mice injected with the IFN-γ-expressing plasmid. These results indicate that IFN-γ and IFN-λ₁ are an attractive therapeutic option for treating infection caused by NS3- and NS5A-mutated HCV.

Therapy of chronic hepatitis C with PEG-IFN α-2b plus ribavirin in patients with genotype 2 or 3: 16 versus 24 weeks, clinical outcome and direct cost analyses

INTRODUCTION

Short antiviral therapy has been proposed for patients with chronic hepatitis C, easy genotypes, low fibrosis score, low viral load at baseline, and rapid virological response (RVR). However, this approach is not completely accepted.

OBJECTIVES

The aims of this study were (a) to evaluate the sustained virological response (SVR) in noncirrhotic patients with genotype 2 or 3, achieving an RVR, randomized to receive pegylated-interferon (IFN) α-2b plus ribavirin for either 16 or 24 weeks and (b) to carry out direct cost analysis comparing patients treated for 16 versus 24 weeks.

RESULTS

Of the 142 initially evaluated patients, 130 were enrolled according to the selection criteria, but independent of the viral load. According to the intention-to-treat analysis, SVR was achieved in 104 patients (80%). Logistic regression analysis showed that RVR (P<0.001) and genotype 2 (P<0.03) were the most important factors independently associated with SVR. Among patients with RVR, SVR was comparable between patients treated for 16 weeks and those treated for 24 weeks (86.2 vs. 89.7%, P=NS). The mean direct costs were €4003.7 for patients treated for 16 weeks and €5676.7 for those treated for 24 weeks, with a 30% difference between the two arms.

CONCLUSION

In patients achieving an RVR, a 16-week treatment with pegylated-interferon plus ribavirin was comparable to a 24-week treatment. Short treatment in patients with RVR allows us to save 30% of the direct costs, independent of the viral load at baseline.

Rapid virological response tailors the duration of treatment in hepatitis C virus genotype 3 patients treated with pegylated interferon alfa-2a and ribavirin in Pakistan

BACKGROUND

Rapid virological response (RVR) is now thought to be the strongest predictor of sustained virological response (SVR) in hepatitis C virus (HCV) patients undergoing antiviral therapy. It can be used as a guide to individualize treatment duration. The aim of this study was to assess the role of RVR in tailoring the duration of treatment.

METHODS

Patients with HCV genotype 3 infections were enrolled and treated with pegylated interferon alfa-2a (PEG IFN alfa-2a) 180 μg/week and ribavirin. HCV RNA was analyzed at weeks 4, 12, 16, and 24. Treatment duration was individualized on the basis of RVR. Patients who achieved RVR and who were aged ≤ 40 years with a body mass index (BMI) ≤ 27 kg/m(2) received 16 weeks of treatment (group A). Patients who achieved RVR and were aged >40 years with a BMI >27 kg/m(2), aged >40 years with a BMI ≤ 27 kg/m(2), and aged ≤ 40 years with a BMI >27 kg/m(2) received 24 weeks of treatment (group B). Patients who did not achieve RVR but who achieved an early virological response (EVR; HCV PCR-negative or ≥ 2 log drop in HCV RNA at week 12) were treated with 24 weeks of therapy (group C).

RESULTS

SVR was observed in 86% in group A, 82.2% in group B, and 46.8% in group C. A difference was observed in SVR for patients with and without RVR and receiving the standard duration of treatment (82.2% vs. 46.8%, p<0 .001). The results show that the rate of SVR is not inferior in those with RVR treated with 16 weeks of therapy compared to 24 weeks (86% vs. 82.2%, p=0.004).

CONCLUSIONS

RVR is useful to individualize the duration of treatment and to predict the treatment outcome. A short treatment of 16 weeks is as effective as 24 weeks in HCV genotype 3 patients who achieve RVR, who have a low BMI, and are younger in age.

Factors influencing rapid and early virological response to interferon therapy in patients with chronic hepatitis C

AIM: To investigate the predictive factors associated with rapid and early virological response to pegylated interferon and ribavirin treatment in patients with chronic hepatitis C to provide the basis for treatment selection and outcome prediction of antiviral therapy.

METHODS: Eighty-one patients with chronic hepatitis C treated with pegylated interferon and ribavirin were followed up at 4, 12, 24, 48 wk and at least 24 wk after discontinuing treatment. Information for the patients was recorded in detail, including sex, age, baseline HCVRNA level, body mass index (BMI), diabetes mellitus, cirrhosis, history of alcohol consumption, fatty liver, blood transfusion history, and previous antiviral treatment history. Patients were divided into rapid virological response (RVR) group, early virological response (EVR) group, no response (NR) group, relapse (RL) group, and sustained virological response (SVR) group according to the treatment situation. Univariate analysis and multivariate logistic stepwise regression analysis were used to analyze the influencing and predicting factors of RVR and EVR.

RESULTS: Of 81 patients, 51 achieved RVR, 65 achieved EVR, 65 achieved SVR, 10 had NR, and 6 had RL. The rates of RVR, EVR, SVR, NR and RL were 62.9%, 80.2%, 80.2%, 12.3% and 7.4%, respectively. In the RVR group, 88.2% of the cases achieved SVR, while in the EVR group the rate of SVR was 90.8%. Sixteen cases (19.8%) did not achieve RVR and EVR, and 6 of them (37.5%) achieved SVR and had no recurrence. The SVR rates were significantly different among the RVR, EVR, and non-RVR/EVR groups (χ² = 20.622, P < 0.05), but the RL rate had no significant difference among them. The rates of RVR and EVR among the SVR, NR and RL groups were significantly different. Univariate analysis showed that RVR was associated with age ≤ 40 years old, HCV RNA < 4 × 10⁵ IU/mL, and no cirrhosis, while EVR was associated with age ≤ 40 years old, HCV RNA < 4 × 10⁵ IU/mL, no cirrhosis, and BMI < 24 kg/m². Multivariate logistic stepwise regression analysis showed that baseline HCV RNA load and cirrhosis were independent factors for predicting RVR and EVR.

CONCLUSION: The acquisition of RVR and EVR is a significant predictor of SVR. In non-RVR and non-EVR groups, a minority of patients still could achieve SVR after one year of treatment. RVR and EVR can not predict recurrence. Predicting factors including age, baseline viral load, liver cirrhosis, and body mass index are closely related to RVR and EVR. Baseline viral load and liver cirrhosis are independent predictive factors for RVR and EVR.

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.

Hepatitis C-related cirrhosis with sustained prevention of hepatocellular carcinoma recurrence by long-term administration of super-low-dose peginterferon-alpha 2b

A 78-year-old male who experienced multiple recurrences of hepatocellular carcinoma (HCC) with hepatitis C virus (HCV)-related cirrhosis underwent transcatheter arterial chemoembolization and ablation and survived for more than 10 years. His serum HCV RNA level was 2.8 log IU/ml and the serotype of HCV was 2. He underwent long-term super-low-dose (20 μg/week) pegylated interferon-alpha 2b therapy to prevent recurrence of HCC. He became negative for HCV RNA 2 months later, and thereafter remained negative after the discontinuation of interferon therapy, and has not experienced a recurrence of HCC for more than 20 months.

Effect of killer immunoglobulin-like receptors in the response to combined treatment in patients with chronic hepatitis C virus infection

Killer immunoglobulin-like receptors (KIRs) are related to the activation and inhibition of NK cells and may play an important role in the innate response against infection with viruses such as hepatitis C virus (HCV). We examined whether the different combinations of KIRs with their HLA class I ligands influenced the response to combined treatment (pegylated alpha interferon and ribavirin) of patients infected by HCV. A total of 186 consecutive patients diagnosed with chronic HCV infection were analyzed. Seventy-seven patients exhibited HCV RNA levels at 6 months posttreatment and were called nonresponders (NR), while 109 cleared viral RNA and were named sustained viral responders (SVR). Patients were typed for HLA-B, HLA-Cw, KIR genes, and HCV genotype. In our study, the frequency of the KIR2DL2 allele was significantly increased in NR (P < 0.001; odds ratio [OR] = 1.95), as was the frequency of the KIR2DL2/KIR2DL2 genotype (P < 0.005; OR = 2.52). In contrast, the frequencies of the KIR2DL3 genotype (P < 0.001) and KIR2DL3/KIR2DL3 genotype (P < 0.05; OR = 0.54) were significantly increased in the SVR. Different combinations of KIR2DL2 and KIR2DL3 alleles with their ligands were analyzed. The frequency of the KIR2DL2/KIR2DL2-HLA-C1C2 genotype was significantly increased in the NR (P < 0.01; OR = 3.15). Additionally, we found a higher frequency of the KIR2DL3/KIR2DL3-HLA-C1C1 genotype in the SVR group (P < 0.05; OR = 0.33). These results were not affected by the HCV genotype. In conclusion, patients who carried the KIR2DL2/KIR2DL2-HLA-C1C2 genotype were less prone to respond to treatment. However, the KIR2DL3/KIR2DL3-HLA-C1C1 genotype clearly correlated with a satisfactory response to treatment, defined by the clearance of HCV RNA.

Viral factors influencing the response to the combination therapy of peginterferon plus ribavirin in chronic hepatitis C

Hepatitis C virus (HCV) is a single-stranded RNA virus known for its high genetic variability owing to the lack of a proofreading mechanism of its RNA dependent RNA polymerase. Until now, numerous studies have been undertaken to clarify the correlation between pretreatment HCV genetic variability and the therapeutic response. Even with the recent combination therapy of peginterferon plus ribavirin for chronic hepatitis C, viral response is variable, and only half of treated patients could clear the virus [sustained viral response (SVR)]. In this review, the contribution of viral genetic variability affecting the treatment outcome is discussed according to each HCV genomic region.

Clinical trial: low plasma cholesterol and oxidative stress predict rapid virological response to standard therapy with peginterferon and ribavirin in HCV patients

BACKGROUND

Rapid virological response (RVR) is the best predictor of sustained response to standard HCV treatment.

AIM

To evaluate predictive factors of RVR.

METHODS

Sixty-five patients (mean age 52.6 +/- 13.8; 37 genotype-1, and 28 genotypes-2/3) were consecutively treated with pegIFN-alpha 2a or 2b once weekly plus daily ribavirin based on body weight for 24 or 48 weeks, according to genotype. RVR was defined as undetectable HCV-RNA at week 4.

RESULTS

Twenty-seven percent of patients achieved RVR in genotypes 1 and 60.7% in genotypes 2/3 (P < 0.01). Rapid responders had higher mean serum baseline total and LDL-cholesterol levels (P < 0.01). RVR was 20.0% in the bottom tertile of total cholesterol and 63.6% in the top tertile (P < 0.01). HCV-RNA levels at week 4 were positively correlated with baseline serum insulin (P < 0.01), HOMA-IR (P < 0.01), body mass index (P < 0.05) and number of components of metabolic syndrome (P < 0.01) and negatively correlated with cholesterol levels (P < 0.05). At multivariate analysis, age, LDL-cholesterol, HCV genotype and serum 8-iso-PGF 2 alpha, a marker of oxidative stress, were independent predictors of RVR.

CONCLUSIONS

Our prospective study supports a role of low serum total and LDL-cholesterol and of oxidative stress as positive independent predictive factors of poor RVR in HCV patients.

The efficacy of interferon-beta monotherapy for elderly patients with type C hepatitis of genotype 2

OBJECTIVE

The aim of this study was to elucidate the efficacy of interferon (IFN)-beta monotherapy for elderly patients of > or = 70 years with type C hepatitis (HCV) of genotype 2.

METHODS

The present study was a retrospective cohort study. Inclusion criteria were type C hepatitis patients with HCV genotype 2a or 2b, > or = 70 years, and IFN-beta monotherapy of within 24 weeks. Thirty-one consecutive patients who satisfied the above criteria were enrolled in the present study. Independent factors that might have influenced the sustained virological response (SVR) were studied using logistic regression analysis.

RESULTS

Background of clinical profiles was as follows: median (range) age = 71 (70-76) years, male/female = 13/18, and median (range) HCV-RNA = 260 (< 5-3,800) KIU/mL. Out of 31, 16 patients (51.6%) had SVR by the intention-to-treat analysis. The SVR was significantly associated with the serum HCV RNA level. Logistic analysis showed that SVR occurred when HCV RNA level was < 100 KIU/mL (p=0.020). Based on the difference of the serum HCV RNA level, the SVR rate was 81.8% (9/11) in patients with a serum HCV RNA level of < 100 KIU/mL and 35.0% (7/20) in patients with a serum HCV RNA level of > or = 100 KIU/mL.

CONCLUSION

IFN-beta monotherapy of < or = 24 week is a possible therapy selection for elderly patients of > or = 70 years with type C hepatitis of genotype 2.

Optimal dose of peginterferon and ribavirin for treatment of chronic hepatitis C

Chronic hepatitis C affects 170 million people worldwide, including up to 4 million people in the United States. The current standard of care therapy with pegylated interferon (PEG-IFN) and ribavirin (RBV) while highly successful in patients with genotype 2 and 3 infection, allows for sustained virologic response in 42-46% of treatment-naïve genotype 1 patients, comprising about 70% of cases of chronic hepatitis C in the USA. While awaiting approval of Specifically Targeted Antiviral Therapy for HCV (STAT-C) agents, which will require the completion of additional clinical trials, it is important to optimize the dose and duration of currently available treatment modalities, namely PEG-IFN and RBV, for treatment of CHC. Results of several recent trials evaluating optimal dosing of RBV and higher than standard dosing of PEG-IFN in treatment-naïve genotype 1 patients, as well as data from retreatment trials with "induction" doses of PEG-IFN or high-dose RBV in prior non-responders to IFN-based therapy will be reviewed here. The possibility of shorter duration of therapy for genotype 2 and 3 patients based on recent publications and presentations will be discussed as well.

Lower-than-standard dose peg-IFN alfa-2a for chronic hepatitis C caused by genotype 2 and 3 is sufficient when given in combination with weight-based ribavirin

Mono-therapy with pegylated interferon (peg-IFN) has shown that a lower-than-standard dose yields the same sustained viral response (SVR) rates as standard doses for chronic hepatitis C virus (HCV) infection caused by genotypes 2 or 3. Our aim was to see if a fixed, lower-than-standard dose of peg-IFN alfa-2a (135 microg weekly) in combination with ribavirin 11 mg/kg daily for 24 weeks yields sufficient SVR rates for genotypes 2 or 3. Hundred consecutive patients with a mean age of 44 years (range 20-69 years), 59 with genotype 3 and 41 with genotype 2, were studied. Rapid viral response (RVR) with HCV-RNA <15 IU/mL at treatment week 4 and SVR were calculated. RVR was achieved by 28/40 (70%) patients with genotype 2 and 41/58 (71%) with genotype 3. Significantly more genotype 2 patients with RVR achieved SVR 27/28 (96%) than genotype 2 patients who failed to achieve RVR, 8/12 (66%), P = 0.009. The corresponding figures for genotype 3 patients were 39/41 (95%) vs 11/17 (65%), respectively, P = 0.002. In total, SVR was achieved by 35/41 (85%) patients with genotype 2 and 51/59 (86%) patients with genotype 3, respectively. We found that 135 microg peg-IFN alfa-2a weekly was sufficient for treatment of genotype 2 and 3 chronic hepatitis C when combined with RBV dosed daily according to body weight. This combination yielded high SVR rates (85-86%) and may be cost-saving.

Pegylated interferon 2a and 2b in combination with ribavirin for the treatment of chronic hepatitis C in HIV infected patients

Coinfection with hepatitis C virus (HCV) and HIV is an increasingly recognized clinical dilemma, particularly since the advent of highly active antiretroviral therapy. Several studies of this population have demonstrated both more rapid progression of liver disease and poorer overall prognosis compared to HCV monoinfected patients. Consensus guidelines, based primarily on the results of 4 major randomized trials, recommend treatment with peginterferon and ribavirin for 48 weeks in coinfected patients. However, this current standard of care is associated with lower response rates to therapy than those seen in monoinfected patients. Important predictors of response include HCV genotype, pretreatment HCV RNA level, and presence of rapid virologic response (RVR) and early virologic response (EVR). Use of weight-based ribavirin dosing appears to be safe and enhances the likelihood of sustained virologic response (SVR). Adverse effects most commonly encountered are anemia and weight loss. Mitochondrial toxicity can occur in the setting of concomitant nucleoside reverse transcriptase inhibitor use, especially didanosine, abacavir, and zidovudine, and these should be discontinued before initiation of ribavirin therapy. Discontinuation of therapy should be considered in patients failing to demonstrate EVR, though ongoing trials are investigating a potential role for maintenance therapy in these patients. Peginterferon combined with weight-based ribavirin is appropriate and safe for treatment of HCV in HIV - HCV coinfected patients. This review summarizes the data supporting these recommendations.

The use of molecular assays in the management of viral hepatitis

Molecular assays are instrumental in the clinical management of viral hepatitis. During the past years, a wide variety of molecular assays have been developed and implemented. This considerably improved the understanding of the natural history and pathogenesis of Hepatitis B virus (HBV), Hepatitis C virus (HCV) or Hepatitis delta virus (HDV) hepatitis, but also caused uncertainties in the selection of the most appropriate assays for clinical requirements. Indeed, a rational choice and application of these assays requires adequate knowledge of the performance of the single test. Moreover, the choice of the most accurate assay for patients' needs and physicians' objectives, needs to be oriented to specific contexts, such as diagnosis, management or treatment. In the past, a hurdle in the routine use of assays for hepatitis viruses nucleic acid quantification was represented by the availability of only "home brew" methods which lacked standardization. Major improvement in addressing the use of molecular assays for viral hepatitis has been derived from recent standardization procedures that allowed a comparison between different tests after results were given as International Units. In addition, it should be reminded that, before getting into the market, molecular assays should be approved by European regulation authorities and validated using internationally recognized standards. A subsequent clinical validation should address the diagnostic accuracy of the assay. These proceedings have the aim of identifying which molecular tests, among those currently available, meet clinical requirements for each specific application.

Sustained virological response based on rapid virological response in genotype-3 chronic hepatitis C treated with standard interferon in the Pakistani population

AIM

To document the sustained virological response (SVR) in rapid virological responders (RVR) of genotype-3 chronic hepatitis C with standard interferon (SdIF).

METHODS

Hepatitis C genotype-3 patients during the period July 2006 and June 2007 were included. Complete blood counts, prothrombin time, ALT, albumin, qualitative HCV RNA were done. SdIF and ribavirin were given for 4 wk and qualitative HCV RNA was repeated. Those testing negative were allocated to group-A while the rest were allocated to group-B. Treatment was continued a total of 16 and 24 wk for group A and B respectively. HCV RNA was repeated after 24 wk of treatment. End virological and sustained virological responses were compared by c2 test. ROC of pretreatment age, ALT and albumin were plotted for failure to achieve SVR.

RESULTS

Of 74 patients treated, RCV RNA after 16 wk of therapy became undetectable in 34 (45.9%) and was detectable in 40 (54.1%) and were allocated to groups A and B respectively. SVR was achieved in 58.8% and 27.8% in groups A and B respectively. SVR rates were significantly higher in patients who had RVR as compared to those who did not (P = 0.0; gamma = 2). Both groups combined ETR and SVR were 70% and 33% respectively. ROC plots of pretreatment age, ALT and albumin for SVR showed only ALT to have a significantly large area under the curve.

CONCLUSION

SVR rates were higher in patients who had RVR with SdIF and high pre treatment ALT values correlated to probability of having RVR.

Response of combination therapy on viral load and disease severity in chronic hepatitis C

Influence of genotypes on viral kinetics and disease severity in chronic hepatitis C (CH-C) patients has been implicated, but requires further investigation. The 41 HCV patients were genotyped by restriction fragment length polymorphism and included for 48 weeks of combination therapy on the basis of clinical (alanine amino transferase > or =60 IU/l) and histological features (histological activity index > or =3). A significant number (30/41) of patients (6/9 of genotype 1, 23/30 of genotype 3 and 1/2 of mixed genotype) attain sustained virological response despite high viral load at baseline. More aggressive treatment was required in genotype 1 than in genotype 3 due to slow response rate. Significant (P < 0.05) difference in the viral load of sustained virological responder and non-responder (NR) was observed after 12 weeks of therapy. Severe course of liver disease was observed in 81.81% (9/11) of NR patients at baseline. Data indicate that genotype 1 was a slow responder compared to genotype 3 on combination therapy. Response to combination therapy was almost independent of baseline viral load. However, a positive correlation of viral load with disease severity was observed. The viral kinetics at 12 weeks is an important tool for determination of virological response.

The efficacy of short-term interferon-beta therapy for chronic hepatitis C patients with low virus load

OBJECTIVE

The aim of this study was to elucidate the efficacy of short-term interferon (IFN) therapy for chronic hepatitis C patients with low virus load.

METHODS

The present study was a retrospective cohort study. Inclusion criteria were biopsy-proven chronic hepatitis, the serum hepatitis C virus (HCV) RNA level of less than 100 KIU/ml, IFN period of 8 weeks or less. One hundred and eleven consecutive patients satisfied above criteria were treated with IFN-beta (dose: 6 MU, daily for 4, 6, or 8 weeks).

RESULTS

Background of clinical profiles were as follows: median (range) age=56 (20-73) years, male/female=64/47, genotype 1b/2a/2b=40/68/3, and median (range) HCV-RNA=34 (4.5-81) KIU/ml. Out of 111, 64 patients (57.7%) had sustained viral response (SVR). Based on the difference of HCV genotype, the SVR rate was 47.5% (19/40) in genotype 1 and 63.3% (45/71) in genotype 2. In genotype 1, the SVR rate in patients treated with the 8-week-regimen was significantly higher than that in patients treated with the 4- or 6-week regimen. In contrast, in genotype 2, the SVR in patients treated with the 8-week regimen was not significantly different from that in patients treated with the 6-week regimen. None of the patients had severe IFN-related side effects.

CONCLUSIONS

The 6 or 8-week regiment of IFN-beta therapy is one selection of therapy for chronic hepatitis C patients who have tended to have a SVR and who show IFN-related adverse events.

The efficacy of short-term interferon-beta therapy for type C cirrhotic patients with genotype 2a and low virus load

OBJECTIVE

The aim of this study was to elucidate the efficacy of short-term interferon (IFN) therapy for type C cirrhotic patients with genotype 2a and low virus load.

METHODS

The present study was retrospective cohort study. Inclusion criteria were liver cirrhosis, hepatitis C virus (HCV) genotype 2a, the serum HCV RNA level of less than 100 KIU/mL, and IFN period of 6 or 8 weeks. Twenty-five consecutive patients who satisfied the above criteria were treated with IFN-beta daily at the dosage of 6 MU for 6 or 8 weeks. Independent factors that might have influenced sustained virologic response (SVR) were studied using multiple logistic regression analysis.

RESULTS

Background of clinical profiles were as follows: median (range) age=64 (53-76) years, male/female=13/12, and median (range) HCV-RNA=31 (8-90) KIU/mL. Out of 25, 14 patients (56.0%) had SVR by the intention-to-treat analysis. The SVR was significantly associated with serum HCV RNA level. Logistic analysis showed that SVR occurred when HCV RNA level was <50 KIU/mL (p=0.047). Based on the difference of the serum HCV RNA level, the SVR rate was 68.4% (13/19) in patients with a serum HCV RNA level of <50 KIU/mL and 16.7% (1/6) in patients with a serum HCV RNA level of > or =50 KIU/mL.

CONCLUSIONS

The 6 or 8-week IFN-beta therapy is a possible selection of therapy for cirrhotic patients with HCV genotype 2a and a serum HCV RNA level of <50 KIU/mL.

Genetic diversity of the hepatitis C virus: Impact and issues in the antiviral therapy

The hepatitis C Virus (HCV) presents a high degree of genetic variability which is explained by the combination of a lack of proof reading by the RNA dependant RNA polymerase and a high level of viral replication. The resulting genetic polymorphism defines a classification in clades, genotypes, subtypes, isolates and quasispecies. This diversity is known to reflect the range of responses to Interferon therapy. The genotype is one of the predictive parameters currently used to define the antiviral treatment strategy and the chance of therapeutic success. Studies have also reported the potential impact of the viral genetic polymorphism in the outcome of antiviral therapy in patients infected by the same HCV genotype. Both structural and non structural genomic regions of HCV have been suggested to be involved in the Interferon pathway and the resistance to antiviral therapy. In this review, we first detail the viral basis of HCV diversity. Then, the HCV genetic regions that may be implicated in resistance to therapy are described, with a focus on the structural region encoded by the E2 gene and the non-structural genes NS3, NS5A and NS5B. Both mechanisms of the Interferon resistance and of the new antiviral drugs are described in this review.