Effect of treatment with interferon alpha-2b and ribavirin in patients infected with genotype 2 hepatitis C virus.

Aim: Nearly 20% of chronic hepatitis C (CHC) patients with genotype 2 hepatitis C virus (HCV) infection are not curable, even by interferon (IFN)-ribavirin combination therapy. The aim of this study is to investigate the factors that determine the efficacy of combination therapy in patients with genotype 2 HCV infection. Methods: Fifty patients with CHC who underwent a treatment of 6 MU IFN alpha-2b with ribavirin for 24 weeks were retrospectively analyzed. Results: All the patients showed no serum HCV-RNA within 12 weeks after starting the therapy. Forty-one of the 50 patients (82%) achieved a sustained virological response (SVR). The age, sex, genotype (2a vs. 2b) and grade/stage of the liver by histopathology and pretreatment viral load werenot different between the sustained responders and relapsers. Univariate analysis showed that an earlier viral clearance from blood and a larger number of amino acid substitutions in the interferon sensitivity determining region (ISDR) were predictors of SVR. Multivariate analysis showed that a large number of amino acid substitutions in the ISDR was a predictor of SVR. Conclusion: The characterization of the amino acid sequences of ISDR may be helpful for predicting a relapse after combination therapy in patients with genotype 2 HCV infection.     

Twenty-four weeks of interferon alpha-2b in combination with ribavirin for Japanese hepatitis C patients: sufficient treatment period for patients with genotype 2 but not for patients with genotype 1.

BACKGROUND: Hepatitis C virus (HCV) RNA titer and HCV genotype are two major determinants of the outcome of interferon (IFN) monotherapy. To clarify the usefulness of combination therapy with IFN and ribavirin in Japanese hepatitis C patients, we treated patients with a relatively high dose of IFN in combination with ribavirin for 24 weeks and examined the effects in relation to the viral parameters. METHODS: Two hundred and ninety-five patients were enrolled in the study. The patients received either 6 or 10 million units (MU) of interferon alpha-2b every day for 2 weeks and then three times a week for 22 weeks with a daily dose of either 600 or 800 mg of ribavirin. The treatment response and safety of this treatment were examined. RESULTS: The sustained virologic response (SVR) rates were 26.8% in genotype 1 and 76.5% in genotype 2 (P < 0.001), and 36.1% with the 6 MU group and 45.8% with the 10 MU group (P = 0.09). Multivariate analysis indicated that SVR was associated with genotype 2, HCV RNA <500 kilointernational unit/ml (kIU/ml), and HCV RNA undetectability at week 8 of treatment. CONCLUSION: Our current study showed that a 24-week course of IFN plus ribavirin combination therapy was effective with respect to virologic response in Japanese hepatitis C patients, particularly in patients with HCV genotype 2.     

Effect of treatment with interferon α-2b and ribavirin in patients infected with genotype 2 hepatitis C virus

Aim:  Nearly 20% of chronic hepatitis C (CHC) patients with genotype 2 hepatitis C virus (HCV) infection are not curable, even by interferon (IFN)–ribavirin combination therapy. The aim of this study is to investigate the factors that determine the efficacy of combination therapy in patients with genotype 2 HCV infection.
Methods:  Fifty patients with CHC who underwent a treatment of 6 MU IFN α-2b with ribavirin for 24 weeks were retrospectively analyzed.
Results:  All the patients showed no serum HCV-RNA within 12 weeks after starting the therapy. Forty-one of the 50 patients (82%) achieved a sustained virological response (SVR). The age, sex, genotype (2a vs. 2b) and grade/stage of the liver by histopathology and pretreatment viral load werenot different between the sustained responders and relapsers. Univariate analysis showed that an earlier viral clearance from blood and a larger number of amino acid substitutions in the interferon sensitivity determining region (ISDR) were predictors of SVR. Multivariate analysis showed that a large number of amino acid substitutions in the ISDR was a predictor of SVR.
Conclusion:  The characterization of the amino acid sequences of ISDR may be helpful for predicting a relapse after combination therapy in patients with genotype 2 HCV infection.     

Prospective study on early virologic response to treatment with interferon alpha-2b plus ribavirin in patients with chronic hepatitis C genotype 1b.

To evaluate the predictive value of early virologic response (EVR) of achieving a sustained virologic response (SVR), an open, prospective trial including 42 patients with chronic hepatitis C genotype 1b was performed with directly observed 24-week treatment with interferon alpha-2b plus ribavirin. We assessed the predictive values of EVR at days 3, 7, 14, and weeks 4, 8, and 12 of the SVR. The SVR in an intention-to-treat analysis was 19.0%. Patients who reached SVR presented a significantly faster reduction in plasma viral load. Stepwise multiple logistic regression analysis of the factors (gender, age, IFN dosage, ribavirin dosage, HCV RNA, ISDR, and loss of HCV RNA at week 4) revealed that loss of HCV RNA at week 4 was the only independent variable of treatment outcome (P=0.0039). A viral load at treatment day 3 above 100kIU/ml, at day 7 above 50kIU/ml, and at day 14 above 10kIU/ml was 100% predictive for virologic non-response in all except 1 patient. The cutoff levels for HCV RNA at days 3 and 14 of treatment were associated with an algorithm of the failure to detect HCV RNA after 12 weeks of treatment. In conclusions, a very early virologic response assessment could be useful for prediction of later outcome of combination therapy in chronic hepatitis C genotype 1b.     

基因1型慢性丙型肝炎初治患者获得持续病毒学应答的相关因素研究

目的研究接受长效干扰素和利巴韦林治疗的基因1型慢性丙型肝炎患者获得持续病毒学应答的预测因素。方法 73例基因1型慢性丙型肝炎患者接受干扰素α-2a联合利巴韦林治疗24周或48周,随访6个月。结果 47.9%患者获得早期病毒学应答,38.4%患者获得持续病毒学应答;分析表明治疗前低病毒载量（小于8×105IU/ml）、体重指数低于25kg/m2和出现早期病毒学应答者更容易获得持续病毒学应答。结论病毒载量、体重指数和是否出现早期病毒学应答与基因1型慢性丙型肝炎初治患者获得持续病毒学应答相关。     

Early decline of the HCV core antigen can predict SVR in patients with HCV treated by Pegylated interferon plus ribavirin combination therapy

OBJECTIVE: Pegylated interferon (PEG‐IFN) plus ribavirin (RBV) combination therapy is now a popular treatment for patients with chronic hepatitis C; however, the reported sustained virologic response (SVR) rate remains at nearly 50% in genotype 1b infected patients. Therefore, it is of clinical benefit to be able to predict the effect of combination therapy on individual patients earlier in the treatment. We estimated the predictive serum HCV core antigen levels for SVR in the early therapeutic stage of combination therapy. METHODS: The HCV core antigen in patients with high‐level HCV viremia, in whom standard PEG‐IFNα2b plus RBV combination therapy had been completed, was measured at baseline and at 3, 7, 14, 28 and 84 days of treatment, and their SVR was determined at 24 weeks after treatment. Sixty genotype 1b‐ and 30 genotype 2‐infected patients were included. RESULTS: Thirty (50%) genotype 1b and 27 (90%) genotype 2 patients achieved a SVR. In genotype 1b patients the decline of HCV core antigen levels was statistically different between the SVR and non‐SVR groups. When we defined a separation level at 500 fmol/L, sensitivity, specificity, positive predictive value, negative predictive value, and accuracy for SVR at day 7 was 79.4%, 88.5%, 90%, 76.7%, and 83.3%, respectively. In genotype 2 patients, there was no significant difference in the HCV core antigen values between the SVR and non‐SVR groups. CONCLUSION: In genotype 1b patients, 500 fmol/L of HCV core antigen level at day 7 was the best predictor for therapeutic response in the early stage of treatment.     

A 48-week duration of therapy with pegylated interferon alpha 2b plus ribavirin may be too short to maximize long-term response among patients infected with genotype-1 hepatitis C virus

The therapeutic response among patients infected with hepatitis C virus (HCV) of genotype 1 remains suboptimal. We examined a large database of patients treated with combination therapy (ribavirin plus an interferon [IFN]). We hypothesized that the longer the duration that the virus load was rendered undetectable in serum, the better would be the probability of a sustained viral response (SVR). A model predicting SVR was generated; it included the following covariates: duration of continuous nondetectability of an HCV load in serum, estimated creatinine clearance, and whether the isolate was of genotype 1. The validation model demonstrated positive and negative predictive values as well as sensitivity and specificity exceeding 90%. The model predicted that patients infected with HCV genotype 1 require continuous nondetectability of virus load in serum for 36 and 32 weeks, to attain 90% and 80% probabilities, respectively, of a SVR. The average time to clear serum of genotype-1 virus was 30.4 weeks, which indicates that the 48-week duration of therapy provided a suboptimal probability of a SVR. For some patients, suboptimal therapy with pegylated IFN plus ribavirin may need to be of longer duration than the currently recommended 48 weeks. This hypothesis requires prospective validation.     

Antiviral therapy: chronic hepatitis C

Summary.  The combination of pegylated interferon (IFN) with ribavirin is the standard of care for chronic hepatitis C. Response rates range from 50 to 90% for genotype 1 and 2/3 which also differ in the duration of treatment (48 vs 24 weeks, respectively). Therapy if given with weight-based dosing may be shortened from 24 to 12, 14 or 16 weeks (genotypes 2 and 3), and from 48 to 24 weeks (genotype 1) in case of hepatitis C virus (HCV) clearance at week 4, without reducing sustained virologic response (SVR). Conversely, prolonging treatment for 72 weeks in those with only a decrease of viral load at week 4, i.e. "slow responders" increases SVR rates by preventing relapse. In spite of such progress, over half of patients are relapsers or nonresponders. If the previous treatment was suboptimal, retreatment with higher doses or longer duration may be beneficial unless an individual was a 'null responder' previously. New promising anti-HCV molecules (antiproteases and antipolymerases), some with potent antiviral activity, are in phase II trials but appear to require the addition of IFN and ribavirin to maintain viral suppression. Other immunomodulatory agents such as new IFN or therapeutic vaccines and alternatives to ribavirin are also under development. Future regimens should improve efficacy and provide shorter and better-tolerated combination therapy.     

Pegylated interferon alfa-2b plus ribavirin in the retreatment of interferon-ribavirin nonresponder patients

BACKGROUND & AIMS: Inadequate data are available about retreatment of nonresponders to interferon (IFN) and ribavirin. Thus, this study evaluated the efficacy and tolerability of a 48-week therapy with pegylated IFN-alpha-2b plus high-dose ribavirin in patients who have failed to respond to the combination. Treatment up to 48 weeks also in patients who have failed to clear hepatitis C virus (HCV) RNA by week 24 was also evaluated. METHODS: One hundred forty-one patients who previously did not respond to IFN and ribavirin, 86% with genotype 1 or 4 infection, 52% with high viral load (>800.000 IU/mL), 22% with cirrhosis, were retreated with pegylated IFN-alpha-2b 1.5 microg/kg per week and ribavirin 1000-1200 mg/day for 48 weeks and followed up for 24 weeks. RESULTS: By intent-to-treat analysis, 20% of patients achieved a sustained virologic response (SVR). SVR of genotype 1 patients was 19%. Independent predictors of SVR were low gamma-glutamyltransferase levels (OR, 22.9; 95% CI: 6.6-79.6) and low viral load (OR, 3.8; 95% CI: 1.1-12.6). Twelve (23%) out of 51 patients who were HCV RNA positive after 24 weeks of therapy achieved a late virologic response (after week 24) and 5 (10%) of them, all with genotype 1, achieved an SVR. Genotype was not associated with response (P = .2) or with early response (P = .3). CONCLUSIONS: Retreatment with pegylated IFN-alpha-2b and ribavirin of multi-experienced and "difficult to treat" nonresponder patients produced a very promising SVR. Accurate selection of patients, such as those with low viral load and low gamma-glutamyltransferase levels, and prolongation of therapy beyond 24 weeks also in HCV RNA-positive patients may further increase the rate of SVR.     

Randomized controlled trial of pegylated interferon-alfa 2a and ribavirin in treatment-naive chronic hepatitis C genotype 6

Hepatitis C virus (HCV) genotype is an important criteria in determining duration of therapy and predictor of sustained virologic response (SVR) to pegylated interferon (PEG IFN) and ribavirin (RBV) therapy. Optimal duration of therapy for patients with HCV genotype 6 is not known. We conducted a multicenter, open-label randomized controlled trial of patients with HCV genotype 6 at five gastroenterology clinics in the western U.S. Patients were stratified by viral load and histologic stage and assigned to receive PEG IFN-α2a 180 μg subcutaneously weekly and weight-based oral RBV 800 to 1,200 mg daily for 24 or 48 weeks. Primary outcome measurement was SVR rate by intention-to-treat analysis. From February 2005 to October 2007 a total of 60 patients (age 51 ± 10 years, 47% male, log HCVRNA 6.3 ± 1.1 IU/mL) were enrolled: 27 patients to 24 weeks and 33 patients to 48 weeks of therapy. In the 24-week and 48-week groups, 96% and 97% achieved early virologic response (P = 0.90); 89% versus 94% achieved end of therapy virologic response (P = 0.48). SVR was achieved in 70% versus 79% of patients assigned to 24 weeks versus 48 weeks (P = 0.45). Rapid virologic response (RVR) was a significant predictor of SVR in the 48-week group and trending towards significance in the 24-week group: 82% and 83% of those with RVR achieved SVR versus 33% and 29% for the 24-week and 48-week groups, respectively (P = 0.07 and P = 0.02). CONCLUSION: There was no significant difference in SVR rates in patients with HCV genotype 6 treated with PEG IFN-α2a and RBV for 24 versus 48 weeks.     

Pegylated interferon therapy in chronic hepatitis C: lights and shadows of an innovative treatment

Pegylated interferon (PEG-IFN) in combination with ribavirin is the standard of treatment for chronic hepatitis C. Several viral andhost factors influence the outcome of treatment, such as hepatitis C virus (HCV) genotype, baseline viral load, viral kinetics, race, bodyweight, advanced liver disease, HIV co-infection, and adherence to therapy. Monitoring the response of HCV to treatment during the earlytime points (4 weeks or 12 weeks) after initiation of therapy has emerged as a critical tool to predict sustained virologic response (SVR),defined as undetectable serum HCV RNA 24 weeks after the end of therapy. To counterbalance the influence of host and viral factors,treatment duration can be individualised to achieve an optimal treatment outcome, potentially reduce costs, and minimize side effects.     

Triple therapy of initial high-dose interferon with ribavirin and amantadine for patients with chronic hepatitis C

Aims: We previously reported the potential effect of combination therapy of an initial high‐dose interferon (IFN) and amantadine on the eradication of HCV‐RNA in patients with chronic hepatitis C. The additive effects of amantadine on interferon and ribavirin combination therapy remain controversial. In this study we investigated the efficacy of initial high‐dose IFN with ribavirin and amantadine on the virological response in patients with chronic hepatitis C with a high viral load of genotype 1b. Methods: Twenty‐two patients with high viral loads of genotype 1b hepatitis C virus were enrolled in this pilot study. Patients were administered IFN‐beta for four weeks and then IFN‐alpha2b for 22 weeks with daily oral administration of ribavirin and amantadine. Results: A sustained virological response (SVR) was shown in 31.8% (seven of 22 patients). With the naïve patients, the SVR rate was 21.4% (three of 14 patients). In patients who could not eradicate HCV‐RNA by previous IFN monotherapy, the SVR rate was 50% (four of eight patients). Conclusion: Triple therapy with an initial high dose of IFN with ribavirin and amantadine may be effective, especially for chronic hepatitis C IFN‐retreatment patients with a high viral load of genotype 1b.     

Antiviral therapy for recurrent hepatitis C after liver transplantation: sustained virologic response is related to genotype 2/3 and response at week 12

OBJECTIVES: Recurrent hepatitis C virus (HCV) infection after liver transplantation (LT) is a major cause of transplant failure in HCV-positive patients. We retrospectively assessed the efficacy and safety of antiviral therapy and determined the factors influencing sustained virologic response (SVR) in LT recipients. METHODS: Between 1998 and 2007, we treated 36 LT recipients for hepatitis C cirrhosis and subsequent HCV recurrence (27 genotype 1 and 9 genotypes 2/3) with pegylated interferon alpha-2a (180 microg/week), pegylated interferon alpha-2b (1.5 microg/kg per week), or standard interferon alpha-2b (3 MIU 3X/week) plus ribavirin (600-1200 mg/day) for 48 weeks. RESULTS: SVR was achieved in seven of 27 (26%) of genotype 1 patients versus nine of nine (100%) genotype 2/3 patients (P=0.0001). Early virologic response at week 12 was associated with permanent viral clearance. Side effects included cytopenia and acute hearing loss, but rate of therapy withdrawal and dose reduction was low. CONCLUSION: Combination therapy in patients with HCV reinfection after LT yields an excellent SVR rate in genotype 2/3 patients, but remains unsatisfactory in genotype 1 patients. Virologic response at week 12 (early virologic response) can determine whether therapy should be continued or not.     

Durability of sustained response shown in paediatric patients with chronic hepatitis C who were treated with interferon alfa-2b plus ribavirin

Long-term studies in adults indicate that sustained virologic response (SVR) after combination treatment for chronic hepatitis C (CHC) predicts long-term clearance. Although peginterferon plus ribavirin is now standard care for children with CHC, long-term follow-up studies are not yet available. This study evaluated durability of virologic response over 5 years in children previously treated with interferon alfa-2b plus ribavirin (IFN/R). Ninety-seven of 147 children with CHC, who were treated with IFN/R and completed the 6-month follow-up in two previous clinical trials, participated in this long-term follow-up study. All were assessed annually for up to 5 years; patients with SVR were assessed for durability of virologic response. Children with SVR (n = 56) and those with detectable hepatitis C virus (HCV) RNA 24-week post-treatment (n = 41) were followed for a median of 284 weeks. Overall, 70% (68/97) of patients completed the 5-year follow-up. One patient with genotype 1a CHC had SVR and relapsed at year 1 of follow-up with the same genotype. Kaplan-Meier estimate for sustained response at 5 years was 98% (95% CI: 95%, 100%). Six patients with low-positive HCV RNA levels (n = 4) or missing HCV RNA at the 24-week follow-up visit (n = 2) in the initial treatment studies had virologic response during this long-term follow-up study. Linear growth rate was impaired during treatment with rapid increases in the immediate 6 months post-treatment. Mean height percentile at the end of the 5-year follow-up was slightly less than the mean pretreatment height percentile. Five patients experienced serious adverse events; none related to study drug exposure. SVR after IFN/R predicts long-term clearance of HCV in paediatric patients; growth normalized in the majority of children during the long-term follow-up. Similar long-term results could be expected after peginterferon alfa-2b plus ribavirin treatment.     

Factors affecting efficacy in patients with genotype 2 chronic hepatitis C treated by pegylated interferon alpha‐2b and ribavirin: reducing drug doses has no impact on rapid and sustained virological responses

Summary. Reducing the dose of drug affects treatment efficacy in pegylated interferon (Peg‐IFN) and ribavirin combination therapy for patients with hepatitis C virus (HCV) genotype 1. The aim of this study was to investigate the impact of drug exposure, as well as the baseline factors and the virological response on the treatment efficacy for genotype 2 patients. Two‐hundred and fifty patients with genotype 2 HCV who were to undergo combination therapy for 24 weeks were included in the study, and 213 completed the treatment. Significantly more patients who achieved a rapid virological response (RVR), defined as HCV RNA negativity at week 4, achieved a sustained virological response (SVR) (92%, 122/133) compared with patients who failed to achieve RVR (48%, 38/80) (P < 0.0001). Multivariate logistic‐regression analysis showed that only platelet counts [odds ratio (OR), 1.68; confidence interval (CI), 1.002–1.139] and RVR (OR, 11.251; CI, 5.184–24.419) were independently associated with SVR, with no correlation being found for the mean dose of Peg‐IFN and ribavirin for RVR and SVR. Furthermore, in the stratification analysis of the timing of viral clearance, neither mean dose of Peg‐IFN (P = 0.795) nor ribavirin (P = 0.649) affected SVR in each group. Among the patients with RVR, the lowest dose group of Peg‐IFN (0.77 ± 0.10 μg/kg/week) and ribavirin (6.9 ± 0.90 mg/kg/day) showed 100% and 94% of SVR. Hence, RVR served as an important treatment predictor, and drug exposure had no impact on both SVR and RVR in combination therapy for genotype 2 patients.     

Splenectomy and antiviral treatment for thrombocytopenic patients with chronic hepatitis C virus infection

Summary. Thrombocytopenic patients with chronic hepatitis C virus (HCV) infection are poor candidates for antiviral treatment with interferon (IFN), but no standard treatment for thrombocytopenia has yet been established. We evaluated the safety of splenectomy and its efficacy for the initiation and continuation of antiviral therapy. From March 2003 to April 2006, 10 patients (mean age 62.5 years) with HCV‐related cirrhosis, low platelet count (≦106 000/mm³) and splenomegaly (spleen size ≧10 cm) underwent splenectomy. Platelet counts significantly increased at 4–8 weeks after splenectomy [pre: 64 200 ± 6900/mm³vs post 209 000 ± 40 600/mm³ (P = 0.004)]. No severe operative complications were observed. All patients subsequently received antiviral therapy. Of the eight patients who were infected with HCV genotype 1 and had a high viral load (≧100 KIU/mL), four received combination therapy with pegylated IFNα‐2b plus ribavirin, and the other four received standard IFNα‐2b plus ribavirin. One patient infected with HCV genotype 2 and another with HCV genotype 1 and a low viral load (<100 KIU/mL) were treated with pegylated IFNα‐2a. Six patients achieved sustained virologic response (SVR). Among four patients who failed to achieve SVR, one was given retreatment with pegylated IFN plus ribavirin, and the other three received low‐dose long‐term IFN therapy. Although this study was small, the treatment results were similar to those for patients without thrombocytopenia and suggested that splenectomy would not reduce the antiviral efficacy of IFNα‐based treatment.     

Sustained virological response of patients with hepatitis C virus genotype 2 depends on pegylated interferon compliance

Aim: Patients infected with hepatitis C virus (HCV) genotype 2 are more sensitive to interferon (IFN) therapy than those infected with genotype 1, but 10–20% of patients do not achieve a sustained viral response (SVR) to combination therapy with pegylated (PEG) IFN and ribavirin (RBV). This study examines the prognostic factors associated with SVR in patients infected with HCV genotype 2 treated with PEG IFN and RBV. Methods: We treated 149 patients with chronic hepatitis C caused by HCV genotype 2. The patients received s.c. PEG IFN‐α‐2b (1.5 µg/kg) and a weekly weight‐adjusted dose of RBV (600, 800 and 1000 mg per <60, 60–80 and >80 kg, respectively) for 24 weeks and then prognostic factors associated with the SVR were examined. Results: Among the 149 patients, 138 completed the combination therapy and a sustained viral response was achieved in 71.8% of them. Univariate analysis showed that age, as well as mean RBV and PEG IFN doses were factors affecting the SVR (P = 0.012, =0.021, =0.014). Multivariate analysis identified age and mean PEG IFN dose (P = 0.021, =0.018, respectively) as factors involved in the SVR, but not mean RBV dose. Conclusion: The SVR of patients infected with HCV genotype 2 depended on the dosage of PEG IFN, but not of RBV. Selecting sufficient doses of PEG IFN for combination with RBV is critical for treating such patients.     

First phase viral kinetic parameters and prediction of response to interferon alpha-2b/ribavirin combination therapy in patients with chronic hepatitis C.

The aim of the present study was to assess parameters in early phase HCV dynamics for predicting the outcome of interferon (IFN)/ribavirin combination therapy in patients with chronic hepatitis C (CH-C). Sixty-five CH-C patients who received IFN alpha-2b/ribavirin combination therapy were enrolled. The serum levels of HCV RNA 0h and 3 months after commencing therapy were serially quantified. HCV kinetic parameters such as quantity, ratio of decline, and half-life were analyzed. In genotype 1 patients, both the quantity and the ratio of decline of HCV RNA 24h after the start of therapy were useful predictors of a poor response. No patients who had serum HCV RNA above 200KIU/ml 24h after the start of therapy achieved a sustained viral response (SVR). In genotype 2 patients, conversely, these two parameters were predictors of a sustained viral response. The efficacy of these parameters in predicting the outcome of therapy was comparable to that of the disappearance of HCV RNA from sera at 4 weeks. These results demonstrate that parameters of HCV kinetics 24h after the start of therapy are useful for the early prediction of outcome in response to IFN alpha-2b/ribavirin combination therapy.     

Tumor necrosis factor- alpha promoter polymorphism at position -308 predicts response to combination therapy in hepatitis C virus infection

The G-->A transition in the tumor necrosis factor (TNF)- alpha promoter region at position -308 (TNF308.2) and -238 (TNF238.2) were determined in 141 patients with chronic hepatitis C virus (HCV) infection. Patients received combination therapy with high-dose interferon (IFN)- alpha and ribavirin for 24 weeks. A total of 100 patients (70.9%) had a sustained virologic response (SVR) after treatment. The TNF308.2 allele was independently associated with an SVR, particularly in patients with HCV genotype 1b infection and >200,000 IU of HCV RNA/mL in serum. In conclusion, the response to combination therapy with high-dose IFN- alpha and ribavirin may be associated, at least in part, with host genetic factors.     

Mutations in the NS5B region of the hepatitis C virus genome correlate with clinical outcomes of interferon-alpha plus ribavirin combination therapy

BACKGROUND AND AIM: Combination treatments of interferon-alpha (IFN) and ribavirin (RBV) are more effective than those of IFN alone in hepatitis C virus (HCV) infection. However, mechanisms of the action of the combination regimen are not well understood. To elucidate the viral genetic basis of IFN plus RBV combination therapy, genetic variabilities of HCV-1b were analyzed. METHODS: We performed pair-wise comparisons of full-length HCV genomic sequences in three patients' sera before and after initiation of IFN plus RBV treatment. Subsequently, we analyzed amino acid sequences of the NS5B region, which codes for the viral RNA-dependent RNA polymerase, and compared these with the outcomes of the therapy in 81 patients. RESULTS: Analysis of the entire HCV sequence in patients who received IFN plus RBV therapy did not show consistent amino acid changes between before and after the initiation of the therapy. NS5B sequence analyses revealed that mutations at positions 300-358 of NS5B, including polymerase motif B to E, occurred more frequently in a group of patients exhibiting a sustained viral response (SVR) or an end-of-treatment response (ETR) compared with a group of patients exhibiting a non-response (NR). Closer examination revealed that mutations at aa 309, 333, 338 and 355 of NS5B occurred significantly more frequently in the SVR plus ETR group than in the NR group (P = 0.0004). Multivariate analysis showed that the number of mutations at these four sites was an independent predictor of SVR plus ETR versus NR. CONCLUSIONS: Particular amino acid changes in the NS5B region of HCV may correlate with outcomes of IFN plus RBV combination therapy.