Hepatitis C virus (HCV) RNA determination after two weeks of induction interferon treatment is an accurate predictor of nonresponse: comparison of two treatment schedules

Interferon alpha treatment stimulates interferon gamma expression in type I NKT cells and enhances their antiviral effect against hepatitis C virus

Interferon (IFN) inhibits hepatitis C virus (HCV) replication through up-regulation of intrahepatic IFN-stimulated gene expression but also through activation of host immune cells. In the present study, we analyzed the immune cell-mediated antiviral effects of IFN-α using HCV-infected mice. Urokinase-type plasminogen activator (uPA)-severe combined immunodeficiency (SCID) mice with transplanted human hepatocytes were infected with genotype 1b HCV and injected with human peripheral blood mononuclear cells (PBMCs). IFN-α treatment following human PBMC transplantation resulted in a significant reduction in serum HCV RNA titers and a higher human CD45-positive mononuclear cell chimerism compared to mice without human PBMC transplantation. In mice with human PBMCs treated with IFN-α, serum concentrations of IFN-γ increased, and natural killer T (NKT) cells, especially type I NKT cells, produced IFN-γ. Mice in which IFN-γ signaling was blocked using antibody or in which transplanted PBMCs were depleted for type I NKT cells showed similar levels of anti-HCV effect compared with mice treated only with IFN-α. These results show that IFN-α stimulates IFN-γ expression in type 1 NKT cells and enhances the inhibition of HCV replication. We propose that type 1 NKT cells might represent a new therapeutic target for chronic hepatitis C patients.

Qualitative application of COBAS AMPLICOR HCV test version 2.0 assays in patients with chronic hepatitis C virus infection and comparison of clinical performance with version 1.0

The objective of this research was to investigate the clinical performance of COBAS AMPLICOR hepatitis C virus (HCV) test version 2.0 Assays (CA V2.0). Eight serial samples with standard HCV ribonucleic acid (RNA) concentration and 10 times serial dilution of the 500 IU/mL samples were tested in triplicate by CA V2.0 (the limit of detection was 50 IU/mL). HCV RNA was investigated with CA V2.0 in 220 specimens from 100 chronic hepatitis C (CHC) patients, 60 chronic hepatitis B patients, and 60 healthy blood donors. The sensitivity was 99% and the specificity was 98.3%. Sera of 84 naïve CHC patients receiving standard interferon plus ribavirin for 24 weeks were tested by CA V2.0 and CA V1.0 at weeks 2, 4 and 8. The positive detection rates of CA V2.0 were significantly higher than CA V1.0 at week 2 (60.7% vs. 51.2%; p < 0.01) and week 8 (27.4% vs. 21.4%; p < 0.05). At weeks 2, 4 and 8, the positive predictive values were 90.91%, 83.02% and 78.69% with CA V2.0, and 90.24%, 82.14% and 72.73% with CA V1.0. The negative predictive values were 58.82%, 77.42% and 86.96% with CA V2.0, and 67.44%, 82.14% and 83.33% with CA V1.0. However, there was no significant difference between CA V2.0 and CA V1.0 for predicting sustained virologic response.

Kinetics of hepatitis C virus RNA load during pegylated interferon alpha-2a and ribavirin treatment in naïve genotype 1 patients

Background

Pegylated interferon given for 24 or 48 weeks constitutes the most effective initial therapy for the treatment of chronic hepatitis C. It has been shown that viral load at week 2 appears the best time for predicting response to treatment. The objectives of this study were to assess whether the hepatitis C virus (HCV) RNA viral decline is predictive of sustained virological response (SVR) and to determine the best time for predicting complete response in our cohort of naïve patients treated with pegylated interferon alpha-2a (Peg-IFN alpha-2a) and ribavirin.

Results

Twenty patients treated with Peg-IFN alpha-2a and ribavirin for 48 weeks were studied. Six months after the end of treatment, a SVR (negative HCV RNA measured by PCR six months after the end of therapy) was obtained in 9 patients. Samples were obtained before and at week 2, 4, 8, and 12. At the end of week 2, viral load decreased more than 1.39 log in 8 out of the 9 patients with SVR and in 1 out of the 11 other patients. When we considered the viral load reduction from baseline to each week of treatment, week 2 appeared to be the best point time for predicting SVR, with a sensitivity of 91% (95%CI: 59;99), a specificity of 89% (52;98), a positive predictive value of 91% (59;99) and a negative predictive value of 89% (57;98).

Conclusion

During treatment with Peg-IFN alpha-2a plus ribavirin in genotype 1 patients, when the main objective of the treatment is viral eradication, viral kinetics showed that week 2 appeared to be the best time point for predicting SVR. Our results must be further confirmed on a larger cohort.

Interferon-alpha2b induction treatment with or without ribavirin in chronic hepatitis C: a multicenter, randomized, controlled trial

We aimed to compare the efficacy of interferon-alpha2b (IFN) induction treatment in combination with ribavirin to IFN induction alone in chronic hepatitis C. In total, 125 patients (66 male, 59 female, mean age: 48 +/- 9, range: 21-70) were enrolled and randomized into two arms: In the first, patients received 5 MU/day of IFN for 4 weeks followed by 3 MU/day for the next 4 weeks. Treatment was continued with 3 MU three times a week IFN for an additional 40 weeks. Ribavirin was administered 1000-1200 mg/day according to the body weight for the entire 48-week period. In the second arm, patients received placebo in addition to IFN. Fifty-nine patients were placed in the ribavirin arm and 66 in placebo arm. All patients were genotype 1. At week 48, 24/66 (36%) from the placebo and 31/59 (52%) from the ribavirin group responded (P > 0.05). However, during the 24-week untreated follow-up period, 13/24 (54%) from the placebo, and 8/31 (26%) from the ribavirin group relapsed (P = 0.002.), resulting in a sustained virologic response (SVR) rate of 17% in the placebo and 39% in the ribavirin group (P = 0.005.) In conclusion, IFN induction treatment in combination with ribavirin is superior to IFN induction treatment alone in genotype 1 patients, and the SVR rate of 39% is encouraging.

Prediction of treatment outcome in patients with chronic hepatitis C: significance of baseline parameters and viral dynamics during therapy

In patients with chronic hepatitis C virus (HCV) infection scheduled for a 48-week treatment period, premature discontinuation of treatment was previously recommended if HCV-RNA levels remained detectable at week 24 of therapy. Considering the number of side effects and treatment costs, measurement of initial viral decline during therapy may identify virologic nonresponse earlier than 24 weeks. We retrospectively analyzed 260 European patients treated with standard or pegylated interferon alfa (IFN-alpha) and ribavirin for 24 to 48 weeks. Early prediction of virologic response by HCV-RNA decline at weeks 4 and 12 (Versant Quantitative [branched DNA (bDNA) 3.0]; Bayer Diagnostics, Emeryville, CA; and Qualitative [transcription-mediated amplification (TMA)] HCV RNA assay; Bayer Diagnostics) as well as clinical, biochemical, virologic, and histologic baseline parameters were analyzed by logistic regression and receiver operating characteristic (ROC) curves. A viral load at treatment week 4 above 450,000 IU/mL and at week 12 above 30,000 IU/mL was 100% predictive for virologic nonresponse in all patients. From multivariate logistic regression analysis of all patients, independent predictors for sustained virologic response were: genotypes 2 and 3 (P <.0001), a low baseline gamma-glutamyltransferase (GGT) level (P <.0001), a high baseline alanine aminotransferase level (P =.002), and a low baseline viral load (P =.04). None of the latter 3 factors were predictive for sustained virologic response when analysis was restricted to the subgroup of genotypes 2- and 3-infected patients. In conclusion, virologic nonresponse can be predicted early at week 12 of treatment independent from the applied therapeutic regimen based on a cutoff level for HCV RNA of 30,000 IU/mL. This algorithm recognizes 53.7% of nonresponders previously identified at week 24 of treatment.