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A Protocol for Analyzing Hepatitis C Virus Replication
Published on: June 26, 2014
HCV genotype 1a shows a better virological response to antiviral therapy than HCV genotype 1b
Adriano M Pellicelli1, Mario Romano, Tommaso Stroffolini
1Liver Unit Azienda Ospedaliera San Camillo Forlanini, Circonvallazione Gianicolense, 87 00149, Rome, Italy. adriano.pellicelli@tiscali.it.
Insights
Hepatitis C genotype 1a shows higher sustained virological response (SVR) rates than genotype 1b when treated with PEGylated interferon plus ribavirin. This difference is independent of other factors influencing viral clearance.
Area of Science:
- Hepatology
- Virology
- Pharmacotherapy
Background:
- Limited data exists on viral subtype impact on SVR for chronic Hepatitis C.
- Investigating differential response to PEG-IFN plus ribavirin for HCV genotypes 1a and 1b.
Purpose of the Study:
- To determine if HCV genotype 1 subtypes 1a and 1b exhibit different response rates to PEG-IFN plus ribavirin therapy.
Main Methods:
- 388 treatment-naïve genotype 1 HCV patients received PEG-IFN (α-2a or α-2b) plus ribavirin for 48 weeks.
- Virological response assessed at weeks 4 (RVR), 12 (EVR), 48 (ETR), and 24 weeks post-treatment (SVR).
Main Results:
- SVR rates were significantly higher in subtype 1a patients (55%) compared to subtype 1b patients (43%).
- Independent predictors of SVR included genotype 1a infection, age <50, ALT <100 IU/ml, HCV-RNA <5.6 log10 IU/ml, and fibrosis score < S3.
Conclusions:
- Dual antiviral therapy with PEG-IFN and ribavirin is more effective against HCV subtype 1a than subtype 1b.
- The observed difference in efficacy between subtypes is not influenced by other factors promoting viral clearance.
Background:
The impact of viral subtype on the rate of sustained virological response (SVR) to antiviral therapy in patients chronically infected with hepatitis C genotype 1 subtype 1a and 1b has not been extensively investigated. The aim of this study is to determine whether the HCV genotype 1 subtypes 1a and 1b respond differently to treatment with PEGylated interferon (PEG-IFN) plus ribavirin.
Methods:
For 48 weeks, 388 "naïve"genotype 1 patients were treated weekly with PEG-IFN α-2a or PEG-INF α-2b combined with daily ribavirin (1000-1200 mg/day). The numbers of patients in whom HCV-RNA was undetectable were compared after 4 (rapid virological response, RVR), 12 (early virological response, EVR), and 48 (end treatment virological response, ETR) weeks of treatment as well as 24 weeks after the last treatment (sustained virological response, SVR).
Results:
The rate of SVR was higher in subtype 1a patients than subtype 1b patients (55% vs. 43%; p < 0.02). Multiple logistic regression analysis showed that infection with genotype 1a (odds ratio(OR) : 1.8; 95% confidence interval (CI): 1.4 to 4.1), age < 50 years (OR:7.0; 95% CI 1.1 to 21.2), alanine aminotransferase level (ALT)<100 IU/ml (OR:2.1; 95% CI: 1.3 to3.5), HCV-RNA < 5.6 log10 IU/ml (OR: 3.2; 95% CI: 2.7 to 6.9) and fibrosis score < S3 (OR: 3.8; 95% CI:3.2 to 7.4), were all independent predictors of SVR.
Conclusion:
Dual antiviral therapy is more effective against HCV subtype 1a than against subtype 1b and this difference is independent of other factors that may favour viral clearance.
Trial Registration:
ClinicalTrials.gov Identifier: NCT01342003.
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