Mutations in the interferon sensitivity determining region and virological response to combination therapy with pegylated-interferon alpha 2b plus ribavirin in patients with chronic hepatitis C-1b infection

Department of Gastroenterology and Hepatology, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo, 113-8519, Japan.
Journal of Gastroenterology (Impact Factor: 4.02). 06/2010; 45(6):656-65. DOI: 10.1007/s00535-009-0195-7
Source: PubMed

ABSTRACT Pegylated-interferon-alpha 2b (PEG-IFN) plus ribavirin (RBV) therapy is currently the de-facto standard treatment for hepatitis C virus (HCV) infection. The aims of this study were to analyze the clinical and virological factors associated with a higher rate of response in patients with HCV genotype 1b infection treated with combination therapy.
We analyzed, retrospectively, 239 patients with chronic hepatitis C-1b infection who received 48 weeks of combination therapy. We assessed clinical and laboratory parameters, including age, gender, pretreatment hemoglobin, platelet counts, HCV RNA titer, liver histology, the number of interferon sensitivity determining region (ISDR) mutations and substitutions of the core amino acids 70 and 91. Drug adherence was monitored in each patient. We carried out univariate and multivariate statistical analyses of these parameters and clinical responses.
On an intention-to-treat (ITT) analysis, 98 of the 239 patients (41%) had sustained virological responses (SVRs). Patients with more than two mutations in the ISDR had significantly higher SVR rates (P<0.01). Univariate analyses showed that stage of fibrosis, hemoglobin, platelet counts, ISDR mutations, serum HCV RNA level, and adherence to PEG-IFN plus RBV were significantly correlated with SVR rates. Multivariate analysis in subjects with good drug adherence extracted the number of ISDR mutations (two or more: odds ratio [OR] 5.181).
The number of mutations in the ISDR sequence of HCV-1b (>or=2) is the most effective parameter predicting a favorable clinical outcome of 48-week PEG-IFN plus RBV therapy in patients with HCV genotype 1b infection.

  • Source
    • "The mean number of mutations within the ISDR that differ from resistant prototype genotype 1a, 1b and 3a strains increases The natural history of acute HCV in HIV+ve MSM the likelihood of SVR (a mean two to four mutations difference confers protection; Pascu et al., 2004; MacQuillan et al., 2004; Nakagawa et al., 2010). A mutation within HCV core – the R70Q substitution is also strongly associated with resistance and lack of early virological response (EVR; Enomoto & Maekawa, 2010). "
    [Show abstract] [Hide abstract]
    ABSTRACT: New insights into the early viral evolution and cellular immune response during acute hepatitis C virus (HCV) infection are being gained following a global outbreak in human immunodeficiency virus-1 (HIV)-positive men who have sex with men. Cross-sectional and longitudinal sequence analysis at both the population and individual level have facilitated tracking of the HCV epidemic across the world and enabled the development of tests of viral diversity in individual patients in order to predict spontaneous clearance of HCV and response to treatment. Immunological studies in HIV-positive cohorts have highlighted the role of the CD4+ T-cell response in the control of early HCV infection and will increase the opportunity for the identification of protective epitopes that could be used in future vaccine development.
    Journal of General Virology 07/2011; 92(Pt 10):2227-36. DOI:10.1099/vir.0.033910-0 · 3.53 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The treatment response to interferon could differ with mutations in the interferon-sensitivity-determining region (ISDR) in patients infected with hepatitis C virus (HCV) genotype-1b (HCV-Ib). We examined the pattern of ISDR mutations and analyzed whether the number of amino acid substitutions influences the treatment response to peginterferon plus ribavirin in chronic hepatitis or cirrhotic patients infected with HCV-Ib. The study population comprised 52 patients who visited Seoul Asan Medical Center and Seoul National University Bundang Hospital from January 2006 to December 2008 and who received peginterferon alpha-2a (n=37) or -2b (n=15) plus ribavirin, and whose serum was stored. We analyzed the early virologic response, end-of-treatment response, and sustained virologic response (SVR), and examined the ISDR using direct sequencing. The proportions of patients with ISDR mutation types of wild (0 mutations), intermediate (1-3 mutations), and mutant (> or =4 mutations) were 50.0%, 42.3%, and 7.7%, respectively, and the corresponding SVR rates were 63%, 50%, and 67% (p>0.05). The SVR rates were 59.4% and 50.0% in patients with <2 and > or =2 mutations, respectively (p>0.05). On univariate analysis, age was the only predictive factor for SVR (p=0.016). The pretreatment HCV RNA titer tended to be lower in those with SVR, but without statistical significance (p=0.069). The frequency of ISDR mutations was low in our cohort of Korean patients infected with HCV-Ib. Therefore, ISDR mutations might not contribute to the response to treatment with peginterferon plus ribavirin.
    The Korean Journal of Hepatology 06/2010; 16(2):158-67. DOI:10.3350/kjhep.2010.16.2.158
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: A combination therapy with pegylated interferon (PEG-IFN) plus ribavirin (RBV) has made it possible to achieve a sustained virological response (SVR) of 50% in refractory cases with genotype 1b and high levels of plasma HCVRNA. Several factors including virus mutation and host factors such as age, gender, fibrosis of the liver, lipid metabolism, innate immunity, and single nucleotide polymorphism (SNPs) are reported to be correlated to therapeutic effects. However, it is difficult to determine which factor is the most important predictor for an individual patient. Data mining analysis is useful for combining all these together to predict the therapeutic effects. It is important to analyze blood tests and to predict therapeutic effects prior to initiating treatment. Since new anti-HCV agents are under development, it will be necessary in the future to select the patients who have a high possibility of achieving SVR if treatment is performed with standard regimen.
    Hepatitis research and treatment 09/2010; 2010:703602. DOI:10.1155/2010/703602
Show more