Predictive factors regarding the responsiveness to interferon therapy for patients with chronic hepatitis C: an assessment of the hypervariable region 1 quasispecies in genotype 1b of chronic hepatitis C

It is widely known that the hepatitis C virus (HCV) genotype 1b is generally resistant to interferon (IFN) therapy. Some reports have described various predictive factors regarding the responsiveness to IFN therapy. In this study, we evaluated predictive factors, the age of the patients, the level of HCV-RNA, the total dose of (IFN) and the level of serum alanine aminotransferase (s-ALT), potentially regarding the responsiveness to IFN therapy for patients with HCV genotype 1b. In addition, the hypervariable region 1 (HVR1) quasispecies in association with interferon inefficacy has been reported. We investigated the HVR1 using a polymerase chain reaction (PCR) — single strand conformation polymorphism (SSCP) analysis and thus attempted to determine whether or not an analysis of HVR1 quasispecies can possibly be used as a predictive factor for the responsiveness to IFN therapy. We studied 104 consecutive cases of chronic hepatitis C patients with HCV genotype 1b. Eighty-four patients from 104 could be assayed for the HVR1 quasispecies. Seventeen patients had complete responses (CR) to interferon therapy, 67 patients had non responses (NR). In addition, there was a significant difference between CR and NR groups regarding the level of HCV-RNA; in contrast, there was no differences for the age of the patients, the total dose of IFN and the HVR1 quasispecies. The above findings thus suggested that the level of HCV-RNA may be a predictive factor regarding the responsiveness to IFN therapy. However, the HVR1 quasispecies was not found to be a predictive factor.