| Theme | Current Topics in Hepatitis viruses | |
|---|---|---|
| Title | The Region of the HCV Gene Associated with the Effect of IFN | |
| Publish Date | 1997/05 | |
| Author | Takeshi Murakami | Second Department of Internal Medicine |
| Author | Nobuyuki Enomoto | Second Department of Internal Medicine |
| [ Summary ] | Hepatitis C virus (HCV) populations in vivo are composed of clones with various genomic mutations, so-called quasispecies. Sensitivity to interferon (IFN) differs among HCV quasispecies simultaneously detected in the same individuals, and IFN-resistant HCV quasispecies are selected during IFN therapy. The comparative nucleotide sequence analysis of the full-length HCV genomes between IFN-resistant and IFN-sensitive HCV pairs from the same individuals showed a significant association between mutations in the amino acid residues spanning 2209 to 2248 of the nonstructural protein 5A gene (NS5A 2209-2248) of HCV-1b and the response to IFN-alpha. Three of 62 patients (5%) with no amino acid substitutions (wild type) showed complete responses. Eight of 64 patients (13%) with 1 to 3 amino acid substitutions (intermediate type) showed complete responses. However, 23 of 25 patients (92%) with 4 or more amino acid substitutions (mutant type) showed complete responses. In patients with chronic HCV-1b infection, there is a significant correlation between responses to IFN and mutations in the NS5A 2209-2248 sequence. | |