CHARACTERIZATION OF THE 5' NONCODING AND STRUCTURAL REGION OF THE HEPATITIS-C VIRUS GENOME FROM PATIENTS WITH NON-A, NON-B-HEPATITIS RESPONDING DIFFERENTLY TO INTERFERON TREATMENT

We examined 14 patients with hepatitis C caused by infection with the hepatitis C virus-II genotype to understand differences in responsiven ess to interferon. The patients were classified into two groups accord ing to their response to interferon: eight responding and six non-resp onding patients. The 5' noncoding and structural regions of the hepati tis C virus-II genome from each patient specimen were amplified by rev erse transcription followed by the polymerase chain reaction. The nucl eotide sequences of these amplified DNAs were then determined. By comp aring the nucleotide sequences and the deduced amino acid sequences of samples from both groups, no group-specific sequence was observed in the analyzed regions despite the presence of considerable sequence div ersity. However, additional cysteine residues were observed in half th e responding group. The degree of micro-heterogeneity in hypervariable region 1 of the hepatitis C virus in relation to the sensitivity to i nterferon treatment was also examined; however, no significant correla tion was observed. In addition, frequent alterations in the amino acid sequences were observed in hypervariable region I during the course o f interferon treatment. (C) Journal of Hepatology.