HEPATITIS-C VIRUS (HCV) GENOTYPE DISTRIBUTION IN GERMAN ISOLATES - STUDIES ON THE SEQUENCE VARIABILITY IN THE E2 AND NS5 REGION

We report on molecular characterization of hepatitis C virus (HCV) iso lates in intravenous drug abusers, as compared to non-drug using patie nts with posttransfusion hepatitis or sporadic hepatitis of unknown or igin. Virus typing was performed by RFLP analysis of PCR products in t he 5' NCR. Subtyping was done by hybridization with subtype specific p robes or by sequencing in the NS4 and NS5 region, respectively. HCV su btype Ib was found most commonly among all the isolates. However, the subtype 3a had a high prevalence (about 46%) in the group of drug addi cts. In these subtype 3a isolates the N-terminal part of the E2 protei n was highly variable. This confirms the presence of a hypervariable r egion (HVR1) in this envelope protein found in all hepatitis C viruses . Each subtype 3a isolate examined had a characteristic unique hyperva riable region in the E2 protein. It is noteworthy that there are four amino acids in this region which were highly conserved between all HCV sequences published. It can be assumed that such conserved amino acid s are significant for structure and function of this viral protein. In our HCV subtype 3a isolates the NS5 sequences were highly conserved.