Variations in the hypervariable region 1 of the envelope region E2 of hepatitis C virus RNA appear associated with virus persistence independently of liver disease.

Abstract

The high genetic variability of the 5' end of the envelope protein-coding region E2 (HVR1 E2) of Hepatitis C Virus (HCV) RNA has been suggested by many authors to play an important role in both virus persistence and outcome of liver disease. We studied the relations between HVR1 E2 variability and HCV genotypes, HCV-RNA levels and liver disease in 8 chronic HCV carriers (5 males and 3 females, median age 41 years, followed-up for a mean period of 3 years). Four were healthy HCV carriers with persistently normal ALT levels and normal liver histology and 4 patients with chronic liver disease. In each patient, the HVR1 E2 variability of 2 serum HCV-RNA isolates obtained at least 12 months apart were evaluated by direct sequencing. Nucleotide and amino acid homologies ranged between 97.6%-57.1% and 92.8%-25% in healthy carriers and 95.2%-55.9% and 89.3%-32.1% in patients, respectively. We did not observe any correlation between HVR1 E2 heterogeneity and HCV genotypes, viraemia levels, presence and extent of liver necroinflammation. Our findings suggest that HVR1 E2 heterogeneity has no direct implications in hepatitis, pathogenesis but it could play a major role in virus persistence.