GENETIC ALTERATION OF THE HEPATITIS-C VIRUS HYPERVARIABLE REGION OBTAINED FROM AN ASYMPTOMATIC CARRIER

Hepatitis C virus (HCV) genome shows extensive sequence diversity at 2 hypervariable regions (HVR1 and HVR2) of the putative envelope glycop rotein (gp70). We recently reported that the amino-acid sequence of HV R1, but not of HVR2, underwent a striking mutation or mutated sequenti ally over a period of several months in patients with chronic hepatiti s (CH). Here, we examined whether these genetic alterations in HVR1 oc curred in an asymptomatic HCV carrier. The level of HCV RNA in serum w as almost the same throughout the 4 time points sampled over 16 months . However, we found that the amino-acid sequence of the HCV HVR1 from this asymptomatic carrier altered with time, as seen in patients with CH. Alterations of amino acids in the HVR1 were correlated with persis tent HCV infection rather than with clinical symptoms. Sequence hetero geneity of HVR1 was not correlated with alanine aminotransferase (ALT) values or liver histological findings. The necessity of clinical foll ow-up of HCV asymptomatic carriers is discussed. (C) 1994 Wiley-Liss, Inc.