Neutralization of pseudotyped vesicular stomatitis virus expressing hepatitis C virus envelope glycoprotein 1 or 2 by serum from patients.

Infection with hepatitis C virus (HCV) generally progresses to chronic disease, although a minority of patients appear to clear viremia spontaneously. In this investigation, serum samples were analyzed for virological parameters, serum alanine aminotransferase (ALT) levels, and neutralizing antibody response against pseudotyped vesicular stomatitis virus (VSV) generated using chimeric envelope glycoprotein 1 (E1) or 2 (E2) of HCV. Testing of sequential serum samples that were collected beginning at the onset of acute-phase disease demonstrated intermittent viremia, elevated ALT levels, and detectable neutralization activity against VSV in 9 of 10 patients. Serum neutralization activity did not exhibit a correlation with the genotype of the infecting HCV or with virus load. On the other hand, patients with chronic HCV infection consistently had detectable amounts of virus present but no significant variation in ALT levels, and serum samples from a majority (>90%) of patients failed to show detectable neutralization activity.