Antibodies to non-structural hepatitis C virus antigens: a link with liver disease activity?

The aim of our study was to evaluate the aetiopathogenetic role of hepatitis C virus (HCV) in the genesis of chronic liver disease and hepatocellular carcinoma and the relationship between presence of circulating antibodies against non-structural HCV antigens and disease activity.

Using a new enzyme-immunoassay capable of detecting, either separately or together, circulating antibodies to structural and non-structural hepatitis C virus antigens, we tested 208 chronic hepatitis B surface antigen (HBsAg) carriers and 144 patients suffering from chronic liver disease.

Among the chronic HBsAg carriers with normal transaminase activity, there were 4% who proved to be anti-HVC positive, compared with 14.5% among those with high serum transaminase. Among subjects with chronic liver disease, 20% of patients with chronic persistent hepatitis, 54% with chronic active hepatitis, 35% with liver cirrhosis and 47% with hepatocellular carcinoma proved to be anti-HCV positive. With regard to the aetiology of liver disease, 13% and 25% of chronic HBV infected patients, with or without anti-delta virus superinfection respectively, had anti-hepatitis C virus antibody. This prevalence was 22% among alcoholic liver disease and 89% among patients with cryptogenic liver diseases. The percentage of subjects with circulating antibodies against non-structural HCV proteins was higher among HBsAg chronic carriers with raised alanine aminotransferase and among patients with chronic active hepatitis and hepatocellular carcinoma.

Many subjects with chronic liver disease have circulating anti-HCV antibodies. Anti-HCV positive subjects, especially those with antibodies to non-structural antigens, are more frequently found among patients with aggressive liver diseases. Among HBsAg chronic carriers the prevalence of anti-HCV was lower in "healthy carriers" and HBeAg positive rather than in HBeAg negative subjects with high alanine aminotransferase. We therefore suggest that there may be a relation between HCV replication, activeness of the liver disease and presence of antibodies to non-structural viral antigens.