Cellular localization of alpha-interferon in hepatitis B virus-infected liver tissue.

Cells expressing alpha 2-interferon were identified by indirect immunofluorescence using both a polyclonal and a monoclonal anti-alpha-interferon antibody reagent. In hepatitis B or delta virus infection, focal clusters of alpha-interferon-positive infiltrating mononuclear cells and (to a lesser extent) fibroblasts were regularly seen in liver sections from patients who had chronic active hepatitis and cirrhosis and evidence of virus replication, but in a minority of patients with chronic persistent hepatitis B and not in nonvirally infected livers. This report provides evidence for local alpha-interferon production near the site of virus replication in hepatitis B infection, identifies mononuclear cells and fibroblasts (but not hepatocytes) as the main cell types producing interferon in this infection and suggests that locally produced alpha-interferon may be a natural regulator of virus replication in HBsAg-positive chronic active hepatitis. Furthermore, serological characterization of the interferon species produced locally may predict which particular interferon species could be of the greatest therapeutic benefit in specific disease states or individual patients.