Serum levels of interferon-α and-γ in acute and chronic hepatitis B virus infection

To evaluate the potential implication of in vivo interferon production in the pathogenesis of different forms of acute and chronic hepatitis B virus infection, serum levels of interferon-α and-γ were measured using immunoassay techniques in 20 patients with acute hepatitis B who subsequently cleared the virus (group Ia), 8 patients with acute hepatitis B who became HBsAg carriers (group Ib), 55 patients with chronic hepatitis B (group II), and 15 healthy controls. None of the controls had interferon-α or-γ detectable in serum, while 15% and 100% of group Ia patients, 25% and 100% of group Ib patients, and 22% and 15% of group II patients, had raised serum levels of interferon-α and-γ, respectively. Serum interferon-γ was detected significantly more frequently in group Ia and Ib patients than in controls and in group II patients. Among patients with acute hepatitis B, serum levels of interferon-α and-γ showed no significant difference between group Ia and group Ib patients. Among patients with chronic hepatitis B, interferon-α was detected significantly more frequently in patients with serum HBV-DNA (31.4% or 11/35) than in those without (5% or 1/20), whereas interferon-γ was detected significantly more frequently in patients with chronic active hepatitis (28% or 7/25) than in those with chronic persistent hepatitis (3.3% or 1/30). In conclusion, in acute hepatitis B, serum levels of interferon-α and-γ did not show a significant difference between patients who subsequently cleared the virus and those who became HBsAg carriers. In chronic hepatitis B, the raised serum levels of interferon-α correlated with the presence of viral replication, while the raised serum levels of interferon-γ correlated with the presence of histological evidence of active hepatitis.