Interferon system in acute viral hepatitis.

Activation of the interferon system is an early antiviral immune defence mechanism. In 16 patients, whose viral hepatitis (A, B, and non-A, non-B) ran a normal course, blood interferon levels rose and cells were rapidly induced into an antiviral states. However, in 6 patients with acute fulminant hepatitis, the antiviral interferon system was grossly defective. Blood interferon levels were not measurable in 5 of them; in all 6, the mononuclear cells were not in an antiviral state and did not produce interferon-alpha or interferon-gamma when stimulated, but their intracellular antiviral mechanism was intact because small amounts of exogenous interferon induced an antiviral state in vitro. 5 of the patients with fulminant hepatitis received interferon-alpha therapy, with rapid activation of their interferon systems, accompanied by rapid and uncomplicated recoveries in 3. It is suggested that interferon be given a trial as an early treatment for severe viral hepatitis.