Blood leukocytes of 16 patients with alcoholic liver cirrhosis and 18 healthy controls were induced for interferon (IFN) production by phytohemagglutinin (PHA) and concanavalin A (ConA) in the presence or absence of isoprinosine and levamisole at concentrations of 10 micrograms/ml and 1 ng/ml. This interferon was neutralized in 87-95% by anti-HuIFN-gamma monoclonal antibodies. In the presence of the drugs the IFN-gamma production was enhanced, however, IFN-gamma titers yielded from leukocytes of cirrhotic patients were still below the titers observed in stimulated and unstimulated blood leukocytes of healthy controls. For example, IFN titers induced by PHA in the presence of levamisole (1 ng/ml) in cirrhotic patients were 2.5 times lower (20.2 +/- 11.1 U/ml) in comparison to healthy subjects (50.6 +/- 27.3 U/ml).