Natural killer (NK) cell activity and its in vitro response to interferon-α(Le) in chronic liver diseases and hepatocellular carcinoma

The natural killer (NK) cell activity of peripheral blood lymphocytes (PBL) in patients with various chronic liver diseases, and its in vitro response to human interferon-alpha(Le) were investigated using a 16-h 51-Cr releasing cytotoxicity assay against YAC-1 or RSa target cells. The NK cell activity was found to be higher in chronic active hepatitis (CAH) and liver cirrhosis (LC) patients without HCC, whereas it was slightly lower in LC patients with hepatocellular carcinoma (HCC), than in normal controls. By the addition of IFN-alpha(Le) in vitro, the NK cell activity was clearly and dose-dependently augmented, even in chronic liver diseases, as well as in normal controls. The magnitude of this augmentation by 10,000 IU/ml of IFN-alpha(Le) in the various chronic liver diseases was not significantly different from that in normal controls. The results suggested that the response of NK cells to IFN-alpha(Le) is not impaired even in chronic liver disease conditions, while the level of NK cell activity may vary according to the type of chronic liver disease and may decrease in patients with HCC.