Defective immunological functions associated with abnormal lymphokine-activated killer activity in patients with hepatocellular carcinoma

The in vitro lymphokine-activated killer (LAK) activity of peripheral blood mononuclear cells (PBMC) from 36 patients with hepatocellular carcinoma was investigated. The activity was greatly diminished in 13 patients and enhanced in seven patients. A flow cytometric study showed that the percentage of OKM1+, Leu-7+-11b+, and Leu-7-11b+ fractions in PBMC was decreased and the percentage of OKT8+ and Leu7+11- fractions was increased significantly in the 13 patients with lower LAK activity, compared with the values of the seven higher LAK activity patients. Furthermore, the response of PBMC to interleukin-2 (IL-2) was deficient in the lower activity group. However, there was no significant difference in IL-2 production by PBMC, IL-2 receptor (p55) expression of PBMC and mitogen (Con-A, PHA) response of PBMC between the two groups. These findings indicate the possibility that diminished LAK activity in hepatoma patients is due to a decreased number of LAK precursor cells and a defective response of LAK precursor cells to IL-2.