Depressed lymphokine-activated killer activity and analysis of the precursor cells in peripheral blood of patients with hepatocellular carcinoma.

The in vitro lymphokine-activated killer activity and natural killer activity of peripheral blood mononuclear cells from 33 patients with hepatocellular carcinoma were investigated. Lymphokine-activated killer and natural killer activities of patients were significantly decreased compared with those of healthy volunteers. Peripheral blood mononuclear cells showed significantly lower lymphokine-activated killer and natural killer activities in patients with larger tumors (greater than or equal to 5 cm in diameter) than in patients with smaller tumors (less than 5 cm in diameter). Of 20 patients with larger tumors, 8 and 6 generated very little or no lymphokine-activated killer and natural killer activities. respectively. Lymphokine-activated killer precursors and natural killer cells were present mainly in the Leu-11+ fraction and partially in the Leu-7+ fraction in patients and normal volunteers. A flow cytometric study showed that the percentage of Leu-7+ 11+ and Leu-7-11+ fractions in peripheral blood mononuclear cells was lower in patients than in normal volunteers. The percentages of Leu-7-11+ and Leu-7+ 11+ fractions were diminished in the peripheral blood mononuclear cells of the patients with little or no lymphokine-activated killer activity. It is suggested that deficient lymphokine-activated killer and natural killer activities partially results from a reduction in the number of their precursor cells in patients with hepatocellular carcinoma.