Serum factor from patients with cirrhosis and hepatocellular carcinoma enhances production of prostaglandin E 2 by U937 cells

The effect of serum from patients with cirrhosis and hepatocellular carcinoma on the release of prostaglandin E 2 by the human histiocytic lymphoma cell line U937 was investigated to explain the mechanism underlying the immunoregulatory dysfunction of monocytes in cirrhosis and hepatocellular carcinoma. Prostaglandin E 2 production by U937 cells cultured with serum from cirrhosis patients (5.9 ± 2.7 ng/ml, p < 0.01) and hepatocellular carcinoma patients (5.4 ± 2.6 ng/ml, p < 0.01) was significantly higher than that of control cultures (2.0 ± 1.0 ng/ml). This activity was decreased after heating and after freezing and thawing. By size exclusion fast protein liquid chromatography, the probable factor was eluted in the fraction with a molecular weight of 150 kD. By anion exchange chromatography with a stepwise increase of the NaCl concentration, the peak activity augmenting prostaglandin E 2 production by U937 cells was eluted in the 0.05 to 0.1 mol/L NaCl fraction. The high level of this factor (monocyte‐regulating factor) in patient serum might be one cause of abnormal monocyte immunoregulatory function in cirrhosis and hepatocellular carcinoma. (H EPATOLOGY 1991;14:1123–1128.)