The in vitro production of the acute-phase mediator interleukin-6 by peripheral blood monocytes derived from patients with various liver diseases was studied. Compared with healthy controls (n = 45; 860 +/- 92 U/ml, mean +/- SEM), monocytes from patients with chronic hepatitis B produced significantly lower amounts of interleukin-6 (n = 14; 424 +/- 126 U/ml) after stimulation with lipopolysaccharide (p = 0.02), whereas monocytes from patients with chronic hepatitis non-A, non-B secreted normal amounts of interleukin-6 (n = 13; 672 +/- 151 U/ml; n.s.). In contrast, monocytes of patients suffering from alcoholic liver cirrhosis (n = 22; 1310 +/- 153 U/ml) or primary biliary cirrhosis (n = 6; 1450 +/- 186 U/ml) produced higher amounts of interleukin-6 than healthy control individuals (p = 0.03, respectively). Lipopolysaccharide-stimulated monocytes derived from patients with acute hepatitis A, B and non-A, non-B showed an interleukin-6 production not different from that seen in healthy control individuals and did not experience a discernible change during the course of the acute disease. These results suggest that the production of the acute-phase mediator interleukin-6 varies in chronic liver disease in accordance with various etiologies with a reduced lipopolysaccharide-inducible interleukin-6 response in chronic hepatitis B and an enhanced response in alcoholic liver cirrhosis and primary biliary cirrhosis.