AIM: To evaluate plasma levels of nitrite/nitrate (NOx),soluble Fas (sFas) antigen, tumor necrosis factor alpha(TNF-α) and interleukin-6 (TL-6) in patients with compensated and acute decompensated cirrhosis and to evaluate mediators causing acute decompensation in liver cirrhosis.METHODS: This prospective study was conducted in the medical intensive care unit of an academic tertiary center. Fifty-five patients with acute decompensation (gastrointestinal hemorrhage, encephalopathy, hydropic decompensation) and twenty-five patients with compensated liver cirrhosis were included. Blood samples were taken for analyses of sfas, Nox, TL-6, TNF-α. Liver enzymes and kidney functions were also tested.RESULTS: In patients with acute decompensation, plasma sfas levels were higher than in non-decompensated patients (15305±4646 vs 12458 ± 4322 pg/mL, P ＜0.05). This was also true for the subgroup of patients with alcoholic liver cirrhosis (P ＜ 0.05). The other mediators were not different and none of the parameters predicted survival, except for ALT (alanine-aminotransferase). In patients with portal-hypertension-induced acute hemorrhage, NOx levels were significantly lower than in patients with other forms of decompensation (70.8 ±48.3 vs 112.9 ± 74.9 pg/mL, P ＜ 0.05). When NOx levels were normalized to creatinine levels, the difference disappeared. IL-6, TNF-α and sfas were not different between bleeders and non-bleeders. In decompensated patients sfas, IL-6 and NOx levels correlated positively with creatinine levels, while IL-6 levels were dependent on Child class.CONCLUSION: In acute decompensated cirrhotic patients sFas is increased, suggesting a role of apoptosis in this process and patients with acute bleeding have lower NOx levels. However, in this acute complex clinical situation, kidney function seems to have a predominant influence on mediator levels.