Ascitic Interleukin 6 Is Associated with Poor Outcome and Spontaneous Bacterial Peritonitis: A Validation in Critically Ill Patients with Decompensated Cirrhosis

Decompensated cirrhosis predisposes to infectious diseases and acute-on-chronic liver failure (ACLF) in critically ill patients. Infections like spontaneous bacterial peritonitis (SBP) are frequently associated with multi-organ failure and increased mortality. Consequently, reliable predictors of outcome and early diagnostic markers of infection are needed to improve individualized therapy. This study evaluates the prognostic role of ascitic interleukin 6 in 64 patients with cirrhosis admitted to our intensive care unit (ICU). In addition, we analysed the diagnostic ability of ascitic interleukin 6 in a subgroup of 19 patients with SBP. Baseline ascitic interleukin 6 performed well in predicting 3-month mortality in patients with decompensated cirrhosis (area under curve (AUC) = 0.802), as well as in patients fulfilling ACLF-criteria (AUC = 0.807). Ascitic interleukin 6 showed a moderate prognostic advantage compared with common clinical scores and proinflammatory parameters. Moreover, ascitic interleukin 6 had a sufficient diagnostic ability to detect SBP (AUC = 0.901) and was well correlated with ascitic polymorphonuclear neutrophils in SBP (p = 0.002). Interestingly, ascitic interleukin 6 revealed a high predictive value to rule out apparent infections on admission to ICU (AUC = 0.904) and to identify patients with “culture-positive SBP” (AUC = 0.856). Ascitic interleukin 6 is an easily-applicable proinflammatory biomarker with high prognostic and diagnostic relevance in critically ill patients with liver cirrhosis.