Interleukin 6 concentration in ascitic fluid of cirrhotic patients: relationship with previous episodes of spontaneous bacterial peritonitis

Background. We aimed to determine whether interleukin (IL)-6 concentrations in plasma and ascitic fluid from cirrhotic patients with previous episodes of spontaneous bacterial peritonitis (SBP) differred from those with no previous episodes of SBP. Methods. Cirrhotic patients with ascites were divided into two groups: G1, without previous episodes of SBP (n = 6), and G2, with previous episodes of SBP (n = 6). Patients with chronic heart failure (n = 5) with ascites, without hepatic diseases, were included as controls (G3). IL-6 concentration was determined in ascitic fluid and plasma by enzyme-linked immunosorbent assay (ELISA). A group of healthy subjects (n = 8) was used as a control for the blood IL-6 assay. Results. IL-6 concentration in ascitic fluid was significantly higher in G1 (P < 0.05) than in G2 or G3. No significant difference in plasma IL-6 concentrations was observed between the groups or between each group and the healthy subjects. A significant positive linear correlation (P < 0.002) was observed between IL-6 concentration and total protein in ascitic fluid. Conclusions. A low concentration of IL-6 in ascitic fluid could predispose cirrhotic patients to SBP.