MicroRNA-155 is upregulated in ascites in patients with spontaneous bacterial peritonitis.

MircoRNA's (miR) have been recognised as important modulators of gene expression and potential biomarkers. However, they have been rarely investigated in bio fluids apart from blood. We investigated the association of miR-125b and miR-155 with complications of cirrhosis. Ascites was prospectively collected from patients with cirrhosis undergoing paracentesis at our department. miR's were determined in the supernatant using qPCR and normalized by SV-40. Clinical parameters were assessed at paracentesis and during follow-up. 76 specimens from 72 patients were analysed. MiR's were not associated to age, sex or aetiology of cirrhosis. MiR-125b levels differed between patients with low and high MELD score, and miR-125b levels showed an inverse correlation to serum creatinine (r2 = -0.23; p = 0.05). MiR-155 was elevated in patients with spontaneous bacterial peritonitis (SBP) (n = 10; p = 0.04). MiR-155 levels differed between patients with and without 30-day survival (p = 0.02). No association of ascites levels of investigated miR's to size of varices, episodes of gastrointestinal bleeding or hepatorenal syndrome was observed. While miR-125b levels in ascites seem to be associated with liver and renal dysfunction, miR-155 might be implicated in local immune response in SBP.