Expression of micro-RNAs in peripheral blood mononuclear cells from primary biliary cirrhosis patients

Aim: The aim of this study was to clarify the relationship between the expression of micro-RNAs (miRNAs) in peripheral blood mononuclear cells (PBMCs) and clinical presentation in patients with primary biliary cirrhosis (PBC). Methods: This study involved 58 patients with PBC, patients with control diseases including 25 patients with autoimmune hepatitis (AIH), six patients with PBC-AIH overlap syndrome, 23 patients with systemic lupus erythematosus (SLE), and 30 healthy controls. After miRNA was extracted from PBMCs, the expressions of miR-26a, miR-328, miR-299-5p, miR-146a, miR155, miR-16, miR-132 and let7a were quantified by real-time PCR. The relationships between all miRNA expressions and clinical test parameters were also examined. Results: In PBC, the expressions of miR-155 and miR-146a were significantly increased compared to those in healthy controls. For miR-26a, miR-299-5p, miR-328 and let-7a, although no significant difference was observed in expression between patients and healthy controls, expressions were significantly increased in PBC compared to those in AIH. Expressions of miR-299-5p were significantly increased in PBC patients resistant to treatment with ursodeoxycholic acid (n = 18) compared to those in healthy controls. In the evaluation of the relationship between miRNA expression and clinical test parameters, significant and positive correlations were found for miR-299-5p with alkaline phosphatase, gamma-glutamyl transpeptidase, total bilirubin and immunoglobulin M levels. Conclusion: The preset results suggest the existence of miRNAs that exhibit disease-specific increases in expression and miRNAs closely correlated with clinical test values in PBC. Further analyses of these miRNAs may contribute to the elucidation of the pathology of PBC.