Objective: To evaluate the expression of microRNA (miR)-let-7b in peripheral blood cells of patients with primary biliary cirrhosis (PBC) and investigate its relationship to clinical disease parameters.
Methods: Peripheral blood and serum samples were obtained for study from 60 PBC patients and 60 healthy controls. Peripheral blood cells were extracted and subjected to real-time PCR to measure miR-let-7b expression. Serum levels of interleukin (IL)-18, total bilirubin (TBIL), alkaline phosphatase (ALP), and gamma-glutamyl transferase (GGT) were measured by standard biochemical assays. The relationship between miR-let-7b expression and disease parameters was assessed by Spearman's rank correlation test.
Results: PBC patients showed significantly lower expression of miR-let-7b in peripheral blood cells than healthy controls (P less than 0.001); moreover, the miR-let-7b expression level decreased in parallel to increases in disease severity (stage I > II / III > IV). In PBC patients, the miR-let-7b expression was significantly correlated with Mayo risk scores (r = -0.4930, P less than 0.001), IL-18 (r = -0.4643, P less than 0.001) and ALP (r = -4119, P less than 0.001), but not with TBIL or GGT.
Conclusion: Decreased expression of miR-let-7b may be associated with development and progression of PBC, and this miRNA may represent a novel target of improved diagnostic and preventive strategies for PBC.