Exosomal microRNA-155 as a biomarker for hepatic fibrosis diagnosis and progression.

Background: Pathological examination of liver biopsies remains the gold standard for evaluating the stage of hepatic fibrosis, which are a number of disadvantages associated with biopsy. The aim of the present study was to investigate the potential of exosomal microRNA (miR)-155 as a non-invasive biomarker for the diagnosis and progression of hepatic fibrosis.

Methods: Exosomal miR-155 quantity was analyzed by sampling serum exosomes of patients with hepatic fibrosis and a hepatic fibrosis rat model. A total of 94 patients were divided into three groups based on Child-Pugh rating. Additionally, 30 patients with primary liver fibrosis who underwent liver transplantation were divided into the low miR-155 expression group and the high expression group; 56 rats were divided into 7 groups (n=8, 0, 2, 4, 6, 8, 10, and 12 weeks). Rats in every group were intravenously injected with CCl4 (3% vol/vol in olive oil; 0.3 mL/100 g body weight) twice weekly to produce different degrees of liver necrosis and liver fibrosis.

Results: Exosomal miR-155 was found to be closely associated with the progression of cirrhosis and clinical prognostic indicators of cirrhosis. Exosomal miR-155 gradually increased with the severity of hepatic necrosis and fibrosis.

Conclusions: The findings of the present study indicate that exosomal miR-155 can act as a non-invasive biomarker for the diagnosis and progression of hepatic fibrosis.