Background: Alanine aminotransferase (ALT) and aspartate aminotransferase (AST)
are the most common markers of liver damage, but serum level interpretation can be complicated.
In hepatocytes, microRNA-122 (miR-122) is the most abundant miRs and its high expression in
the serum is a characteristic of liver disease.
Objective: We aimed to compare the circulatory level of miR-122 in patients with Chronic Hepatitis
C (CHC), Hepatitis C Virus (HCV) infected Liver Transplant Candidates (LTC) and healthy
controls to determine if miR-122 can be considered as an indicator of chronic and advanced stage
of liver disease.
Methods: MiR-122 serum level was measured in 170 Interferon-naïve (IFN-naïve) CHC patients,
62 LTC patients, and 132 healthy individuals via TaqMan real-time PCR. Serum levels of miR-122
were normalized to the serum level of Let-7a and miR-221. Also, the ALT and AST levels were
Results: ALT and AST activities and the expression of circulatory miR-122 were similar in the
CHC and LTC groups, but it had significantly increased compared to healthy individuals (P<0.001
and P<0.001, respectively). Up-regulation of miR-122 in the sample of patients with normal ALT
and AST activities was also observed, indicating that miR-122 is a good marker with high sensitivity
and specificity for diagnosing liver damage.
Conclusion: miR-122 seemed to be more specific for liver diseases in comparison with the routine
ALT and AST liver enzymes. Since the lower levels of circulating miR-122 were observed in the
LTC group compared to the CHC group, advanced liver damages might reduce the release of
miR-122 from the hepatocytes, as a sign of liver function deficiency.