Absolute quantification of serum microRNA-122 and its correlation with liver inflammation grade and serum alanine aminotransferase in chronic hepatitis C patients

• Absolute quantification of serum microRNA-122 improved the reliability of assay.
• Serum microRNA-122 levels were elevated in acute hepatitis and CHC patients.
• Serum microRNA-122 levels correlated with ALT levels in acute hepatitis patients.
• Serum microRNA-122 levels didn’t correlate with ALT levels in CHC patients.
• Serum microRNA-122 couldn’t reflect liver inflammation activities in CHC patients.

SummaryObjectivesMicroRNA-122 has been shown to be crucial for efficient HCV RNA replication in vitro. Pretreatment intrahepatic microRNA-122 levels in chronic hepatitis C (CHC) patients have been associated with the outcomes of interferon therapy. Here, we determined microRNA-122 serum levels in CHC patients and healthy donors using an absolute quantification approach and evaluated the correlation with liver inflammation grades and serum alanine aminotransferase (ALT) levels.MethodsSerum samples were collected from 105 treatment-naive CHC patients, 11 acute hepatitis patients, and 33 healthy donors. Serum microRNA-122 was measured using the TaqMan RT-qPCR. The cycle threshold values were converted to copy numbers by drawing a standard curve using a chemical synthetic standard. For accurate quantification, copy numbers were further normalized according to the recovery ratios of spiked-in cel-miR-39.ResultsSerum levels of microRNA-122 were significantly higher in acute hepatitis and CHC patients than in healthy donors (p < 0.001). However, there was no significant association between microRNA-122 and ALT serum levels or liver inflammation grades.ConclusionsThe present study showed that serum microRNA-122 was elevated in acute and chronic hepatitis patients. However, this biomarker for acute liver injury did not reflect the liver inflammation activity in CHC patients.