Correlation of serum microRNA-122 level with the levels of Alanine aminotransferase and HBV-DNA in Chronic HBV-infected patients

The microRNA‐122 (miR‐122) is a liver‐specific microRNA that can be used as a potential molecular marker for predicting liver injury. There is a positive correlation between miR‐122 level in serum and hepatitis B virus (HBV) replication in patients infected with this virus. The present study was conducted to study the clinical importance and expression of miR-122 in asymptomatic and symptomatic patients with HBV infection in comparison to the healthy group.

This study was performed on 60 samples to examine the presence of HBsAg and total HBc antibody (IgM-IgG) using an enzyme-linked immunosorbent assay. HBV-DNA extraction and real time polymerase chain reaction (PCR) assay were performed on all samples via the Real ART HBV LC PCR kit on a LightCycler instrument. RNA was extracted from the serum of all participants. Next, miRNA expression was assessed using quantitative real time reverse-transcription PCR. Also, ALT levels were measured as a surrogate parameter for liver injury using Pars Azmoon Biochemical assay Kit on Hitachi autoanalyzer. The Levene , Kruskal Wallis, Mann-Whitney and Spearman’s correlation tests were used for assessing the differences between the studied groups.

  Based on the obtained results, miR-122 expression in patients with HBV without clinical symptoms was 1.6 times, while in patients with clinical symptoms was 2.7 times more than the control group (p=0.001). A significant increase was observed in the ALT enzyme of symptomatic patients (p=0.001). HBV DNA in the people with clinical symptoms was higher than 105 copies/mL and in the asymptomatic group was less than 103 copies/mL, suggesting a statistically significant increase in a group with clinical symptoms (p=0.001). Finally, it was found that the miR‐122 serum concentration correlated with HBV DNA and serum ALT (p=0.001).

Based on the obtained results, measuring the miR-122 levels can serve as a biomarker and an indicator of hepatitis B replication, especially in cases where ALT levels are unchanged; however, more research and more samples are needed.