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

Background: 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. Methods: 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. Results: 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). Conclusion: 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.