Novel insights of HBV RNA in hepatitis B virus pathogenesis and clinical application

Hepatitis B virus (HBV) infection is still a severe health problem in the world, and chronic hepatitis B (CHB) is the major cause of serious HBV-related complications, including fibrosis, hepatic failure, and hepatocellular carcinoma. It is difficult for CHB patients to achieve complete cure as the currently available antiviral drugs can hardly eradicate covalently closed circular DNA (cccDNA) in the infected liver. Since detecting intrahepatic cccDNA needs invasive procedure, it is urgent to find a noninvasive indicator to reflect the activity of cccDNA. Recently, growing numbers of studies have indicated that serum HBV RNA could be regarded as a new biomarker for CHB activity. In order to illustrate the molecular biology and clinical characteristics of HBV RNA, we systematically reviewed the latest research to summarize the role of HBV RNA in HBV replication and pathogenicity, and to better estimate its potential function as a remarkable biomarker in clinical application. Meanwhile, we will also point out the deficiencies of current research, and discuss the future direction of HBV RNA study