Characterization of Serum HBV RNA in Patients with Untreated HBeAg-Positive and -Negative Chronic Hepatitis B Infection

Background: The serum hepatitis B virus (HBV) RNA is suggested as a potential new biomarker of HBV infection. However, it is not fully understood. Objectives: The current study aimed at characterizing serum HBV RNA in patients with untreated chronic hepatitis B (CHB) and genotype B and C HBV infection. Methods: A large cohort of 483 patients with hepatitis B e antigen (HBeAg)-positive and -negative was performed. The routine serum biomarkers of HBV infection were tested. HBV genotyping was carried out by direct sequencing. Serum HBV RNA levels were quantified using a method described in the authors’ previous study (lower limit of detection: 66.7 IU/mL). Results: Serum HBV RNA was detected in 92.5% (394/426) of the patients with HBeAg-positive and 31.6% (18/57) of HBeAg-negative ones; a positive association was observed between HBeAg and HBV RNA statuses in the subjects. Alanine aminotransferase (ALT), HBV DNA, and genotype were the independent predictors in patients with HBeAg-positive CHB (P = 0.024, 0.001 and 0.014, respectively), while it was HBV DNA in the negative ones (P = 0.000) for serum HBV RNA detectability. Serum HBV RNA was positively correlated with ALT, aspartate transaminase (AST) and HBV DNA, regardless of HBeAg status, and with hepatitis B surface antigen (HBsAg) in HBeAg-positive ones (P < 0.05). Conclusions: Serum HBV RNA may be affected by HBeAg status, serum HBV DNA, HBsAg levels, HBV genotype, ALT, and AST levels. There might be some similarities between the characteristics of serum HBV RNA, and serum HBV DNA and HBsAg, regardless of its distinctive features. The roles of serum HBV RNA in viral replication, infection, survival, disease progression, and antiviral responses need to be investigated in further studied.