ABSTRACT
Chronic hepatitis B virus (HBV) infection and end-stage liver disease caused by such infection pose a serious threat to the health of Chinese citizens. The presence of HBV cccDNA is the main reason for the difficulties in the treatment of chronic hepatitis B and recurrence after drug withdrawal. HBV RNA, as a new serum marker, is produced by cccDNA transcription, and theoretically, it can reflect the level and transcriptional activity of cccDNA in hepatocytes. This article mainly introduces the formation of serum HBV RNA and analyzes its significance in evaluating the activity or status of cccDNA in liver tissue and predicting patients’ response during antiviral therapy and after drug withdrawal. Moreover, it is pointed out that further large-scale clinical studies are needed to verify and improve the clinical significance of serum HBV RNA measurement, so as to further optimize the regimens of antiviral therapy and guide the precision treatment of patients.
ABSTRACT
Objective@#To analyze serum HBV-RNA levels in patients with chronic hepatitis B whose serum HBV-DNA has dropped to undetected levels after treatment with entecavir, and to explore the correlation between HBV-RNA level and liver biochemical parameters, which lay the research foundation for the clinical significance of new serological marker HBV-RNA.@*Methods@#HBeAg negatively detected 107 cases with chronic hepatitis B whose serum HBV-DNA test results were lower than detection level for six consecutive months after receiving standard nucleoside therapy for more than 12 months were included. HBV-RNA level was detected by Perkin-Elmer reagent. HBV-DNA level was detected by Roche Cobas. Hitachi automatic biochemical analyzer was used to detect ALT and AST. Architect chemiluminescence analyzer was used to detect HBsAg, HBeAg, anti-HBe and anti-HBc. RStudio software was performed to analyze the correlation between HBV-RNA level and liver biochemical parameters. Logistic regression was used to analyze the independent factors influencing HBV-RNA level.@*Results@#The positive detection rate of serum HBV-RNA in patients with chronic hepatitis B whose serum HBV-DNA had dropped to undetected levels after ETV treatment was 22.43%. HBsAg, ALT and AST levels in HBV-RNA positive group were slightly higher than HBV-RNA negative group, while anti-HBc levels were slightly higher in HBV-RNA negative group. There was no difference in the level of anti-HBe between the HBV-RNA negative and the positive group. Logistic regression analysis showed that anti-HBc was an independent factor influencing the level of HBV-RNA detection (P = 0.021).@*Conclusion@#HBV-RNA can be detected in some patients with chronic hepatitis B whose serum HBV-DNA level has dropped to undetected levels after ETV treatment. Serum HBV-RNA only comes from the direct transcription of cccDNA, so it is better than HBV-DNA and HBsAg to reflect cccDNA level or activity. Anti-HBc, as an independent factor influencing the level of HBV-RNA, may be used in combination as a new marker to predict the efficacy of antiviral therapy.
ABSTRACT
Objective To investigate the role of mutations in C region that may contribute to occult hepatitis B virus infection.Methods C genes were amplified from two OBI blood donor samples respectively.Plasmids with mutations in C region of hepatitis B virus were constructed by overlapping PCR.HBsAg and HBeAg in Huh7 cells and in the serum of Balb/c mice were detected by CMLA.HBcAg in liver tissue was detected by immunohistochemistry,while HBV-RNA was tested by RT-PCR.Results Mutations in C region significantly reduced the expression level of HBeAg and HBcAg,but had no significant effect on HBsAg and HBV-RNA.Conclusion The mutations in C region affect the expression level of HBeAg and HBcAg,which may play an important role in the occurrence of OBI.
ABSTRACT
Hepatitis B virus (HBV) covalently closed circular DNA (cccDNA) in infected hepatocytes is the main cause of off-therapy viral rebound. The half-life of cccDNA is only 33-50 days, so the conversion of newly synthesized rcDNA to cccDNA in the nucleus is essential for the maintenance of cccDNA pool in infected hepatocytes. Though not directly targeting the existing cccDNA, current nucleos(t)ide analogues (NAs) may exhaust the cccDNA reservoir by blocking the rcDNA formation. Indeed, a prolonged consolidation therapy post loss of serum HBV DNA can achieve sustained remission and thus safe drug discontinuation in a small proportion of chronic hepatitis B (CHB) patients. In recent studies, we and others have demonstrated that it is the serum HBV RNA that reflects the cccDNA activity in infected hepatocytes, particularly among the patients on NAs. Here we suggest that instead of measuring serum HBV DNA only, simultaneous measurement of both viral DNA and RNA would improve the accuracy to reflect the cccDNA activity; therefore, the virological response should be redefined as consistent loss (less than the lower limit of detection) of both serum HBV DNA and RNA, which indicates the safety of drug discontinuation. Accumulating evidence has suggested that for the CHB patients with lower serum HBsAg, switch-to or add-on pegylated interferon (Peg-IFN) treatment would result in loss of serum HBsAg in a relatively large proportion of CHB patients. Since serum HBV RNA is an ideal biomarker to reflect the intrahepatic cccDNA activity, for the patients with a serum HBsAg level lower than 1 500 IU/ml after long-term NAs treatment, the serum HBV RNA should be measured. If serum HBV RNA is detected, peg-IFN should be added on; if serum HBV RNA is not detected, NAs treatment should be switched to peg-IFN treatment. We believe the therapy based on serum HBV RNA would make the functional cure of CHB (serum HBsAg loss or even conversion to anti-HBs) more efficient.