Clinical Value of Hepatitis B Virus RNA Detection in Patients with Chronic Hepatitis B Infection

Objective:To study the clinical value of hepatitis B virus pregenomic RNA(HBV-pgRNA)detection in the treatment of hepatitis B.Methods:60 patients with hepatitis B were included in the study.Serum HBV-pgRNA and HBV DNA levels in different phases of infection and during treatment were detected,and serum hepatitis B surface antigen(HbsAg)titer was detected by chemiluminescent immunoassay.DNA was extracted from liver biopsy tissue,and covalently closed circular DNA was detected to predict the therapeutic value in patients.Results:At the initial stage of treatment,the level of HBV-pgRNA in phase I,II,III,and IV showed a gradual decrease.Comparing the levels of HBV-pgRNA before and after treatment,we found that the level of HBV-pgRNA was significantly lower after treatment(P<0.05).Among the indicators for predicting HBsAg seroconversion,the accuracy of HBV-pgRNA level was 85.0%(51/60).Conclusion:The clinical value of HBV-pgRNA detection in the treatment of hepatitis B is high.

Hepatitis B virus replication

Hepadnaviruses, including human hepatitis B virus （HBV）, replicate through reverse transcription of an RNA intermediate, the pregenomic RNA （pgRNA）. Despite this kinship to retroviruses, there are fundamental differences beyond the fact that hepadnavirions contain DNA instead of RNA. Most peculiar is the initiation of reverse transcription： it occurs by protein-priming, is strictly committed to using an RNA hairpin on the pgRNA, ε, as template, and depends on cellular chaperones; moreover, proper replication can apparently occur only in the specialized environment of intact nucleocapsids. This complexity has hampered an in-depth mechanistic understanding. The recent successful reconstitution in the test tube of active replication initiation complexes from purified components, for duck HBV （DHBV）, now allows for the analysis of the biochemistry of hepadnaviral replication at the molecular level. Here we review the current state of knowledge at all steps of the hepadnaviral genome replication cycle, with emphasis on new insights that turned up by the use of such cellfree systems. At this time, they can, unfortunately, not be complemented by three-dimensional structural information on the involved components. However, at least for the ~ RNA element such information is emerging, raising expectations that combining biophysics with biochemistry and genetics will soon provide a powerful integrated approach for solving the many outstanding questions. The ultimate, though most challenging goal, will be to visualize the hepadnaviral reverse transcriptase in the act of synthesizing DNA, which will also have strong implications for drug development.

Effect of oxymatrine on the replication cycle of hepatitis B virus in vitro

AIM:To determine the antiviral mechanism or target of oxymatrine against hepatitis B virus(HBV).METHODS:HepG2.2.15 cells were incubated with culture medium containing 500 μg/mL of oxymatrine for 2 and 5 d.The surface antigen of HBV(HBsAg) and e antigen of HBV(HBeAg) in supernatant were determined by ELISA.HBV DNA in supernatant,and intracellular covalently closed circular DNA(cccDNA),relaxed circular DNA(rcDNA) and pregenomic RNA(pgRNA) were quantif ied by specif ic real-time polymerase chain reaction(PCR) or reverse transcription(RT)-PCR.RESULTS:Treatment with oxymatrine for 2 d and 5 d reduced the production of HBV by the cell line,as indicated by the decline of HBsAg(22.67%,t = 5.439,P = 0.0322 and 22.39%,t = 5.376,P = 0.0329,respectively),HBeAg(55.34%,t = 9.859,P = 0.0101 and 43.97%,t = 14.080,P = 0.0050) and HBV DNA(40.75%,t = 4.570,P = 0.0447 and 75.32%,t = 14.460,P = 0.0047) in the supernatant.Intracellular cccDNA was also markedly reduced by 63.98%(t = 6.152,P = 0.0254) and 80.83%(t = 10.270,P = 0.0093),and intracellular rcDNA by 34.35%(t = 4.776,P = 0.0413) and 39.24%(t = 10.050,P = 0.0097).In contrast,intracellular pgRNA increased by 6.90-fold(t = 8.941,P = 0.0123) and 3.18-fold(t = 7.432,P = 0.0176) after 500 μg/mL of oxymatrine treatment for 2 d and 5 d,respectively.CONCLUSION:Oxymatrine may inhibit the replication of HBV by interfering with the process of packaging pgRNA into the nucleocapsid,or inhibiting the activity of the viral DNA polymerase.

Serum hepatitis B core-related antigen as a surrogate marker of hepatitis B e antigen seroconversion in chronic hepatitis B

BACKGROUND Quantitative hepatitis B core-related antigen(qHBcrAg)has a better correlation with intrahepatic hepatitis B virus(HBV)covalently closed circular DNA(cccDNA)than HBV DNA or hepatitis B e antigen(HBeAg),but data are still lacking for its clinical application.AIM The aim was to investigate serum qHBcrAg levels in patients with chronic hepatitis B and assess the correlation of serum qHBcrAg with pregenomic RNA(pgRNA),cccDNA,and HBeAg seroconversion.METHODS This study was a secondary analysis of patients who underwent percutaneous liver biopsy between July 2014 and June 2019 in two multicenter randomized controlled clinical trials of peginterferon vs nucleos(t)ide analog(NUC)-based therapy(NCT03509688 and NCT03546530).Serum qHBcrAg,pgRNA,HBV DNA,hepatitis B core antigen,HBeAg,liver cccDNA,and HBV DNA were measured.The correlations of serum qHBcrAg with other biomarkers were analyzed.RESULTS A total of 139 patients were included.The mean qHBcrAg levels were 5.32±1.18 log10 U/mL at baseline and decreased during treatment(all P<0.0001).Serum qHBcrAg levels were positively correlated with pgRNA(r=0.597,P<0.0001)and cccDNA(r=0.527,P<0.0001)levels.The correlation of serum qHBcrAg level and intrahepatic HBV DNA levels at baseline was weak but significant(r=0.399,P<0.0001).HBcrAg predicted HBeAg seroconversion,with areas under the receiver operating characteristics curve of 0.788 at 24 wk and 0.825 at 48 wk.Log HBcrAg at wk 24 and 48 was independently associated with HBeAg seroconversion[odds ratio(OR)=2.402,95%confidence interval(CI):1.314-4.391,P=0.004;OR=3.587,95%CI:1.315-9.784,P=0.013].CONCLUSION Serum HBcrAg levels were correlated with HBV virological markers and could be used to predict HBeAg seroconversion.

Hepatitis B core-related antigen:Are we near a treatment endpoint?

Different serological and virological markers in chronic hepatitis B patients guide staging of viral infection,and initiation and response to therapy.Due to the persistence of intrahepatic covalently closed circular DNA(cccDNA)in the hepatocyte nucleus,hepatitis B is not curable.Even after undetectable hepatitis B virus DNA levels,the persistence of hepatitis B surface antigen and novel markers such as hepatitis B core-related antigen(HBcrAg)indicate the persistence of intrahepatic cccDNA.In this study,HBcrAg levels at baseline and after 24 and 48 wk of antiviral therapy predicted hepatitis B e antigen seroconversion.Due to the poor sensitivity of assays and detectable levels in HBsAg-negative patients,the long-term utility of HBcrAg needs future research.

Inhibition of Hepatitis B Virus Replication and Expression in Vitro and in Vivo by the Hammerhead Ribozymes Targeted Different Sites

Objective To develop an effective and specific medicine targeting hepatitis B virus(HBV) pregenome. Based on the identified accessible target sites for hammerhead ribozyme in our previous researches, a recombinant hepatitis delta virus(HDV) ribozyme was chosen and used to demonstrate the effective cleavage in vitro and in vivo. Methods Three hammerhead ribozymes for potential target sites(S, X and C genes) and co-expression plasmid(pTr-dB, pTdδ-dB, pTrX-dB and pTrC-dB) as well as four HDV-ribozyme chimera constructs with HBV(pTdXX, pTdXC, pTdSX and pTdSC) were severally chosen to validate the inhibition of the replication and expression of HBV. The co-expression plasmids(pTdδ and pTr-Db) in physiological saline were hydrodynamically injected to mice by tail vein. Results Compared with the group injected with pTr-dB in Huh-7 cell, hepatitis B surface antigen(HBsAg) was reduced by 31% in the group injected with pTdδ-dB, by 54%, 26%, 72% and 97% in the group injected with recombinant-ribozymes pTdSX, pTdSC, pTdXC and pTdXX, respectively. The inhibiting effects of endogenous ribozymes RzX and RzC on the HBsAg expression were 66% and 57%, respectively. Compared with the positive control, the amount of HBsAg was decreased in mice injected with pTdXX through tail vein by 88% and 96% on the second day and the third day, respectively. HBsAg was undetectable on the 6th day and could not primitively be detected on the 9th day in the sera from all mice. HBV DNA was not detected in the sera of BALB/c mice injected with pTdXX-dB, pTrX-dB or replicating-defective plasmid pHBV, while HBV DNA replication in control group could be detected on the 6th day. While HBcAg could not be detected in liver tissues of mice injected with plasmid pTdXX-dB on the 3rd day. Conclusions Encoding regions of HBV S, C and X gene were the effective cleavage sites for hammerhead ribozyme in vitro and in vivo, which provides basis for further construction of therapeutic recombinant HDV and the development of targeting antiviral gene therapy.

Adverse Effect of Nonalcoholic Fatty Liver Disease on the Therapeutic Response in Patients with Chronic Hepatitis B

Background and Aims:The impact of nonalcoholic fatty liver disease(NAFLD)on the treatment outcome of chronic hepatitis B(CHB)is undefined and deserves an in-depth investigation.Methods:Histologically-proven CHB receiving first-line antiviral regimens as initial therapy was enrolled and grouped by the concurrence of NAFLD,and followed up at six monthly intervals.Therapeutic response related data were recorded and compared at multiple time points.Kaplan-Meier and Cox regression analyses were utilized to estimate the impact of NAFLD on complete virological response(CVR).Results:We enrolled 267 patients(CHB:164;CHB with NAFLD:103)with comparable follow-up durations.They were also comparable in baseline HBV DNA levels and HBeAg positivity.Patients with concomitant NAFLD showed less significant decline in HBV DNA,qHBsAg,pgRNA,and liver enzyme levels over time;moreover,their cumulative incidences of CVR were significantly lower and that of low-level viremia(LLV)were significantly higher at 6,12,18,24 months.First CVR of CHB was delayed with the presence NAFLD(11.0 vs.7.0 months,p<0.001)and further prolonged with higher grade of liver steatosis(Grade 2–3 vs.1:13.0 vs.9.0 months).On multivariate analysis,HBeAg positivity(HR:0.650,p=0.036),grade of steatosis(G2[HR:0.447,p=0.004];G3[HR:0.085,p=0.002])and HBV DNA(log10 IU/mL)(HR:0.687,p<0.001)were significantly associated with delayed CVR,whereas grade of necroinflammation(HR:1.758,p<0.001)accelerated the CVR.Conclusions:In CHB patients receiving initial antiviral therapy,NAFLD was associated with higher levels of HBV DNA,pgRNA,and liver enzymes,and higher incidence of LLV and delayed CVR.

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.