3.A short half-life of cccDNA offer or ignite hope for hepatitis B cure under nucleos(t)ide analogues treatment.
Lin GAO ; Tian Hao MAO ; Si Wen PENG ; Jie WANG ; Xiang Mei CHEN ; Feng Min LU
Chinese Journal of Hepatology 2022;30(1):99-102
Covalently closed circular DNA (cccDNA) of hepatitis B virus (HBV) is the template for HBV replication. Currently, there is a lack of therapeutic drugs that directly target cccDNA. Therefore, blocking cccDNA supplements as fast as possible and reducing the existing cccDNA is the key to achieving a complete cure of chronic hepatitis B. Previous studies have suggested that cccDNA had a long half-life, but a recent study showed that it only took a few months to update cycle of cccDNA pool, and its number was much less than previously predicted. In the future, with the advent of new antiviral drugs that can completely inhibit HBV replication, it is expected that the cccDNA pool will be completely cleared due to its supplement complete blockade, so as to achieve virological cure of chronic hepatitis B.
Antiviral Agents/therapeutic use*
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DNA, Circular/genetics*
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DNA, Viral
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Half-Life
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Hepatitis B/drug therapy*
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Hepatitis B virus/genetics*
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Hepatitis B, Chronic/drug therapy*
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Humans
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Virus Replication
4.A conceptual framework for dynamics of cccDNA in hepatitis B virus.
Chinese Journal of Hepatology 2023;31(5):545-550
The resolution of the hepatitis C issue has raised expectations for a chronic hepatitis B cure, driving the industry to expand investment in research and development efforts to strengthen functional cure strategies. These strategies have a wide variety of types, and the published research findings are heterogeneous. The theoretical analysis of these strategies is of great significance for determining prioritized research orientations as well as sensibly allocating research and development resources. However, due to a paucity of necessary conceptual models, current theoretical analysis has not been able to unify various therapeutic strategies into a proper theoretical framework. In view of the fact that the decrease in the quantity of cccDNA is an inevitable core event accompanied by the process of functional cure, this paper intends to analyze several chronic hepatitis B cure strategies using cccDNA dynamics as a framework. Furthermore, there are currently few studies on the dynamics of the cccDNA field, hoping that this article can promote recognition and research in this field.
Humans
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Hepatitis B virus/genetics*
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Hepatitis B, Chronic/drug therapy*
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Antiviral Agents/therapeutic use*
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Virus Replication
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DNA, Circular/therapeutic use*
;
DNA, Viral/genetics*
;
Hepatitis B/drug therapy*
5.Rational selection of virologic and immunological biomarkers and therapeutic endpoints in the clinical trials of new drugs treating chronic hepatitis B.
Chinese Journal of Hepatology 2022;30(4):429-438
Hepatitis B virus (HBV) infection remains to be the major cause of chronic liver diseases in China. Since the nucleos(t)ide analogues and pegylated interferon-alpha do not directly target the covalently closed circular DNA (cccDNA) in the nuclei of HBV-infected hepatocytes, those standard-of-care medications cannot efficiently cure the infected hepatocytes and rarely achieve the functional cure of chronic hepatitis B (CHB). Therefore, new antiviral drugs targeting distinct steps of HBV replication and immunotherapeutics reinvigorating antiviral immune responses are urgently needed for the functional cure of CHB. Based on the extensive discussion of the biological and clinical significance of new virologic biomarkers and distinct mechanism of drug candidates currently in clinical development, we propose that the selection of virologic and immunological biomarkers for evaluation of therapeutic efficacy as well as setting the therapeutic endpoints in the clinical trials should be based on the mode of action of investigational drugs. In addition, due to the complexity of CHB pathogenesis, selection of specific subpopulation of CHB patients for the clinical trials of drugs with a specific mode of action should also be considered.
Antiviral Agents/therapeutic use*
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Biomarkers
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DNA, Circular
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DNA, Viral
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Hepatitis B/drug therapy*
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Hepatitis B Surface Antigens
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Hepatitis B virus/genetics*
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Hepatitis B, Chronic
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Humans
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Virus Replication
6.Clinical significance of hepatitis B virus pgRNA for deciding antiviral therapy discontinuation in patients with chronic hepatitis B.
Jin Zhi HE ; Yi Fan XU ; Xue Zhong LEI
Chinese Journal of Hepatology 2022;30(9):970-975
Objective:b> To explore the clinical significance of hepatitis B pregenomic RNA (pgRNA) for deciding antiviral therapy discontinuation in patients with chronic hepatitis B (CHB). Methods:b> Data of patients with CHB who were treated with long-term antiviral therapy in the Center for Infectious Diseases, West China Hospital of Sichuan University from January 2019 to December 2019 were collected. Drug discontinuity after evaluation of high-sensitivity HBV DNA and HBV pgRNA (HBV DNA ≤20 IU/ml and HBV pgRNA<150 copies/ml) was observed. The prospective observational study on 91 patients with HBeAg-negative CHB was conducted. The clinical conditions were followed up 3, 6 and 12 months after the drug discontinuation. The relationship between HBV pgRNA and relapse after drug discontinuation was analyzed. Results:b> From observation to 12 months after drug discontinuation, a total of 34 patients (37.4%) had developed recurrence and resumed antiviral therapy, and the cumulative recurrence rate within 12 months of drug discontinuation was 46.8%. Among the relapsed patients, 14 (41.2%) had biochemical breakthroughs, and all achieved good biochemical and virological responses after the resumption of antiviral therapy. The Cox multivariate proportional hazards regression analysis showed that the level of HBV pgRNA before drug discontinuation and the type of antiviral drugs taken were associated with recurrence after drug discontinuation. The risk of recurrence after drug withdrawal in the HBV pgRNA ≤50 copies/ml group was 2.316 times higher than that in the HBV pgRNA negative group (HR=2.316, 95%CI: 1.047-5.126, P=0.038). The risk of recurrence after drug withdrawal in the HBV pgRNA >50 copies/ml group was 3.45 times higher than that in the HBV pgRNA negative group (HR=3.450, 95%CI: 1.338-8.892, P=0.010). Conclusion:b> HBV pgRNA can be used to predict the risk of recurrence after antiviral therapy discontinuation in patients with CHB. Patients with negative serum HBV pgRNA before drug discontinuation have a relatively low risk of relapse after drug discontinuation, and drug discontinuation is not recommended for patients with HBV pgRNA >50 copies/ml.
Humans
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Hepatitis B virus/genetics*
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Hepatitis B e Antigens
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Hepatitis B, Chronic/drug therapy*
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DNA, Viral
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RNA
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Antiviral Agents/therapeutic use*
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Recurrence
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Hepatitis B Surface Antigens
10.Evolution of hepatitis B virus quasispecies during antiviral therapy in one chronic hepatitis B patient.
Pan-pan LIANG ; Jin-jun GUO ; Qing-ling LI ; Qiang LUO ; Xiao-feng SHI ; Ai-long HUANG
Chinese Journal of Hepatology 2011;19(7):516-520
<b>OBJECTIVEb>To investigate the evolution of hepatitis B virus (HBV) quasispecies in one patient during lamivudine (LAM) monotherapy and switching to entecavir (ETV) rescue treatment.
<b>METHODSb>Serum samples were taken at seven different time points during antiviral therapy (0, 24, 48, 60, 72, 96, 152 weeks, respectively), the HBV DNA polymerase gene was amplified, cloned and sequenced to analyze the amino acid substitutions within HBV DNA polymerase gene and distribution of virus quasispecies. Quantitative detection of the HBV wild strains and total virus was performed by amplification refractory mutation system real-time PCR (ARMS-PCR).
<b>RESULTSb>Three mutation patterns detected during antiviral therapy in the patient: rtM204V, rtM204V+rtL180M and rtM204I. The HBV quasispecies were found always in dynamic variation. The HBV populations were completely replaced with the LAM-resistant variants when the viral breakthrough was encountered during LAM monotherapy. Interestingly, the wild-type variants presented gradually dominant (79.3%) with the decline of HBV DNA load after switching to ETV rescue administration. ARMS-PCR results showed that the wild-type variants account ed for 68.55% of the HBV populations at baseline and this proportion declined to 0.21% when the viral breakthrough emerged under LAM therapy. The wild-type variants gradually increased from week 24 after switching to ETV rescue therapy and the proportion of HBV wild-type variants in the population fluctuated between 16.01% to 26.93%.
<b>CONCLUSIONSb>The distribution of virus quasispecies were always in dynamic variation during sequential therapy with nucleotide analogs in chronic hepatitis B patients. Different patterns of dynamic HBV quasispecies may have different contribution in ETV resistance in LMV refractory patients with ETV administration.
Adult ; Antiviral Agents ; therapeutic use ; DNA, Viral ; genetics ; Drug Resistance, Viral ; genetics ; Genotype ; Hepatitis B virus ; drug effects ; genetics ; Hepatitis B, Chronic ; drug therapy ; virology ; Humans ; Male ; Mutation