Hepatitis B virus （HBV） exclusively infects liver parenchymal cells and forms covalently closed circular DNA （cccDNA） within their nuclei. HBV cccDNA serves as the essential template for viral gene transcription， the sole source of progeny virus production， and the key driver of viral antigen expression， and it is the molecular basis for the persistence of HBV infection. Therefore， elimination and/or functional silencing of cccDNA is the key to eradicate chronic HBV infection. This article discusses the critical scientific issues that need to be solved during elimination of the harm of HBV infection from the perspectives of the synthesis， transcription， and clearance of cccDNA， as well as the impact of nonparenchymal cells on cccDNA， in order to provide a reference for eradicating HBV infection in the future.

Hepatitis B virus （HBV） is a unique hepatotropic DNA virus that forms covalently closed circular DNA within the nucleus of hepatocytes and can partially integrate into the host genome， establishing the molecular basis for persistent viral infection. HBV infection and replication depends on multiple hepatocyte-enriched host factors and is modulated by the hepatic microenvironment. The host achieves natural control and clearance of HBV through various mechanisms， including cytolytic elimination mediated by cellular immunity such as cytotoxic T lymphocytes and natural killer cells， innate immunity and noncytolytic clearance driven by interferons and various cytokines， and antibody-mediated protection and clearance as part of humoral immune response. In addition， intracellular restriction factors and pathways， hepatocyte turnover through division and replacement， and changes in the hepatic microenvironment （such as the increase in matrix stiffness） collectively influence the efficiency and outcome of viral control and clearance. This article clarifies and elaborates on related mechanisms， so as to deepen the understanding of HBV chronicity， spontaneous resolution， and cure and provide a theoretical basis for optimizing clinical management and developing novel therapeutic strategies.

Cure of chronic hepatitis B virus （HBV） infection is the ultimate goal in HBV-related research， and exploring potential curative pathways may help to identify key research directions. Covalently closed circular DNA （cccDNA）， as the most difficult genetic material to be eliminated within the HBV replication cycle， is not only a primary impediment to achieving cure， but also a key issue for establishing an analytical framework for cure strategies. This article reviews the thinking framework of “cccDNA dynamics”， further elaborates on its core implications， and systematically discusses the main strategies to promote cccDNA decay.

HBV DNA integration （iDNA） is the core barrier that must be overcome to achieve functional cure for chronic hepatitis B （CHB） and to prevent the occurrence of hepatocellular carcinoma （HCC）. During reverse transcription， 5%　—　10% of viral genomes are converted into double-stranded linear DNA that is randomly inserted into host chromosomes， generating stable iDNA and continuously producing HBsAg， thereby driving B- and T-cell immune exhaustion and locking the host in an immune-tolerant state. The process of iDNA runs throughout the entire natural history of HBV infection， and the viral enhancers it carries can promote clonal hyperplasia of indeterminate potential， accumulate pre-neoplastic mutations， and ultimately lead to HCC. Although long-term nucleos（t）ide analog or interferon therapy can suppress viral replication and reduce the formation of new integrations， existing therapies still fail to eliminate existing iDNA. Therefore， there is an urgent need for innovative strategies that can precisely target integration breakpoints， epigenetically silence iDNA， or eradicate integrated clones， so as to significantly increase the functional cure rate of CHB and fundamentally reduce the risk of HCC.

Hepatitis B virus （HBV） infection is one of the major global health problems， and it can lead to the development of liver cirrhosis and hepatocellular carcinoma. Due to the strict species specificity of HBV infection， no animal model has yet been established to fully support the complete life cycle of HBV infection and accurately reflect host immune responses and pathogenesis. Current animal models used for HBV research include various hosts such as chimpanzees， tree shrews， and mice， as well as surrogate models based on related hepatotropic viruses. Although these models have contributed significantly to the research on HBV replication， immune response， and antiviral drug evaluation， they still have certain limitations such as ethical concerns， low infection efficiency， high costs， and a lack of persistent infection. In recent years， the development of novel strategies， such as humanized mouse models with reconstituted human liver and immune systems， transgenic models， and viral vector-mediated infection systems， has greatly promoted the research on HBV biology. In the future， with the integration of emerging technologies including gene editing， tissue engineering， and multi-system reconstruction， it is possible to establish HBV infection models that can more closely mimic human pathophysiology， thereby laying a robust foundation for understanding virus-host interactions， exploring the pathways for viral clearance， and developing radical treatment strategies.

Chronic hepatitis B is still one of the main chronic Iiver diseases in China. Although antiviral therapy has achieved good therapeutic effects， there are still many problems that have not been solved. To assist clinical physicians in accurately and reasonably diagnosing and treating chronic hepatitis B， this consensus elaborateson the understanding， diagnosis， and treatment of chronic hepatitis B from both perspectives of traditional Chinese and Western medicine， It comprehensively and deeply presents the Iatest research progress in this field， so as to provide a reference for clinical practice.

Hepatic vascular diseases （such as portal vein thrombosis， porto-sinusoidal vascular disease， hereditary hemorrhagic telangiectasia， arterioportal fistula， and sinusoidal obstruction syndrome， Budd-Chiari syndrome） are characterized by diverse clinical manifestations， difficulties in diagnosis， and various treatment regimens， which brings huge challenges to clinical diagnosis and treatment， and at present， there are still no guidelines or consensus statements on the diagnosis and treatment of hepatic vascular diseases in China. To standardize and improve the diagnosis and treatment of hepatic vascular diseases in China， Committee on Liver Diseases （Integrated Traditional Chinese and Western Medicine） of China Research Hospital Association， Committee on Interventional Medicine of China Research Hospital Association， and Branch for Multidisciplinary Diagnosis and Treatment of Portal Hypertension of Beijing Medical Doctor Association organized the experts in related fields to develop expert consensus on clinical practice for the diagnosis and treatment of hepatic vascular diseases （2025 edition） based on the latest evidence-based medical research and the clinical practice in China， with a focus on the diagnosis and treatment of hepatic vascular diseases.

ObjectiveTo investigate the efficacy of sequential tenofovir alafenamide fumarate （TAF） therapy versus the regimen of entecavir （ETV） combined with TAF in chronic hepatitis B （CHB） patients experiencing low-level viremia （LLV） after ETV therapy， as well as their impact on virologic response， liver and renal function， and blood lipid levels. MethodsA total of 217 CHB patients with LLV after ETV treatment who were admitted to Shuguang Hospital Affiliated to Shanghai University of Traditional Chinese Medicine from May 2020 to December 2023 were enrolled， and according to the treatment regimen， they were divided into TAF group （180 patients receiving sequential TAF therapy） and combined group （37 patients receiving ETV+TAF therapy）. The propensity score matching （PSM） method was used to match the patients at a ratio of 1∶1， and finally 37 patients were included in each group to balance the baseline confounding factors. The two groups were compared in terms of hepatitis B virus DNA （HBV DNA） clearance rate， hepatitis B envelope antigen （HBeAg） clearance rate， liver and renal function parameters （liver stiffness measurement ［LSM］， platelet count ［PLT］， aspartate aminotransferase ［AST］， alanine aminotransferase ［ALT］， and creatinine ［Cr］）， blood lipid levels （total cholesterol ［TC］， triglyceride ［TG］， high-density lipoprotein cholesterol ［HDL-C］， and low-density lipoprotein cholesterol ［LDL-C］）， and the incidence rate of adverse reactions. The independent samples t-test was used for comparison of normally distributed continuous data between two groups， and the paired t-test was used for comparison within each group； the chi-square test was used for comparison of categorical data between groups. ResultsAfter 48 weeks of treatment， compared with the TAF group， the combined group had significantly higher HBV DNA clearance rate （86.49% vs 59.46%， χ²=6.852， P=0.009） and HBeAg clearance rate （59.46% vs 35.14%， χ²=4.391， P=0.036）. After treatment， compared with the TAF group， the combined group had significantly lower levels of LSM （7.01±1.50 kPa vs 7.90±1.68 kPa， t=2.404， P=0.019）， AST （18.02±2.28 U/L vs 21.12±2.85 U/L， t=5.166， P<0.001）， and ALT （19.85±3.86 U/L vs 22.00±3.90 U/L， t=2.383， P=0.020） and significantly higher levels of PLT ［（218.35±42.60）×10⁹/L vs （192.82±44.13）×10⁹/L， t=2.532， P=0.014］ and Cr （70.92±6.54 μmoL/L vs 67.60±6.13 μmoL/L， t=2.253， P=0.027）. After treatment， there was a slight increase in the level of TC in both the TAF group （5.60±0.89 mmol/L vs 5.18±0.85 mmol/L， t=2.076， P=0.041） and the combined group （5.45±0.80 mmol/L vs 5.02±0.83 mmol/L， t=2.269， P=0.026）. There was no significant difference in the incidence rate of adverse reactions between the TAF group and the combined group （21.62% vs 18.92%， χ²=0.084， P=0.772）. ConclusionFor ETV-treated CHB patients experiencing LLV， compared with sequential TAF therapy， the ETV+TAF combined therapy can effectively increase virologic response rate， alleviate liver fibrosis， and improve liver function， whereas sequential TAF therapy has less impact on renal function. Sequential or combined therapy with TAF may induce a slight increase in the level of TC， which should be taken seriously in clinical practice.

ObjectiveTo investigate the status of overlapping hepatitis B virus （HBV） infection in patients with chronic hepatitis C virus （HCV） infection and the serological characteristics of such patients. MethodsA total of 8 637 patients with HCV infection who were hospitalized from January 1， 2010 to December 31， 2020 and had complete data of HBV serological markers were enrolled， and the composition ratio of patients with overlapping HBV serological markers was analyzed among the patients with HCV infection. The patients were divided into groups based on age and year of birth， and serological characteristics were analyzed， and the distribution of HBV-related serological characteristics were analyzed across different HCV genotypes. ResultsThe patients with HCV/HBV overlapping infection accounted for 5.85%， and the patients with previous HBV infection accounted for 48.10%； the patients with protective immunity against HBV accounted for 14.67%， while the patients with a lack of protective immunity against HBV accounted for 31.39%. The patients were divided into groups based on age： in the 0 — 17 years group， the patients with protective immunity against HBV accounted for 61.41% （304 patients）； the 18 — 44 years group was mainly composed of patients with previous HBV infection （698 patients， 37.31%）， the 45 — 59 years group was predominantly composed of patients with previous HBV infection （1 945 patients， 50.38%）， and the ≥60 years group was also predominantly composed of patients with previous HBV infection （1 486 patients， 61.66%）. The patients were divided into groups based on the year of birth： in the pre-1992 group， the patients with previous HBV infection accounted for 51.63% （4 112 patients）； in the 1992 — 2005 group， the patients with protective immunity against HBV accounted for 54.72% （168 patients）； in the post-2005 group， the patients with protective immunity against HBV accounted for 64.38% （235 patients）. In this study， 6 301 patients underwent HCV genotype testing： the patients with genotype 1b accounted for the highest proportion of 51.71% （3 258 patients）， followed by those with genotype 2a （1 769 patients， 28.07%）， genotype 3b （63 patients， 1.00%）， genotype 3a （10 patients， 0.16%）， genotype 4 （21 patients， 0.33%）， and genotype 6a （5 patients， 0.08%）. ConclusionWith the implementation of hepatitis B planned vaccination program in China， there has been a significant reduction in the proportion of patients with previous HBV infection among the patients with HCV/HBV overlapping infection， but there is still a relatively high proportion of patients with a lack of protective immunity against HBV.

ObjectiveTo investigate the effect and mechanism of transplantation of human umbilical cord mesenchymal stem cell （hUC-MSC） with overexpression of the Numb gene in the treatment of cholestatic liver fibrosis （CLF）. MethodsThe technique of lentiviral transfection was used to induce the overexpression of the Numb gene in hUC-MSC （hUC-MSC^Numb-OE）， and hUC-MSC transfected with empty vector （hUC-MSC^OE-EV） was used as negative control. Bile duct ligation （BDL） was performed to establish a rat model of CLF， and then the rats were randomly divided into BDL group， hUC-MSC group， hUC-MSC^OE-EV group， and hUC-MSC^Numb-OE group， while a sham-operation group was also established. The rats in the intervention groups were given a single splenic injection of the corresponding cells after BDL， and samples were collected at the end of week 4. Related indicators were measured， including serum biochemistry， liver histopathology， the content of hydroxyproline （Hyp） in the liver， hepatic stellate cell activation， ductular reaction， liver regeneration， and the expression levels of key molecules in the Numb-p53 signaling axis. A one-way analysis of variance was used for comparison of continuous data between multiple groups， and the least significant difference t-test was used for further comparison between two groups. ResultsCompared with the BDL group， the hUC-MSC group and the hUC-MSC^OE-EV group had significant reductions in the levels of serum biochemical parameters （aspartate aminotransferase， gamma-glutamyl transpeptidase， total bile acid， total bilirubin， and direct bilirubin）， liver fibrosis markers （the content of Hyp and the expression levels of alpha-smooth muscle actin， tumor necrosis factor-α， and transforming growth factor-beta 1）， and ductular reaction markers （the expression levels of CK7 and CK19） （all P <0.05）， and compared with the hUC-MSC^OE-EV group， the hUC-MSC^Numb-OE group had significantly greater improvements in the above indicators （all P <0.05）. In addition， compared with the hUC-MSC^OE-EV group， the hUC-MSC^Numb-OE group had significant improvements in the expression levels of liver regeneration-related markers （albumin and hepatocyte nuclear factor 4α） and the molecules associated with the Numb-p53 signaling axis （Numb， pNumb， Mdm2， and p53） （all P <0.05）. ConclusionOverexpression of the Numb gene can enhance the therapeutic effect of hUC-MSC on CLF， possibly by activating the Numb-PTB^L-p53-HNF4α axis， promoting the hepatic differentiation of hUC-MSCs and subsequently enhancing liver regeneration.