A major goal of curative hepatitis B virus (HBV) treatments is the reduction or inactivation of intrahepatic viral covalently closed circular DNA (cccDNA). Hence, precise cccDNA quantification is essential in preclinical and clinical studies. Southern blot (SB) permits cccDNA visualisation but lacks sensitivity and is very laborious. Quantitative PCR (qPCR) has no such limitations but inaccurate quantification due to codetection of viral replicative intermediates (RI) can occur. The use of different samples, preservation conditions, DNA extraction, nuclease digestion methods and qPCR strategies has hindered standardisation. Within the ICE-HBV consortium, available and novel protocols for cccDNA isolation and qPCR quantification in liver tissues and cell cultures were compared in six laboratories to develop evidence-based guidance for best practices.
Reference material (HBV-infected humanised mouse livers and HepG2-NTCP cells) was exchanged for cross-validation. Each group compared different DNA extraction methods (Hirt extraction, total DNA extraction with or without proteinase K treatment (+PK/-PK)) and nuclease digestion protocols (plasmid-safe ATP-dependent DNase (PSD), T5 exonuclease, exonucleases I/III). Samples were analysed by qPCR and SB.
Hirt and -PK extraction reduced coexisting RI forms. However, both cccDNA and the protein-free relaxed circular HBV DNA (pf-rcDNA) form were detected by qPCR. T5 and Exo I/III nucleases efficiently removed all RI forms. In contrast, PSD did not digest pf-rcDNA, but was less prone to induce cccDNA overdigestion. In stabilised tissues (eg, Allprotect), nucleases had detrimental effects on cccDNA.
We present here a comprehensive evidence-based guidance for optimising, controlling and validating cccDNA measurements using available qPCR assays.

Hepatitis B virus (HBV) infection continues to be a worldwide public health problem. In Mexico, at least three million adults are estimated to have acquired hepatitis B (total hepatitis B core antibody [anti-HBc]-positive), and of those, 300,000 active carriers (hepatitis B surface antigen [HBsAg]-positive) could require treatment. Because HBV is preventable through vaccination, its universal application should be emphasized. HBV infection is a major risk factor for developing hepatocellular carcinoma. Semi-annual liver ultrasound and serum alpha-fetoprotein testing favor early detection of that cancer and should be carried out in all patients with chronic HBV infection, regardless of the presence of advanced fibrosis or cirrhosis. Currently, nucleoside/nucleotide analogues that have a high barrier to resistance are the first-line therapies.

Hepatitis B virus (HBV) infection continues to be a worldwide public health problem. In Mexico, at least three million adults are estimated to have acquired hepatitis B (total hepatitis B core antibody [anti-HBc]-positive), and of those, 300,000 active carriers (hepatitis B surface antigen [HBsAg]-positive) could require treatment. Because HBV is preventable through vaccination, its universal application should be emphasized. HBV infection is a major risk factor for developing hepatocellular carcinoma. Semi-annual liver ultrasound and serum alpha-fetoprotein testing favor early detection of that cancer and should be carried out in all patients with chronic HBV infection, regardless of the presence of advanced fibrosis or cirrhosis. Currently, nucleoside/nucleotide analogues that have a high barrier to resistance are the first-line therapies.

In order to standardize the effective prevention, early screening and diagnosis of the population at risk of primary liver cancer, the Chinese Society of Hepatology and Chinese Medical Association organized the relevant domestic experts to formulate the \"Consensus on Secondary Prevention of Primary Liver Cancer (2021 version),\" based on the basic, clinical and preventive research progress, combined with the actual situation at home and abroad, so as to provide an important basis for the prevention, screening and early diagnosis of primary liver cancer in the population of chronic liver disease.
为了规范原发性肝癌危险人群的有效预防、早期筛查及诊断，中华医学会肝病学分会组织国内有关专家，以国内外原发性肝癌的基础、临床、预防研究进展为依据，结合现阶段我国的实际情况，制定《原发性肝癌二级预防共识（2021年版）》，为慢性肝病人群原发性肝癌的预防、筛查及早期诊断提供重要依据。.

Despite access to effective antiviral drugs and vaccines, hepatitis B virus (HBV) infection remains a major health issue worldwide. HBV is highly infectious and may cause chronic infection, progressive liver damage, hepatocellular cancer (HCC) and death. Early diagnosis, proper management and timing of treatment are crucial. The Swedish Reference group for Antiviral Treatment (RAV) here provides updated evidence-based guidelines for treatment and management of HBV infection which may be applicable also in other countries. Tenofovir alafenamide (TAF) has been introduced as a novel treatment option and new principles regarding indication and duration of treatment and characterization of hepatitis B have been gradually introduced which justifies an update of the previous guidelines from 2007. Updated guidelines on HCC surveillance in HBV-infected patients, treatment and prophylaxis for patients undergoing liver transplantation as well as management of pregnant women and children with HBV infection are also provided.

Hepatitis E virus (HEV) infection is one of the main causes of acute hepatitis in both developed and developing countries. This infectious disease has a high prevalence and incidence in Europe. HEV infection has a greater clinical impact in vulnerable populations, such as immunosuppressed patients, pregnant women and patients with underlying liver disease. Therefore, the Study Group for Viral Hepatitis (Grupo de Estudio de Hepatitis Víricas, GEHEP) of the Spanish Society of Infectious Diseases and Clinical Microbiology (Sociedad Española de Enfermedades Infecciosas y Microbiología Clínica, SEIMC) believed it very important to prepare a consensus document to help in decision-making regarding diagnosis, clinical and therapeutic management, and prevention of HEV infection.

The estimated prevalence of hepatitis C virus (HCV) infection in India is between 0.5 and 1.5% with hotspots showing much higher prevalence in some areas of northeast India, in some tribal populations and in certain parts of Punjab. Genotype 3 is the most prevalent type of infection. Recent years have seen development of a large number of new molecules that are revolutionizing the treatment of hepatitis C. Some of the new directly acting agents (DAAs) like sofosbuvir have been called game-changers because they offer the prospect of interferon-free regimens for the treatment of HCV infection. These new drugs have not yet been approved in India and their cost and availability is uncertain at present. Till these drugs become available at an affordable cost, the treatment that was standard of care for the whole world before these newer drugs were approved should continue to be recommended. For India, cheaper options, which are as effective as the standard-of-care (SOC) in carefully selected patients, are also explored to bring treatment within reach of poorer patients. It may be prudent to withhold treatment at present for selected patients with genotype 1 or 4 infection and low levels of fibrosis (F1 or F2), and for patients who are non-responders to initial therapy, interferon intolerant, those with decompensated liver disease, and patients in special populations such as stable patients after liver and kidney transplantation, HIV co-infected patients and those with cirrhosis of liver.

Globally, around 150 million people are infected with hepatitis C virus (HCV). India contributes a large proportion of this HCV burden. The prevalence of HCV infection in India is estimated at between 0.5% and 1.5%. It is higher in the northeastern part, tribal populations and Punjab, areas which may represent HCV hotspots, and is lower in western and eastern parts of the country. The predominant modes of HCV transmission in India are blood transfusion and unsafe therapeutic injections. There is a need for large field studies to better understand HCV epidemiology and identify high-prevalence areas, and to identify and spread awareness about the modes of transmission of this infection in an attempt to prevent disease transmission.

The goal of chronic hepatitis B (CHB) treatment is to improve survival by preventing disease progression to decompensated cirrhosis and hepatocellular carcinoma which is the cause of over 1 million deaths annually. The risk of disease progression is reduced when a sustained reduction of hepatitis B virus (HBV) DNA to undetectable levels and suppression of HBV replication are obtained which can result in regression of liver fibrosis and may even reverse cirrhosis. However, even if HBsAg loss occurs, HBV is not completely eradicated by treatment, and long-term therapy is required in patients who are HBeAg(-) and HBeAg(+) who do not maintain off-treatment virological suppression and in those with advanced liver disease. The recently updated European Association of the Study of the Liver (EASL) clinical practical guidelines for HBV have clarified, first, how to treat HBV (interferon or the most potent oral drugs with optimal resistance profiles, i.e. entecavir and tenofovir disoproxil fumarate, should be used as first-line monotherapies); second, who should be treated (CHB in patients with significant liver disease but also patients who are HBsAg(+) and are receiving immunosuppressive treatment, patients coinfected with HBV and human immunodeficiency virus, mothers who are HBsAg(+) with high viral load in late pregnancy associated with sero vaccination to reduce the risk of vertical transmission of HBV; and third, when to stop antiviral therapies. The aim of this review was to clarify how to treat HBV and who should be treated, as well as when to stop treatment. Although the answer to these questions is clear for pegylated interferon, it is more debatable for nucleos(t)ide analogues (anti-HBe seroconversion, HBsAg loss or anti-HBs seroconversion with undetectable HBV DNA are clear indications to discontinue treatment but sustained undetectable HBV DNA in patients who are anti-HBe(+) without significant fibrosis might be another indication).