Isabelle Chemin

• PhD
• Head team Hepatocarcinogenesis and viral infections at French Institute of Health and Medical Research

Objectives This study sought to determine the prevalence of hepatitis B virus (HBV)-hepatitis D virus (HDV) co-infection and to characterize isolates of both viruses in a Chadian population of HBV surface antigen (HBsAg)-positive pregnant women and students. Methods This was a cross-sectional retrospective study using archived samples from pregnan...

The GeneXpert HBV Viral Load test is a simplified tool to scale up screening and HBV monitoring in resource-limited settings, where HBV is endemic and where molecular techniques to quantify HBV DNA are expensive and scarce. However, the accuracy of field diagnostics compared to gold standard assays in HBV-endemic African countries has not been well...

Objectives Chronic hepatitis B virus (HBV) infection remains a major health problem worldwide. This infection is more severe when combined with hepatitis Delta virus (HDV). Moreover, Plasmodium falciparum (Pf) malaria infection during pregnancy can have severe consequences for the mother and the newborn. Importantly, the manifestation of these thre...

Background & Aims Transcription termination fine tunes gene expression and contributes to specify the function of RNAs in eukaryotic cells. Transcription termination of hepatitis B virus (HBV) is subjected to the recognition of the canonical polyadenylation signal (cPAS) common to all viral transcripts. The regulation of the usage of this cPAS and...

A total of 20 Mauritanian patients with the HBs antigen (HBsAg), seen in consultation and having benefited from blood samples after consent in August 2023 at one of the two research institutes in Mauritania (INRSP or INHV), were included. The research of AgHBs and AgHBe was carried out using an immunofluorescence technique (MiniVidas, Biomérieux),...

Background & Aims: Transcription termination fine tunes gene expression and contributes to specify the function of RNAs in eukaryotic cells. Transcription termination of hepatitis B virus (HBV) is subjected to the recognition of the canonical polyadenylation signal (cPAS) common to all viral transcripts. The regulation of the usage of this cPAS and...

Hepatitis B is a “silent epidemic” that is fifty to a hundred (50–100) times more infectious than HIV and is a potentially life-threatening liver infection [...]

Background and aims Hepatitis B virus (HBV) infection affects 300 million individuals worldwide, representing a major factor for the development of hepatic complications. Although existing antivirals are effective in suppressing replication, eradication of HBV is not achieved. Therefore, a multi-faceted approach involving antivirals and immunomodul...

Objective: Despite the availability of a highly effective and safe vaccine against hepatitis B virus (HBV) infection for 40 years, still almost 300 million persons are estimated to be chronically infected by this virus worldwide. The World Health Organization (WHO) has proposed a plan for hepatitis elimination by 2030. However, several factors, su...

Hepatitis B virus (HBV) genotypes E to J are understudied genotypes. Genotype E is found almost exclusively in West Africa. Genotypes F and H are found in America and are rare in other parts of the world. The distribution of genotype G is not completely known. Genotypes I and J are found in Asia and probably result from recombination events with ot...

Background: Chronic liver disease is a major cause of premature death in sub-Saharan Africa. Efficacy of antiviral therapy among patients with hepatitis B virus (HBV)-related cirrhosis is not well established in Africa. We described the clinical characteristics and outcomes of patients with cirrhosis and hepatocellular carcinoma in The Gambia and...

Hepatitis B virus (HBV) and Hepatitis D virus (HDV) coinfection confers a greater risk for accelerated liver disease progression. Full-length characterization of HDV genome is necessary to understand pathogenesis and treatment response. However, owing to its high variability and tight structure, sequencing approaches remain challenging. Herein, we...

Background: To reduce mortality associated with hepatitis B virus (HBV) infection, timely detection of cirrhosis and early-stage hepatocellular carcinoma (HCC) is essential. In low-income countries, however, HBV-infected people have limited access to liver histopathology, a reference test. Recently, Asian studies have suggested the usefulness of a...

To achieve the World Health Organization’s (WHO) goals of eradicating viral hepatitis globally by 2030, the regional prevalence and epidemiology of hepatitis B virus (HBV) and hepatitis delta virus (HDV) coinfection must be known in order to implement preventiveon and treatment strategies. HBV/HDV coinfection is considered the most severe form of v...

Primary liver cancer is the sixth most common cancer in men and seventh in women, with hepatocellular carcinoma (HCC) being the most common form (75–85% of primary liver cancer cases) and the most frequent etiology being viral infections (HBV and HCV). In 2020, mortality represented 92% of the incidence—830,180 deaths for 905,677 new cases. Few tre...

Background & Aims: Strategies to implement HBV screening and treatment are critical to achieve HBV elimination but have been inadequately evaluated in sub-Saharan Africa (sSA). Methods: We assessed the feasibility of screen-and-treat interventions in 3 real-world settings (community, workplace, and hospital) in Senegal. Adult participants were scre...

Introduction: Chronic infection with hepatitis B virus (HBV) is a leading cause of morbidity and death, especially in sub-Saharan Africa (sSSA), where approximately 60 million adults are infected. More than 90% of these patients are unaware of their HBV status. Areas covered: Scaling-up of HBV screening programs in SSA are essential to increase...

Hepatitis B virus (HBV) infection remains a global public health issue: a number of barriers still hamper the control of the HBV epidemic and in finding a cure for HBV [...]

Background Prevalence of occult hepatitis B infection (OBI) and its clinical outcomes have been poorly studied in Africa. Method Using the PROLIFICA cohort, we compared the prevalence of OBI between HBsAg-negative healthy adults screened from the general population (controls) and HBsAg-negative patients with advanced liver disease (cases) and esti...

Hepatitis B virus (HBV) contains a 3.2 kb DNA genome and causes acute and chronic hepatitis. HBV infection is a global health problem, with 350 million chronically infected people at increased risk of developing liver disease and hepatocellular carcinoma (HCC). Methylation of HBV DNA in a CpG context (5mCpG) can alter the expression patterns of vir...

The clinical utility of quantifying hepatitis B surface antigen (qHBsAg) levels in African subjects with chronic hepatitis B virus (HBV) infection has been poorly documented.From a multicenter cohort of 944 HBV‐infected African patients we aimed to assess whether qHBsAg alone can accurately identify i) those in a HBeAg‐negative chronic HBV infectio...

Hepatitis B virus (HBV) classification comprises up to 10 genotypes with specific geographical distribution worldwide, further subdivided into 40 subgenotypes, which have different impacts on liver disease outcome. Though extensively studied, the classification of subgenotype A sequences remains ambiguous. This study aimed to characterize HBV isola...

Background A promising avenue for cancer treatment is exacerbating the deregulation of the DNA repair machinery that would normally protect the genome. To address the applicability of poly(ADP-ribose) polymerase (PARP) inhibitors (PARPi) combined with radiotherapy for the treatment of hepatocellular carcinoma (HCC) two approaches were used: firstly...

Background and aims Sub-Saharan Africa (SSA) is the region with the most patients co-infected with the human immunodeficiency virus (HIV) and the hepatitis B virus (HBV) worldwide. However, few studies have focused on SSA children who are at a higher risk of developing a chronic infection than adults. Furthermore, children on first-line antiretrovi...

Hepatitis delta virus (HDV) is a defective human virus that lacks the ability to produce its own envelope proteins and is thus dependent on the presence of a helper virus, which provides its surface proteins to produce infectious particles. Hepatitis B virus (HBV) was so far thought to be the only helper virus described to be associated to HDV. How...

Background Although hepatitis B virus (HBV) is a major cause of death in Africa, its genetic variability has been poorly documented. This study aimed to address whether HBV genotype and surface gene variants are associated with HBV-related liver disease in The Gambia. Methods We conducted a case-control study nested in the PROLIFICA programme. Con...

Hepatitis B virus (HBV) chronic infection is responsible for almost 900.000 deaths each year, due to cirrhosis or hepatocellular carcinoma (HCC). Ten HBV genotypes have been described (A–J). HBV genotype F and H circulate in America. HBV genotypes have been further classified in subgenotypes. There is a strong correlation between the genetic admixt...

Methylation of viral DNA in a CpG context (5mCpG) can alter the expression patterns of viral genes related to infection and cellular transformation. Moreover, it may also provide clues to why certain infections are cleared, or persist with or without progression to cancer. The detection 5mCpG often requires techniques that damage DNA or introduce b...

A basic question linked to differential patterns of gene expression is how cells reach different fates despite using the same DNA template. Since 5-hydroxymethylcytosine (5hmC) emerged as an intermediate metabolite in active DNA demethylation, there have been increasing efforts to elucidate its function as a stable modification of the genome, inclu...

Hepatitis C virus (HCV) is still one of the main causes of liver disease worldwide. Metabolic disorders, including non-alcoholic fatty liver disease (NAFLD), induced by HCV have been shown to accelerate the progression of fibrosis to cirrhosis and to increase the risk of hepatocellular carcinoma. An optimal peroxisome proliferator-activated recepto...

Integration of HBV DNA into host chromosomes was found in most of the patients with chronic hepatitis B (CHB). In this study, using inverse nested PCR (invPCR), we found the integration site chrX: 111,009,033, which inserted into the p21-activated kinase 3 (PAK3) gene in HepG2.2.15 cells. The viral-human chimeric transcripts were also observed and,...

Purpose Trans-acting splicing factors (SF) shape the eukaryotic transcriptome by regulating alternative splicing (AS). This process is recurrently modulated in liver cancer suggesting its direct contribution to the course of liver disease. The aim of our study was to investigate the relationship between the regulation of SFs expression and liver da...

Despite the existence of an effective vaccine, HBV infects 257 million people worldwide and is the cause of the majority of HCC. With an annual mortality rate of 887 000 patients in 2015, this cancer is the second deadliest. Low-income countries such as ones in sub-Saharan Africa are the most at risk due to the limited access to healthcare. To over...

Background: To eliminate hepatitis B virus (HBV) infection, it is essential to scale up testing and treatment. However, conventional tools to assess treatment eligibility, particularly nucleic acid testing (NAT) to quantify HBV DNA, are hardly available and affordable in resource-limited countries. We therefore assessed the performance of novel im...

How cells reach different fates despite using the same DNA template, is a basic question linked to differential patterns of gene expression. Since 5-hydroxymethylcytosine (5hmC) emerged as an intermediate metabolite in active DNA demethylation, there have been increasing efforts to elucidate its function as a stable modification of the genome, incl...

Despite the existence of an effective vaccine, HBV infects 257 million people worldwide and is the cause of the majority of HCC. With an annual mortality rate of 887 000 patients in 2015, this cancer is the second deadliest. Low-income countries such as ones in sub-Saharan Africa are the most at risk due to the limited access to healthcare. To over...

Objectives: Toll-like receptor 9 (TLR9) plays a crucial role in the innate immune response against viral infections. The failure of this system may result, in an attenuated immune response against HBV. Recent research has focused on the possibility of targeting the defects in TLR9 pathway as a novel approach for anti-HBV treatment. Our study aimed...

Effective B cell responses such as cytokine secretion, proliferation, and Ab-specific responses are essential to clear hepatitis B virus (HBV) infection. However, HBV alters numerous immune pathways to persist in the host. B cell activity depends on activation of the innate sensor TLR9 by viral or bacterial DNA motifs. How HBV can deregulate B cell...

Background & aims: To eliminate hepatitis B virus (HBV) infection, it is essential to scale up antiviral treatment through decentralized services. However, access to the conventional tools to assess treatment eligibility (liver biopsy/Fibroscan®/HBV DNA) is limited and not affordable in resource-limited countries. We developed and validated a simp...

Chronic HBV infection affects more than 240 million people worldwide and is a major risk factor for developing cancer in which 10–30% of cases will progress towards liver cirrhosis and hepatocellular carcinoma. Infection outcome relies on the immune system maturity. Toll-like receptor 9 (TLR9) is a sensor of viral and bacterial DNA motifs and activ...

Hepatitis B virus (HBV) infection remains a major public health concern worldwide with 240 million individuals chronically infected and at risk of developing cirrhosis and hepatocellular carcinoma. Current treatments rarely cure chronic hepatitis B infection, highlighting the need for new anti-HBV drugs. Nucleic acid polymers (NAPs) are phosphoroth...

Infections with the human Hepatitis B (HBV) and Hepatitis D Virus (HDV) depend on species-specific host factors like the receptor human sodium taurocholate cotransporting polypeptide hNTCP. Complementation of mouse hepatocytes with hNTCP confers susceptibility to HDV but not HBV indicating the requirement of additional HBV-specific factors. As an e...

Despite the introduction of immunisation for hepatitis B virus (HBV) in the 1990s, HBV-related morbidity and mortality remain high in sub-Saharan Africa. Identification and treatment of asymptomatic people with chronic HBV infection should reduce the disease burden. We therefore assessed the feasibility of a screen-and-treat programme for HBV infec...

Hepatitis B virus (HBV) is a major cause of chronic liver disease worldwide. HBV infection is diagnosed by serological tests, while real-time polymerase chain reaction (qRT-PCR) assays are used to quantify viral load, which is a crucial parameter to determine viral replication and to monitor antiviral treatments. However, measuring viral load in re...

We previously showed that pre-treatment serum anti-E1E2 predicted hepatitis C virus (HCV) RNA viral kinetics (VKs) and treatment outcome in patients with chronic hepatitis C receiving pegylated interferon/ribavirin (Peg-IFN/RBV) double therapy. Here, we determined whether baseline anti-E1E2 was correlated with the on-treatment VK and could predict...

Background Hepatocellular carcinoma is the third cause of cancer related death for which new treatment strategies are needed. Targeting DNA repair pathways to sensitize tumor cells to chemo- or radiotherapy is under investigation for the treatment of several cancers with poly(ADP-ribose) polymerase (PARP) inhibitors showing great potential. The aim...

BACKGROUND: Morocco is one of low to intermediate endemic areas for hepatitis B virus (HBV) infection but no reports have been published on Occult HBV infection (OBI). AIMS: To determine the prevalence of OBI and its clinical impact among patients with cryptogenic and HCV-related chronic liver disease in Morocco. METHODS: A total of 152 HBsAg-negat...

Morocco is one of low to intermediate endemic areas for hepatitis B virus (HBV) infection but no reports have been published on Occult HBV infection (OBI). To determine the prevalence of OBI and its clinical impact among patients with cryptogenic and HCV-related chronic liver disease in Morocco. A total of 152 HBsAg-negative patients (60 patients w...

Unlabelled: Despite a high prevalence of hepatitis B virus (HBV) infection in endangered apes, no HBV infection has been reported in small, old-world monkeys. In search for a small, nonhuman primate model, we investigated the prevalence of HBV infection in 260 macaque (Cercopithecidae) sera of various geographical origins (i.e., Morocco, Mauritius...

Unique serum anti-E1E2 antibodies were shown to be associated with spontaneous recovery or predictive of sustained virological response (SVR) in patients with chronic hepatitis C receiving pegylated-interferon/ribavirin (PEG-IFN/RBV) therapy. The objectives were (1) to establish the relationship between pretreatment anti-E1E2 titers and HCV RNA kin...

Hepatocellular carcinoma is the most common form of primary liver cancer which is the fifth most common cancer in men and the seventh in women and the third most common cause of cancer-related death worldwide. Only 10-20% of patients are eligible for curative treatments that result in a 5-year survival rate of 40% to 70%. Therefore, the development...

For functional analysis of HBV isolates, epidemiological studies and correct identification of recombinant genomes, the amplification of complete genomes is necessary. A method for completely in vitro amplification of full-length HBV genomes starting from serum RC-DNA is described. This uses in vitro completion/ligation of plus-strand HBV RC-DNA an...

Background: The potential reservoir role of serum and peripheral blood mononuclear cells (PBMCs) for total HBV DNA (tDNA) and cccDNA still remains unknown. Material and methods: We analyzed tDNA and cccDNA with a single sensitive and validated standardized real-time PCR method in serum and PBMCs in two populations of chronic HBV infection coinfe...

In regions with high prevalence of chronic hepatitis B virus (HBV) infection and dietary aflatoxin B(1) (AFB(1)) exposure, hepatocellular carcinomas (HCCs) often contain TP53 mutation at codon 249 (R249S). Furthermore, a C-terminal truncated HBx protein expressed from hepatocyte integrated HBV is associated with HCC development. This study evaluate...

A number of risk factors appear to play a role in hepatocellular carcinoma (HCC), hepatitis B infection being one of the most important. Hepatitis B surface antigen (HBsAg) is the hallmark of hepatitis B virus (HBV) since it is the best and most reliable diagnostic marker. However, since most studies do not rely on longitudinal observations but mos...

Hepatitis B virus (HBV) is one of the most common human pathogens that cause aggressive hepatitis and advanced liver disease (AdLD), including liver cirrhosis and Hepatocellular Carcinoma. The persistence of active HBV replication and liver damage after the loss of hepatitis B e antigen (HBeAg) has been frequently associated with mutations in the p...

Genotypes/Subgenotypes and GenBank accession numbers for the HBV reference sequences used in this study. (DOC)

The Wnt pathway is a key regulator of embryonic development and stem cells, and its aberrant activation is associated with human malignancies, most notably hepatocellular carcinoma (HCC). Epigenetic deregulation of the genes encoding the secreted frizzled-related proteins (sFRPs), the Wnt signalling antagonists, has been linked with aberrant hypera...

In regions with high prevalence of chronic hepatitis B virus (HBV) infection and dietary aflatoxin B(1) (AFB(1)) exposure, hepatocellular carcinomas (HCCs) often contain TP53 mutation at codon 249 (R249S). Furthermore, a C-terminal truncated HBx protein expressed from hepatocyte integrated HBV is associated with HCC development. This study evaluate...

Primary human liver cancer, of which hepatocellular carcinoma (HCC) is by far the predominant type, is a major cause of cancer death worldwide, accounting for 700,000 deaths per year. The epidemiology of HCC is particular with both geographic and temporal patterns of incidence paralleling exposure to viral etiologic factors. The highest HCC inciden...

Occult hepatitis B infection (OBI) is characterized by the presence of hepatitis B virus (HBV) DNA in the absence of HBsAg in the serum of patients. The aim of this study was to characterize HBV infection among a Piaroa community, an Amerindian group which exhibits significant evidence of exposure to HBV but relatively low presence of HBsAg, and to...

Infection by hepatitis B virus (HBV) and dietary exposure to aflatoxin B(1) (AFB(1)) are the main risk factors for the development of chronic liver disease and hepatocellular carcinoma (HCC). How these factors cooperate is still largely unknown. AFB(1) activation leads to DNA adduction and mutagenesis, with a specific mutation at codon 249 in TP53...

Suppressed IFN-α production is not caused by increased pDC apoptosis. pDCs were treated with CpG 2216 ± HBV at MOI 100 or 50 for 12h. Cells were stained with Annexin VFITC by flow cytometry and percentages in gate R1 represent early apoptotic pDCs. (TIF)

Over-expression of IRF7 in HEK293 cells leads to IFNα4 promoter activation. Cells were co-transfected with IFNα4-pGL3 reporter plasmid together with the indicated plasmids. After 48h luciferase assay was assessed as described previously [20] . (TIF)

HBV does not impair TLR7-induced IFN-α and does not modulate TLR7 transcripts. pDCs were stimulated with TLR7 ligand loxoribine (Lox) at 1mM (A) or TLR7/8 ligand resiquimod (Res) at 1µM (B) ±HBV at MOI 50 or 100. Supernatants were collected after 24h and tested for IFN-α (pg/ml) by ELISA. Experiments were performed on cells isolated from 3 differen...

Plasmacytoid dendritic cells (pDCs) play a key role in detecting pathogens by producing large amounts of type I interferon (IFN) by sensing the presence of viral infections through the Toll-Like Receptor (TLR) pathway. TLR9 is a sensor of viral and bacterial DNA motifs and activates the IRF7 transcription factor which leads to type I IFN secretion...

The aim of this study was to determine the prevalence of Hepatitis B Virus (HBV) genotypes, subgenotypes, HBV surface antigen (HBsAg) subtypes and naturally occurring mutations in Major Hydrophilic region (MHR) of HBsAg among Moroccan patients with chronic HBV infection. The study included 200 patients chronically infected with HBV. The HBV genotyp...