Update on Hepatitis B Virus Infection: Focus on Treatment

Hepatitis B and C screening needs among different ethnic groups: A population-based study in Amsterdam, the Netherlands

Data on the prevalence of chronic hepatitis B (HBV) and hepatitis C (HCV) virus infections, including the proportion of individuals aware of infection, are scarce among migrants living in Europe. We estimated the prevalence of past and present HBV and HCV infection, along with their determinants and peoples' awareness of infection status, among different groups of first-generation migrants and Dutch-origin residents of Amsterdam.

METHODS

Cross-sectional data of 998 Surinamese (mostly South-Asian and African-Surinamese), 500 Ghanaian, 497 Turkish, 498 Moroccan and 500 Dutch-origin participants from the observational population-based HELIUS study were used. Blood samples of participants were tested for HBV and HCV infection. Infection awareness was determined using records from participants' general practitioners.

RESULTS

Age- and gender-adjusted chronic HBV prevalence was highest among Ghanaian participants (5.4%), followed by Turkish (4.1%), African-Surinamese (1.9%), Moroccan (1.2%), South-Asian Surinamese (0.9%) and Dutch (0.4%) participants. A total of 58.1% of the cases were aware of their infection. In multinomial logistic regression analyses, Ghanaian (adjusted odds ratio [aOR] 42.23; 95% confidence interval [CI] 9.29-192.01), African-Surinamese (aOR 6.16; 95% CI 1.27-29.79), and Turkish (aOR 13.44; 95% CI 2.94-61.39) participants were at increased risk of chronic HBV infection compared with those of Dutch origin. Older participants were also at increased risk (aOR 1.02 per year; 95% CI 1.00-1.05), whereas women were at lower risk (aOR 0.49; 95% CI 0.29-0.83). HCV prevalence was 0.4% (95% CI 0.1-1.3%) among Dutch and African-Surinamese and 0% (95% CI 0.0-0.5%) for each of the other groups; all cases with follow-up data were aware of their infection.

CONCLUSIONS

Ghanaian, Turkish and African-Surinamese first-generation migrants are at increased risk of chronic HBV infection and many are unaware of their infection, whereas HCV prevalence was low among all ethnic groups. Screening campaigns are urgently warranted and need to consider specific ethnic groups.

LAY SUMMARY

First-generation migrants of Ghanaian, Turkish and African-Surinamese origin were at increased risk of chronic hepatitis B infection, with most infections occurring in older individuals and males. Since over 40% of people were unaware of their chronic hepatitis B infection, screening of these migrant groups is urgently needed. The proportion of first-generation migrants chronically infected with hepatitis C virus was very low among all groups studied.

Design and Synthesis of Orally Bioavailable 4-Methyl Heteroaryldihydropyrimidine Based Hepatitis B Virus (HBV) Capsid Inhibitors

Targeting the capsid protein of hepatitis B virus (HBV) and thus interrupting normal capsid formation have been an attractive approach to block the replication of HBV viruses. We carried out multidimensional structural optimizations based on the heteroaryldihydropyrimidine (HAP) analogue Bay41-4109 (1) and identified a novel series of HBV capsid inhibitors that demonstrated promising cellular selectivity indexes, metabolic stabilities, and in vitro safety profiles. Herein we disclose the design, synthesis, structure-activity relationship (SAR), cocrystal structure in complex with HBV capsid proteins and in vivo pharmacological study of the 4-methyl HAP analogues. In particular, the (2S,4S)-4,4-difluoroproline substituted analogue 34a demonstrated high oral bioavailability and liver exposure and achieved over 2 log viral load reduction in a hydrodynamic injected (HDI) HBV mouse model.

CRISPR/Cas9-based tools for targeted genome editing and replication control of HBV

Hepatitis B virus (HBV) infection remains a major global health problem because current therapies rarely eliminate HBV infections to achieve a complete cure. A different treatment paradigm to effectively clear HBV infection and eradicate latent viral reservoirs is urgently required. In recent years, the development of a new RNA-guided gene-editing tool, the CRISPR/Cas9 (clustered regularly interspaced short palindromic repeats/CRISPR-associated nuclease 9) system, has greatly facilitated site-specific mutagenesis and represents a very promising potential therapeutic tool for diseases, including for eradication of invasive pathogens such as HBV. Here, we review recent advances in the use of CRISPR/Cas9, which is designed to target HBV specific DNA sequences to inhibit HBV replication and to induce viral genome mutation, in cell lines or animal models. Advantages, limitations and possible solutions, and proposed directions for future research are discussed to highlight the opportunities and challenges of CRISPR/Cas9 as a new, potentially curative therapy for chronic hepatitis B infection.