Investigational drugs in development for Hepatitis D

Migratory flow and hepatitis delta infection in Italy: A new challenge at the beginning of the third millennium

In Italy, HDV infection endemicity has greatly decreased overtime. Migratory flow may change this scenario as migrants often come from high HDV endemicity areas. Here, we studied characteristics of HDV infection in Italy, particularly addressed to the birth area of subjects. Chronic HBsAg carriers consecutively referring to 9 units in Italy prospectively enrolled for a six-month period in 2019 were tested for anti-HDV by ELISA. Multiple logistic regression analysis was performed to identify anti-HDV positivity independent predictors. A total of 894 HBsAg-positive subjects were enrolled. Of them, 786 (87.9%) were tested for anti-HDV. Anti-HDV overall prevalence was 9.9% (6.4% in Italian natives and 26.4% in non-natives; P < .001). HDV-RNA was checked in 63 (80.8%) of the 78 anti-HDV+ subjects, and 49 (77.8%) tested positive. Compared to non-natives, Italians were more likely males (male/female 1.6 vs 0.6; P < .05) and older (median age 57 years vs 46 years; P < .05). Multivariate analysis showed that non-natives (OR = 6.02; CI 95% = 3.06-11.84) and cirrhosis (OR 9.6; CI 95% = 5.39-17.30) were independently associated with anti-HDV positivity. A remarkable changing pattern in some characteristics of anti-HDV-positive subjects was observed over 1987-2019: a decreasing male/female ratio, an increasing mean age and proportion of cirrhotic subjects. Anti-HDV prevalence decreased from 7.4% to 6.4% among Italians, increasing from 12.2% to 26.4% among non-natives during 2001-2019. Hence, HDV infection in Italians is further decreasing and mostly affects old people and subjects with advanced disease reflecting a survival effect. Conversely, non-natives are sixfold more likely anti-HDV-positive with an increasing trend. Migratory flow may be a new challenge for HDV infection at the beginning of the third millennium.

Hepatitis B Virus: Advances in Prevention, Diagnosis, and Therapy

Currently, despite the use of a preventive vaccine for several decades as well as the use of effective and well-tolerated viral suppressive medications since 1998, approximately 250 million people remain infected with the virus that causes hepatitis B worldwide. Hepatitis C virus (HCV) and hepatitis B virus (HBV) are the leading causes of liver cancer and overall mortality globally, surpassing malaria and tuberculosis. Linkage to care is estimated to be very poor both in developing countries and in high-income countries, such as the United States, countries in Western Europe, and Japan. In the United States, by CDC estimates, only one-third of HBV-infected patients or less are aware of their infection. Some reasons for these low rates of surveillance, diagnosis, and treatment include the asymptomatic nature of chronic hepatitis B until the very late stages, a lack of curative therapy with a finite treatment duration, a complex natural history, and a lack of knowledge about the disease by both care providers and patients. In the last 5 years, more attention has been focused on the important topics of HBV screening, diagnosis of HBV infection, and appropriate linkage to care. There have also been rapid clinical developments toward a functional cure of HBV infection, with novel compounds currently being in various phases of progress. Despite this knowledge, many of the professional organizations provide guidelines focused only on specific questions related to the treatment of HBV infection. This focus leaves a gap for care providers on the other HBV-related issues, which include HBV's epidemiological profile, its natural history, how it interacts with other viral hepatitis diseases, treatments, and the areas that still need to be addressed in order to achieve HBV elimination by 2030. Thus, to fill these gaps and provide a more comprehensive and relevant document to regions worldwide, we have taken a global approach by using the findings of global experts on HBV as well as citing major guidelines and their various approaches to addressing HBV and its disease burden.

Combined small molecule and loss-of-function screen uncovers estrogen receptor alpha and CAD as host factors for HDV infection and antiviral targets

OBJECTIVE

Hepatitis D virus (HDV) is a circular RNA virus coinfecting hepatocytes with hepatitis B virus. Chronic hepatitis D results in severe liver disease and an increased risk of liver cancer. Efficient therapeutic approaches against HDV are absent.

DESIGN

Here, we combined an RNAi loss-of-function and small molecule screen to uncover host-dependency factors for HDV infection.

RESULTS

Functional screening unravelled the hypoxia-inducible factor (HIF)-signalling and insulin-resistance pathways, RNA polymerase II, glycosaminoglycan biosynthesis and the pyrimidine metabolism as virus-hepatocyte dependency networks. Validation studies in primary human hepatocytes identified the carbamoyl-phosphatesynthetase 2, aspartate transcarbamylase and dihydroorotase (CAD) enzyme and estrogen receptor alpha (encoded by ESR1) as key host factors for HDV life cycle. Mechanistic studies revealed that the two host factors are required for viral replication. Inhibition studies using N-(phosphonoacetyl)-L-aspartic acid and fulvestrant, specific CAD and ESR1 inhibitors, respectively, uncovered their impact as antiviral targets.

CONCLUSION

The discovery of HDV host-dependency factors elucidates the pathogenesis of viral disease biology and opens therapeutic strategies for HDV cure.

High prevalence of hepatitis delta virus in Cameroon

Hepatitis delta virus (HDV), a satellite virus of hepatitis B virus (HBV), infects an estimated 15–20 million people worldwide and confers a greater risk for accelerated progression to liver disease. However, limited HDV surveillance data are available in sub-Saharan Africa where HDV diversity is high. To determine the prevalence and diversity of HDV in Cameroon, serological and molecular characterization was performed on 1928 HBsAg positive specimens selected from retrospective viral surveillance studies conducted in Cameroon from 2010–2016. Samples were screened for HDV antibodies on the Abbott ARCHITECT instrument and for HDV RNA on the Abbott m2000 instrument by research assays. HDV positive specimens with sufficient viral load were selected for genomic sequencing. The seroprevalence of HDV in HBsAg positive samples from Cameroon was 46.73% [95% CI; 44.51–48.96%], with prevalence of active HDV infection being 34.2% [95% CI; 32.09–36.41%]. HDV genotypes 1, 6, 7 and 8 were identified amongst N = 211 sequences, including N = 145 genomes. HDV prevalence is high within the study cohort, indicating that a large portion of HBV infected individuals in Cameroon are at elevated risk for severe hepatitis and death. Collectively, these results emphasize the need for HBV vaccination and HDV testing in HBsAg positive patients in Cameroon.