Role of hepatitis D virus infection in development of hepatocellular carcinoma among chronic hepatitis B patients treated with nucleotide/nucleoside analogues

Role of Air Pollution in Development of Hepatocellular Carcinoma Among Chronic Hepatitis B Patients Treated With Nucleotide/Nucleoside Analogues

BACKGROUND AND AIMS

To investigate the association between air pollution and hepatocellular carcinoma (HCC) in chronic hepatitis B (CHB) patients treated with nucleotide/nucleoside analogues.

METHODS

We enrolled 1298 CHB patients treated with nucleotide/nucleoside analogues and analysed the incidence and risk factors for HCC. Daily estimates of air pollutants were estimated since the previous year from the enrolment date.

RESULTS

The annual incidence of HCC was 2.1/100 person-years after a follow-up period of over 4840.5 person-years. Factors with the strongest association with HCC development were liver cirrhosis (hazard ratio [HR]/95% confidence interval [CI]: 3.00/1.55-5.81; p = 0.001), male sex (2.98/1.51-5.90; p = 0.02), body mass index (1.11/1.04-1.18; p = 0.002) and age (1.06/1.04-1.09; p < 0.001). Among patients with cirrhosis, the factors associated with HCC development were male sex (HR/95% CI: 2.10/1.00-4.25; p = 0.04) and NO2 (per one-unit increment, parts per billion; 1.07/1.01-1.13; p = 0.01). Moreover, patients with the highest quartile of annual NO2 exposure had more than a three-fold risk of HCC than those with the lowest quartile of annual exposure (HR/95% CI: 3.26/1.34-7.93; p = 0.01). Among patients without cirrhosis, the strongest factors associated with HCC development were male sex (HR/95% CI: 5.86/1.79-19.23; p = 0.004), age (1.12/1.07-1.17; p < 0.001) and platelet count (0.99/0.98-1.00; p = 0.04).

CONCLUSIONS

Air pollution influences HCC development in CHB patients who receive nucleotide/nucleoside analogue therapy. Long-term NO2 exposure might accelerate HCC development in CHB patients with cirrhosis receiving nucleotide/nucleoside analogue treatment.

Air Pollution Associated With Mortality Among Chronic Hepatitis B Patients Treated With Nucleotide/Nucleoside Analogues

BACKGROUND AND AIMS

Air pollution is associated with advanced liver fibrosis in patients with chronic liver diseases, including chronic hepatitis B (CHB). This study aimed to investigate the association between air pollution and mortality in patients with CHB treated with nucleotide/nucleoside analogues.

METHODS

We enrolled 697 patients with CHB treated with nucleotide/nucleoside analogues and analysed the incidence and risk factors for mortality. Daily air pollutant concentrations were estimated from the year before enrolment.

RESULTS

All-cause mortality showed an annual incidence of 1.1/100 person-years after a follow-up period of 3798.1 person-years. Factors with the strongest association with all-cause mortality were liver cirrhosis (hazard ratio [HR]/95% confidence interval [CI]: 3.95/1.69-9.23; p = 0.02), age ([HR]/CI: 1.07/1.03-1.17, p < 0.001) and pre-treatment gamma-glutamyl transferase (GGT) levels (HR/CI: 1.004/1.001-1.006, p = 0.004). Among patients with cirrhosis, the factors associated with all-cause mortality were age (HR/CI: 1.08/1.04-1.12, p < 0.001), pre-treatment GGT levels (HR/CI: 1.004/1.001-1.008, p = 0.01), platelet count (HR/CI: 0.988/0.977-0.998, p = 0.02) and NOx concentration (per unit increment, ppb) (1.045/1.001-1.091; p = 0.046). The best NOx cut-off value for predicting all-cause mortality in patients with cirrhosis was 25.5 ppb (AUROC 0.63; p = 0.03). NOx levels > 25.5 ppb were associated with a higher incidence of mortality in patients with cirrhosis (HR/CI:2.49/1.03-6.02; p = 0.04).

CONCLUSIONS

Air pollution influences all-cause mortality in patients with CHB receiving nucleotide/nucleoside analogue therapy. Long-term NOx exposure may increase liver-related mortality in patients with chronic hepatitis B and cirrhosis receiving nucleotide/nucleoside analogue treatment.

Multisociety consensus recommendations on hepatitis delta virus infection

ABSTRACT

Hepatitis D virus (HDV) prevalence data and country-specific HDV guidelines are not widely available in the Gulf Cooperation Council (GCC) states. We developed consensus recommendations to guide healthcare professionals, policymakers, and researchers in improving HDV management and patient health outcomes in three GCC states: Kuwait, Saudi Arabia, and the United Arab Emirates. A consensus panel comprising hepatology experts (n = 6) from the three GCC societies was formed. The panel identified two broader areas related to clinical practice (screening and diagnosis, and treatment and management), addressed critical questions, and developed draft recommendations in February 2024. The strength of the final set of recommendations was subjected to consensus voting in March 2024. A majority was defined apriori with a two-thirds vote (67%). The paper outlines those recommendations alongside showcasing the current epidemiology of HDV in the GCC states, emphasizing the variability in prevalence, demographic patterns, and region-specific risk factors. It also highlights the current state of screening and diagnosis practices, identifying key obstacles, such as access to advanced screening protocols and diagnostic tools. Furthermore, HDV treatment landscape and preventative strategies are outlined, focusing on vaccination, public health initiatives, and the crucial role of public awareness and education. Ethical and sociocultural considerations are discussed, underscoring the importance of culturally sensitive healthcare practices. These recommendations present a comprehensive overview of the challenges and strategies for managing HDV in these states. Policy recommendations are provided to support HDV management, including standardizing care protocols and promoting public health measures.

Epidemiological, diagnostic, therapeutic and prognostic impact of hepatitis B and D virus infection on hepatocellular carcinoma: A review of the literature

BACKGROUND

Hepatocellular carcinoma (HCC) accounts for >90% of primary liver cancer cases, and chronic infections with hepatitis B virus (HBV) and hepatitis D virus (HDV) are major contributors.

METHODS

A comprehensive literature review was conducted using the MEDLINE (PubMed) database, focusing on studies related to HBV, HDV, and HCC.

RESULTS

HBV contributes to HCC through mechanisms like viral integration into the host genome, chronic inflammation, and immune modulation, leading to genomic instability and altered cell signaling. HDV exacerbates HBV-induced liver damage, accelerating fibrosis and cirrhosis, and significantly increasing HCC risk. Antiviral therapies and vaccinations have majorly reduced the burden of HBV-related HCC, but HDV remains challenging to treat due to limited therapeutic options. Emerging treatments like Bulevirtide showed promising results.

CONCLUSION

This review highlights the critical impact of HBV and HDV co-infections on HCC development, emphasizing the need for more effective therapeutic strategies. While advances in antiviral therapies have reduced the incidence of HBV-related HCC, the high burden of HDV-related complications persists. Future research should focus on improving treatments for HDV and understanding its unique contribution to HCC pathogenesis.

The Changing Face of Hepatitis Delta Virus Associated Hepatocellular Carcinoma

Hepatitis delta virus (HDV) infection requires the presence of hepatitis B virus (HBV), and chronic HBV-HDV coinfection is considered the most severe form of viral hepatitis. When compared with HBV mono-infection, HBV-HDV coinfection is associated with higher rates of liver cirrhosis and hepatocellular carcinoma (HCC). In this review, we aim to elucidate the complex relationship between HDV infection and the development of HCC. The exact mechanisms underlying the carcinogenic potential of HDV remain to be fully elucidated. Evidence suggests that HDV has both indirect and direct oncogenic effects. Indirect effects promote accelerated progression to liver cirrhosis, which results in a different tumor microenvironment. Direct oncogenic effects are suggested by a distinct molecular signature. The recent epidemiological data regarding HBV-HDV coinfection should make us reconsider the HCC screening strategy, with special focus in younger non-cirrhotic patients. Finally, treating HCC in patients with chronic HDV poses unique challenges due to the complex interplay between HBV and HDV and the severity of liver disease. An in-depth understanding of the epidemiology and pathophysiology of HDV infection and carcinogenesis is essential to improve disease management in this high-risk population.

Hepatitis B surface antigen loss in chronic hepatitis B patients with low-viral-load

BACKGROUND AND AIM

Among low viral load (DNA of hepatitis B virus (HBV) was < 2000 IU/mL), the factor of the loss of hepatitis B surface antigen (HBsAg) remained elusive.

METHODS

The retrospective study recruited patients with chronic hepatitis B (CHB) who were negative low for hepatitis B e-antigen (HBeAg), had a low viral load, and experienced HBsAg loss during follow-up. CHB patients with low-viral load but without consequent HBsAg loss were also enrolled at the ratio of 1:4. The factors contributing to HBsAg loss were analyzed.

RESULTS

A total of 80 patients were recruited for the current study, with a mean age of 63.9 years and 61.3% being male. Among them, 62.5% patients (50/80) were treated with potent nucleoside/nucleotide analogues (NAs) during the follow-up period. Additionally, 12.5% patients (10/80) had a prior history of NAs treatment before enrolment. During the follow-up, HBsAg loss occurred in 17 patients (21.3%). Compared with patients without HBsAg loss, those with HBsAg loss were younger (57.9 years vs 65.5 years; P = 0.01), had lower HBV DNA levels (1.3 log10 IU/mL vs 2.3 log10 IU/mL; P = 0.003), and higher proportion of prior NAs-treated history. Logistic regression analysis revealed that the factors associated with factors associated with HBsAg loss were age < 60 years (OR/CI: 3.95/1.15-13.60, P = 0.03), prior NAs-treated history (OR/CI: 7.59/1.42-40.51, P = 0.01) and current NAs-treated (OR/CI: 0.19/0.05-0.71, P = 0.01).

CONCLUSIONS

In the study, older age and prior NAs were positively associated with HBsAg loss, and current NAs was negatively associated with HBsAg loss. Additionally, some patients experienced HBsAg loss during the NAs therapy.

Characteristics and outcome of anti-hepatitis D virus positive patients with hepatocellular carcinoma

BACKGROUND & AIMS

Chronic hepatitis D virus (HDV) often leads to end-stage liver disease and hepatocellular carcinoma (HCC). Comprehensive data pertaining to large populations with HDV and HCC are missing, therefore we sought to assess the characteristics, management, and outcome of these patients, comparing them to patients with hepatitis B virus (HBV) infection.

METHODS

We analysed the Italian Liver Cancer database focusing on patients with positivity for HBV surface antigen and anti-HDV antibodies (HBV/HDV, n = 107) and patients with HBV infection alone (n = 588). Clinical and oncological characteristics, treatment, and survival were compared in the two groups.

RESULTS

Patients with HBV/HDV had worse liver function [Model for End-stage Liver Disease score: 11 vs. 9, p < .0001; Child-Turcotte-Pugh score: 7 vs. 5, p < .0001] than patients with HBV. HCC was more frequently diagnosed during surveillance (72.9% vs. 52.4%, p = .0002), and the oncological stage was more frequently Milan-in (67.3% vs. 52.7%, p = .005) in patients with HBV/HDV. Liver transplantation was more frequently performed in HBV/HDV than in HBV patients (36.4% vs. 9.5%), while the opposite was observed for resection (8.4% vs. 20.1%, p < .0001), and in a competing risk analysis, HBV/HDV patients had a higher probability of receiving transplantation, independently of liver function and oncological stage. A trend towards longer survival was observed in patients with HBV/HDV (50.4 vs. 44.4 months, p = .106).

CONCLUSIONS

In patients with HBV/HDV, HCC is diagnosed more frequently during surveillance, resulting in a less advanced cancer stage in patients with more deranged liver function than HBV alone. Patients with HBV/HDV have a heightened benefit from liver transplantation, positively influencing survival.

Association of hepatitis delta virus with liver morbidity and mortality: A systematic literature review and meta-analysis

BACKGROUND AND AIMS

Studies have suggested that patients with chronic hepatitis B, either co- or superinfected, have more aggressive liver disease progression than those with the HDV. This systematic literature review and meta-analysis examined whether HDV RNA status is associated with increased risk of advanced liver disease events in patients who are HBsAg and HDV antibody positive.

APPROACH AND RESULTS

A total of 12 publications were included. Relative rates of progression to advanced liver disease event for HDV RNA+/detectable versus HDV RNA-/undetectable were extracted for analysis. Reported OR and HRs with 95% CI were pooled using the Hartung-Knapp-Sidik-Jonkman method for random-effects models. The presence of HDV RNA+ was associated with an increased risk of any advanced liver disease event [random effect (95% CI): risk ratio: 1.48 (0.93, 2.33); HR: 2.62 (1.55, 4.44)]. When compared to the patients with HDV RNA- status, HDV RNA+ was associated with a significantly higher risk of progressing to compensated cirrhosis [risk ratio: 1.74 (1.24, 2.45)] decompensated cirrhosis [HR: 3.82 (1.60, 9.10)], HCC [HR: 2.97 (1.87, 4.70)], liver transplantation [HR: 7.07 (1.61, 30.99)], and liver-related mortality [HR: 3.78 (2.18, 6.56)].

CONCLUSIONS

The patients with HDV RNA+ status have a significantly greater risk of liver disease progression than the patients who are HDV RNA-. These findings highlight the need for improved HDV screening and linkage to treatment to reduce the risk of liver-related morbidity and mortality.

Hepatitis Delta Virus and Hepatocellular Carcinoma

The hepatitis D virus (HDV) is a compact, enveloped, circular RNA virus that relies on hepatitis B virus (HBV) envelope proteins to initiate a primary infection in hepatocytes, assemble, and secrete new virions. Globally, HDV infection affects an estimated 12 million to 72 million people, carrying a significantly elevated risk of developing cirrhosis, liver failure, and hepatocellular carcinoma (HCC) compared to an HBV mono-infection. Furthermore, HDV-associated HCC often manifests at a younger age and exhibits more aggressive characteristics. The intricate mechanisms driving the synergistic carcinogenicity of the HDV and HBV are not fully elucidated but are believed to involve chronic inflammation, immune dysregulation, and the direct oncogenic effects of the HDV. Indeed, recent data highlight that the molecular profile of HCC associated with HDV is unique and distinct from that of HBV-induced HCC. However, the question of whether the HDV is an oncogenic virus remains unanswered. In this review, we comprehensively examined several crucial aspects of the HDV, encompassing its epidemiology, molecular biology, immunology, and the associated risks of liver disease progression and HCC development.

Progression of liver disease and associated risk of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the primary liver cancer type, often seen in individuals with chronic liver disease. Once the patient progresses to the cirrhotic stage, the annual incidence of HCC is approximately 2%-4%. As it exceeds the minimum threshold of 1.0%-1.5% per year, HCC screening every 6 months through abdominal ultrasound is indicated in the cirrhotic population. While the incidence of viral hepatitis-associated HCC is decreasing, there is a notable rise of HCC associated with metabolic dysfunction-related steatotic liver disease and alcohol-related liver disease, particularly in high-income countries. The most effective approach for oncological prevention remains addressing the cause of liver disease. The indications for HCC screening in patients without cirrhosis depend on the etiology of liver disease and the stage of fibrosis, assessed by liver biopsy or noninvasive tests such as FIB-4 or transient elastography. However, clear recommendations for HCC screening in patients without cirrhosis and for the different etiologies are currently unavailable. Research efforts should focus on identifying markers, or combinations thereof, to provide a more accurate estimate of HCC occurrence. Such advancements would enable the effective targeting of populations at the highest risk of HCC and the establishment of the correct timing to start the screening.

Air pollution as a potential risk factor for hepatocellular carcinoma in Taiwanese patients after adjusting for chronic viral hepatitis

BACKGROUND

Air pollution is a risk factor for hepatocellular carcinoma (HCC). However, the effect of air pollution on HCC risk in patients with hepatitis remains unclear.

METHODS

This cross-sectional study recruited 348 patients with chronic hepatitis who were tested for serum hepatitis B surface antigen (HBsAg) and for antibodies against hepatitis B core antigen (HBcIgG) and hepatitis C virus (anti-HCV) in 2022. The diagnosis of HCC was based on the International Classification of Diseases, 10th revision (ICD-10). Daily estimates of air pollutants were aggregated into mean estimates for the previous year based on the date of recruitment or HCC diagnosis.

RESULTS

Out of 348 patients, 12 had HCC (3.4%). Patients with HCC were older (71.7 vs 50.9 years; p = 0.004), had higher proportion of HBsAg seropositivity (41.7% vs 5.1%; p < 0.001), and substantially higher levels of particulate matter 2.5 (PM 2.5 ) (21.5 vs 18.2 μg/m 3 ; p = 0.05). Logistic regression analysis revealed that the factors associated with HCC were age (odds ratio [OR]: 1.10; CI, 1.03-1.17; p = 0.01), PM 2.5 level (OR: 1.51; CI, 1.02-2.23; p = 0.04), and HBsAg seropositivity (OR: 6.60; CI, 1.51-28.85; p = 0.01) ( Table 3 ). There was a combined effect of PM 2.5 and HBsAg seropositivity on the risk of HCC development (OR: 22.17; CI, 3.33-147.45; p = 0.001).

CONCLUSION

In this study, we demonstrated that PM 2.5 and HBsAg seropositivity were associated with HCC occurrence and had synergistic effects after adjusting for confounding factors.

Review of Related Factors for Persistent Risk of Hepatitis B Virus-Associated Hepatocellular Carcinoma

Chronic hepatitis B virus (HBV) infection is the largest global cause of hepatocellular carcinoma (HCC). Current HBV treatment options include pegylated interferon-alpha and nucleos(t)ide analogues (NAs), which have been shown to be effective in reducing HBV DNA levels to become undetectable. However, the literature has shown that some patients have persistent risk of developing HCC. The mechanism in which this occurs has not been fully elucidated. However, it has been discovered that HBV's covalently closed circular DNA (cccDNA) integrates into the critical HCC driver genes in hepatocytes upon initial infection; additionally, these are not targets of current NA therapies. Some studies suggest that HBV undergoes compartmentalization in peripheral blood mononuclear cells that serve as a sanctuary for replication during antiviral therapy. The aim of this review is to expand on how patients with HBV may develop HCC despite years of HBV viral suppression and carry worse prognosis than treatment-naive HBV patients who develop HCC. Furthermore, HCC recurrence after initial surgical or locoregional treatment in this setting may cause carcinogenic cells to behave more aggressively during treatment. Curative novel therapies which target the life cycle of HBV, modulate host immune response, and inhibit HBV RNA translation are being investigated.

Five-year follow-up of 96 weeks peginterferon plus tenofovir disoproxil fumarate in hepatitis D

BACKGROUND & AIMS

Until recently, pegylated interferon-alfa-2a (PEG-IFNa) therapy was the only treatment option for patients infected with hepatitis D virus (HDV). Treatment with PEG-IFNa with or without tenofovir disoproxil fumarate (TDF) for 96 weeks resulted in HDV RNA suppression in 44% of patients at the end of therapy but did not prevent short-term relapses within 24 weeks. The virological and clinical long-term effects after prolonged PEG-IFNa-based treatment of hepatitis D are unknown.

METHODS

In the HIDIT-II study patients (including 40% with liver cirrhosis) received 180 μg PEG-IFNa weekly plus 300 mg TDF once daily (n = 59) or 180 μg PEG-IFNa weekly plus placebo (n = 61) for 96 weeks. Patients were followed until week 356 (5 years after end of therapy).

RESULTS

Until the end of follow-up, 16 (13%) patients developed liver-related complications (PEG-IFNa + TDF, n = 5 vs PEG-IFNa + placebo, n = 11; p = .179). Achieving HDV suppression at week 96 was associated with decreased long-term risk for the development of hepatocellular carcinoma (p = .04) and hepatic decompensation (p = .009). Including complications irrespective of PEG-IFNa retreatment status, the number of patients developing serious complications was similar with (3/18) and without retreatment with PEG-IFNa (16/102, p > .999) but was associated with a higher chance of HDV-RNA suppression (p = .024, odds ratio 3.9 [1.3-12]).

CONCLUSIONS

Liver-related clinical events were infrequent and occurred less frequently in patients with virological responses to PEG-IFNa treatment. PEG-IFNa treatment should be recommended to HDV-infected patients until alternative therapies become available. Retreatment with PEG-IFNa should be considered for patients with inadequate response to the first course of treatment.

CLINICAL TRIAL REGISTRATION

NCT00932971.

Hepatitis E virus infection and risk of hepatocellular carcinoma: A systematic review and meta-analysis

BACKGROUND

The potential role of hepatitis E virus (HEV) infection in developing hepatocellular carcinoma (HCC) is controversial and poorly investigated. We conducted a meta-analysis of observational studies to evaluate whether HEV infection increases the risk of HCC.

METHODS

We searched international databases (PubMed/Medline, Web of Science Collection, Embase, and Scopus) for peer-reviewed research articles published from inception to May 1, 2023. The pooled estimates of the odds ratios (ORs) and corresponding 95% confidence intervals (95%CIs) were calculated using random-effects models. Between-study heterogeneity was measured using I² and Q-statistic. Sensitivity and cumulative analyses were performed to examine the stability of our results.

RESULTS

We identified seven eligible studies involving 1873 HCC cases and 8679 control subjects; the latter included 7382 healthy controls and 1297 patients with chronic liver diseases (CLD). Overall, we observed statistically significant associations between HEV infection and risk of HCC (OR 1.94; 95%CI 1.26-3.0). According to the types of the controls, the association was significant when healthy individuals were the controls (OR 2.28, 95%CI 1.43-3.64), whereas the association was not significant when the patients had CLD (OR 1.66, 95%CI 0.76-3.61). The Egger's test and funnel plot indicated that there is no publication bias (p = 0.1) in the studies included in the meta-analysis. Sensitivity and cumulative analyses also indicated stability of our results.

CONCLUSIONS

Our findings indicate that individuals with HEV infection had an increased risk of HCC; however, further well-designed clinical and experimental studies are needed to confirm these observations. Furthermore, whether various genotypes of HEV differ in promoting HCC also needs to be investigated.

Diagnostic Efficacy of Serological Antibody Detection Tests for Hepatitis Delta Virus: A Systematic Review and Meta-Analysis

Background and Aims Coinfection of hepatitis delta virus (HDV) with hepatitis B virus (HBV) causes the most severe form of viral hepatitis, and the global prevalence of HDV infection is underestimated. Although serological testing of anti-HDV antibodies is widely used in the diagnosis of HDV, its diagnostic efficacy remains unclear. This study aimed to evaluate the diagnostic efficacy of HDV serological tests, the results of which may assist in the diagnosis of HDV. Methods Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines were followed. The PubMed, Web of Science and Cochrane Library databases were searched from the beginning to 31 May 2023. Study quality was assessed using the Quality Assessment of Diagnostic Accuracy Studies-2 (QUADAS-2) tool. STATA SE was used for the meta-analysis of the sensitivity, specificity, positive likelihood ratio and negative likelihood ratio. Results Among a total of 1376 initially identified studies, only 12 articles met the final inclusion criteria. The pooled sensitivity and specificity were 1.00 (95% CI: 0.00-1.00) and 0.71 (95% CI: 0.50-0.78) for HDV total antibodies, 0.96 (95% CI: 0.83-0.99) and 0.98 (95% CI: 0.82-1.00) for anti-HDV IgM and 0.95 (95% CI: 0.86-0.98) and 0.96 (95% CI: 0.67-1.00) for anti-HDV IgG. The pooled sensitivity and specificity for HDV serological tests were 0.99 (95% CI: 0.96-1.00) and 0.90 (95% CI: 0.79-0.96). Conclusions This meta-analysis suggests that serological tests have high diagnostic performance in detecting antibodies against HDV, especially in HDV IgM and IgG. However, this conclusion is based on studies of a limited number and quality, and the development of new diagnostic tools with higher precision and reliability is still necessary.

EASL Clinical Practice Guidelines on hepatitis delta virus

Hepatitis D virus (HDV) is a defective virus that requires the hepatitis B virus to complete its life cycle and cause liver damage in humans. HDV is responsible for rare acute and chronic liver diseases and is considered the most aggressive hepatitis virus. Acute infection can cause acute liver failure, while persistent infection typically causes a severe form of chronic hepatitis which is associated with rapid and frequent progression to cirrhosis and its end-stage complications, hepatic decompensation and hepatocellular carcinoma. Major diagnostic and therapeutic innovations prompted the EASL Governing Board to commission specific Clinical Practice Guidelines on the identification, virologic and clinical characterisation, prognostic assessment, and appropriate clinical and therapeutic management of HDV-infected individuals.

Hepatitis D virus: Improving virological knowledge to develop new treatments

Hepatitis delta virus (HDV), a satellite of hepatitis B virus (HBV), possesses the smallest viral genome known to infect animals. HDV needs HBV surface protein for secretion and entry into target liver cells. However, HBV is dispensable for HDV genome amplification, as it relies almost exclusively on cellular host factors for replication. HBV/HDV co-infections affect over 12 million people worldwide and constitute the most severe form of viral hepatitis. Co-infected individuals are at higher risk of developing liver cirrhosis and hepatocellular carcinoma compared to HBV mono-infected patients. Bulevirtide, an entry inhibitor, was conditionally approved in July 2020 in the European Union for adult patients with chronic hepatitis delta (CHD) and compensated liver disease. There are several drugs in development, including lonafarnib and interferon lambda, with different modes of action. In this review, we detail our current fundamental knowledge of HDV lifecycle and review antiviral treatments under development against this virus, outlining their respective mechanisms-of-action. Finally, we describe the antiviral effect these compounds are showing in ongoing clinical trials, discussing their promise and potential pitfalls for managing HDV infected patients.

Molecular and Clinical Features of Hepatocellular Carcinoma in Patients with HBV-HDV Infection

Hepatitis D virus (HDV) infection affects more than 10 million people worldwide, with an estimated prevalence of nearly 4.5% among HBsAg-positive individuals. Epidemiological studies have shown a significant increase in the prevalence of hepatocellular carcinoma (HCC) in patients with chronic HDV infection compared to those with chronic hepatitis B virus (HBV) mono-infection. Despite the clinical findings, data on molecular oncogenic mechanisms are limited and fragmentary. Moreover, the role of HDV in promoting the development of HCC has so far been controversial, because it is difficult to weigh the respective contributions of the two viruses. In this review, we focused on the direct oncogenic action of HDV, its role in modifying the tumor microenvironment, and the genetic signature of HDV-related HCC, comparing these features with HBV-related HCC.

Hepatitis delta virus: Disease assessment and stratification

Hepatitis D virus (HDV) causes one of the most severe forms of hepatitis in people with chronic hepatitis B (CHB) infection. Timely and accurate assessment of hepatitis delta virus (HDV) and disease stratification is mandatory for thorough pre-therapeutic evaluation for prioritizing treatment and outcome prediction. Viral biomarkers associated with HDV and hepatitis B virus (HBV) are crucial to aid in diagnosis, and monitoring of serum viral nucleic acids for both viruses is recommended. Liver biopsy remains the gold standard for staging of liver fibrosis and grading of histological activity and should remain central for diagnostic purposes, but is also of importance for research to enhance our understanding of HDV. The emergence of novel non-invasive tests for the assessment of liver fibrosis in HDV patients coupled with the well-recognized potential complications of liver biopsy has resulted in reduced utility of liver biopsy in clinical practice. Preliminary data suggest that these emerging non-invasive modalities appear to be reliable, and their use is supported, similar to other viral hepatitis. Nevertheless, further validation is required before their widespread adoption into clinical practice.

Hepatitis Delta: Current Knowledge and Future Directions

Hepatitis delta virus (HDV) infection is caused by a unique circular RNA virus that relies on both the hepatitis B virus (HBV) antigen and human host polymerases for its transmission and replication. HDV infection can be acquired simultaneously with HBV as a coinfection or as a superinfection in patients already chronically infected with HBV. Chronic HDV is the most severe and progressive form of viral hepatitis-induced liver disease, accounting for significant morbidity and mortality worldwide. Despite the severity of disease and poor clinical outcomes, there are few therapeutic options for the treatment of HDV infection. This article discusses the epidemiology of HDV globally and in the United States, the diagnosis and clinical course of HDV infection, and the current and future therapeutic options for the management of HDV infection.

Molecular epidemiology and clinical characteristics of hepatitis D virus infection in Canada

Background & Aims

HDV affects 4.5-13% of chronic hepatitis B (CHB) patients globally, yet the prevalence of HDV infection in Canada is unknown. To investigate the prevalence, genotype, demographics, and clinical characteristics of HDV in Canada, we conducted a retrospective analysis of (1) HDV antibody and RNA positivity among referred specimens, and (2) a cross-sectional subset study of 135 HDV seropositive +/-RNA (HDV+) patients compared with 5,132 HBV mono-infected patients in the Canadian HBV Network.

Methods

Anti-HDV IgG-positive specimens collected between 2012 and 2019 were RNA tested and the genotype determined. Patients enrolled in the Canadian HBV Network were >18 years of age and HBsAg-positive. Clinical data collected included risk factors, demographics, comorbidities, treatment, fibrosis assessment, and hepatic complications.

Results

Of the referred patients, 338/7,080 (4.8%, 95% CI 4.3-5.3) were HDV seropositive, with 219/338 RNA-positive (64.8%, 95% CI 59.6-69.7). The HDV+ cohort were more likely to be born in Canada, to be White or Black/African/Caribbean than Asian, and reporting high-risk behaviours, compared with HBV mono-infected patients. Cirrhosis, complications of end-stage liver disease, and liver transplantation were significantly more frequent in the HDV+ cohort. HDV viraemia was significantly associated with elevated liver transaminases and cirrhosis. Five HDV genotypes were observed among referred patients but no association between genotype and clinical outcome was detected within the HDV+ cohort.

Conclusions

Nearly 5% of the Canadian HBV referral population is HDV seropositive. HDV infection is highly associated with risk behaviours and both domestic and foreign-born patients with CHB. HDV was significantly associated with progressive liver disease highlighting the need for increased screening and surveillance of HDV in Canada.

Lay summary

Evidence of HDV infection was observed in approximately 5% of Canadians who were infected with HBV referred to medical specialists. HDV-positive patients were more likely to be male, born in Canada, or White or Black/African/Caribbean compared to Asian, and to have reported high-risk activities such as injection or intranasal drug use or high-risk sexual contact compared with patients infected with only HBV. Patients infected with HDV were also more likely to suffer severe liver disease, including liver cancer, compared with HBV mono-infected patients.

Hepatocellular Carcinoma in Chronic Viral Hepatitis: Where Do We Stand?

Hepatocellular carcinoma (HCC) is one of the major causes of cancer-related death. Although the burden of alcohol- and NASH-related HCC is growing, chronic viral hepatitis (HBV and HCV) remains a major cause of HCC development worldwide. The pathophysiology of viral-related HCC includes liver inflammation, oxidative stress, and deregulation of cell signaling pathways. HBV is particularly oncogenic because, contrary to HCV, integrates in the cell DNA and persists despite virological suppression by nucleotide analogues. Surveillance by six-month ultrasound is recommended in patients with cirrhosis and in "high-risk" patients with chronic HBV infection. Antiviral therapy reduces the risks of development and recurrence of HCC; however, patients with advanced chronic liver disease remain at risk of HCC despite virological suppression/cure and should therefore continue surveillance. Multiple scores have been developed in patients with chronic hepatitis B to predict the risk of HCC development and may be used to stratify individual patient's risk. In patients with HCV-related liver disease who achieve sustained virological response by direct acting antivirals, there is a strong need for markers/scores to predict long-term risk of HCC. In this review, we discuss the most recent advances regarding viral-related HCC.

On-treatment gamma-glutamyl transferase predicts the development of hepatocellular carcinoma in chronic hepatitis B patients

BACKGROUND & AIMS

Gamma-glutamyl transferase (GGT) has been predictive of chronic hepatitis C-related hepatocellular carcinoma (HCC) development. Its role in the risk of HCC in chronic hepatitis B (CHB) patients treated with nucleotide/nucleoside analogues (NAs) is elusive.

METHODS

A total of 2172 CHB patients from East Asia were randomized into development and validation groups in a 1:2 ratio. Serum GGT levels before and 6 months (M6) after initiating NAs and the potential risk factors were measured. The primary endpoint was HCC development 12 months after NA initiation.

RESULTS

The annual incidence of HCC was 1.4/100 person-years in a follow-up period of 11 370.7 person-years. The strongest factor associated with HCC development was high M6-GGT levels (>25 U/L; hazard ratio [HR]/95% confidence interval [CI]: 3.31/2.02-5.42, P < .001), followed by cirrhosis (HR/CI: 2.06/1.39-3.06, P < .001), male sex (HR/CI: 2.01/1.29-3.13, P = .002) and age (HR/CI: 1.05/1.03-1.17, P < .001). Among cirrhotic patients, the incidence of HCC did not differ between those with high or low M6-GGT levels (P = .09). In contrast, among non-cirrhotic patients, the incidence of HCC was significantly higher for those with M6-GGT level >25 U/L than for their counterparts (P < .001). Cox regression analysis revealed that the strongest factor associated with HCC development in non-cirrhotic patients was high M6-GGT levels (HR/CI: 5.05/2.52-10.16, P < .001), followed by age (HR/CI: 1.07/1.04-1.09, P < .001). Non-cirrhotic elderly patients with high M6-GGT levels had a similarly high HCC risk as cirrhotic patients did (P = .29).

CONCLUSIONS

On-treatment serum GGT levels strongly predicted HCC development in CHB patients, particularly non-cirrhotic patients, treated with NAs.

Beyond the Usual Suspects: Hepatitis E Virus and Its Implications in Hepatocellular Carcinoma

Hepatitis E virus infections are the leading cause of viral hepatitis in humans, contributing to an estimated 3.3 million symptomatic cases and almost 44,000 deaths annually. Recently, HEV infections have been found to result in chronic liver infection and cirrhosis in severely immunocompromised patients, suggesting the possibility of HEV-induced hepatocarcinogenesis. While HEV-associated formation of HCC has rarely been reported, the expansion of HEV's clinical spectrum and the increasing evidence of chronic HEV infections raise questions about the connection between HEV and HCC. The present review summarizes current clinical evidence of the relationship between HEV and HCC and discusses mechanisms of virus-induced HCC development with regard to HEV pathogenesis. We further elucidate why the development of HEV-induced hepatocellular carcinoma has so rarely been observed and provide an outlook on possible experimental set-ups to study the relationship between HEV and HCC formation.

The Prevalence and Serological Association of Hepatitis D Virus Genotypes in Taiwan

Hepatitis Delta Virus (HDV) is an RNA virus that requires the presence of hepatitis B surface antigen (HBsAg) to propagate into hepatocytes, with Genotype I being more prevalent globally. However, the prevalence of HDV genotypes in Taiwan is unknown. Accordingly, a cohort including 24 chronic HBV patients who received nucleos(t)ides (NUCs) between January 2002 and July 2018 was used to determine HDV genotypes and genotype specific serological association in chronic HBV carriers. HDV-positive genotypes in 18/24 (75%) males and 6/24 (25%) females were identified among chronic HBV patients. Viremia was lower in HDV-IV patients than in patients affected with other HDV genotypes (1.34 log₁₀ copies/mL vs. 3.30 log₁₀ copies/mL; p = 0.009). A logistics regression analysis revealed that HDV-IV was inversely proportional to HDV RNA (odds ratio [OR]/95% confidence intervals [CI]: 0.370/0.164-0.830; p = 0.017). The serologic association study indicated lower levels of creatinine (p = 0.047) and HDV-RNA (p = 0.009) in the HDV-IV group than the non-HDV-IV group but did not indicate any significant differences in the AST, ALT, bilirubin levels or other laboratory test factors. The three genotypes evident in Taiwan were HDV-I (4/24, 16.7%), HDV-II (6/24, 25.0%), and HDV-IV (14/24, 58.3%), and HDV-IV is the predominant HDV genotype in Taiwan. These results anticipate a clear understanding of HDV genotype serological association in chronic HBV carriers.