Epidemiology, Natural History, and Treatment of Hepatitis Delta Virus Infection in HIV/Hepatitis B Virus Coinfection

Hepatitis B Virus Exposure, Seroprotection Status, and Susceptibility in Health Care Workers From Lao People's Democratic Republic: Cross-Sectional Study

Background

Despite the high prevalence of chronic hepatitis B virus (HBV) infection in adults in Lao People's Democratic Republic (Lao PDR), Lao health care workers (HCWs) have previously been shown to have low levels of protection against infection. Furthermore, the prevalence of hepatitis D virus (HDV), which increases disease severity in individuals infected with HBV, is not known in Lao PDR.

Objective

This study aimed to estimate the exposure and seroprotection against HBV, as well as exposure to HDV, in Lao HCWs from 5 provinces.

Methods

In 2020, a total of 666 HCWs aged 20 to 65 years from 5 provinces of Lao PDR were recruited, and their sera were tested by enzyme-linked immunosorbent assay to determine their HBV and HDV coinfection status.

Results

HBV exposure, as indicated by the presence of anti-hepatitis B core antibodies, was 40.1% (267/666) overall and significantly higher for HCWs from Oudomxay province (21/31, 67.7%; adjusted odds ratio 3.69, 95% CI 1.68-8.12; P=.001). The prevalence of hepatitis B surface antigen was 5.4% (36/666) overall and increased with age, from 3.6% (9/248) in those aged ≤30 years to 6.8% (8/118) in those aged ≥50 years. Only 28.7% (191/666) of participants had serological indication of immunization. We could find no evidence for HDV exposure in this study.

Conclusions

The study found intermediate hepatitis B surface antigen prevalence among HCWs in Lao PDR, with no evidence of HDV coinfection. Notably, a significant proportion of HCWs remains susceptible to HBV, indicating a substantial gap in seroprotection against the disease.

Frequency of hepatitis D virus with different hepatitis B virus serological markers and coinfections in hospital patients from Argentina: synchronous testing of anti-HDV antibodies and HDV RNA

BACKGROUND

Hepatitis D virus (HDV) RNA-positive cases with total anti-HDV antibodies nonreactive were documented. Moreover, HDV infection was observed in subjects with occult hepatitis B virus infection. The prevalence of HDV infection in Argentina is low; however, further research in different populations is needed.

OBJECTIVE

This study aimed to perform synchronous HDV detection in reactive hepatitis B virus patients treated in a public hospital in the province of Buenos Aires, Argentina, some of whom were coinfected with hepatitis C virus and/or HIV. A total of 189 hepatitis B virus-reactive serum samples with or without hepatitis C virus and/or HIV coinfection were synchronously analyzed for anti-HDV antibodies and HDV RNA.

RESULTS

HDV prevalence was 4.2% with HDV RNA found in 61 samples, most of which were nonreactive to anti-HDV antibodies and hepatitis B surface antigen. Genotype 1 was identified in all HDV sequences. Moreover, triple and quadruple infections were observed, showing a high frequency of HDV infection in hospitalized patients not following the recommended diagnostic algorithm.

CONCLUSIONS

This study is evidence that the synchronous testing of anti-HDV antibodies and HDV RNA is necessary for the diagnosis of HDV infection in Argentina. Finally, further research is necessary to identify high-risk populations and improve prevention and control strategies for triple and quadruple infections and their potential consequences.

Current perspectives of viral hepatitis

Viral hepatitis represents a major danger to public health, and is a globally leading cause of death. The five liver-specific viruses: Hepatitis A virus, hepatitis B virus, hepatitis C virus, hepatitis D virus, and hepatitis E virus, each have their own unique epidemiology, structural biology, transmission, endemic patterns, risk of liver complications, and response to antiviral therapies. There remain few options for treatment, in spite of the increasing prevalence of viral-hepatitis-caused liver disease. Furthermore, chronic viral hepatitis is a leading worldwide cause of both liver-related morbidity and mortality, even though effective treatments are available that could reduce or prevent most patients' complications. In 2016, the World Health Organization released its plan to eliminate viral hepatitis as a public health threat by the year 2030, along with a discussion of current gaps and prospects for both regional and global eradication of viral hepatitis. Today, treatment is sufficiently able to prevent the disease from reaching advanced phases. However, future therapies must be extremely safe, and should ideally limit the period of treatment necessary. A better understanding of pathogenesis will prove beneficial in the development of potential treatment strategies targeting infections by viral hepatitis. This review aims to summarize the current state of knowledge on each type of viral hepatitis, together with major innovations.

Molecular genetic association of rs8099917 and rs1800795 polymorphisms in the progression of hepatitis Delta virus liver disease

Background

The relationship between viral infections and host factors holds high hopes for identifying the role of Interferon Lambda 3 (IFNL3) and Interleukin 6 (IL-6) polymorphisms in the development of Chronic Liver Disease (CLD) in patients infected with hepatitis Delta virus (HDV) in the Western Brazilian Amazon.

Methods

Cross-sectional study conducted with a cohort of 40 chronic HDV patients, 27 with CLD and 13 without evident liver damage. Biological samples from the participants were analyzed using the polymerase chain reaction (PCR) technique, followed by sequencing by the automated Sanger method.

Results

The rs8099917 T allele, from the IFNL3 gene, showed a higher frequency in both groups; however, it was not possible to establish an association with HDV infection [OR = 1.42 (0.42 - 4.75; p = 0.556 (95% CI). For IL-6, the rs1800795 G allele was superior to rs1800795 C. Analyzing both distributions in the studied groups, any association with HDV was absent (p > 0.05).

Conclusion

The results suggest that the rs8099917 T/G (IFNL3) and rs1800795 G/C (IL-6) polymorphisms are not associated with the evolution of HDV in the studied population.

[Delta hepatitis in Africa: epidemiological and clinical particularities]

In 2022, the World Health Organization (WHO) estimated that hepatitis B virus (HBV) infections caused 1.5 million deaths, mostly attributable to complications from chronic infections, cirrhosis and hepatocellular carcinoma (HCC). Despite the availability of a vaccine, 296 million people were chronically infected in 2019. Asia and Africa are the continents most affected by this infection, with around 100 million people infected in Africa as a whole.Hepatitis Delta or D virus (HDV), which is a "satellite" virus of HBV, is often misunderstood and its diagnosis remains neglected. However, it is associated with acute fulminant forms and chronic forms of hepatitis leading to a more rapid evolution towards cirrhosis and HCC than during HBV mono-infection. Research on these two viruses HBV and HDV has progressed a lot in recent years, and new treatments are currently in development.In people living with the human immunodeficiency virus (PlHIV), liver disease is a major cause of morbidity and mortality. Due to common modes of transmission, dual or triple HIV/HBV or HIV/HBV/HDV infections are relatively common, particularly in HBV endemic regions such as Africa. However, while today most co-infected patients benefit from effective treatment against both HIV and HBV, the latter is not active against HDV. In Africa, hepatitis B and D have already been the subject of several studies. However, the frequency and clinical consequences of these co-infections have been little studied in the general population and in PlHIV.This review seeks to update the epidemiological and clinical data and the therapeutic perspectives of HDV co-infections or triple infections (HIV-HBV-HDV) in Africa.

Hepatitis B core-related antigen serum levels may be a predictor of acute flare of chronic hepatitis B among pregnant women in the immune-tolerant phase of chronic HBV infection after short-course antiviral therapy

BACKGROUND

Studies have shown acute flares of chronic hepatitis B (CHB) might be related to immunologic changes that occur during pregnancy. However, the indicators for predicting acute flares of CHB among pregnant women still need further study. We aimed to distinguish the relevance between serum levels of HBcrAg and acute flares of CHB in pregnant women in the immune-tolerant phase of chronic HBV infection after short-course antiviral therapy.

METHODS

A total of 172 chronic HBV-infected pregnant women who were judged to be in the immune-tolerant phase were recruited in our research. All patients received short-course antiviral therapy with TDF. The biochemical, serological, and virological parameters were measured using standard laboratory procedures. The serum levels of HBcrAg were tested by ELISA.

RESULTS

Fifty-two (30.2%) out of 172 patients had acute flares of CHB. At postpartum week 12 (TDF cessation), serum HBcrAg (OR, 4.52; 95% CI, 2.58-7.92) and HBsAg (OR, 2.52; 95% CI, 1.13-5.65) were associated with acute flares of CHB. The serum HBcrAg levels were beneficial for confirmation of patients with acute flares of CHB, with an area under the ROC curve of 0.84 (95% CI, 0.78-0.91).

CONCLUSIONS

For pregnant women with chronic HBV infection in the immune-tolerant phase, serum HBcrAg and HBsAg levels at postpartum week 12 were associated with acute flares of CHB after short-course antiviral therapy with TDF. The serum HBcrAg level can correctly identify acute flares of CHB and may be a predictor of the need for continuing antiviral therapy after 12 weeks postpartum.

Prevalence and determinants of hepatitis delta virus infection among HIV/hepatitis B-coinfected adults in care in the United States

Hepatitis delta virus (HDV) infection increases the risk of liver complications compared to hepatitis B virus (HBV) alone, particularly among persons with human immunodeficiency virus (HIV). However, no studies have evaluated the prevalence or determinants of HDV infection among people with HIV/HBV in the US. We performed a cross-sectional study among adults with HIV/HBV coinfection receiving care at eight sites within the Center for AIDS Research Network of Integrated Clinical Systems (CNICS) between 1996 and 2019. Among patients with available serum/plasma specimens, we selected the first specimen on or after their initial HBV qualifying test. All samples were tested for HDV IgG antibody and HDV RNA. Multivariable log-binomial generalized linear models were used to estimate prevalence ratios (PRs) with 95% CIs of HDV IgG antibody-positivity associated with determinants of interest (age, injection drug use [IDU], high-risk sexual behaviour). Among 597 adults with HIV/HBV coinfection in CNICS and available serum/plasma samples (median age, 43 years; 89.9% male; 52.8% Black; 42.4% White), 24/597 (4.0%; 95% CI, 2.4%-5.6%) were HDV IgG antibody-positive, and 10/596 (1.7%; 95% CI, 0.6%-2.7%) had detectable HDV RNA. In multivariable analysis, IDU was associated with exposure to HDV infection (adjusted PR = 2.50; 95% CI, 1.09-5.74). In conclusion, among a sample of adults with HIV/HBV coinfection in care in the US, 4.0% were HDV IgG antibody-positive, among whom 41.7% had detectable HDV RNA. History of IDU was associated with exposure to HDV infection. These findings emphasize the importance of HDV testing among persons with HIV/HBV coinfection, especially those with a history of IDU.

Triple Threat: HDV, HBV, HIV Coinfection

Hepatitis delta virus (HDV) only infects patients with hepatitis B virus (HBV) due to its reliance on HBV surface proteins to form its envelope. With shared routes of transmission, HDV coinfection is estimated to occur in 15% of patients with HIV and HBV. However, HDV is often underdiagnosed and may be missed particularly in people living with HIV (PLWH) who are already on antiretroviral therapy with anti-HBV activity and coincidental HBV suppression. At the same time, HDV causes the most severe form of chronic viral hepatitis and leads to faster progression of liver disease and hepatocellular carcinoma. Thus, increased recognition and effective treatment are paramount, and as novel treatment options approach global markets, the study of their efficacy in PLWH should be pursued.

Treatment of hepatitis delta and HIV infection

Hepatitis delta virus (HDV) is a defective agent that only infects individuals with hepatitis B virus (HBV). Around 5-10% of chronic hepatitis B patients worldwide are superinfected with HDV, which means 15-25 million people. Hepatitis delta is the most severe of all chronic viral hepatitis, leading to cirrhosis, liver cancer and/or transplantation in most patients. Despite it, many HDV patients remain undiagnosed. The only treatment available until recently was peginterferon alfa, with poor results and significant side effects. The recent approval of bulevirtide, a lipopeptide that blocks HBV/HDV entry, has revolutionized the field. Another drug, lonafarnib, already approved to treat progeria, is expected to be available soon as HDV therapy. Since there is no cell reservoir for the HDV RNA genome, hypothetically viral clearance could be achieved if complete blocking of viral replication occurs for a minimum time frame. This is what happens in hepatitis C using direct-acting antivirals, with the achievement of cure in nearly all treated patients. We envision the cure of hepatitis delta using combination antiviral therapy. Given that sexual and parenteral transmission routes are the most frequent for the acquisition of HBV and HDV, shared with HIV infection and HBV/HDV and HIV coinfection. The clinical outcome of hepatitis delta is worst in the HIV setting, with more frequent liver complications. Since most persons infected with HIV are on regular health care follow-up, we propose that HIV-HDV patients should be prioritized for moving forward new and potentially curative treatments for hepatitis delta.

[Hepatitis Delta in HIV/HBV Infected Individuals: Why does this Issue Matter?]

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HIV-1/HBV Coinfection Accurate Multitarget Prediction Using a Graph Neural Network-Based Ensemble Predicting Model

HIV and HBV infection are both serious public health challenges. There are more than approximately 4 million patients coinfected with HIV and HBV worldwide, and approximately 5% to 15% of those infected with HIV are coinfected with HBV. Disease progression is more rapid in patients with coinfection, which significantly increases the likelihood of patients progressing from chronic hepatitis to cirrhosis, end-stage liver disease, and hepatocellular carcinoma. HIV treatment is complicated by drug interactions, antiretroviral (ARV) hepatotoxicity, and HBV-related immune reconditioning and inflammatory syndromes. Drug development is a highly costly and time-consuming procedure with traditional experimental methods. With the development of computer-aided drug design techniques, both machine learning and deep learning have been successfully used to facilitate rapid innovations in the virtual screening of candidate drugs. In this study, we proposed a graph neural network-based molecular feature extraction model by integrating one optimal supervised learner to replace the output layer of the GNN to accurately predict the potential multitargets of HIV-1/HBV coinfections. The experimental results strongly suggested that DMPNN + GBDT may greatly improve the accuracy of binary-target predictions and efficiently identify the potential multiple targets of HIV-1 and HBV simultaneously.

Hepatitis B virus and hepatitis D virus infection in women with or at risk for HIV infection in the United States

Hepatitis D virus (HDV) requires co-infection with hepatitis B virus (HBV). Human immunodeficiency virus (HIV) shares transmission routes with these viruses. Among 4,932 US women infected with or at-risk for HIV during 1994-2015, HBV surface antigen (HBsAg) positivity was more common in women with HIV (2.8% vs. 1.2%; p = 0.001); HDV was more common among participants enrolled during 2013-2015 (p = 0.0004) and those with resolved rather than active hepatitis C (1.9% vs. 0.5%; p = 0.02). Among HBsAg-positive women (n = 117), HDV antibody prevalence was 22% and did not vary by HIV status; HDV infection was associated with the presence of advanced fibrosis/cirrhosis at enrollment (adjusted odds ratio, 5.70; 95% confidence interval, 1.46-22.29). Our results demonstrate the importance of HDV testing in HBV-infected US women.

Hepatitis B and Hepatitis D Viruses: A Comprehensive Update with an Immunological Focus

Hepatitis B virus (HBV) and hepatitis delta virus (HDV) are highly prevalent viruses estimated to infect approximately 300 million people and 12-72 million people worldwide, respectively. HDV requires the HBV envelope to establish a successful infection. Concurrent infection with HBV and HDV can result in more severe disease outcomes than infection with HBV alone. These viruses can cause significant hepatic disease, including cirrhosis, fulminant hepatitis, and hepatocellular carcinoma, and represent a significant cause of global mortality. Therefore, a thorough understanding of these viruses and the immune response they generate is essential to enhance disease management. This review includes an overview of the HBV and HDV viruses, including life cycle, structure, natural course of infection, and histopathology. A discussion of the interplay between HDV RNA and HBV DNA during chronic infection is also included. It then discusses characteristics of the immune response with a focus on reactions to the antigenic hepatitis B surface antigen, including small, middle, and large surface antigens. This paper also reviews characteristics of the immune response to the hepatitis D antigen (including small and large antigens), the only protein expressed by hepatitis D. Lastly, we conclude with a discussion of recent therapeutic advances pertaining to these viruses.

Underestimated Prevalence of HIV, Hepatitis B Virus (HBV), and Hepatitis D Virus (HDV) Triple Infection Globally: Systematic Review and Meta-analysis

BACKGROUND

Hepatitis delta virus (HDV) is a satellite RNA virus that relies on hepatitis B virus (HBV) for transmission. HIV/HBV/HDV coinfection or triple infection is common and has a worse prognosis than monoinfection.

OBJECTIVE

We aimed to reveal the epidemiological characteristics of HIV/HBV/HDV triple infection in the global population.

METHODS

A systematic literature search in PubMed, Embase, and the Cochrane Library was performed for studies of the prevalence of HIV/HBV/HDV triple infection published from January 1, 1990, to May 31, 2021. The Der Simonian-Laird random effects model was used to calculate the pooled prevalence.

RESULTS

We included 14 studies with 11,852 participants. The pooled triple infection rate in the global population was 7.4% (877/11,852; 95% CI 0.73%-29.59%). The results of the subgroup analysis showed that the prevalence of triple infection was significantly higher in the Asian population (214/986, 21.4%; 95% CI 7.1%-35.8%), in men (212/5579, 3.8%; 95% CI 2.5%-5.2%), and in men who have sex with men (216/2734, 7.9%; 95% CI 4.3%-11.4%). In addition, compared with people living with HIV, the HIV/HBV/HDV triple infection rate was higher in people with hepatitis B.

CONCLUSIONS

This meta-analysis suggests that the prevalence of HIV/HBV/HDV triple infection in the global population is underestimated, and we should focus more effort on the prevention and control of HIV/HBV/HDV triple infection.

TRIAL REGISTRATION

PROSPERO CRD42021273949; https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=273949.

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.

Hepatitis B Virus Genotypes and Antiviral Resistance Mutations in Romanian HIV-HBV Co-Infected Patients

Background and Objectives: Romania has one of the highest prevalence of hepatitis B virus (HBV) infection in human immunodeficiency virus (HIV) patients, mostly in those parenterally infected during childhood; nevertheless, there are scarce data on the virological profile of co-infection. The objective of this study was to assess the prevalence of HBV genotypes and antiviral resistance-associated mutations (RAMs) in these co-infected patients, in order to monitor the viral factors associated with the evolution of liver disease. Materials and Methods: HBV genotypes and RAMs were detected using nested PCR and line probe assays (INNO-LiPA HBV genotyping assay, and INNO-LiPA HBV DR v2, Innogenetics). Results: Out of 117 co-infected patients, 73.5% had detectable HBV-DNA, but only 38.5% presented an HBV viral load >1000 IU/mL. HBV genotype A was present in 66.7% of the cases and was dominant in patients parenterally infected during early childhood, who experienced multiple treatment regimens, with a mean therapy length of 15.25 years, and present numerous mutations associated with lamivudine (LAM) resistance, but very rarely active liver disease. HBV genotype D was detected in 33.3% of the cases, mostly in recently diagnosed injecting drug users who are treatment naïve, but, nevertheless, present RAMs in 63.5% of the cases, suggesting transmitted drug resistance, and display more frequently advanced liver fibrosis (36.1% vs. 12.3%; p = 0.033). The most frequently encountered RAMs are M204V/I: 48.8%, L180M: 33.3%, L80V: 28.8%, and V173L: 42.2%. There are no significant differences in the distribution of RAMs in patients infected with different HBV genotypes, except for the L80V and N236T mutations, which were more frequently found in HBV genotype A infections (p = 0.032 and p = 0.004, respectively). Conclusions: HBV genotypes A and D are the only genotypes present in HIV−HBV co-infected patients from Romania, with different distributions according to the infection route, and are frequently associated with multiple RAMs, conferring extensive resistance to LAM.

HIV Infection Predisposes to Increased Chances of HBV Infection: Current Understanding of the Mechanisms Favoring HBV Infection at Each Clinical Stage of HIV Infection

Human immunodeficiency virus (HIV) selectively targets and destroys the infection-fighting CD4+ T-lymphocytes of the human immune system, and has a life cycle that encompasses binding to certain cells, fusion to that cell, reverse transcription of its genome, integration of its genome into the host cell DNA, replication of the HIV genome, assembly of the HIV virion, and budding and subsequent release of free HIV virions. Once a host is infected with HIV, the host’s ability to competently orchestrate effective and efficient immune responses against various microorganisms, such as viral infections, is significantly disrupted. Without modern antiretroviral therapy (ART), HIV is likely to gradually destroy the cellular immune system, and thus the initial HIV infection will inexorably evolve into acquired immunodeficiency syndrome (AIDS). Generally, HIV infection in a patient has an acute phase, a chronic phase, and an AIDS phase. During these three clinical stages, patients are found with relatively specific levels of viral RNA, develop rather distinctive immune conditions, and display unique clinical manifestations. Convergent research evidence has shown that hepatitis B virus (HBV) co-infection, a common cause of chronic liver disease, is fairly common in HIV-infected individuals. HBV invasion of the liver can be facilitated by HIV infection at each clinical stage of the infection due to a number of contributing factors, including having identical transmission routes, immunological suppression, gut microbiota dysbiosis, poor vaccination immune response to hepatitis B immunization, and drug hepatotoxicity. However, there remains a paucity of research investigation which critically describes the influence of the different HIV clinical stages and their consequences which tend to favor HBV entrenchment in the liver. Herein, we review advances in the understanding of the mechanisms favoring HBV infection at each clinical stage of HIV infection, thus paving the way toward development of potential strategies to reduce the prevalence of HBV co-infection in the HIV-infected population.

Viral hepatitis in 2021: The challenges remaining and how we should tackle them

Viral hepatitis results in 1.4 million deaths annually. The World Health Organization (WHO) set an ambitious target to eliminate viral hepatitis by 2030, but significant challenges remain. These include inequalities in access to healthcare, reaching at risk populations and providing access to screening and effective treatment. Stigma around viral hepatitis persists and must be addressed. The WHO goal of global elimination by 2030 is a worthy aim, but remains ambitious and the coronavirus 2019 pandemic undoubtedly has set back progress. This review article will focus on hepatitis A to E, highlighting problems that have been resolved in the field over the past decade, those that remain to be resolved and suggest directions for future problem solving and research.

Viral Hepatitis and Hepatocellular Carcinoma: State of the Art

Viral hepatitis is one of the main causes leading to hepatocellular carcinoma (HCC). The continued rise in incidence of HCC suggests additional factors following infection may be involved. This review examines recent studies investigating the molecular mechanisms of chronic hepatitis and its association with hepatocarcinogenesis. Hepatitis B virus patients with genotype C display an aggressive disease course leading to HCC more than other genotypes. Furthermore, hepatitis B excretory antigen (HBeAg) seems to be a more sensitive predictive tumor marker exhibiting a six-fold higher relative risk in patients with positive HBsAg and HBeAg than those with HBsAg only. Single or combined mutations of viral genome can predict HCC development in up to 80% of patients. Several mutations in HBx-gene are related with higher HCC incidence. Overexpression of the core protein in HCV leads to hepatocellular lipid accumulation associated with oncogenesis. Reduced number and decreased functionality of natural killer cells in chronic HCV individuals dysregulate their surveillance function in tumor and viral cells resulting in HCC. Furthermore, high T-cell immunoglobulin and mucin 3 levels supress CD8+ T-cells, which lead to immunological dysregulation. Hepatitis D promotes HCC development indirectly via modifications to innate immunity, epigenetic alterations and production of reactive oxygen species with the LHDAg being the most highly associated with HCC development. Summarizing the results, HBV and HCV infection represent the most associated forms of viral hepatitis causing HCC. Further studies are warranted to further improve the prediction of high-risk patients and development of targeted therapeutics preventing the transition from hepatic inflammation–fibrosis to cancer.

Identification of hepatitis delta superinfection when investigating transaminitis in HIV/hepatitis B virus co-infection

Hepatitis delta virus (HDV) is a highly pathogenic virus which can cause rapidly progressive liver disease in individuals with chronic hepatitis B virus and for which treatment options are limited. The incidence of sexually transmitted HDV infection is unknown. Here we report the case of a HDV seronegative man with pre-existent HIV/hepatitis B virus, taking effective tenofovir-containing antiretroviral therapy, who experienced a significant acute transaminitis with HDV antibody seroconversion and viraemia and no other identifiable cause.

Hepatitis delta virus: From infection to new therapeutic strategies

The hepatitis delta virus (HDV) is a small RNA virus that encodes a single protein and which requires the hepatitis B virus (HBV)-encoded hepatitis B surface antigen (HBsAg) for its assembly and transmission. HBV/HDV co-infections exist worldwide and show a higher prevalence among selected groups of HBV-infected populations, specifically intravenous drug users, practitioners of high-risk sexual behaviours, and patients with cirrhosis and hepatocellular carcinoma. The chronic form of HDV-related hepatitis is usually severe and rapidly progressive. Patterns of the viral infection itself, including the status of co-infection or super-infection, virus genotypes (both for HBV and HDV), and persistence of the virus’ replication, influence the outcome of the accompanying and manifested liver disease. Unfortunately, disease severity is burdened by the lack of an effective cure for either virus type. For decades, the main treatment option has been interferon, administered as mono-therapy or in combination with nucleos(t)ide analogues. While its efficacy has been reported for different doses, durations and courses, only a minority of patients achieve a sustained response, which is the foundation of eventual improvement in related liver fibrosis. The need for an efficient therapeutic alternative remains. Research efforts towards this end have led to new treatment options that target specific steps in the HDV life cycle; the most promising among these are myrcludex B, which inhibits virus entry into hepatocytes, lonafarnib, which inhibits farnesylation of the viral-encoded L-HDAg large hepatitis D antigen, and REP-2139, which interferes with HBsAg release and assembly.

Current impact of viral hepatitis on liver cancer development: The challenge remains

Chronic infections due to hepatitis B and hepatitis C viruses are responsible for most cases of hepatocellular carcinoma (HCC) worldwide, and this association is likely to remain during the next decade. Moreover, viral hepatitis-related HCC imposes an important burden on public health in terms of disability-adjusted life years. In order to reduce such a burden, some major challenges must be faced. Universal vaccination against hepatitis B virus, especially in the neonatal period, is probably the most relevant primary preventive measure against the development of HCC. Moreover, considering the large adult population already infected with hepatitis B and C viruses, it is also imperative to identify these individuals to ensure their access to treatment. Both hepatitis B and C currently have highly effective therapies, which are able to diminish the risk of development of liver cancer. Finally, it is essential for individuals at high-risk of HCC to be included in surveillance programs, so that tumors are detected at an early stage. Patients with hepatitis B or C and advanced liver fibrosis or cirrhosis benefit from being followed in a surveillance program. As hepatitis B virus is oncogenic and capable of leading to liver cancer even in individuals with early stages of liver fibrosis, other high-risk groups of patients with hepatitis B are also candidates for surveillance. Considerable effort is required concerning these strategies in order to decrease the incidence and the mortality of viral hepatitis-related HCC.

Is hepatitis delta underestimated?

Hepatitis D virus may be underestimated because it is a significant problem in HBsAg-positive patients, especially those who inject drugs, have HIV or HCV co-infections and/or live in certain endemic regions. In the past few decades, the prevalence of HDV was expected to have decreased as a result of improvements in public healthcare policies and universal HBV vaccination programs. However, HDV has continued to spread in low-income countries, with local outbreaks and migration to less endemic areas, so that its prevalence has remained stable or even increased in certain regions. As a result, research has been focused on the epidemiology of HDV. Contradicting data from three large recent meta-analyses have reported that the prevalence of HDV may be between 0.16% and 1.00% in the global general population, and 4.5% and 14.6% in HBsAg-positive patients, with an estimated 12 to 70 million HDV patients worldwide. The exact prevalence and estimated number of HDV patients is still a subject of debate for several reasons, including the unreliable assessment of the infection and a lack of real-world screening. HDV infection is associated with an increased risk of progression to cirrhosis and the development of HCC compared to patients with HBV mono-infection, a risk which is even higher in patients with HIV co-infection. Morbidity and mortality from HDV-related cirrhosis should not be overlooked. In conclusion, hepatitis D virus is probably underestimated and certainly underdiagnosed, and screening for HDV should be performed in all HBsAg-positive patients in clinical practice.

The changing context of hepatitis D

The global epidemiology of hepatitis D is changing with the widespread implementation of vaccination against hepatitis B. In high-income countries that achieved optimal control of HBV, the epidemiology of hepatitis D is dual, consisting of an ageing cohort of domestic patients with advanced liver fibrosis who represent the end stage of the natural history of HDV, and of a younger generation of immigrants from endemic countries who account for the majority of new infections. As observed in Europe in the 1980s, the distinctive clinical characteristic of chronic hepatitis D in endemic countries is the accelerated progression to cirrhosis and hepatocellular carcinoma. Despite some recent progress, the therapeutic management of HDV remains unsatisfactory, as most patients are not cured of HDV with currently available medicines. This review article describes the current epidemiology and clinical features of chronic hepatitis D, based on the literature published in the last 10 years.