Interaction between HDV and HBV infection in HBsAg-chronic carriers

Hepatitis D: A Review

Importance

Hepatitis D virus (HDV) infection occurs in association with hepatitis B virus (HBV) infection and affects approximately 12 million to 72 million people worldwide. HDV causes more rapid progression to cirrhosis and higher rates of hepatocellular carcinoma than HBV alone or hepatitis C virus.

Observations

HDV requires HBV to enter hepatocytes and to assemble and secrete new virions. Acute HDV-HBV coinfection is followed by clearance of both viruses in approximately 95% of people, whereas HDV superinfection in an HBV-infected person results in chronic HDV-HBV infection in more than 90% of infected patients. Chronic hepatitis D causes more rapidly progressive liver disease than HBV alone. Approximately 30% to 70% of patients with chronic hepatitis D have cirrhosis at diagnosis and more than 50% die of liver disease within 10 years of diagnosis. However, recent studies suggested that progression is variable and that more than 50% of people may have an indolent course. Only approximately 20% to 50% of people infected by hepatitis D have been diagnosed due to lack of awareness and limited access to reliable diagnostic tests for the HDV antibody and HDV RNA. The HBV vaccine prevents HDV infection by preventing HBV infection, but no vaccines are available to protect those with established HBV infection against HDV. Interferon alfa inhibits HDV replication and reduces the incidence of liver-related events such as liver decompensation, hepatocellular carcinoma, liver transplant, or mortality from 8.5% per year to 3.3% per year. Adverse effects from interferon alfa such as fatigue, depression, and bone marrow suppression are common. HBV nucleos(t)ide analogues, such as entecavir or tenofovir, are ineffective against HDV. Phase 3 randomized clinical trials of bulevirtide, which blocks entry of HDV into hepatocytes, and lonafarnib, which interferes with HDV assembly, showed that compared with placebo or observation, these therapies attained virological and biochemical response in up to 56% of patients after 96 weeks of bulevirtide monotherapy and 19% after 48 weeks of lonafarnib, ritonavir, and pegylated interferon alfa treatment.

Conclusions and Relevance

HDV infection affects approximately 12 million to 72 million people worldwide and is associated with more rapid progression to cirrhosis and liver failure and higher rates of hepatocellular carcinoma than infection with HBV alone. Bulevirtide was recently approved for HDV in Europe, whereas pegylated interferon alfa is the only treatment available in most countries.

Hepatitis D virus interferes with hepatitis B virus RNA production via interferon-dependent and -independent mechanisms

BACKGROUND & AIMS

Chronic coinfection with HBV and HDV leads to the most aggressive form of chronic viral hepatitis. Herein, we aimed to elucidate the molecular mechanisms underlying the widely reported observation that HDV interferes with HBV in most coinfected patients.

METHODS

Patient liver tissues, primary human hepatocytes, HepaRG cells and human liver chimeric mice were used to analyze the effect of HDV on HBV using virological and RNA-sequencing analyses, as well as RNA synthesis, stability and association assays.

RESULTS

Transcriptomic analyses in cell culture and mouse models of coinfection enabled us to define an HDV-induced signature, mainly composed of interferon (IFN)-stimulated genes (ISGs). We also provide evidence that ISGs are upregulated in chronically HDV/HBV-coinfected patients but not in cells that only express HDV antigen (HDAg). Inhibition of the hepatocyte IFN response partially rescued the levels of HBV parameters. We observed less HBV RNA synthesis upon HDV infection or HDV protein expression. Additionally, HDV infection or expression of HDAg alone specifically accelerated the decay of HBV RNA, and HDAg was associated with HBV RNAs. On the contrary, HDAg expression did not affect other viruses such as HCV or SARS-CoV-2.

CONCLUSIONS

Our data indicate that HDV interferes with HBV through both IFN-dependent and IFN-independent mechanisms. Specifically, we uncover a new viral interference mechanism in which proteins of a satellite virus affect the RNA production of its helper virus. Exploiting these findings could pave the way to the development of new therapeutic strategies against HBV.

IMPACT AND IMPLICATIONS

Although the molecular mechanisms remained unexplored, it has long been known that despite its dependency, HDV decreases HBV viremia in patients. Herein, using in vitro and in vivo models, we showed that HDV interferes with HBV through both IFN-dependent and IFN-independent mechanisms affecting HBV RNA metabolism, and we defined the HDV-induced modulation signature. The mechanisms we uncovered could pave the way for the development of new therapeutic strategies against HBV by mimicking and/or increasing the effect of HDAg on HBV RNA. Additionally, the HDV-induced modulation signature could potentially be correlated with responsiveness to IFN-α treatment, thereby helping to guide management of HBV/HDV-coinfected patients.

Current knowledge on Hepatitis Delta Virus replication

Hepatitis B Virus (HBV) that infects liver parenchymal cells is responsible for severe liver diseases and co-infection with Hepatitis Delta Virus (HDV) leads to the most aggressive form of viral hepatitis. Even tough being different for their viral genome (relaxed circular partially double stranded DNA for HBV and circular RNA for HDV), HBV and HDV are both maintained as episomes in the nucleus of infected cells and use the cellular machinery for the transcription of their viral RNAs. We propose here an update on the current knowledge on HDV replication cycle that may eventually help to identify new antiviral targets.

Comprehensive Analysis of the mRNA-lncRNA Co-expression Profile and ceRNA Networks Patterns in Chronic Hepatitis B

Background:

Long non-coding RNAs (lncRNAs) are emerging as important regulators in the modulation of virus infection by targeting mRNA transcription. However, their roles in chronic hepatitis B (CHB) remain to be elucidated.

Objective:

The study aimed to explore the lncRNAs and mRNA expression profiles in CHB and asymp-tomatic HBsAg carriers (ASC) and construct mRNA-lncRNA co-expression profile and ceRNA net-works to identify the potential targets of diagnosis and treatment in CHB.

Methods:

We determined the expression profiles of lncRNAs and mRNAs in CHB and ASC using mi-croarray analysis. Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) path-way enrichment analyses were performed to explore their function. We also constructed co-expression, cis-regulatory, and competing endogenous RNA (ceRNA) networks with bioinformatics methods.

Results:

We identified 1634 mRNAs and 5550 lncRNAs that were differentially expressed between CHB and ASC. Significantly enriched GO terms and pathways were identified, many of which were linked to immune processes and inflammatory responses. Co-expression analysis showed 1196 relation-ships between the top 20 up/downregulated lncRNAs and mRNA, especially 213 lncRNAs interacted with ZFP57. The ZFP57-specific ceRNA network covered 3 lncRNAs, 5 miRNAs, and 17 edges. Cis-correlation analysis showed that lncRNA T039096 was paired with the most differentially expressed gene, ZFP57. Moreover, by expending the clinical samples size, the qRT-PCR results showed that the expression of ZFP57 and T039096 increased in CHB compared to ASC.

Conclusion:

Our study provides insights into the roles of mRNA and lncRNA networks in CHB, high-lighting potential applications of lncRNA-T039096 and mRNA-ZFP57 for diagnosis and treatment.

HDV infection in immigrant populations

AIMS

Little data have been published so far on the epidemiological aspects of hepatitis D virus (HDV) infection in immigrant populations and even poorer is the information on the virological, phylogenetic, and clinical aspects of this infection in these populations. This review article, aimed primarily at physicians caring for immigrants, summarizes the information available on HDV infection and analyzes data on this topic concerning the immigrant populations.

METHODS AND RESULTS

The prevalence of HDV infection in HBsAg-positive immigrants varies according to the country of origin. For example, in immigrants from sub-Saharan Africa, this prevalence is higher in those born in Equatorial Guinea (24.4%) than those from other African countries (10.3%). The epidemiological impact of HDV infection linked to migratory flows is a function of the different endemicity between countries of origin and countries in which a new existence has been established. This impact is high when immigrants from areas endemic to HDV infection (eg, Equatorial Guinea) settle in areas of low endemicity (eg, Germany or England, with a prevalence of around 4%), while the impact is lesser or nonexistent if the migratory flows are directed toward countries with intermediate endemicity (eg, Italy and Greece, with a prevalence of around 10%).

CONCLUSION

This impact of immigration on HDV epidemiology can be strong when HDV endemicity is high in the country of origin and low in the host country and slight when immigrants move to high or medium endemic countries.

Prevalence of Hepatitis C virus genotypes in nine selected European countries: A systematic review

BACKGROUND

Hepatitis C virus (HCV) infection is a global health problem especially for its increasing level of mortality. Detailed knowledge of HCV genotypes prevalence has clinical relevance since the efficacy of therapies is impacted by genotypes and subtypes distribution. Moreover, HCV exhibits a great genetic variability regionally. To date, there are no published studies assessing HCV genotypes distribution in specific countries of the Mediterranean basin. The aim of this study was to review data published from 2000 to 2017 with the purpose to estimate genotypes distribution of HCV infection in nine European countries all located in the Mediterranean basin.

METHODS

A systematic research of peer-reviewed journals indexed in PubMed, Scopus, and EMBASE databases selected if containing data regarding distribution of HCV genotypes in nine selected European countries (Albania, Bosnia, Croatia, France, Greece, Italy, Montenegro, Slovenia, and Spain) was performed.

RESULTS

Genotype 1 is the most common (61.0%), ranging from 80.0% in Croatia to 46.0% in Greece, followed by genotype 3 (20.0%), varying from 38.0% in Slovenia to 7.0% and 8.0%, respectively, in Italy and in Albania and by genotype 4 (10.0%) that shows an increase of 1.1% with respect to data obtained till 2014 probably due to the increasing migrants arrivals to Southern Europe. G2, the fourth most frequent genotype (8.5%), particularly common in Italy (27.0%) and Albania (18.0%) might be probably introduced in Southern Italy as a result of Albanian campaign during Second World War and more and more increased by the migration flows from Albania to Italy in the 90s.

CONCLUSION

Epidemiology of HCV infection shows a high variability across the European countries that border the Mediterranean Sea. HCV genotyping is a relevant tool to monitor the dynamic process influenced by both evolving transmission trends and new migration flows on HCV scenario.

Prevalence of Hepatitis C virus genotypes in nine selected European countries: A systematic review

BACKGROUND

Hepatitis C virus (HCV) infection is a global health problem especially for its increasing level of mortality. Detailed knowledge of HCV genotypes prevalence has clinical relevance since the efficacy of therapies is impacted by genotypes and subtypes distribution. Moreover, HCV exhibits a great genetic variability regionally. To date, there are no published studies assessing HCV genotypes distribution in specific countries of the Mediterranean basin. The aim of this study was to review data published from 2000 to 2017 with the purpose to estimate genotypes distribution of HCV infection in nine European countries all located in the Mediterranean basin.

METHODS

A systematic research of peer-reviewed journals indexed in PubMed, Scopus, and EMBASE databases selected if containing data regarding distribution of HCV genotypes in nine selected European countries (Albania, Bosnia, Croatia, France, Greece, Italy, Montenegro, Slovenia, and Spain) was performed.

RESULTS

Genotype 1 is the most common (61.0%), ranging from 80.0% in Croatia to 46.0% in Greece, followed by genotype 3 (20.0%), varying from 38.0% in Slovenia to 7.0% and 8.0%, respectively, in Italy and in Albania and by genotype 4 (10.0%) that shows an increase of 1.1% with respect to data obtained till 2014 probably due to the increasing migrants arrivals to Southern Europe. G2, the fourth most frequent genotype (8.5%), particularly common in Italy (27.0%) and Albania (18.0%) might be probably introduced in Southern Italy as a result of Albanian campaign during Second World War and more and more increased by the migration flows from Albania to Italy in the 90s.

CONCLUSION

Epidemiology of HCV infection shows a high variability across the European countries that border the Mediterranean Sea. HCV genotyping is a relevant tool to monitor the dynamic process influenced by both evolving transmission trends and new migration flows on HCV scenario.

Differential prevalence and geographic distribution of hepatitis C virus genotypes in acute and chronic hepatitis C patients in Vietnam

BACKGROUND

The highest burden of disease from hepatitis C virus (HCV) is found in Southeast Asia, but our understanding of the epidemiology of infection in many heavily burdened countries is still limited. In particular, there is relatively little data on acute HCV infection, the outcome of which can be influenced by both viral and host genetics which differ within the region. We studied HCV genotype and IL28B gene polymorphism in a cohort of acute HCV-infected patients in Southern Vietnam alongside two other cohorts of chronic HCV-infected patients to better understand the epidemiology of HCV infection locally and inform the development of programs for therapy with the increasing availability of directly acting antiviral therapy (DAAs).

METHODS

We analysed plasma samples from patients with acute and chronic HCV infection, including chronic HCV mono-infection and chronic Human Immunodeficiency Virus (HIV)-HCV coinfection, who enrolled in four epidemiological or clinical research studies. HCV infection was confirmed with RNA testing. The 5' UTR, core and NSB5 regions of HCV RNA positive samples were sequenced, and the genotype and subtype of the viral strains were determined. Host DNA from all HCV positive patients and age- and sex-matched non-HCV-infected control individuals were analysed for IL28B single nucleotide polymorphism (SNP) (rs12979860 and rs8099917). Geolocation of the patients were mapped using QGIS.

RESULTS

355 HCV antibody positive patients were analysed; 54.6% (194/355) and 46.4% (161/355) were acute and chronic infections, respectively. 50.4% (81/161) and 49.6.4% (80/161) of chronic infections had HCV mono-infection and HIV-HCV coinfection, respectively. 88.7% (315/355) and 10.1% (36/355) of the patients were from southern and central regions of Vietnam, respectively. 92.4% (328/355) of patients were HCV RNA positive, including 86.1% (167/194) acute and 100% (161/161) chronic infections. Genotype could be determined in 98.4% (322/328) patients. Genotypes 1 (56.5%; 182/322) and 6 (33.9%; 109/322) predominated. Genotype 1 including genotype 1a was significantly higher in HIV-HCV coinfected patients compared to acute HCV patients [43.8% (35/80) versus 20.5% (33/167)], (p = <0.001), while genotype 6 was significantly higher in chronic HCV mono-infected patients [(44.4% (36/81) versus 20.0% (16/80)] (p = < 0.004) compared to HIV-HCV coinfected patients. The prevalence of IL28B SNP (rs12979860) homozygous CC was 86.46% (83/96) in control individuals and was significantly higher in acutely-infected compared to chronically-infected patients [93.2 (82/88) versus 76.1% (35/46)] (p = < 0.005).

CONCLUSION

HCV genotype 6 is highly prevalent in Vietnam and the high prevalence in treatment naïve chronic HCV patients may results from poor spontaneous clearance of acute HCV infection with genotype 6.

Profile of HBV Integration in the Plasma DNA of Hepatocellular Carcinoma Patients

Background:

Hepatitis B Viral (HBV) infection is one of the major causes of Hepatocellular Carcinoma (HCC). Mounting evidence had provided that the HBV integration might be a critical con-tributor of HCC carcinogenesis.

Objective and Methods:

To explore the profile of HBV integration in the plasma DNA, the method of next-generation sequencing, HBV capture and bioinformatics had been employed to screen for HBV in-tegration sites in the plasma samples.

Results:

In the initial experiment, a total of 87 breakpoints were detected in the 20 plasma samples. The distribution of breakpoints showed that there was significant enrichment of breakpoints in the region of intron. Furthermore, the HBV breakpoints were prone to occur in the region of X protein (1,700-2,000bp) in the plasma samples. The pathway analysis had revealed that the HBV integrations sites were specifically enriched in the cancer pathway.

Conclusion:

Altogether, our results had provided direct evidence for the HBV integration in plasma DNA, and they might be potentially useful for future HCC prognosis and diagnosis.

Nine-year distribution pattern of hepatitis C virus (HCV) genotypes in Southern Italy

INTRODUCTION

It has been greatly described that different hepatitis C virus (HCV) genotypes are strictly correlated to various evolution, prognosis and response to therapy during the chronic liver disease. Aim of this study was to outline the changes in the epidemiology of Hepatitis C genotypes in Southern Italy regions from 2006 to 2014.

MATERIAL/METHODS

Prevalence of HCV genotypes was analyzed in 535 HCV-RNA positive patients with chronic Hepatitis C infection, selected during the period 2012-2014, and compared with our previous data, referred to periods 2006-2008 and 2009-2011.

RESULTS

In all the three periods analyzed, genotype 1b is predominant (51.8% in 2006-08, 48.3% in 2009-11 and 54.4% in 2012-14) while genotype 2 showed an increase in prevalence (27.9% in 2006-08, 31.7% in 2009-11 and 35.2% in 2012-14) and genotypes 3a and 1a a decrease during the same period (6.8% in 2006-08, 4.7% in 2009-11 and 3.2% in 2012-14 and 7.9% in 2006-08, 4.7% in 2009-11 and 2.6% in 2012-14, respectively). Subtype 1b seems to be equally distributed between males and females (52.7% vs 56.6%) and the prevalence in the age range 31-40 years is significantly higher in the 2012-14 period than in both previous periods (53.8% vs. 16.6% in 2009-11, p< 0.001 and 13.4% in 2006-08, p < 0.001).

CONCLUSIONS

Genotype 1b is still the most prevalent, even if shows a significantly increase in the under 40 years old population. Instead, genotype 3a seems to have a moderate increase among young people. Overall, the alarming finding is the "returning" role of the iatrogenic transmission as risk factor for the diffusion of Hepatitis C infection.

Pathogenesis of and New Therapies for Hepatitis D

Hepatitis delta virus (HDV) infection of humans was first reported in 1977, and now it is now estimated that 15-20 million people are infected worldwide. Infection with HDV can be an acute or chronic process that occurs only in patients with an hepatitis B virus infection. Chronic HDV infection commonly results in the most rapidly progressive form of viral hepatitis; it is the chronic viral infection that is most likely to lead to cirrhosis, and it is associated with an increased risk of hepatocellular carcinoma. HDV infection is the only chronic human hepatitis virus infection without a therapy approved by the US Food and Drug Administration. Peginterferon alfa is the only recommended therapy, but it produces unsatisfactory results. We review therapeutic agents in development, designed to disrupt the HDV life cycle, that might benefit patients with this devastating disease.

Concurrent and reactivation of hepatitis B virus infection in diffuse large B-cell lymphoma: risk factors and survival outcome

Objective

To determine the clinical features and survival difference of HBV related and Non-HBV related diffuse large B-cell lymphoma (DLBCL) and to evaluate the occurrence of HBV reactivation in DLBCL patients and related risk factors for HBV reactivation after R-CHOP therapy.

Methods

A total of 246 patients diagnosed with CD20+ DLBCL were enrolled from June 2010 to June 2015. The medical records and survival data were analysed. Multivariate logistic regression analysis was used to identify predictors of HBV reactivation. Survival curves were performed by the Kaplan-Meier method.

Results

Among patients enrolled, 80 patients were HBsAg sero-positive and 166 patients were HBsAg sero-negative. Findings showed that HBsAg sero-negative patients were significantly older than that of patients with HBsAg sero-positive (P <  0.001). Proportion of B symptom positive patients in HBsAg sero-positive were higher (p = 0.002). Higher LDH level (P = 0.019) and late Ann Arbor stage (P = 0.010) were more often observed in patients with HBsAg sero-positive. The rate of complete response, partial response, stable disease and progress disease in HBsAg sero-negative group were 63.9, 16.9, 1.1 and 18.1%, respective, which is significantly higher than that in HBsAg sero-positive group (36.2, 18.8, 1.2 and 43.8%). Kaplan-Meier analysis showed that DLBCL patients with HBsAg sero-negative had better prognosis. In total, 17 patients showed HBV reactivation among 166 patients (10.2%) with HBsAg sero-negative after R-CHOP treatment, while a significant higher HBV reactivation 18.75% (9/48) in HBsAb negative group were observed, with 8.25% (8/97) patients in HBsAb level 10-100 U/mL group, and 0% patients in HBsAb level higher than 100 U/mL group. Multivariable analysis showed that serum HBsAb and serum HBcAb were independent risk factors for HBV reactivation in DLBCL patients.

Conclusion

Our data revealed that characteristics and prognosis were significantly different between HBV related DLBCL than non-HBV related DLBCL patients. DLBCL patients with resolved hepatitis B are at a higher risk of developing HBV reactivation after R-CHOP chemotherapy compared with HBsAg-negative/HBcAb negative patients.

Tenofovir disoproxil fumarate reduce incidence of HCC development in CHB-patients with compensated cirrhosis

Background

The impact of different anti-virus regimens on prognosis of Chronic hepatitis B (CHB) related cirrhosis remains to be explored. We aim to investigate whether CHB-related HCC patients receiving nucleoside analogue regimen or not have a different prognosis.

Methods

Two hundred forty-two CHB-related compensated cirrhosis patients were attributed into groups regarding their anti-virus regimens containing tenofovir disoproxil fumarate (TDF) or not. The results of two groups were reviewed and investigated. The probability of hepatocellular carcinoma (HCC) development among each group were analyzed and compared.

Results

Two hundred forty-two CHB-related compensated cirrhosis patients from 2008 June to 2011 December were included in our study. One hundred twenty-seven patients received anti-virus regimen containing TDF and 115 patients received anti-virus regimen without TDF. Child-Pugh score, alanine aminotransferase (ALT), total bilirubin level, status of hepatitis B e antigen (HBeAg) and serum HBV DNA level were compared between groups. The cumulative probability of HCC development in TDF-contained group were significantly lower than it in non-TDF-contained group (p < 0.05). Multi-variant analysis indicated that TDF-containing regimen treatment was significantly associated with lower probability of HCC development, (hazard ratio, 0.18; 95% confidence interval range, 0.07-0.45, p < 0.05).

Conclusion

Anti-virus regimen containing TDF benefits for the prognosis of CHB-related liver cirrhosis patients.

Hepatitis delta virus and hepatocellular carcinoma: an update

Hepatitis delta virus (HDV) is a defective RNA virus that depends on the presence of hepatitis B virus (HBV) for the creation of new virions and propagation of the infection to hepatocytes. Chronic infection with HDV is usually associated with a worsening of HBV infection, leading more frequently to cirrhosis, increased risk of liver decompensation and hepatocellular carcinoma (HCC) occurrence. In spite of a progressive declining prevalence of both acute and chronic HDV infection observed over several years, mainly due to increased global health policies and mass vaccination against HBV, several European countries have more recently observed stable HDV prevalence mainly due to migrants from non-European countries. Persistent HDV replication has been widely demonstrated as associated with cirrhosis development and, as a consequence, development of liver decompensation and occurrence of HCC. Several treatment options have been attempted with poor results in terms of HDV eradication and improvement of long-term prognosis. A global effort is deemed urgent to enhance the models already existing as well as to learn more about HDV infection and correlated tumourigenesis mechanisms.

Dynamics of in vivo hepatitis D virus infection

Hepatitis-D virus (HDV) is a satellite virus of hepatitis-B virus (HBV) whose intracellular products are required for the completion of the HDV life cycle. HDV can replicate in a cell without the presence of HBV but needs hepatitis B surface antigen (HBsAg) to complete virus assembly and packaging. In order to better understand HDV dynamics, we developed a mathematical model and successfully simulated HBV and HDV data under a range of scenarios. Compared to HBV mono-infection, dual HDV infection resulted in lower chronic HBV DNA levels, with more marked suppression for coinfection (1 logs HBV DNA copies/ml lower) compared to superinfection (0.6 logs HBV DNA copies/ml). Although they have no effect on HBV, prenylation inhibitors may provide the best therapy for reducing HDV viremia irrespective of the stage in which they are commenced. We found that highly effective long term pegylated interferon (IFN) therapy (99.99%) eliminates HBV and HDV viremia while less effective long term IFN therapy (99%) will only produce approximately 2.03 logs and no decrease in HBV and HDV viremia respectively in both coinfection and superinfection settings. Our study also suggests that there is a substantial difference in the outcome of therapies depending upon the time of commencement.

CONCLUSION

Mathematical modeling of HDV infection can describe the complex interplay between this virus and HBV. Simulations suggest that HDV impacts on the feedback mechanisms that maintain cccDNA levels and that targeting these mechanisms may result in new therapeutic agents for both viruses.

Hepatitis B and Delta Virus: Advances on Studies about Interactions between the Two Viruses and the Infected Hepatocyte

The mechanisms determining persistence of hepatitis B virus (HBV) infection and long-term pathogenesis of HBV-associated liver disease appear to be multifactorial. Although viral replication can be efficiently suppressed by the antiviral treatments currently available, viral clearance is generally not achieved since HBV has developed unique replication strategies, enabling persistence of its genome within the infected hepatocytes. Moreover, no direct antiviral therapy exists for the more than 15 million people worldwide that are also coinfected with the hepatitis delta virus (HDV), a defective virus that needs the HBV envelope proteins for propagation. The limited availability of robust HBV and HDV infection systems has hindered the understanding of the complex network of virus-virus and virus-host interactions that are established in the course of infection and slowed down progress in drug development. Since chronic HBV/HDV coinfection leads to the most severe form of chronic viral hepatitis, elucidation of the molecular mechanisms regulating virus-host interplay and pathogenesis are urgently needed. This article summarizes the current knowledge regarding the interactions among HBV, HDV, and the infected target cell and discusses the dependence of HDV on HBV activity and possible future therapeutic approaches.

HBeAg-positive hepatitis delta: virological patterns and clinical long-term outcome

BACKGROUND AND AIMS

The presence of the hepatitis B virus (HBV)-eAg in patients with hepatitis B is associated with higher HBV replication and with an increased risk to develop liver-related clinical endpoints defined as liver related death, liver transplantation, development of hepatocellular carcinoma and hepatic decompensation. The aim of this study was to investigate the role of HBeAg in patients co-infected with the hepatitis D virus (HDV).

METHODS

We studied virological markers of HBV and HDV infection and as well as biochemical and clinical features of liver disease in a cohort of 534 anti-HDV-positive patients. In addition, we compared the clinical long-term outcome of HBeAg-positive HDV-infected patients with HBeAg-negative control patients matched for age, gender and baseline-MELD score.

RESULTS

HBeAg-positive hepatitis delta was detected in 71 of 534 patients (13.3%). HBeAg positivity was associated with a higher biochemical disease activity and higher HBsAg levels in HDV co-infected patients. Sixty one per cent of the HBeAg-positive HDV-infected patients presented with HBV DNA levels below 2000 IU/ml, at least once during follow-up. Both HBeAg-positive and -negative patients showed a similar severe clinical long-term course with about half of the patients developing a liver-related clinical complication after a median follow-up period of 51 months (range: 9-193 months).

CONCLUSIONS

HBV DNA levels are low in both HBeAg-negative and HBeAg-positive patients suggesting suppressive effects of HDV on HBV irrespective of the phase of HBV infection. The clinical long-term outcome of HBeAg-positive patients is not different to HBeAg-negative patients infected with the HDV.

Hepatocellular carcinoma in hepatitis D: does it differ from hepatitis B monoinfection?

BACKGROUND/AIM

Hepatitis D virus (HDV) superinfection in patients with chronic hepatitis B leads to accelerated liver injury, early cirrhosis, and decompensation. It may be speculated that hepatocellular carcinoma (HCC) may differ in these patients from hepatitis B virus (HBV) monoinfection. The aim of this study was to compare clinical aspects of hepatocellular carcinoma in patients of hepatitis D with HBV monoinfection.

PATIENTS AND METHODS

A total of 92 consecutive HCC cases seropositive for antibody against HDV antigen (HDV group) were compared with 92 HBsAg-positive and anti-HDV-negative cases (HBV group).

RESULTS

The features including sex, body mass index, presence of ascites, serum biochemistry, gross tumor appearance, child class, barcelona cancer liver clinic and okuda stages were not significantly different between the 2 groups. Decreased liver size was noticed more in cases of HDV compared with HBV group where the liver size was normal or increased (P=0.000). HDV patients had lower platelets (P=0.053) and larger varices on endoscopy (P=0.004). Multifocal tumors and elevated alpha-fetoprotein level >1000 IU/mL were more common in HBV group (P=0.040 and P= 0.061). TNM classification showed more stage III-IV disease in HBV group (P=0.000).

CONCLUSION

Decreased liver size and indirect evidence of more severe portal hypertension and earlier TNM stage compared with HBV monoinfection indicate that HDV infection causes HCC in a different way, possibly indirectly by inducing inflammation and cirrhosis.

Virologic and clinical expressions of reciprocal inhibitory effect of hepatitis B, C, and delta viruses in patients with chronic hepatitis

We studied 648 hepatitis B surface antigen (HBsAg)- and/or anti-hepatitis C virus (HCV)-positive patients to evaluate the virologic and clinical characteristics of multiple hepatitis viral infection. We defined as Case B-C an HBsAg/anti-HCV positive patient and as Case b-C an anti-HCV/anti-HBc-positive, HBsAg/anti-HBs-negative patient. For each Case B-C we scheduled as Control-B an HBsAg positive and anti-HCV negative patient and as Control-C an HBsAg/anti-HBs/anti-hepatitis B core antigen (HBc)-negative and anti-HCV-positive patient. Control group C was used as the control also for Case group b-C. Serum HBV DNA by molecular hybridization was found more frequently in Control group B (54% of 161 patients) than in Case group B-C (35.7% of 84, P <.01). The prevalence of HBV wild type was similar in Case group B-C (14. 3%) and in Control group B (17.4%), whereas the e-minus strain was less frequent in Case group B-C (10.7% vs. 33%; P <.01). HBV DNA by polymerase chain reaction (PCR) was detected in 40.8% of 71 patients in Case group b-C. HCV RNA was detected more frequently in Control group C (90.7% of 130 patients) than in Case group B-C (65.2% of 69, P <.0001). Moderate or severe chronic hepatitis or cirrhosis were more frequent in Case group B-C (62.9% of 65 patients) than in Control group B (46.7% of 90, P <.05) or C (40.8% of 98, P <.005), and in Case group b-C (71.1% of 76) than in Control group C. Thus, in multiple hepatitis we observed a reciprocal inhibition of the viral genomes and a more severe liver disease. In Case group b-C, serum HBV DNA was frequent and the clinical presentation was severe.

Hepatitis delta virus RNA in serum of patients with chronic delta hepatitis

We studied 28 patients with chronic delta hepatitis for the presence of hepatitis delta virus (HDV) RNA in serum. The hot start polymerase chain reaction (PCR) method, in which the reaction begins at 60-80 degrees C, showed a higher sensitivity than conventional PCR reaction. Additionally, the presence of hepatitis B (HBV) and C virus (HCV) infections were determined by PCR. HDV RNA was detected in 26 patients (93%), HBV DNA in 22 (79%), and HCV RNA in only one. Detection of HDV RNA correlated very well with detection of hepatitis delta antigen by immunostaining in the liver. In six patients HDV RNA was detectable despite the absence of HBV DNA in serum, suggesting that high levels of HBV are not required for HDV replication. Of 29 control patients with chronic hepatitis B without antibody to HDV, none had detectable HDV RNA, while all had HBV DNA in serum. Detection of HDV RNA with PCR proved highly sensitive and specific, demonstrating that virtually all patients with chronic HDV infection had ongoing viral replication.