Is there a need for universal double reflex testing of HBsAg-positive individuals for hepatitis D infection?

Hepatitis D virus(HDV)can infect HBsAg-positive individuals,causing rapid fibrosis progression,early decompensation,increased hepatocellular carcinoma risk,and higher mortality than hepatitis B virus(HBV)mono-infection.Most countries lack high-quality HDV prevalence data,and the collection techniques employed often bias published data.In recent meta-analyses,HDV prevalence in HBsAg-positive patients reaches 5%-15%and is even significantly higher in endemic areas.Since HBV vaccination programs were implemented,HDV prevalence has decreased among younger populations.However,owing to immigrant influx,it has increased in some Western countries.The current practice of HDV screening in HBsAg-positive individuals is stepwise,based on physician’s discretion,and limited to at-risk populations and may require numerous visits.Double reflex testing,which includes anti-HDV testing in all HBsAg-positive individuals and then HDV RNA testing for anti-HDV-positive ones,is uncommon.Reflex testing can identify more HDV infection cases and link identified patients to further care and follow-up.Moreover,laboratory-based double reflex screening is less biased than physician-led testing.Therefore,health-care providers should learn about reflex testing,and federal and provincial hepatitis control programs should implement laboratory-based double reflex testing to obtain reliable HDV prevalence estimates.The test’s cost-effectiveness depends on the number of HBV-positive patients screened to identify one HDV-positive patient.Such testing may be viable in areas with low HBsAg but high HDV prevalence.However,its economic impact on areas with low HDV prevalence needs further study.

Hepatitis D virus dual-infection among Chinese hepatitis B patient related to hepatitis B surface antigen,hepatitis B virus DNA and age

The screening practices for hepatitis D virus(HDV)are diverse and nonstandardized worldwide,and the exact prevalence of HDV is uncertain.AIM To estimate HDV prevalence and investigate viral marker quantity trends in patients with hepatitis D.METHODS We collected 5594 serum samples from patients with hepatitis B in Jilin Province,China(3293 males and 2301 females,age range of 2 to 89 years).We then conducted tests for hepatitis B surface antigen(HBsAg),hepatitis B Virus(HBV)DNA,anti-hepatitis D antigen(HDAg),and HDV RNA.RESULTS We found that the prevalence of anti-HDAg and HDV RNA among hepatitis B patient were 3.6%(3.2-4.2%)and 1.2%(0.9-1.5%),respectively,87.69%of hepatitis D patients were 51-70 years old.HDV infection screening positive rate of patients with HBV DNA levels below 2000 IU/mL(2.0%)was higher than those above 2000 IU/mL(0.2%).Among anti-HDAg positive patients,the HDV RNA positive rate was positively correlated with the HBsAg level and anti-HDAg level.There was a weak correlation between HBsAg and anti-HDAg levels among hepatitis D patients.CONCLUSION Our study highlights the importance of considering multiple factors when assessing the severity of HDV infection,comprehensive evaluation of patients’clinical and laboratory parameters is necessary for proper diagnosis and treatment.

Hepatitis D virus infection, replication and cross-talk with the hepatitis B virus

Viral hepatitis remains a worldwide public health problem.The hepatitis D virus(HDV)must either coinfect or superinfect with the hepatitis B virus(HBV).HDV contains a small RNA genome(approximately 1.7 kb)with a single open reading frame(ORF)and requires HBV supplying surface antigens(HBsAgs)to assemble a new HDV virion.During HDV replication,two isoforms of a delta antigen,a small delta antigen(SDAg)and a large delta antigen(LDAg),are produced from the same ORF of the HDV genome.The SDAg is required for HDV replication,whereas the interaction of LDAg with HBsAgs is crucial for packaging of HDV RNA.Various clinical outcomes of HBV/HDV dual infection have been reported,but the molecular interaction between HBV and HDV is poorly understood,especially regarding howHBV and HDV compete with HBsAgs for assembling virions.In this paper,we review the role of endoplasmic reticulum stress induced by HBsAgs and the molecular pathway involved in their promotion of LDAg nuclear export.Because the nuclear sublocalization and export of LDAg is regulated by posttranslational modifications(PTMs),including acetylation,phosphorylation,and isoprenylation,we also summarize the relationship among HBsAg-induced endoplasmic reticulum stress signaling,LDAg PTMs,and nuclear export mechanisms in this review.

Innate immune recognition and modulation in hepatitis D virus infection

Hepatitis D virus(HDV)is a global health threat with more than 15 million humans affected.Current treatment options are largely unsatisfactory leaving chronically infected humans at high risk to develop liver cirrhosis and hepatocellular carcinoma.HDV is the only human satellite virus known.It encodes only two proteins,and requires Hepatitis B virus(HBV)envelope protein expression for productive virion release and spread of the infection.How HDV could evolve and why HBV was selected as a helper virus remains unknown.Since the discovery of Na+-taurocholate co-transporting polypeptide as the essential uptake receptor for HBV and HDV,we are beginning to understand the interactions of HDV and the immune system.While HBV is mostly regarded a stealth virus,that escapes innate immune recognition,HBV-HDV coinfection is characterized by a strong innate immune response.Cytoplasmic RNA sensor melanoma differentiation antigen 5 has been reported to recognize HDV RNA replication and activate innate immunity.Innate immunity,however,seems not to impair HDV replication while it inhibits HBV.In this review,we describe what is known up-to-date about the interplay between HBV as a helper and HDV’s immune evasion strategy and identify where additional research is required.

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-hepatitiscaused 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.

"Defective" mutations of hepatitis D viruses in chronic hepatitis D patients

AIM: To verify whether 'defective' mutations existed in hepatitis D virus (HDV).METHODS: Hepatitis delta antigen (HDAg)-codingsequences were amplified using Pfu DNA polymerases with proof-reading activities from sera of five patients with chronic hepatitis D. Multiple colonies were sequenced for each patient. Pfu analyzed a total of 270 HDV clones.Three representative defective HDV clones were constructed in expression plasmids and transfected into a human hepatoma cell line. Cellular proteins were extracted and analyzed by Western blot.RESULTS: Four of five cases (80%) showed defective HDV genomes in their sera. The percentage of defective genomes was 3.7% (10/270). The majority (90%) of the defective mutations were insertions or deletions that resulted in frameshift and abnormal stop translation of the HDAg. The predicted mutated HDAg ranged from 45amino acids to ＞214 amino acids in length. Various domains of HDAg associated with viral replication or packaging were affected in different HDV isolates. Western blot analysis showed defected HDAg in predicted positions.CONCLUSION: 'Defective' viruses do exist in chronic HDV infected patients, but represented as minor strains. The clinical significance of the 'defected' HDV needs further study to evaluate.

Viral hepatitis update: Progress and perspectives

Viral hepatitis,secondary to infection with hepatitis A,B,C,D,and E viruses,are a major public health problem and an important cause of morbidity and mortality.Despite the huge medical advances achieved in recent years,there are still points of conflict concerning the pathogenesis,immune response,development of new and more effective vaccines,therapies,and treatment.This review focuses on the most important research topics that deal with issues that are currently being solved,those that remain to be solved,and future research directions.For hepatitis A virus we will address epidemiology,molecular surveillance,new susceptible populations as well as environmental and food detections.In the case of hepatitis B virus,we will discuss host factors related to disease,diagnosis,therapy,and vaccine improvement.On hepatitis C virus,we will focus on pathogenesis,immune response,direct action antivirals treatment in the context of solid organ transplantation,issues related to hepatocellular carcinoma development,direct action antivirals resistance due to selection of resistanceassociated variants,and vaccination.Regarding hepatitis D virus,we describe diagnostic methodology,pathogenesis,and therapy.Finally,for hepatitis E virus,we will address epidemiology(including new emerging species),diagnosis,clinical aspects,treatment,the development of a vaccine,and environmental surveillance.

Viral hepatitis and hepatocellular carcinoma:From molecular pathways to the role of clinical surveillance and antiviral treatment

Hepatocellular carcinoma(HCC)is a global health challenge.Due to the high prevalence in low-income countries,hepatitis B virus(HBV)and hepatitis C virus infections remain the main risk factors for HCC occurrence,despite the increasing frequencies of non-viral etiologies.In addition,hepatitis D virus coinfection increases the oncogenic risk in patients with HBV infection.The molecular processes underlying HCC development are complex and various,either independent from liver disease etiology or etiology-related.The reciprocal interlinkage among non-viral and viral risk factors,the damaged cellular microenvironment,the dysregulation of the immune system and the alteration of gutliver-axis are known to participate in liver cancer induction and progression.Oncogenic mechanisms and pathways change throughout the natural history of viral hepatitis with the worsening of liver fibrosis.The high risk of cancer incidence in chronic viral hepatitis infected patients compared to other liver disease etiologies makes it necessary to implement a proper surveillance,both through clinical-biochemical scores and periodic ultrasound assessment.This review aims to outline viral and microenvironmental factors contributing to HCC occurrence in patients with chronic viral hepatitis and to point out the importance of surveillance programs recommended by international guidelines to promote early diagnosis of HCC.

Impact of comorbidities on the severity of chronic hepatitis B at presentation

AIM:To evaluate the clinical relevance of each cofactor on clinical presentation of chronic hepatitis B.METHODS:Out of 1366 hepatitis B surface antigen(HBsAg) positive subjects consecutively observed in 79 Italian hospitals,53(4.3%) showed as the only cofactor hepatitis D virus(HDV) infection [hepatitis B virus(HBV)/HDV group],130(9.5%) hepatitis C virus(HCV)(group HBV/HCV),6(0.4%) human immunodeficiencyvirus(HIV)(group HBV/HIV),138(10.2%) alcohol abuse(group HBV/alcohol);109(8.0%) subjects had at least two cofactors and 924 were in the cofactor-free(CF) group.RESULTS:Compared with patients in group CF those in group HBV/alcohol were older and more frequently had cirrhosis(P < 0.001),those in group HBV/HDV were younger(P < 0.001),more frequently resided in the south of the country and had cirrhosis(P <0.001),those in group HBV/HCV were older(P < 0.001) and more frequently had cirrhosis(P < 0.001).These cofactors were all independent predictors of liver cirrhosis in HBsAg positive patients.Multivariate analysis showed that an older age [odds ratio(OR) 1.06,95% CI:1.05-1.08],alcohol abuse with more than 8 drinks daily(OR 2.89,95% CI:1.81-4.62) and anti-HDV positivity(OR 3.48,95% CI:2.16-5.58) are all independently associated with liver cirrhosis.This association was found also for anti-HCV positivity in univariate analysis,but it was no longer associated(OR 1.23,95% CI:0.84-1.80) at multivariate analysis.CONCLUSION:Older age,HDV infection and alcohol abuse are the major determinants of severe liver disease in chronic HBV infection,while HCV replication plays a lesser role in the severity of hepatic damage.

Update on the management and treatment of viral hepatitis

This review aims to summarize the current evidence on the treatment of viral hepatitis,focusing on its clinical management.Also,future treatment options and areas of potential research interest are detailed.PubMed and Scopus databases were searched for primary studies published within the last ten years.Keywords included hepatitis A virus,hepatitis B virus(HBV),hepatitis C virus,hepatitis D virus(HDV),hepatitis E virus,and treatment.Outcomes reported in the studies were summarized,tabulated,and synthesized.Significant advances in viral hepatitis treatment were accomplished,such as the advent of curative therapies for hepatitis C and the development and improvement of hepatitis A,hepatitis B,and hepatitis E vaccination.Drugs that cure hepatitis B,going beyond viral suppression,are so far unavailable;however,targeted antiviral drugs against HBV(immunomodulatory therapies and gene silencing technologies)are promising approaches to eradicating the virus.Ultimately,high vaccination coverage and large-scale test-and-treat programmes with high screening rates may eliminate viral hepatitis and mitigate their burden on health systems.The development of curative hepatitis C treatment renewed the enthusiasm for curing hepatitis B,albeit further investigation is required.Novel therapeutic options targeting HDV life cycle are currently under clinical investigation.

Co-treatment with pegylated interferon alfa-2a and entecavir for hepatitis D: a randomized trial

AIM: To investigate the efficacy of pegylated interferon alfa(PEG-IFNα) therapy with and without entecavir in patients with chronic hepatitis D. METHODS: Forty hepatitis D virus(HDV) RNA positive patients were randomized to receive either PEG-IFNα-2a 180 μg weekly in combination with entecavir 0.5 mg daily(n = 21) or PEG-IFNα alone(n =19). Patients who failed to show 2 log reduction in HDV RNA level at 24 wk of treatment, or had detectable HDV RNA at 48 wk of therapy were considered as treatment failure. Treatment was continued for 72 wk in the rest of the patients. All the patients were followed for 24 wk post treatment. Intention to treat analysis was performed.RESULTS: The mean age of the patients was 26.7 ± 6.8 years, 31 were male. Two log reduction in HDV RNA levels at 24 wk of therapy was achieved in 9(43%) patients receiving combination therapy and 12(63%) patients receiving PEG-IFNα alone(P = 0.199). Decline in hepatitis B surface antigen(HBs Ag) levels was insignificant. At the end of treatment, HDV RNA was negative in 8 patients(38%) receiving combination therapy and 10 patients(53%) receiving PEG-IFNα-2a alone. Virological response persisted in 7(33%) and 8(42%) patients, respectively at the end of the 24 wk follow-up period. One responder patient in the combination arm lost HBs Ag and became hepatitis B surface antibody positive. Six out of 14 baseline hepatitis B e antigen reactive patients seroconverted and four of these seroconverted patients had persistent HDV RNA clearance.CONCLUSION: Administration of PEG-IFNα-2a with or without entecavir, resulted in persistent HDV RNA clearance in 37% of patients. The addition of entecavir did not improve the overall response.

Theoretical basis of a beneficial role for vitamin D in viral hepatitis

Abnormal bone metabolism and dysfunction of the calcium-parathyroid hormone-vitamin D axis have been reported in patients with viral hepatitis. Some studies suggested a relationship between vitamin D and viral hepatitis. Genetic studies have provided an opportunity to identify the proteins that link vitamin D to the pathology of viral hepatitis (i.e., the major histocompatibility complex class Ⅱ molecules, the vitamin D receptor, cytochrome P 450 , the renin-angiotensin system, apolipoprotein E, liver X receptor, toll-like receptor, and the proteins regulated by the Sp1 promoter gene). Vitamin D also exerts its effects on viral hepatitis via non-genomic factors, i.e., matrix metalloproteinase, endothelial vascular growth factor, prostaglandins, cyclooxygenase-2, and oxidative stress. In conclusion, vitamin D could have a beneficial role in viral hepatitis. Calcitriol is best used for viral hepatitis because it is the active form of the vitamin D 3 metabolite.

Hepatitis D:advances and challenges

Hepatitis D virus(HDV)infection causes the most severe form of viral hepatitis with rapid progression to cirrhosis,hepatic decompensation,and hepatocellular carcinoma.Although discovered>40 years ago,little attention has been paid to this pathogen from both scientific and public communities.However,effectively combating hepatitis D requires advanced scientific knowledge and joint efforts from multi-stakeholders.In this review,we emphasized the recent advances in HDV virology,epidemiology,clinical feature,treatment,and prevention.We not only highlighted the remaining challenges but also the opportunities that can move the field forward.