Reactivation of hepatitis B virus infection – an important aspect of multifaceted problem

In this editorial we comment on the article published in the recent issue of the W orld Journal of Gastroenterology.We focus specifically on the problem of occult hepatitis B virus(HBV)infection,that is a result of previous hepatitis B(PHB)and a source for reactivation of HBV.The prevalence of PHB is underestimated due to the lack of population testing programs.However,this condition not only com-plicate anticancer treatment,but may be responsible for the development of other diseases,like cancer or autoimmune disorders.Here we unveil possible mecha-nisms responsible for realization of these processes and suggest practical approa-ches for diagnosis and treatment.

Hepatitis B surface antigen-negative but hepatitis B envelope antigen-positive false occult hepatitis B virus infection:A case report

BACKGROUND Occult hepatitis B infection(OBI)is characterized by the detection of hepatitis B virus(HBV)DNA in serum(usually HBV DNA<200 IU/mL)or the liver but negativity for hepatitis B surface antigen(HBsAg).The diagnosis of OBI relies on the sensitivity of assays used in the detection of HBV DNA and HBsAg.HBsAg assays with inadequate sensitivity or inability to detect HBV S variants may lead to misdiagnosis of OBI in people with overt HBV infection.CASE SUMMARY We report a HBsAg-negative but hepatitis B envelope antigen-positive patient who had a significant HBV DNA level.The patient was initially diagnosed as having OBI.However,sequence analysis revealed a unique insertion of amino acid residues at positions 120-124 in the S protein,which affects the formation of a disulfide bond that is associated with the formation of a loop.It is well known that there is an overlap between the S protein and Pol protein.We found that this new insertion site occurred in polymerase/reverse transcriptase domain,indi-cating that this insertion might be involved in HBV pathogenicity.The patient was finally diagnosed with a false OBI.CONCLUSION An insertion of amino acid residues at positions 120-124 of the S protein affects the formation of immunodominant epitopes and results in negative HBsAg levels.

Perception of Medical Students towards Hepatitis B Virus Infection and Hepatitis B Vaccination in a Private Tertiary Hospital in Jos North Local Government, Plateau State, Nigeria

Background: Prevention is one of the safe schemes against the high prevalence of viral Hepatitis. Negative perceptions or perceptions about the risks of hepatitis B among medical students and health care workers may influence the behavioral pattern and adoption of preventive measures against the virus and can affect the uptake of the Hepatitis B vaccine. This study assesses the perception of medical students towards Hepatitis B virus infection and Hepatitis B Vaccination in a Private Tertiary Hospital in Jos North Local Government, Plateau State, Nigeria. Methods: This was a descriptive cross-sectional study done in August 2021 among 236 clinical medical students using a multistage sampling technique. Data was collected using an interviewer-administered structured questionnaire and analysed using the IBM SPSS 28 (Statistical Package for the Social Sciences). Ethical approval was granted by Bingham University Teaching Hospital, Ethics Committee, Jos, Plateau State. Results: Two-thirds of respondents were of the opinion that they are at risk of contracting HBV. Half were of the opinion that the risk is very much while a third believed the risk is moderate. Among those who think they are not at risk of contracting HBV, the majority felt so because they are vaccinated while 10.3% believe that they are safe. 43.2% of respondents think that HBV Vaccine is very effective in preventing HBV infection while 39.8% think it is slightly effective, and 7.6% think it is not effective. Almost all respondents, 99.2% are of the opinion that HBV Vaccination is important for students while 0.8% think it is not important. The majority of the respondents at 95.8% were willing to be screened for HBV. The majority (85.6%) of respondents are willing to pay for HBV Vaccine as against 14.4% of respondents who are not willing to pay. Conclusion: Summarily, 21 (8.9%) of the students had a negative perception of Hepatitis B Vaccination, and 215 (91.1%) had a positive perception of Hepatitis B Vaccination. Perception-sustaining events like seminars, workshops, road shows, and campaigns should be organized among students and health workers.

Chronic hepatitis B and occult infection in chemotherapy patients-evaluation in oncology and hemato-oncology settings:The CHOICE study

BACKGROUND Reactivation of hepatitis B virus(HBV)infection is a well-known risk that can occur spontaneously or following immunosuppressive therapies,including cancer chemotherapy.HBV reactivation can cause significant morbidity and even mortality,which are preventable if at-risk individuals are identified through screening and started on antiviral prophylaxis.AIM To determine the prevalence of chronic HBV(CHB)and occult HBV infection(OBI)among oncology and hematology-oncology patients undergoing chemo-therapy.METHODS In this observational study,the prevalence of CHB and OBI was assessed among patients receiving chemotherapy.Serological markers of HBV infection[hepatitis B surface antigen(HBsAg)/anti-hepatitis B core antigen(HBc)]were evaluated for all patients.HBV DNA levels were assessed in those who tested negative for HBsAg but positive for total anti-HBc.RESULTS The prevalence of CHB in the study cohort was determined to be 2.3%[95%confidence interval(95%CI):1.0-4.2].Additionally,the prevalence of OBI among the study participants was found to be 0.8%(95%CI:0.2-2.3).CONCLUSION The findings of this study highlight the importance of screening for hepatitis B infection in oncology and hematology-oncology patients undergoing chemotherapy.Identifying individuals with CHB and OBI is crucial for implementing appropriate antiviral prophylaxis to prevent the reactivation of HBV infection,which can lead to increased morbidity and mortality.

Risk of hepatitis B virus reactivation in cancer patients undergoing treatment with tyrosine kinase-inhibitors

This editorial commented on an article in the World Journal of Gastroenterology titled“Risks of Reactivation of Hepatitis B Virus in Oncological Patients Using Tyrosine Kinase-Inhibitors:Case Report and Literature Analysis”by Colapietro et al.In this editorial,we focused on providing a more comprehensive exploration of hepatitis B virus reactivation(HBVr)associated with the usage of tyrosine kinase inhibitors(TKIs).It includes insights into the mechanisms underlying HBV reactivation,the temporal relationship between TKIs and HBV reactivation,and preventive measures.The aim is to understand the need for nucleos(t)ide analogs(NAT)and serial blood tests for early recognition of reactivation and acute liver injury,along with management strategies.TKIs are considered to be an intermediate(1%-10%)of HBVr.Current guidelines stipulate that patients receiving therapy with high or moderate risks of reactivation or recent cancer diagnosis must have at least tested hepatitis B surface antigen,anti-hepatitis B core antigen(HBc),and anti-hepatitis B surface antibody.Anti-HBc screening in highly endemic areas means people with negative tests should be vaccinated against HBV.Nucleoside or nucleotide analogs(NAs)like entecavir(ETV),tenofovir disoproxil fumarate(TDF),and tenofovir alafenamide(TAF)form the basis of HBV reactivation prophylaxis and treatment during immunosuppression.Conversely,lamivudine,telbivudine,and adefovir are generally discouraged due to their reduced antiviral efficacy and higher risk of fostering drug-resistant viral strains.However,these less effective NAs may still be utilized in cases where ETV,TDF,and TAF are not feasible treatment options.

Risk of hepatic decompensation from hepatitis B virus reactivation in hematological malignancy treatments

In this editorial,we discussed the apparent discrepancy between the findings described by Colapietro et al,in their case report and data found in the literature.Colapietro et al reported a case of hepatitis B virus(HBV)-related hepatic decompensation in a patient with chronic myeloid leukemia and a previously resolved HBV infection who was receiving Bruton’s tyrosine kinase(BTK)inhibitor therapy.First of all,we recapitulated the main aspects of the immune system involved in the response to HBV infection in order to underline the role of the innate and adaptive response,focusing our attention on the protective role of anti-HBs.We then carefully analyzed literature data on the risk of HBV reactivation(HBVr)in patients with previous HBV infection who were treated with either tyrosine kinase inhibitors or BTK inhibitors for their hematologic malignancies.Based on literature data,we suggested that several factors may contribute to the different risks of HBVr:The type of hematologic malignancy;the type of therapy(BTK inhibitors,especially second-generation,seem to be at a higher risk of HBVr than those with tyrosine kinase inhibitors);previous exposure to an anti-CD20 as first-line therapy;and ethnicity and HBV genotype.Therefore,the warning regarding HBVr in the specific setting of patients with hematologic malignancies requires further investigation.

Inhibition of hepatitis B virus via selective apoptosis modulation by Chinese patent medicine Liuweiwuling Tablet

BACKGROUND Liuweiwuling Tablet(LWWL)is a Chinese patent medicine approved for the treatment of chronic inflammation caused by hepatitis B virus(HBV)infection.Previous studies have indicated an anti-HBV effect of LWWL,specifically in terms of antigen inhibition,but the underlying mechanism remains unclear.AIM To investigate the potential mechanism of action of LWWL against HBV.METHODS In vitro experiments utilized three HBV-replicating and three non-HBV-replicating cell lines.The in vivo experiment involved a hydrodynamic injectionmediated mouse model with HBV replication.Transcriptomics and metabolomics were used to investigate the underlying mechanisms of action of LWWL.RESULTS In HepG2.1403F cells,LWWL(0.8 mg/mL)exhibited inhibitory effects on HBV DNA,hepatitis B surface antigen and pregenomic RNA(pgRNA)at rates of 51.36%,24.74%and 50.74%,respectively.The inhibition rates of LWWL(0.8mg/mL)on pgRNA/covalently closed circular DNA in HepG2.1403F,HepG2.2.15 and HepG2.A64 cells were 47.78%,39.51%and 46.74%,respectively.Integration of transcriptomics and metabolomics showed that the anti-HBV effect of LWWL was primarily linked to pathways related to apoptosis(PI3K-AKT,CASP8-CASP3 and P53 pathways).Apoptosis flow analysis revealed that the apoptosis rate in the LWWL-treated group was significantly higher than in the control group(CG)among HBV-replicating cell lines,including HepG2.2.15(2.92%±1.01%vs 6.68%±2.04%,P<0.05),HepG2.A64(4.89%±1.28%vs 8.52%±0.50%,P<0.05)and HepG2.1403F(3.76%±1.40%vs 7.57%±1.35%,P<0.05)(CG vs LWWL-treated group).However,there were no significant differences in apoptosis rates between the non-HBV-replicating HepG2 cells(5.04%±0.74%vs 5.51%±1.57%,P>0.05),L02 cells(5.49%±0.80%vs 5.48%±1.01%,P>0.05)and LX2 cells(6.29%±1.54%vs 6.29%±0.88%,P>0.05).TUNEL staining revealed a significantly higher apoptosis rate in the LWWL-treated group than in the CG in the HBVreplicating mouse model,while no noticeable difference in apoptosis rates between the two groups was observed in the non-HBV-replicating mouse model.CONCLUSION Preliminary results suggest that LWWL exerts a potent inhibitory effect on wild-type and drug-resistant HBV,potentially involving selective regulation of apoptosis.These findings offer novel insights into the anti-HBV activities of LWWL and present a novel mechanism for the development of anti-HBV medications.

Chronic Hepatitis B in Indian Americans: Lack of Screening and Poor Linkage to Care

Background: Chronic hepatitis B (CHB) is a major cause of liver-related morbidity and mortality in the United States (US) and globally. CHB disproportionately affects Asian Americans and many other immigrant minority populations, primarily owing to the high prevalence of CHB in their countries of origin. India is a country with a medium-to-high prevalence of hepatitis B (HB) (>2%) and has over 40 million people infected with hepatitis B virus (HBV), with more than 115,000 deaths annually from HBV-related complications. Indian Americans are one of the largest immigrant populations in the US but remain underdiagnosed and poorly linked to clinical care. We, therefore, assessed the HBV prevalence and evaluated the linkage-to-care (LTC) among Indian Americans to develop strategic plans to reduce the impact of HBV in the US. Methods: Between April 2022 and January 2024, serologic screening and surveys were provided to 328 Indian American adults (age 20 - 80) in New York City. All participants were tested for a triple panel consisting of hepatitis B surface antigen (HBsAg), hepatitis B surface antibody (anti-HBs), and hepatitis B core IgG antibody (anti-HBc). A survey was conducted on the subjects chronically infected with HBV regarding their histories of infection. Self-administered questionnaires were employed to evaluate demographic and epidemiologic characteristics. Results: Of 328 screened and evaluated (246 males and 82 females), 10 (3.0%) were HBV-infected, 222 (67.7%) were susceptible to HBV, and 96 (29.3%) were immune. The prevalence of chronic HBV varied between the age groups: 4.6% (age 20 - 40), 3.4% (age 41 - 60), and 1.7% (age 61 - 80). Of 10 chronically infected, only two subjects had been previously diagnosed but were not engaged in care. Conclusion: HBV disproportionately affects Asian Americans, primarily owing to immigration from parts of the world where the disease is endemic. Indian Americans belong to an intermediate-risk group, with an HBV prevalence of >2%, but remain underdiagnosed and poorly linked to care. Our pilot study on Indian American populations, the first of its kind, demonstrates a 3% prevalence of CHB, none of whom are linked to care. In addition, this population has a high percentage of unimmune subjects, creating a large reservoir for future infection. With the growing population of Indian Americans, our findings can be used to develop community-based strategies for HBV screenings and LTC that target high-risk groups.

Chronic hepatitis B:Prevent,diagnose,and treat before the point of no return

Hepatitis B remains a significant global health challenge,contributing to substantial morbidity and mortality.Approximately 254 million people world-wide live with Chronic hepatitis B(CHB),with the majority of cases occurring in sub-Saharan Africa and the Western Pacific regions.Alarmingly,only about 13.4%of the individuals infected with this disease have been diagnosed,and awareness of hepatitis B virus(HBV)infection status is as low as 1%in sub-Saharan Africa.In 2022,CHB led to 1.1 million deaths globally.The World Health Organization(WHO)has set a target of eliminating hepatitis B as a public health concern by 2030;however,this goal appears increasingly unattainable due to multiple challenges.These challenges include low vaccination coverage;a large number of undiagnosed cases;a low proportion of patients eligible for treatment under current guidelines;limited access to healthcare;and the costs associated with lifelong treatment.Treatment of HBV can yield significant clinical benefits within a long window of opportunity.However,the benefits of therapy are markedly diminished when the disease is detected at the advanced cirrhosis stage.This editorial aim to highlight the current challenges in hepatitis care and the necessary steps to achieve the WHO's hepatitis elimination goals for 2030.

Demyelinating neuropathy in patients with hepatitis B virus: A case report

BACKGROUND Hepatitis B rarely leads to demyelinating neuropathy,despite peripheral neuropathy being the first symptom of hepatitis B infection.CASE SUMMARY A 64-year-old man presented with sensorimotor symptoms in multiple peripheral nerves.Serological testing showed that these symptoms were due to hepatitis B.After undergoing treatment involving intravenous immunoglobulin and an antiviral agent,there was a notable improvement in his symptoms.CONCLUSION Although hepatitis B virus(HBV)infection is known to affect hepatocytes,it is crucial to recognize the range of additional manifestations linked to this infection.The connection between long-term HBV infection and demyelinating neuropathy has seldom been documented;hence,prompt diagnostic and treatment are essential.The patient's positive reaction to immunoglobulin seems to be associated with production of the antigen-antibody immune complex.

Hepatitis B virus reactivation in patients treated with monoclonal antibodies

Hepatitis B virus(HBV)reactivation poses a significant clinical challenge,espe-cially in patients undergoing immunosuppressive therapies,including mono-clonal antibody treatments.This manuscript briefly explores the complex rela-tionship between monoclonal antibody therapy and HBV reactivation,drawing upon current literature and clinical case studies.It delves into the mechanisms underlying this phenomenon,highlighting the importance of risk assessment,monitoring,and prophylactic measures for patients at risk.The manuscript aims to enhance the understanding of HBV reactivation in the context of monoclonal antibody therapy,ultimately facilitating informed clinical decision-making and improved patient care.This paper will also briefly review the definition of HBV activation,assess the risks of reactivation,especially in patients treated with monoclonal antibodies,and consider management for patients with regard to screening,prophylaxis,and treatment.A better understanding of patients at risk can help clinicians provide optimum management to ensure successful patient outcomes and prevent morbidity.

Hepatitis B virus infection in patients with Wilson disease:A large retrospective study

BACKGROUND Wilson disease(WD)is the most common genetic metabolic liver disease.Some studies have shown that comorbidities may have important effects on WD.Data on hepatitis B virus(HBV)infection in patients with WD are limited.AIM To investigate the prevalence and clinical impact of HBV infection in patients with WD.METHODS The clinical data of patients with WD were analyzed retrospectively,and the data of patients with concurrent WD and HBV infection were compared with those of patients with isolated WD.RESULTS Among a total of 915 WD patients recruited,the total prevalence of current and previous HBV infection was 2.1%[95%confidence interval(CI):1.2%-3.0%]and 9.2%(95%CI:7.3%-11.1%),respectively.The main finding of this study was the identification of 19 patients with concurrent WD and chronic hepatitis B(CHB)infection.The diagnosis of WD was missed in all but two patients with CHB infection.The mean delay in the diagnosis of WD in patients with concurrent WD and CHB infection was 32.5 mo,which was significantly longer than that in patients with isolated WD(10.5 mo).The rates of severe liver disease and mortality in patients with concurrent WD and CHB infection were significantly higher than those in patients with isolated WD(63.1%vs 19.3%,P=0.000 and 36.8%vs 4.1%,P<0.001,respectively).Binary logistic regression analysis revealed a significantly higher risk of severe liver disease at the diagnosis of WD in patients with current HBV infection[odds ratio(OR)=7.748;95%CI:2.890-20.774;P=0.000)]or previous HBV infection(OR=5.525;95%CI:3.159-8.739;P=0.000)than in patients with isolated WD.CONCLUSION The total prevalence of current HBV infection in patients with WD was 2.1%.The diagnosis of WD in CHB patients is usually missed.HBV infection is an independent risk factor for severe liver disease in WD patients.The diagnosis of WD should be ruled out in some patients with CHB infection.

Locked nucleic acid real-time polymerase chain reaction method identifying two polymorphisms of hepatitis B virus genotype C2 infections,rt269L and rt269I

BACKGROUND The presence of two distinct hepatitis B virus(HBV)Pol RT polymorphisms,rt269L and rt269I,could contribute to the unique clinical or virological phenotype of HBV genotype C2.Therefore,a simple and sensitive method capable of identifying both types in chronic hepatitis B(CHB)patients infected with genotype C2 should be developed.AIM To develop a novel simple and sensitive locked nucleic acid(LNA)-real timepolymerase chain reaction(RT-PCR)method capable of identifying two rt269 types in CHB genotype C2 patients.METHODS We designed proper primer and probe sets for LNA-RT-PCR for the separation of rt269 types.Using synthesized DNAs of the wild type and variant forms,melting temperature analysis,detection sensitivity,and endpoint genotyping for LNA-RT-PCR were performed.The developed LNA-RT-PCR method was applied to a total of 94 CHB patients of genotype C2 for the identification of two rt269 polymorphisms,and these results were compared with those obtained by a direct sequencing protocol.RESULTS The LNA-RT-PCR method could identify two rt269L and rt269I polymorphisms of three genotypes,two rt269L types[‘L1’(WT)and‘L2’]and one rt269I type(‘I’)in single(63 samples,72.4%)or mixed forms(24 samples,27.6%)in 87(92.6%sensitivity)of 94 samples from Korean CHB patients.When the results were compared with those obtained by the direct sequencing protocol,the LNA-RT-PCR method showed the same results in all but one of 87 positive detected samples(98.9%specificity).CONCLUSION The newly developed LNA-RT-PCR method could identify two rt269 polymorphisms,rt269L and rt269I,in CHB patients with genotype C2 infections.This method could be effectively used for the understanding of disease progression in genotype C2 endemic areas.

The woodchuck as an animal model for pathogenesis and therapy of chronic hepatitis B virus infection

This review describes the woodchuck and the woodchuck hepatitis virus (WHV) as an animal model for pathogenesis and therapy of chronic hepatitis B virus (HBV) infection and disease in humans. The establishment of woodchuck breeding colonies, and use of laboratory-reared woodchucks infected with defined WHV inocula, have enhanced our understanding of the virology and immunology of HBV infection and disease pathogenesis, including major sequelae like chronic hepatitis and hepatocellular carcinoma. The role of persistent WHV infection and of viral load on the natural history of infection and disease progression has been firmly established along the way. More recently, the model has shed new light on the role of host immune responses in these natural processes, and on how the immune system of the chronic carrier can be manipulated therapeutically to reduce or delay serious disease sequelae through induction of the recovery phenotype. The woodchuck is an outbred species and is not well defined immunologically due to a limitation of available host markers. However, the recent development of several key host response assays for woodchucks provides experimental opportunities for further mechanistic studies of outcome predictors in neonatal- and adult-acquired infections. Understanding the virological and immunological mechanisms responsible for resolution of self-limited infection, andfor the onset and maintenance of chronic infection, will greatly facilitate the development of successful strategies for the therapeutic eradication of established chronic HBV infection. Likewise, the results of drug efficacy and toxicity studies in the chronic carrier woodchucks are predictive for responses of patients chronically infected with HBV. Therefore, chronic WHV carrier woodchucks provide a well-characterized mammalian model for preclinical evaluation of the safety and efficacy of drug candidates, experimental therapeutic vaccines, and immunomodulators for the treatment and prevention of HBV disease sequelae.

Bacterial infection triggers and complicates acute-on-chronic liver failure in patients with hepatitis B virus-decompensated cirrhosis: A retrospective cohort study

BACKGROUND Reports on bacterial infection(BI)in decompensated cirrhosis(DC)is mainly from alcoholic cirrhosis.The role of BI as a trigger or complication of acute-onchronic liver failure(ACLF)in patients with hepatitis B virus decompensated cirrhosis(HBV-DC)remains to be investigated.AIM To investigate the impact of BI on the outcomes of the patients with HBV-DC admitted into the hospital with or without ACLF.METHODS This retrospective study included patients with HBV-DC admitted to two tertiary centers in China.In-hospital overall survival,90-d transplant-free survival,5-year post-discharge survival,and cumulative incidence of ACLF were evaluated.Risk factors for death were analyzed considering liver transplantation as a competing event.RESULTS A total of 1281 hospitalized HBV-DC patients were included;284 had ACLF at admission.The overall prevalence of BI was 28.1%.The patients with BI had a significantly lower in-hospital survival and transplant-free 90-d survival than those without,in both the patients admitted with and without ACLF.The presence of BI significantly increased the risk of developing ACLF[subdistribution hazard ratio(sHR)=2.52,95%CI:1.75-3.61,P<0.001]in the patients without ACLF.In the patients discharged alive,those who had an episode of BI had a significantly lower 5-year transplant-free survival.BI was an independent risk factor for death in the patients admitted without ACLF(sHR=3.28,95%CI:1.93-5.57),while in ACLF admissions,the presence of pneumonia,but not other type of BI,independently increased the risk of death(sHR=1.87,95%CI:1.24-2.82).CONCLUSION BI triggers ACLF in patients with HBV-DC and significantly impairs short-term survival.HBV-DC patients should be monitored carefully for the development of BI,especially pneumonia,to avoid an adverse outcome.

Pathogenesis of occult chronic hepatitis B virus infection

Occult hepatitis B infection(OBI) is characterized by hepatitis B virus(HBV) DNA in serum in the absence of hepatitis B surface antigen(HBsAg) presenting HBsAg-negative and anti-HBc positive serological patterns.Occult HBV status is associated in some cases with mutant viruses undetectable by HBsAg assays;but more frequently it is due to a strong suppression of viral replication and gene expression.OBI is an entity with world-wide diffusion.The failure to detect HBsAg,despite the persistence of the viral DNA,is due in most cases to the strong suppression of viral replication and gene expression that characterizes this"occult"HBV infection;although the mechanisms responsible for suppression of HBV are not well understood.The majority of OBI cases are secondary to overt HBV infection and represent a residual low viremia level suppressed by a strong immune response together with histological derangements which occurred during acute or chronic HBV infection.Much evidence suggests that it can favour the progression of liver fibrosis and the development of hepatocellular carcinoma.

New therapeutic options for persistent low-level viremia in patients with chronic hepatitis B virus infection:Increase of entecavir dosage

Chronic hepatitis B virus(HBV)infection(CHB)is a public health concern worldwide.Current therapies utilizing nucleos(t)ide analogs(NA)have not resulted in a complete cure for CHB.Furthermore,patients on long-term NA treatment often develop low-level viremia(LLV).Persistent LLV,in addition to causing the progression of liver disease or hepatocellular carcinoma,may shed light on the current plight of NA therapy.Here,we review the literature on LLV,NA treatment,and various doses of entecavir to find a strategy for improving the efficacy of this antiviral agent.For LLV patients,three therapeutic options are available,switching to another antiviral monotherapy,interferon-αswitching therapy,and continuing monotherapy.In real-world clinical practice,entecavir overdose has been used in antiviral therapy for CHB patients with NA refractory and persistent LLV,which encouraged us to conduct further in-depth literature survey on dosage and duration related entecavir studies.The studies of pharmacodynamics and pharmacokinetics show that entecavir has the maximal selected index for safety,and has great potential in inhibiting HBV replication,in all of the NAs.In the particular section of the drug approval package published by the United States Food and Drug Administration,entecavir doses 2.5-20 mg/d do not increase adverse events,and entecavir doses higher than 1.0 mg/d might improve the antiviral efficacy.The literature survey led us to two suggestions:(1)Increasing entecavir dose to 1.0 mg/d for the treatment of NA naïve patients with HBV DNA>2×106 IU/mL is feasible and would provide better prognosis;and(2)Further research is needed to assess the long-term toxic effects of higher entecavir doses(2.5 and 5.0 mg/d),which may prove beneficial in treating patients with prior NA treatment,partial virological response,or LLV state.

T cell immunopathogenesis and immunotherapeutic strategies for chronic hepatitis B virus infection

Hepatitis B is caused by the host immune response and T cells play a major role in the immunopathogenesis. More importantly,T cells not only destroy hepatocytes infected by hepatitis B virus(HBV),but also control HBV replication or eradicate HBV in a noncytolytic manner.Therefore,analysis of T cell immune response during acute and chronic HBV infection is important to develop a strategy for successful viral control,which could lead to immunotherapy for terminating persistent HBV infection.There have been many attempts at immunotherapy for chronic HBV infection,and some have shown promising results.High viral load has been shown to suppress antiviral immune responses and immunoinhibitory signals have been recently elucidated, therefore,viral suppression by nucleos(t)ide analogs, stimulation of antiviral immune response,and suppression of the immunoinhibitory signals must be combined to achieve desirable antiviral effects.

Relationship between cytokine gene polymorphisms and chronic hepatitis B virus infection

Hepatitis B virus (HBV) infection is still a public health problem worldwide, being endemic in some parts of the world. It can lead to serious liver diseases such as chronic hepatitis, cirrhosis, and hepatocellular cancer. The differences in host immune response can be one of the reasons for the various clinical presentations of HBV infection. Polymorphisms of genes encoding the proinflammatory and antiinflammatory cytokines, which are responsible for regulation of the immune response, can affect the clinical presentation of the infection. Particularly, the polymorphisms of the genes encoding cytokines such as interleukin (IL)-1, IL-6, IL-8, IL-10, IL-18, IL-28B, interferon-&#x003b3;, tumor necrosis factor-&#x003b1;, tumor growth factor-&#x003b2;1, and regulatory molecules like vitamin D receptor and chemokine receptor 5 can be responsible for different clinical presentations of HBV infections. The genomic information about cytokines and other mediators can be important for determining high-risk people for developing chronic hepatitis or hepatocellular cancer and may be used to plan treatment and preventive approaches for these people. In this review, the current knowledge in the literature on the association between cytokine/regulatory molecule gene polymorphisms and clinical course of chronic HBV infection is summarized, and the clinical implementations and future prospects regarding this knowledge are discussed.

Role of occult hepatitis B virus infection in chronic hepatitis C

The development of sensitive assays to detect small amounts of hepatitis B virus(HBV) DNA has favored the identification of occult hepatitis B infection(OBI), a virological condition characterized by a low level of HBV replication with detectable levels of HBV DNA in liver tissue but an absence of detectable surface antigen of HBV(HBs Ag) in serum. The gold standard to diagnose OBI is the detection of HBV DNA in the hepatocytes by highly sensitive and specific techniques, a diagnostic procedure requiring liver tissue to be tested and the use of non-standardized non-commercially available techniques. Consequently, in everyday clinical practice, the detection of anti-hepatitis B core antibody(antiHBc) in serum of HBs Ag-negative subjects is used as a surrogate marker to identify patients with OBI. In patients with chronic hepatitis C(CHC), OBI has been identified in nearly one-third of these cases. Considerable data suggest that OBI favors the increase of liver damage and the development of hepatocellular carcinoma(HCC) in patients with CHC. The data from other studies, however, indicate no influence of OBI on the natural history of CHC, particularly regarding the risk of developing HCC.