Hepatitis B virus infection

Asian-Pacific consensus statement on the management of chronic hepatitis B: a 2012 update

Large volume of new data on the natural history and treatment of chronic hepatitis B virus (HBV) infection have become available since 2008. These include further studies in asymptomatic subjects with chronic HBV infection and community-based cohorts, the role of HBV genotype/naturally occurring HBV mutations, the application of non-invasive assessment of hepatic fibrosis and quantitation of HBV surface antigen and new drug or new strategies towards more effective therapy. To update HBV management guidelines, relevant new data were reviewed and assessed by experts from the region, and the significance of the reported findings was discussed and debated. The earlier "Asian-Pacific consensus statement on the management of chronic hepatitis B" was revised accordingly. The key terms used in the statement were also defined. The new guidelines include general management, indications for fibrosis assessment, time to start or stop drug therapy, choice of drug to initiate therapy, when and how to monitor the patients during and after stopping drug therapy. Recommendations on the therapy of patients in special circumstances, including women in childbearing age, patients with antiviral drug resistance, concurrent viral infection, hepatic decompensation, patients receiving immune suppression or chemotherapy and patients in the setting of liver transplantation and hepatocellular carcinoma, are also included.

Incidence and determinants of spontaneous seroclearance of hepatitis B e antigen and DNA in patients with chronic hepatitis B

BACKGROUND & AIMS

The spontaneous seroclearance of hepatitis B e antigen (HBeAg) and hepatitis B virus (HBV) DNA are important markers of progression of chronic HBV infection. We performed a long-term cohort study to elucidate the incidence and determinants of HBeAg and HBV DNA seroclearance in patients with chronic hepatitis B.

METHODS

A total of 1289 participants with a serum HBV DNA level of 10,000 copies/mL or more and without cirrhosis when the study began (1991-1992) were followed up until June 2004. A subset of patients that tested positive for HBeAg at baseline (n = 439) was included in the analysis of HBeAg seroclearance. Cox proportional hazards models were used to estimate seroclearance rate ratios for various determinants associated with the outcomes.

RESULTS

After 3161.2 person-years of follow-up evaluation, HBeAg seroclearance occurred in 187 participants (incidence rate, 5.9 per 100 person-years). The cumulative lifetime incidence of HBeAg seroclearance among patients who were 30 to 40, or 50, 60, 70, or 74 years old was 38.8%, 69.4%, 81.9%, 89.1%, and 95.5%, respectively. Major predictors of HBeAg seroclearance included female sex, genotype B, the precore 1896 mutant, increased serum levels of alanine aminotransferase, and low baseline serum levels of HBV DNA. The median (interquartile range) serum level of HBV DNA at the time of HBeAg seroclearance was 177,801 copies/mL (4941-3,247,560 copies/mL). HBV DNA seroclearance occurred in 199 participants (15.4%) during the mean follow-up period of 7.8 years (incidence rate, 1.97 per 100 person-years). The cumulative lifetime incidence of HBV DNA seroclearance at 40, 50, 60, 70, and 77 years old was 10.0%, 25.0%, 38.8%, 54.2%, and 82.8%, respectively. Lower levels of HBV DNA at study entry and among those with the precore 1896 wild-type variant were associated with an increased rate of HBV DNA seroclearance. Among individuals who were HBeAg-seropositive at study entry and cleared serum HBV DNA during the follow-up period, 89% had cleared HBeAg by the time they had an undetectable serum level of HBV DNA.

CONCLUSIONS

Serum level of HBV DNA is the most important predictor of seroclearance of HBeAg and HBV DNA. This finding supports current clinical guidelines for antiviral treatments of chronic hepatitis B.

High levels of hepatitis B surface antigen increase risk of hepatocellular carcinoma in patients with low HBV load

BACKGROUND & AIMS

Patients with chronic hepatitis B virus (HBV) infection have a high risk for developing hepatocellular carcinoma (HCC). Patients with lower levels of hepatitis B surface antigen (HBsAg) have higher chances of losing HBsAg than those with high levels. However, little is known about whether higher levels of HBsAg increase risk for HCC.

METHODS

We followed 2688 Taiwanese HBsAg-positive patients without evidence of cirrhosis for a mean time period of 14.7 years. In addition to the known risk factors of HCC, we investigated the association between levels of HBsAg and development of HCC.

RESULTS

Of the patients followed, 191 developed HCC, with an average annual incidence rate of 0.5%. Baseline levels of HBsAg and HBV were associated with development of HCC, and risk increased with level. Compared to HBsAg level, by receiver operating characteristic curve analysis, HBV DNA level better predicted the development of HCC during 10-year and 15-year periods (both, P < .001). However, when we evaluated hepatitis B e antigen-negative patients with levels of HBV DNA <2000 IU/mL, factors that determined HCC risk included sex, age, and levels of alanine aminotransferase and HBsAg (≥1000 IU/mL), but not level of HBV DNA. Multivariate analysis showed that the adjusted hazard ratio for HCC in patients with levels of HBsAg ≥1000 IU/mL versus <1000 IU/mL was 13.7 (95% confidence interval: 4.8-39.3).

CONCLUSIONS

Among patients infected with HBV genotype B or C, determinants of HCC risk include their sex, age, hepatitis B e antigen status, HBV genotype, and levels of alanine aminotransferase and HBV DNA, but not level of HBsAg. Among hepatitis B e antigen-negative patients with low viral loads, HCC risk is determined by levels of HBsAg and alanine aminotransferase and age, but not HBV DNA.

Association between obesity, hypertriglyceridemia and low hepatitis B viral load

OBJECTIVE

This study aimed to investigate the metabolic risk factors of high hepatitis B viral load.

DESIGN

Large-scale, community-based cross-sectional study.

SUBJECTS

A total of 3587 hepatitis B virus (HBV)-infected participants without liver cirrhosis at study entry were investigated. High HBV viral load was defined as a serum level 10(4) copies per ml for hepatitis B e antigen (HBeAg) seronegatives or 10(8) copies per ml for HBeAg seropositives.

RESULTS

Among HBeAg seropositives (n=545), high HBV viral load was reversely associated with extreme obesity (odds ratio (OR), 0.30; 95% confidence interval (CI), 0.13-0.68; P=0.004) or central obesity (OR, 0.53; 95% CI, 0.34-0.82; P=0.004) after adjustment for gender, hypertriglyceridemia, hyperuricemia and history of hypertension. High HBV viral load remained significantly inversely associated with extreme obesity (OR, 0.17; 95% CI, 0.05-0.63; P=0.008) and central obesity (OR, 0.44; 95% CI, 0.25-0.78; P=0.005) in male HBeAg-seropositive participants in stratification analyses by gender. Among HBeAg seronegatives (n=3042), however, high HBV viral load was inversely associated with hypertriglyceridemia (OR, 0.74; 95% CI, 0.61-0.89, P=0.002) after adjustment for age, gender, high serum alanine aminotransferase level, and extreme obesity or central obesity. High HBV viral load was still inversely associated with hypertriglyceridemia in both female (OR, 0.70; 95% CI, 0.50-0.97; P=0.041) and male (OR, 0.75; 95% CI, 0.60-0.94; P=0.011) HBeAg-seronegative participants.

CONCLUSION

Extreme obesity and central obesity were associated with a low prevalence of high HBV viral load in HBeAg seropositives, especially in men; while hypertriglyceridemia was associated with a low prevalence of high viral load in HBeAg seronegatives in both women and men.

Effects of telbivudine treatment on the circulating CD4⁺ T-cell subpopulations in chronic hepatitis B patients

CD4⁺ T cells serve as master regulators of the adaptive immune response to HBV. However, CD4⁺ T-cell subsets are heterogeneous, and it remains unknown how the antiviral agents affect the different CD4⁺ T cell subtypes. To this end, the expressions of signature transcription factors and cytokines of CD4⁺ T-cell subtypes were examined in hepatitis B patients before and after treatment with telbivudine. Results showed that, upon the rapid HBV copy decrease induced by telbivudine treatment, the frequencies and related cytokines of Th17 and Treg cells were dramatically decreased, while those for Th2 cells were dramatically increased. No obvious changes were observed in Th1 cell frequencies; although, IFN-γ expression was upregulated in response to telbivudine treatment, suggesting another cell source of IFN-γ in CHB patients. Statistical analyses indicated that Th17 and Tr1 (a Treg subtype) cells were the most sensitive subpopulations of the peripheral blood CD4⁺ T cells to telbivudine treatment over 52 weeks. Thus, Th17 and Tr1 cells may represent a suitable and effective predictor of responsiveness during telbivudine therapy. These findings not only improve our understanding of hepatitis pathogenesis but also can aid in future development of appropriate therapeutic strategies to control viral hepatitis.

T cell responses and viral variability in blood donation candidates with occult hepatitis B infection

BACKGROUND & AIMS

Occult HBV infection (OBI) is defined by the presence of HBV DNA in the liver and/or serum and negative HBsAg testing. Since the implementation of highly sensitive HBV DNA screening, OBI is also detected in healthy blood donors. The aims of this study were to investigate HBV-specific immune responses and genetic variability in donors with OBI, established by HBV DNA in serum.

METHODS

HBV-specific T-cell responses to HBV antigens were tested in 34 OBI donors by IFN-γ ELISpot, cytometric bead array, and intracellular cytokine staining. As comparison populations, 36 inactive HBV carriers, 22 donors with spontaneously resolved HBV infection, 24 vaccinated donors, and 25 seronegative donors were also included. Surface, pre-S, and pre-c/core genes from 44 genotype D isolates (24 OBI and 20 HBsAg-positive) were sequenced.

RESULTS

The immune response of OBI donors to the 3 HBV antigens was 29-41%, similar to the response in subjects with resolved HBV infection and higher than that in HBsAg-positive subjects. On sequence analysis, OBI donors presented a higher HBsAg mutation rate than HBsAg-positive subjects. Mutations were clustered in the major hydrophilic region of HBsAg, and no stop codons or relevant mutations that could affect antigen formation or detection were observed.

CONCLUSIONS

Our results suggest that immune response can suppress viral replication to low levels and HBsAg expression to undetectable levels in OBI blood donors. Relevant mutations were not found in the genomic HBsAg coding region. Hence, the fact that HBsAg was not detected in OBI is likely due to low HBsAg production, rather than to a failure of laboratory reagents.

Functional characterization of glycine N-methyltransferase and its interactive protein DEPDC6/DEPTOR in hepatocellular carcinoma

Glycine N-methyltransferase (GNMT) is a tumor suppressor for hepatocellular carcinoma (HCC). High rates of Gnmt knockout mice developed HCC. Epigenetic alteration and dysregulation of several pathways including wingless-type MMTV integration site (Wnt), mitogen-activated protein kinase (MAPK) and Janus kinase and signal transducer and activator of transcription (JAK-STAT) are associated with HCC development in Gnmt knockout mice. We hypothesized that GNMT may regulate signal transduction through interacting with other proteins directly. In this report, we identified a mammalian target of rapamycin (mTOR) inhibitor (DEP domain containing MTOR-interacting protein [DEPDC6/DEPTOR]) as a GNMT-binding protein by using yeast two-hybrid screening. Fluorescence resonance energy transfer assay demonstrated that the C-terminal half of GNMT interact with the PSD-95/Dlg1/ZO-1 (PDZ) domain of DEPDC6/DEPTOR. Immunohistochemical staining showed that 27.5% (14/51) of HCC patients had higher expression levels of DEPDC6/DEPTOR in the tumorous tissues than in tumor-adjacent tissues, especially among HCC patients with hepatitis B viral infection (odds ratio 10.3, 95% confidence interval [CI] 1.05-11.3) or patients with poor prognosis (death hazard ratio 4.51, 95% CI 1.60-12.7). In terms of molecular mechanism, knockdown of DEPDC6/DEPTOR expression in HuH-7 cells caused S6K and 4E-BP activation, but suppressed Akt. Overexpression of DEPDC6/DEPTOR activated Akt and increased survival of HCC cells. Overexpression of GNMT caused activation of mTOR/raptor downstream signaling and delayed G2/M cell cycle progression, which altogether resulted in cellular senescence. Furthermore, GNMT reduced proliferation of HuH-7 cells and sensitized them to rapamycin treatment both in vitro and in vivo. In conclusion, GNMT regulates HCC growth in part through interacting with DEPDC6/DEPTOR and modulating mTOR/raptor signaling pathway. Both GNMT and DEPDC6/DEPTOR are potential targets for developing therapeutics for HCC.

Hepatitis B surface antigen levels: association with 5-year response to peginterferon alfa-2a in hepatitis B e-antigen-negative patients

Purpose

To investigate the durability of response to peginterferon alfa-2a up to 5 years post-treatment and factors associated with response in hepatitis B e-antigen (HBeAg)-negative patients.

Methods

HBeAg-negative patients received peginterferon alfa-2a (180 μg/week) ± lamivudine (100 mg/day) for 48 weeks as part of a multicenter, randomized study. The planned 5-year efficacy analysis included patients (n = 230) enrolled in the long-term follow-up study. On-treatment hepatitis B surface antigen (HBsAg) decline kinetics were analyzed retrospectively in a subgroup of patients with HBsAg data available at baseline, weeks 12, 24, and 48 on-treatment, and 6 months post-treatment (n = 120). Receiver operating characteristic analyses identified the on-treatment HBsAg levels associated with response at 1 and 5 years post-treatment.

Results

HBV DNA ≤2,000 IU/mL and HBsAg clearance at 5 years post-treatment were achieved by 23 and 12% of patients, respectively. High rates of HBsAg clearance at 5 years post-treatment were achieved by patients with HBV DNA ≤2,000 IU/mL at 1 year post-treatment (28%). Rates of HBV DNA ≤2,000 IU/mL at 1 year post-treatment were 47.2 and 43.4% in patients with ≥10% decline from baseline at weeks 12 and 24, respectively, compared with 16.4% (p = 0.0003) and 13.2% (p < 0.0004) in patients with a <10% decline. Rates of HBsAg clearance at 5 years post-treatment were 22.6 and 22.4% in patients with ≥10% decline at weeks 12 and 24, respectively, compared with 7.5% (p = 0.0161) and 3.8% (p < 0.0001) in patients with <10% decline.

Conclusions

Peginterferon alfa-2a results in increasing rates of HBsAg clearance during post-treatment follow-up in HBeAg-negative patients. On-treatment decline in HBsAg is significantly associated with long-term post-treatment response.

Genetic analysis of precore/core and partial pol genes in an unprecedented outbreak of fulminant hepatitis B in India

We investigated an unprecedented outbreak of fulminant hepatitis B virus (HBV) that occurred in Modasa, Gujarat (India) in 2009. Genomic analysis of all fulminant hepatic failure cases confirmed exclusive predominance of subgenotype D1. A1762T, G1764A basal core promoter (BCP) mutations, insertion of isoleucine after nt 1843, stop codon mutation G1896A, G1862T transversion plus seven other mutations in the core gene caused inhibition of HBeAg expression implicating them as circulating precore/BCP mutant virus. Two rare mutations at amino acids 89 (Ile→Ala) and 119 (Leu→Ser) in addition to other mutations in the polymerase (pol) gene may have caused some alteration in either of four pol gene domains to affect encapsidation of pregenomic RNA to enhance pathogenicity. Sequence similarity among patients' sequences suggested an involvement of a single hepatitis B mutant strain/source to corroborate the finding of gross and continued usage of HBV mutant-contaminated syringes/needles by a physician which resulted in this unprecedented outbreak of fulminant hepatitis B. The fulminant exacerbation of the disease might be attributed to mutations in the BCP/precore/core and pol genes that may have occurred due to selection pressure during rapid spread/mutation of the virus.

Enhanced peripheral γδT cells cytotoxicity potential in patients with HBV-associated acute-on-chronic liver failure might contribute to the disease progression

BACKGROUND

The current study explored the characteristics of γδ T cells in the blood of HBV-associated acute-on-chronic liver failure (HBV-ACLF) patients and examined the relationship between γδ T cells and the clinical parameters.

METHODS

Blood samples were obtained from 26 patients with HBV-ACLF, 40 patients with chronic hepatitis B virus (HBV) infection (CHBV), and 25 healthy controls (HC). The frequencies of γδ T cells, subtype Vδ1T or Vδ2T, and CD45RO(+)γδ T cells were determined using flow cytometry. Intracellular cytokine staining analysis was used to evaluate the proportion of the IFN-γ-, TNF-α-, or IL-17-producing γδ T cells, and CD107a- or granzyme B-positive γδ T cells.

RESULTS

We found that the proportion of γδ T cells in blood samples from HBV-ACLF patients was much lower than in samples from CHBV patients or healthy controls. After stimulation with PMA and ionomycin, γδ T cells from HBV-ACLF patients produced the greatest amount of TNF-α or IL-17 among the three groups. Granzyme B- or CD107a-positive γδ T cells were significantly more frequent than in CHBV or control samples. There was a negative correlation between the percent of TNF-α(+)γδ T cells and ALT or AST levels, and between the percent of CD107a(+)γδ T cells and TBiL or DBiL levels.

CONCLUSIONS

These results suggest that γδ T cells might participate in liver injury in HBV-ACLF patients by producing increased amounts of inflammatory cytokines and/or cytotoxicity ability. These findings provide novel information regarding the pathogenesis of HBV-ACLF.

A comparison of telbivudine and entecavir for chronic hepatitis B in real-world clinical practice

OBJECTIVES

To evaluate the efficacy of telbivudine and entecavir in chronic hepatitis B (CHB) patients over a 1 year period.

METHODS

Ninety-seven telbivudine-naive and 98 entecavir-naive CHB patients who had been treated for at least 1 year were enrolled. Serial serum hepatitis B virus (HBV) DNA levels were checked at baseline and at weeks 24 and 48 after treatment.

RESULTS

Entecavir and telbivudine groups had similar baseline HBV DNA levels (5.9 ± 1.7 versus 6.0 ± 1.5 log copies/mL, P=0.529). The undetectable rate of HBV DNA after 1 year of treatment was significantly higher in the entecavir group than the telbivudine group (94.9% versus 82.0%, P=0.009). Resistance developed in 6.7% of the telbivudine-naive patients after 1 year compared with none of the entecavir-naive patients (P=0.009). However, there was a significant difference between the telbivudine and entecavir groups in hepatitis B e antigen (HBeAg) seroconversion 24 weeks after treatment (40% versus 12.5%, P=0.007). Multiple logistic regression analysis revealed that baseline alanine aminotransferase (ALT) >200 IU/L (P=0.008) was independently associated with HBeAg seroconversion. Applying the roadmap concept with ALT >2× upper limit of normal at baseline, telbivudine and entecavir had favourable outcomes in PCR negativity, ALT normalization, HBeAg seroconversion and resistance.

CONCLUSIONS

In real-world clinical practice, telbivudine resulted in higher rates of HBeAg seroconversion and drug resistance at week 48 compared with entecavir. A combination with baseline ALT plus 24 week HBV DNA levels led to the lowest rates of resistance in HBeAg-positive telbivudine-naive patients and had the highest probability of HBeAg seroconversion in both entecavir- and telbivudine-naive patients.

HBsAg Quantification in Clinical Practice

Several standardized commercial assays for quantification of hepatitis B surface antigen (qHBsAg) are now available. Studies on HBsAg kinetics from Asia and Europe have demonstrated that HBsAg levels are highest during the immune-tolerant phase, become lower during immune-clearance phase and are the lowest in hepatitis B 'e' antigen (HBeAg)-negative inactive low-replicative phase with a rise during HBeAg-negative chronic hepatitis B (CHB). Combined use of hepatitis B virus-deoxyribonucleic acid (HBV-DNA) and HBsAg levels may help in differentiating true inactive carrier state from HBeAg-negative CHB. Several retrospective studies have demonstrated a role for decline in HBsAg level for predicting response and nonresponse to therapy. In HBeAg-positive patients treated with pegylated-interferon (PEG-IFN), a lack of decline of qHBsAg at week 12 predicts nonresponders while a decline of qHBsAg at week 24 predicts responders to PEG-IFN. In HBeAg-negative patients, if at week 12, there is no decline in qHBsAg and the HBV-DNA decline is < 2 log, the patient is unlikely to respond, then stopping of PEG-IFN should be considered. With nucleos(t)ide analogs, the decline in HBsAg is lower than that with PEG-IFN and more marked in patients with HBeAg-positive chronic hepatitis, with elevated alanine aminotransaminase (ALT), thus suggesting that active immune response against HBV is required to lower HBsAg. In patients with HBeAg-negative chronic hepatitis, fall in HBsAg may help in developing stopping rules to reduce the need for lifelong therapy. Information provided by HBsAg is complementary to HBV-DNA and cannot replace the same. Prospective studies on HBsAg kinetics from all regions of the world are required to define optimum time of testing and cutoff levels before stopping rules can be recommended.

HBV-related hepatocellular carcinoma susceptibility gene KIF1B is not associated with development of chronic hepatitis B

BACKGROUND

A recent genome-wide association study has identified a new susceptibility locus, kinesin family member 1B gene (KIF1B), strongly associated with progression from chronic hepatitis B (CHB) to hepatitis B virus-related hepatocellular carcinoma (HCC) in Chinese population, this study was carried out to explore the role of the genetic variants in KIF1B in the development of chronic hepatitis B.

METHODOLOGY/PRINCIPAL FINDINGS

Three KIF1B polymorphisms (rs8019, rs17401924, and rs17401966) were selected and genotyped in 473 CHB patients and 580 controls with no history of CHB. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated by logistic regression model. None of these three SNPs showed association with CHBs after adjusting for age and gender. Equivalence-based method analysis confirmed the absence of association. In the further haplotype analysis, three common haplotypes were observed in this study population, but no significant effect was also found for haplotypes in the progression to CHB.

CONCLUSIONS/SIGNIFICANCE

This study showed the new locus identified for HCC, KIF1B, was not associated with progression to CHB, implying distinct genetic susceptibility factor contributes to the progression from hepatitis B virus infection to HCC. Nevertheless, further comprehensive analyses are warranted to dissect the mechanism.

Fatal fulminant primary hepatitis B virus infections with G1896A precore viral mutants in southeastern France

Fulminant hepatitis has been shown to occur in about 1% of acute hepatitis B virus (HBV) infections, and its mortality rate is nearly 70%. Specific HBV genotypic features have been pointed out in fulminant acute hepatitis B worldwide, but these associations remain controversial. We describe all four primary HBV infections diagnosed in 2008 in our institution in Marseille, southeastern France, including two fatal cases. HBV genotypes were D or E. Precore G1896A HBV mutants were detected in both fatal fulminant primary HBV infections. Hepatitis B surface antigen and hepatitis B e antigen (HBeAg) were negative in two and three cases, respectively, despite HBV DNA detection. Primary HBV infection remains a cause of death in France. The impact of the precore G1896A mutation on the severity of AHB deserves to be assessed in larger studies in this country.

Early serum HBsAg level as a strong predictor of sustained response to peginterferon alfa-2a in HBeAg-negative chronic hepatitis B

BACKGROUND

The roles remain unclear of early on-treatment quantitative serum HBsAg and hepatitis B virus (HBV) DNA levels in the prediction of a sustained response (SR) to peginterferon alfa-2a therapy in HBeAg-negative chronic hepatitis B (CHB) patients infected with genotype B or C.

AIMS

To determine their roles in HBeAg-negative CHB patients infected with genotype B or C.

METHODS

Sixty-one patients were treated with peginterferon alfa-2a for 48 weeks. Serum HBsAg levels were quantified using the Abbott Architect HBsAg QT assay throughout treatment. Multiple regression analyses were performed to identify independent predictors of SR.

RESULTS

Nineteen patients (31%) achieved SR with serum HBV DNA levels <312 copies/mL at 24 weeks post-treatment. Serum HBsAg levels at 12 (OR 31.9; 95% CI 4.8-209.6; P = 0.0003) and 24 weeks of therapy (OR 8.8; 95% CI 2.0-38.0; P = 0.0035), and HBV DNA levels at baseline (OR 7.0; 95% CI 1.3-36.2; P = 0.0203), 12 (OR 7.9; 95% CI 1.2-48.4; P = 0.0249) and 24 weeks of therapy (OR 22.3; 95% CI 2.2-224.0; P = 0.0083) were early independent predictors of SR. A serum HBsAg cut-off of 150 IU/mL at week 12 had an AUC, sensitivity, specificity and positive and negative predictive values of 0.75, 63%, 95%, 86% and 85% with respect to predicting SR respectively.

CONCLUSIONS

A quantitative serum HBsAg level at 12 weeks of therapy can be used for the early prediction of SR to peginterferon therapy in HBeAg-negative CHB patients infected with genotype B or C.

Hepatitis B infection: current concepts and future challenges

Chronic hepatitis B (CHB) is a global health problem affecting more than 350 million people worldwide. Chronic carriage of HBV is related to the age when the infection occurs; the younger the age the higher the chronicity rate. Knowledge of the natural history of CHB is important for the management of the disease. The goal of hepatitis B treatment is to prevent cirrhosis, liver decompensation and hepatocellular carcinoma. In clinical practice, treatment response is determined by the suppression of serum HBV DNA levels. However, current antiviral therapies are usually unable to achieve sustained off-treatment responses and eradicate the infection. Impairment of immune responses including defective innate non-cytolytic antiviral function together with exhausted T cells and the tolerogenic liver environment may all contribute to the poor clinical response. A more comprehensive understanding of the immunological phases of CHB, potential triggers of liver flares and molecular mechanisms underlying viral persistence and immunopathology will help to tailor future therapeutic strategies. A synergistic approach of boosting the immune response of the host by specific immunotherapeutic interventions and effective viral load suppression will be needed to promote sustained viral clearance in chronic infection.

Serial HBV DNA levels in patients with persistently normal transaminase over 10 years following spontaneous HBeAg seroconversion

Earlier studies addressing the hepatitis B virus (HBV) DNA cut-off level for inactive chronic HBV infection largely involved patients with normal alanine aminotransferase (ALT) for only 1-2 years and based on a single time HBV DNA assay. This study was conducted to address this issue using serial HBV DNA assays in patients with persistently normal ALT (PNALT) over 10 years following spontaneous hepatitis B e antigen (HBeAg) seroconversion. Serial serum specimens (mean 9 samples per patient) of 62 patients with PNALT and no disease progression over 10 years (median 18.1 years) after spontaneous HBeAg seroconversion were assayed for HBV DNA. Excluding assays within 1 year after HBeAg seroconversion, 21% and 82.3% of the patients with PNALT had HBV DNA levels persistently lower than 4 log(10) and 5 log(10) copies/mL, respectively, and only 8% had a level ≥ 5 log(10) copies/mL in at least two assays. Of the 27 patients with PNALT defined by ALT <30 U/L for male and <19 U/L for female, only 33% had serum HBV DNA level persistently <4 log(10) copies/mL. There was no significant difference in the serial HBV DNA changes among patients with different gender, HBV genotype or age at HBeAg seroconversion. Liver biopsy in nine patients invariably showed minimal necroinflammation and one showed Ishak fibrosis score 4. These results suggest that 5 log(10) copies/mL (20,000 IU/mL) is a more appropriate cut-off HBV DNA level for inactive chronic HBV infection in the setting of PNALT.

Hepatitis B prevention, diagnosis, treatment and care: a review

Hepatitis B virus (HBV) infection is a major cause of morbidity and mortality worldwide. Chronic hepatitis B (CHB) infection is associated with an increased risk of cirrhosis, hepatic decompensation and hepatocellular carcinoma (HCC). The likelihood of developing CHB is related to the age at which infection is acquired; the risk being lowest in adults and >90% in neonates whose mothers are hepatitis B e antigen positive. Treatment of CHB infection aims to clear HBV DNA and prevent the development of complications. There are currently seven drugs available for the treatment of CHB: five nucleos(t)ide analogues and two interferon-based therapies. Long-term treatment is often required, and the decision to treat is based on clinical assessment including the phase of CHB infection and the presence and extent of liver damage. A safe and effective HBV vaccine has been available since the early 1980s. Vaccination plays a central role in HBV prevention strategies worldwide, and a decline in the incidence and prevalence of HBV infection following the introduction of universal HBV vaccination programmes has been observed in many countries including the USA and parts of South East Asia and Europe. Post-exposure prophylaxis (PEP) with HBV vaccine +/- hepatitis B immunoglobulin is highly effective in preventing mother to child transmission and in preventing transmission following sharps injuries, sexual contact and other exposures to infected blood and body fluids. Transmission of HBV in the health care setting has become an increasingly rare event in developed nations. However, it remains a significant risk in developing countries reflecting the higher prevalence of CHB, limited access to HBV vaccination and PEP and a lack of adherence to standard infection control precautions.

HBV DNA suppression in HBeAg-positive chronic hepatitis B patients treated with peginterferon or placebo

The aim of the present study was to compare the decline of HBV DNA during peginterferon (PEG-IFN) therapy with spontaneous HBV DNA decline in placebo-treated patients with hepatitis B e antigen (HBeAg)-positive chronic hepatitis B. A total of 136 patients who participated in a randomized trial were treated with PEG-IFN alfa-2b for 52 weeks. These patients were compared with 167 patients who received a placebo for 48 weeks using linear mixed regression analysis. Response was defined as loss of HBeAg at the end of treatment (EOT). Overall, decline of HBV DNA at the EOT was significantly greater in the PEG-IFN group than in the placebo group (mean decline 2.3 log vs. 1.0 log, P < 0.001) and varied according to HBV genotype. Viral suppression was greater in the PEG-IFN group from week 4 throughout the entire treatment period (P < 0.001). The response rate was 32% for the PEG-IFN group and 11% for the placebo group (P < 0.001). Among responders, HBV DNA decline was greater for patients treated with PEG-IFN than with a placebo: the mean difference in HBV DNA decline was 0.7 log (P = 0.001) at 4 weeks and 2 log (P < 0.001) at the EOT. ALT flares (>5 times the upper limit) were associated with a greater HBV DNA decline during PEG-IFN. In conclusion, PEG-IFN therapy resulted in a greater HBV DNA decline in positive HBeAg patients than a placebo. The decline of HBV DNA was greater in patients with HBeAg loss or who exhibited an ALT flare during PEG-IFN than in patients with spontaneous HBeAg loss or flares during placebo therapy.

Determinants of spontaneous surface antigen loss in hepatitis B e antigen-negative patients with a low viral load

Loss of hepatitis B surface antigen (HBsAg) usually indicates the cure of hepatitis B virus (HBV) infection. In spontaneous hepatitis B e antigen (HBeAg) seroconverters, lower serum HBsAg and HBV DNA levels have been shown to be associated with HBsAg loss over time. However, little is known about their impacts on HBsAg loss in HBeAg-negative patients with limited viral replication. A total of 688 HBeAg-negative patients with baseline serum HBV DNA levels <2000 IU/mL were enrolled in Taiwan. The relationships of HBsAg and HBV DNA levels with subsequent HBsAg loss were investigated. In a mean follow-up of 11.6 years, the average annual rate of HBsAg loss was 1.6%. Baseline HBsAg and HBV DNA levels were inversely associated with subsequent HBsAg loss. When compared to patients who had HBsAg levels >1000 IU/mL, the rates of HBsAg loss were significantly higher in patients with HBsAg levels of 100-999, 10-99, and <10 IU/mL, with hazard ratios of 2.5 (95% confidence interval [CI], 1.6-4.0), 2.8 (95% CI, 1.6-5.0), and 13.2 (95% CI, 8.1-21.5), respectively. Multivariate analysis showed that HBsAg level, but not HBV DNA, remained as an independent factor. The adjusted hazard ratio of HBsAg loss was 13.2 (95% CI, 7.8-22.1) for HBsAg level <10 versus ≥ 1000 IU/mL. When compared to HBV DNA level by receiver operating characteristic curve analysis, HBsAg level served as a better predictor of both 5-year and 10-year HBsAg loss.

CONCLUSION

In HBeAg-negative patients with HBV genotype B or C infection who have HBV DNA level <2000 IU/mL, HBsAg level <10 IU/mL is the strongest predictor of HBsAg loss.

Viral load, genotypes, and mutants in hepatitis B virus-related hepatocellular carcinoma: special emphasis on patients with early hepatocellular carcinoma

BACKGROUND/AIMS

The role of viral factors in the pathogenesis of hepatitis B virus (HBV)-related hepatocellular carcinoma (HCC) is still inconclusive. Whether virological features such as viral load or mutants might change with the progression of HCC remains unknown. A case-control study including patients with early HCC and HBsAg carriers who are presumed to be at the minimal potential of HCC as controls might better identify factors significantly associated with HCC development.

METHODS

Virological features were compared between 59 patients with early HCC (a solitary tumor of size ≤ 3 cm) and 101 patients with non-early HCC. A case-control study was performed by comparing 59 patients with early HCC and 1:2 age-matched inactive carriers with persistent normal alanine aminotransferase (ALT) levels.

RESULTS

HBV DNA levels, HBV genotypes, and the frequency of precore A1896 and basal core promoter T1762/A1764 mutations showed no significant difference between patients with early HCC and those with non-early HCC. In the case-control study, patients with early HCC had significantly higher HBV DNA levels, and higher frequencies of genotype C HBV and basal core promoter T1762/A1764 mutation, but a similar frequency of precore A1896 mutation. Multiple logistic regression analysis identified HBV DNA levels ≥ 2,000 IU/mL and basal core promoter T1762/A1764 mutation as being independent factors for HCC development. Additionally, there was a synergistic effect between high viral load and basal core promoter T1762/A1764 mutation on HCC development.

CONCLUSIONS

Virological features did not change significantly with the progression of HCC. HBV DNA levels ≥ 2,000 IU/mL and basal core promoter T1762/A1764 mutation were two independent viral factors for HCC.

Entecavir versus lamivudine in the treatment of chronic hepatitis B patients with hepatic decompensation

BACKGROUND

Lamivudine has been widely used in chronic hepatitis B patients with hepatic decompensation, but its use is limited by drug resistance. This outcome research aimed to investigate the comparative efficacy and safety of entecavir versus lamivudine in decompensated patients.

METHODS

Between November 2004 and February 2010, 126 consecutive treatment-naive patients received either entecavir (n=53) or lamivudine (n=73) for decompensated chronic hepatitis B. All patients presented with both hyperbilirubinaemia and coagulopathy. Primary outcome was mortality within 1 year; secondary outcomes included liver-related mortality, biochemical and virological response, and improvement of hepatic dysfunction.

RESULTS

Both treatment groups were comparable in baseline characteristics. A total of 19 (35.8%) entecavir and 33 (45.2%) lamivudine receivers expired within 1 year, respectively (P=0.29, log rank test). Age (hazard ratio [HR] 1.04 per year, 95% CI 1.01, 1.06), cirrhosis (HR 2.07, 95% CI 1.02, 4.23), and international normalized ratio for prothrombin time (HR 1.44, 95% CI 1.20, 1.74) were independent baseline predictors for all-cause mortality. Antiviral therapy was also unrelated to liver-specific death. However, more patients taking entecavir tended to attain aminotransferase normalization (76.5% versus 52.5%; P=0.05) and viral DNA undetectability (100% versus 58.3%; P=0.06). Moreover, entecavir was associated with significantly greater reduction of the model for end-stage liver disease scores (median 10.0 versus 4.3; P=0.02). Overall, 3 (7.5%) lamivudine but no entecavir users acquired drug resistance in 1 year (P=0.25).

CONCLUSIONS

Entecavir as compared with lamivudine is similar in the effect on short-term mortality but is associated with greater clinical improvement among chronic hepatitis survivors who recovered from hepatic decompensation.

Prevalence of HBV infection among different HIV-risk groups in Hai Phong, Vietnam

Hepatitis B virus (HBV) infection in Hai Phong, northern Vietnam, was characterized by analyzing the prevalence and genotype distribution of HBV as well as co-infection with human immunodeficiency virus type 1 (HIV-1) among five different risk groups for HIV infection. Plasma samples were collected from intravenous drug users (n=760, anti-HIV-1 antibody positive rate: 35.9%), female sex workers (FSWs; n=91, 23.1%), seafarers (n=94, 0%), pregnant women (n=200, 0.5%), and blood donors (n=210, 2.9%) in 2007 [Ishizaki et al. (2009): AIDS Res Hum Retroviruses 25:175-182]. Samples were screened for the hepatitis B surface antigen (HBsAg) and anti-HBs antibody and analyzed genetically. The cumulative HBV incidence rate (HBsAg+anti-HBs) was 53.2% (10.7+42.5%) in intravenous drug users, 51.6% (11.0+40.6%) in FSWs, 54.3% (9.6+44.7%) in seafarers, 50.5% (12.5+38.0%) in pregnant women, and 51.0% (18.1+32.9%) in blood donors; there was no significant difference among these groups. Of 163 HBsAg-positive samples, 113 could be analyzed genetically. Phylogenetic analysis, based on the preS1 region, revealed genotype B4 was most prevalent (90/113; 79.6%), followed by C1 (17.7%), I1 (1.8%), and B2 (0.9%). There was no significant difference in HBV genotype distribution among different HIV infection-risk groups. The prevalence of HBsAg was 10.3% (31/301) in HIV-1-infected individuals and 12.5% (132/1,054) in non-HIV-1-infected individuals, which was not significant. In addition, no significant difference in HBV genotype distribution was observed between HBV/HIV-1 coinfected and HBV mono-infected groups. These results suggest that, although HBV and HIV-1 share modes of transmission, major transmission routes of HBV have been different from those of HIV-1 in Hai Phong, Vietnam.

Longitudinal assessment of liver stiffness by transient elastography for chronic hepatitis B patients treated with nucleoside analog

AIM

  To evaluate the association between liver stiffness measured by transient elastography (FibroScan) and the efficacy of long-term nucleoside analog (NA) treatment for patients with chronic hepatitis B.

METHODS

  Study 1: Forty-four chronic HBV patients had liver stiffness measured by FibroScan and underwent liver biopsy. Study 2: Group A: 22 patients started NA treatment at entry and FibroScan was done annually for 3 years. Group B: 23 patients started NA treatment prior to pretreatment FibroScan measurement, and FibroScan was done for from 3 to 5 years after the start of NA treatment.

RESULTS

  Study 1: The FibroScan values were significantly correlated with fibrosis stage (r = 0.672, P < 0.0001). Optimal cutoff of FibroScan values were 6.1 kPa for ≥ F1, 6.3 kPa for ≥ F2, 8.9 kPa for ≥ F3 and 12.0 kPa for F4. Study 2: For Group A, the baseline median FibroScan value was 8.2 kPa. FibroScan values significantly decreased annually for 3 years after the start of NA treatment (6.4 kPa, 5.8 kPa and 5.3 kPa at years 1, 2 and 3, respectively). For Group B, the FibroScan values did not significantly improve over the 3 years after the start of NA treatment.

CONCLUSIONS

  Liver stiffness, measured by transient elastography, of chronic hepatitis B patients treated with NA showed a rapid decline in the first 3 years followed by a more steady transition for from 3 to 5 years irrespective of long term virological effect.

Factors predicting the efficacy of adefovir dipivoxil on treatment-naïve chronic hepatitis B patients at 48 weeks

BACKGROUND/AIMS

To reveal possible factors predicting the effect of adefovir dipivoxil (ADV) treatment on chronic hepatitis B (CHB) and optimize the utilization of ADV.

METHODS

In total, 168 treatment-naïve CHB patients were enrolled, including 117 hepatitis B e antigen (HBeAg)-positive patients and 51 HBeAg-negative patients who met the inclusion criteria. All patients were treated with ADV 10 mg per day for 48 weeks. Multiple logistic regression analyses were used to investigate baseline factors, and responses at weeks 12 and 24 were analyzed as predictive values.

RESULTS

Multiple regression analyses showed that baseline HBeAg status and HBV DNA levels significantly affected the virological response (VR) (p<0.05), baseline ALT levels were an independent predictor of serological response (SR) (p<0.05) and the body mass index (BMI) may affect the biochemical response (BR) (p<0.05). There was a statistically significant difference in the VR and SR between patients with a primary nonresponse (PNR) at week 12 and those with a VR at week 12 (p<0.01). Additionally, the VR was significantly different between patients with HBV DNA lower than 10(3) copies/mL at week 24 and those with greater than 10(3) copies/mL (p<0.01).

CONCLUSIONS

Patients with negative HBeAg, lower HBV DNA levels and higher ALT values at baseline are more suitable for ADV treatment, whereas patients with lower BMIs may be more amenable to ALT normalization. Adjustments for treatment strategy should be considered if PNR at week 12 or HBV DNA ≥10(3) copies/mL at week 24 is observed.

Effect and Predictive Elements for 52 Weeks' Telbivudine Treatment on Naïve HBeAg positive Chronic Hepatitis B

BACKGROUND

Antiviral treatment with nucleoside analogs has been used for chronic hepatitis B (CHB). Each kind of nucleoside analog has its own characteristics and suitability for patients. Telbivudine (LdT, brand name: Sebivo, Beijing Novartis Pharma Ltd) is the newest nucleoside analog, with strong and rapid viral suppression. However, its resistance rate is relatively high during long-term application, due to low genetic barriers to resistance. So, it is necessary to increase the effect and reduce resistance with effective management, according to baseline factors and early on-treatment responses.

OBJECTIVES

To reveal possible predictive factors of the effect of telbivudine (LdT) treatment on naïve HBeAg-positive chronic hepatitis B (CHB) patients to optimize treatment.

PATIENTS AND METHODS

A total 71 naïve chronic hepatitis B (CHB) patients who met the inclusion criteria were enrolled. All patients were treated with LdT 600 mg Qd for at least 52 weeks. Multiple logistic regression analyses were done to investigate the predictive values of baseline factors and responses at Week 24.

RESULTS

The reduction in hepatitis virus B (HBV) DNA level was 6.44 ± 2.38 lg copies/mL at Week 52 compared with baseline. The complete virus response (CVR), biochemical response (BR), serological response (SR), and drug resistance (DR) were 61.99%, 77.46%, 35.21%, and 8.45% respectively. By multiple regression analysis, baseline alanine aminotransferase (ALT) levels significantly affected CVR (P = 0.024, OR = 1.008), and baseline ALT and baseline HBV DNA levels were independent compact factors of SR (P = 0.012, OR = 1.007; P = 0.001, OR = 0.423). The differences in CVR, SR, and DR in patients with ALT > 120 Iu/mL compared with patients with ALT ≤ 120 Iu/mL were statistically significant. The differences in SR in patients with HBV DNA > 107 copies/mL compared with patients with HBV DNA ≤ 107 copies/mL were statistically significant. Additionally, CVR, BR, and SR were differed significantly between patients with HBV DNA lower than 300 copies/mL at Week 24 and patients with HBV DNA higher than 300 copies/mL (P = 0.000, P = 0.0016, and P = 0.000, respectively).

CONCLUSIONS

There were more responders among naïve HBeAg-positive chronic hepatitis B patients with lower HBV DNA levels (especially lower than 107 copies/mL) and higher ALT values (especially higher than 120 Iu/mL at baseline) to LdT treatment. Adjustments for treatment strategy should be considered if HBV DNA > 300 copies/mL at Week 24 is observed.

Molecular characterization of a novel entecavir mutation pattern isolated from a multi-drug refractory patient with chronic hepatitis B infection

BACKGROUND

Prolonged antiviral treatment results in selection and accumulation of resistant strains in quasispecies pool in hepatitis B virus (HBV) infection.

OBJECTIVES

The aim of this study was to characterise a novel HBV pattern which shows resistance to lamivudine, adefovir dipivoxil and entecavir using in vitro phenoyping assay.

STUDY DESIGN

A male 36 years old patient diagnosed with anti HBe-positive chronic hepatitis B (CHB) had received lamivudine treatment for 7 years following an initial unsuccessfull interferon treatment. The therapy had been switched to adefovir and then to entecavir when breakthrough occcured during each treatment. This led only to a temporary HBV DNA decline which soon was followed by viral breakthrough despite the lack of known entecavir resistance mutations. Patient died after 9 months of entecavir treatment from liver failure. A total of 434 clones from 6 different serum samples were analysed retrospectively. HBV genomes bearing mutation patterns suggestive of antiviral resistance were analysed by in vitro phenotyping assay.

RESULTS

Dominance of a clone carrying L80LV, L91I, M204I, S219A, N238D, Y245H changes was detected in the last serum sample of the patient just before his death. This pattern displayed 30.4 fold resistance to entecavir when compared with the wild type HBV by in vitro phenotyping assay.

CONCLUSION

A novel mutation pattern showing a high degree of resistance to entecavir was documented. In this pattern, the S219A and Y245H mutations mainly seem to contribute to the emergence of ETV resistance.

Hepatocellular carcinoma and other liver disease among Greenlanders chronically infected with hepatitis B virus: a population-based study

BACKGROUND

In Greenland, the prevalence of hepatitis B surface antigen carriers, reflecting chronic hepatitis B virus (HBV) infection, is 5%-10%. However, the incidence of cirrhosis and hepatocellular carcinoma in this population has been reported to be low. We investigated this discrepancy in a large population-based cohort study.

METHODS

In total, 8879 Greenlanders (16% of the population) were recruited for population-based surveys performed from May 5 to July 7, 1987, and from November 1 to November 21, 1998, with follow-up until March 31, 2010. HBV status was based on serological testing, supplemented by data from all available HBV registries in Greenland to determine changes in HBV status over time. Information on morbidity and mortality was obtained from the Patient Discharge Registry, the Cancer Registry, and the Central Registration System. Sex, age, ethnicity, and period-adjusted incidence rate ratios (IRRs) were estimated using Poisson regression. World standardized rates were derived from these and World Health Organization data.

RESULTS

The 650 chronically HBV-infected persons had higher rates of hepatocellular carcinoma (adjusted IRR = 8.70; 95% CI = 2.06 to 36.7), liver disease (adjusted IRR = 5.73, 95% CI = 3.52 to 9.34), and all-cause mortality (adjusted IRR = 1.47; 95% CI = 1.21 to 1.79) than the 5160 HBV-negative persons. However, the world standardized incidence rates of hepatocellular carcinoma (38.5 cancers per 100 000 person-years) and cirrhosis (24 cases per 100 000 person-years) among chronically HBV-infected persons were low compared with results from population-based studies from countries with low, intermediate, and high rates of endemic HBV infection.

CONCLUSION

The relatively low incidence of hepatocellular carcinoma and other HBV-related morbidity among chronic HBV-infected persons in Greenland suggest a more benign course of HBV among the Greenlandic Inuit than in populations in other parts of the world.

Changes in serum levels of HBV DNA and alanine aminotransferase determine risk for hepatocellular carcinoma

BACKGROUND & AIMS

It is not clear whether risk for hepatocellular carcinoma can be accurately determined from long-term changes in serum levels of hepatitis B virus (HBV) DNA or alanine aminotransferase (ALT).

METHODS

We measured serum levels of HBV DNA and ALT at enrollment and during follow-up analysis of 3160 participants in the REVEAL-HBV study. Development of hepatocellular carcinoma was determined from follow-up examinations and computerized linkage with National Cancer Registry and National Death Certification profiles. Multivariate-adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated using Cox regression models.

RESULTS

During 38,330 person-years of follow-up, 81 participants developed hepatocellular carcinoma (incidence rate, 211.3/100,000 person-years). The risk for hepatocellular carcinoma was only slightly higher for participants whose follow-up levels of HBV DNA spontaneously decreased to <10,000 copies/mL compared with those with baseline levels of HBV DNA<10,000 copies/mL (control group; HR, 2.25; 95% CI, 0.68-7.37). Compared with the control group, the HRs (95% CI) for long-term levels of HBV DNA that persisted at 10,000 to 100,000 copies/mL, decreased to/persisted at 100,000 to 1,000,000 copies/mL, or decreased to/persisted at 1,000,000 to 10,000,000 copies/mL were 3.12 (1.09-8.89), 8.85 (3.85-20.35), and 16.78 (7.33-38.39), respectively. A gradient in ALT level was significantly associated with hepatocellular carcinoma risk: from all low-normal, to ever high-normal, to transient abnormal, to persistent abnormal (Ptrend<.001).

CONCLUSIONS

Long-term changes in serum levels of HBV DNA and ALT are independent predictors of risk for hepatocellular carcinoma. Regular monitoring of levels of HBV DNA and ALT is important in clinical management of chronic carriers of HBV.

Cytokeratins in hepatitis

Experimental and clinical evidence suggests that cytokeratins (CK), among other physiological functions, are expressed in hepatocytes and can be released in the bloodstream after acute or chronic inflammatory liver injury. Interest in CK in viral and nonviral hepatitis has been rapidly increasing during the last years, especially as they have been proposed as circulating biomarkers of hepatocyte necrosis and apoptosis. In the present review, we sought to summarize and discuss the alterations in circulating CK levels in different form viral and nonviral hepatitis, as well as their potential relation with liver histology. Understanding the mechanisms of hepatitis impact on CK and vice versa is a promising area of research that will positively enhance our understanding of the complexity of acute and chronic inflammatory liver injury.

Comparison of a novel real-time PCR assay with sequence analysis, reverse hybridization, and multiplex PCR for hepatitis B virus type B and C genotyping

We compared a novel real-time genotyping and quantitative PCR (GQ-PCR) assay, direct sequence analysis, reverse hybridization, and multiplex PCR for genotyping hepatitis B virus (HBV) in 127 HBV-infected patients. We found that GQ-PCR had the highest concordance with sequence analysis and the highest detection rate for mixed genotype detecting.

Clinical and virological characteristics of chronic hepatitis B with concurrent hepatitis B E antigen and antibody detection

The concurrent detection of hepatitis B e antigen (HBeAg) and its corresponding antibody (anti-HBe) in patients with chronic hepatitis B virus (HBV) infection is well established but the clinical features remain poorly understood. Demographic information, clinical and laboratory data were collected from 1624 consecutive inpatient records of patients with chronic hepatitis B. Viral genotype, basic core promoter and precore mutations were determined by direct sequencing. In vitro HBeAg and anti-HBe binding experiments were conducted with three pairs of HBeAg-positive and anti-HBe-positive serum samples, which were mixed at variable ratios and incubated at 37°C for 3-24h. Of the 1624 chronic patients, 169 (10.4%) had concurrent HBeAg and anti-HBe positivity, and this was associated with intermediate age and HBV-DNA load, higher alanine aminotransferase level and more pronounced liver damage compared with HBeAg-positive or anti-HBe-positive patients alone. HBeAg and anti-HBe titres (median and interquartile range, S/CO) in the concurrent positive group were 4.2 (1.8-9.6) and 0.54 (0.27-0.72), which were closer to their respective cut-off values than those of HBeAg-positive or anti-HBe-positive groups alone. For the cases successfully sequenced, 110/134 (82.1%) harboured T1762/A1764 or/and A1896 mutants. The binding experiments showed that HBeAg and anti-HBe could be concurrently observed provided an optimal ratio (HBeAg to anti-HBe) was chosen. In antiviral treatment-naive patients, concurrence of HBeAg and anti-HBe was not uncommon, and such patients had profound liver disease. An optimal ratio between HBeAg and anti-HBe led to their concurrent detection when sera were tested by sensitive assays.

The YMDD and rtA194T mutations result in decreased replication capacity in wild-type HBV as well as in HBV with precore and basal core promoter mutations

BACKGROUND

A recent study indicated that addition of the hepatitis B e antigen (HBeAg) precore (PC) or basal core promoter (BCP) mutations to wild-type HBV offset the reduced replication of the HBV polymerase rtA194T±rtL180M+rtM204V mutations. rtA194T was reportedly associated with tenofovir resistance. We investigated these findings in genotype D HBV, where both PC and BCP naturally occur in vivo.

METHODS

A plasmid containing a wild-type 1.3 genome length genotype D HBV laboratory strain was used as a parent for PC, BCP, rtA194T±rtL180M+rtM204V, rtL180M+rtM204V and rtM204I mutants. Viral replication was evaluated by Southern blot analysis of intracellular HBV core DNA following transient transfection of HepG2 cells. Drug susceptibility was evaluated by quantitative PCR of intracellular HBV DNA.

RESULTS

PC and BCP mutations each increased HBV DNA replication by approximately 200% over wild-type. rtA194T reduced replication by <40%, whereas rtL180M+rtM204V, rtL180M+rtA194T+rtM204V or rtM204I each reduced by >75% from their respective wild-type, PC or BCP genome backbone (P<0.05). The enhanced replication by PC or BCP offset the reduction by rtA194T; however, the other reverse transcriptase (RT) mutations in PC or BCP backbones remained significantly lower than wild-type (P<0.05). Regardless of the backbone, rtA194T±rtL180M+rtM204V remained susceptible to tenofovir in vitro. rtA194T alone remained susceptible to lamivudine, while rtL180M+rtM204V and rtL180M+rtA194T+rtM204V were resistant.

CONCLUSIONS

PC or BCP mutations increased HBV DNA replication, offset the decreased replication by rtA194T alone, but they did not fully rescue the impaired replication conferred by other RT mutations as compared with wild-type. rtA194T±rtL180M+rtM204V did not confer tenofovir resistance.

[Genetic susceptibility to infections]

Infectious diseases are among the leading causes of morbidity and mortality worldwide. The spectrum of clinical manifestations of infections is highly variable, ranging from asymptomatic infection or mild illness to rapid progression of disease and death. Twin studies first showed an inheritable component of many infections and epidemiological and genetic studies revealed definite gene loci and polymorphisms for most of the clinically relevant infectious diseases. Reliable genetic markers which represent susceptibility or resistance to infections, prognosis of disease and response to treatment are necessary to define risk populations and to plan therapy regimens. Genetic research can also help in identifying target structures for novel therapy strategies and anitimicrobial agents. In this article the genetic background of important infections is reviewed and examples of successful exploitation of genetic findings and translation into practical medicine are given.

Design, synthesis, and biological evaluation of triazolo-pyrimidine derivatives as novel inhibitors of hepatitis B virus surface antigen (HBsAg) secretion

The high levels of hepatitis B virus (HBV) surface antigen (HBsAg)-bearing subviral particles in the serum of chronically infected individuals play an important role in suppressing HBV-specific immune response and are only mildly affected by the current small molecule therapies. Thus, a therapy that specifically reduces HBsAg serum levels could be used in combination therapy with nucleos(t)ide drugs or permit therapeutic vaccination for the treatment of HBV infection. Herein, we report the design, synthesis, and evaluation of novel triazolo-pyrimidine inhibitors (1, 3, and 4) of HBsAg cellular secretion, with activity against drug-resistant HBV variants. Extensive SAR led to substantial improvements in the EC(50) of the parent compound, 5 (HBF-0259), with the best being 3c, with EC(50) = 1.4 ± 0.4 μM, SI ≥ 36. The lead candidates, both 1a (PBHBV-001) and 3c (PBHBV-2-15), were well-tolerated in both normal and HBV-transgenic mice and exhibited acceptable pharmacokinetics and bioavailability in Sprague-Dawley rats.

Clinical utility of hepatitis B surface antigen quantitation in patients with chronic hepatitis B: a review

This clinically relevant review focuses on recent findings concerning hepatitis B surface antigen (HBsAg) quantitation in untreated patients and treated patients with chronic hepatitis B. Recent studies and emerging data have shown that both HBsAg and hepatitis B virus (HBV) DNA levels decline during the natural course of a chronic HBV infection; they are lowest in the inactive phase, which is also characterized by the highest HBsAg/HBV DNA ratio. It has been demonstrated that the combined use of HBsAg and HBV DNA levels might help in the identification of true inactive carriers with high accuracy. Retrospective analyses of HBsAg levels in patients undergoing therapy have suggested a role for HBsAg quantitation in monitoring the response to therapy. In comparison with nucleos(t)ide analogues (NAs), interferon-based therapy results in greater overall declines in serum HBsAg levels. A rapid on-treatment decline in HBsAg levels appears to be predictive of a sustained response. With the aid of HBsAg quantitation, it appears that we can anticipate an individualized approach to tailoring the treatment duration. The proposal of early stopping rules for patients not responding to pegylated interferon (according to a lack of any HBsAg decline) represents a step toward a response-guided approach. The development of stopping rules for patients treated with NAs is desirable for reducing the need for lifelong therapy. However, before stopping rules for antiviral therapy can be applied, we need to learn more about the kinetics of HBsAg declines during the natural history of the infection and as a response to therapy so that we can better define the best timing, the relevant HBsAg cutoff levels, and the best ways to apply these rules in clinical practice.

Serum hepatitis B surface antigen levels predict surface antigen loss in hepatitis B e antigen seroconverters

BACKGROUND & AIMS

Loss of hepatitis B surface antigen (HBsAg) usually indicates that hepatitis B virus (HBV) infection has been cured. However, little is known about factors predicting HBsAg loss in patients who spontaneously clear hepatitis B e antigen (HBeAg).

METHODS

We studied 390 Taiwanese HBeAg-positive patients with chronic hepatitis who had spontaneously cleared HBeAg (seroconversion) during follow-up. Serum levels of HBV DNA and HBsAg were determined 1 year after HBeAg seroconversion, and their relationships with subsequent HBsAg loss were investigated.

RESULTS

In a mean follow-up of 7.4 years, the average annual rate of HBsAg loss was 0.62%. Serum levels of HBsAg and HBV DNA were inversely associated with HBsAg loss in a dose-response manner. Compared with patients with HBsAg levels ≥1000 IU/mL, the HBsAg loss rate was higher for those with HBsAg levels of 100 to 999 and <100 IU/mL, with hazard ratios of 4.4 (95% confidence interval, 1.1-17.0) and 24.3 (8.7-67.5), respectively. Among those who underwent HBsAg loss within 6 years of follow-up, serum HBsAg levels were a better predictor than HBV DNA levels by receiver operating characteristic curve analysis (area under the receiver operating characteristic curve, 0.90 vs 0.69; P = .012); an HBsAg level <100 IU/mL predicted HBsAg loss within 6 years with a diagnostic accuracy of 91.5%, sensitivity of 83.3%, specificity of 92.1%, positive predictive value of 45.5%, and negative predictive value of 98.6% in patients with an HBV DNA level <200 IU/mL.

CONCLUSIONS

Low serum levels of HBsAg, alone or in combination with HBV DNA levels, 1 year after HBeAg seroconversion can predict HBsAg loss in patients with HBV genotype B or C infection.

Quantification of complex precore mutations of hepatitis B virus by SimpleProbe real time PCR and dual melting analysis

BACKGROUND

Hepatitis B virus (HBV) precore G1896A mutation is associated with Hepatitis B e antigen (HBeAg) seroconversion. This mutation and the adjacent G1899A mutation also appear to associate with increased risk of hepatocellular carcinoma. Quantitative mutant dynamics may help determine the potential of these mutants as clinical biomarkers. However, a reliable method to quantify either mutant is not available, partly because the viral genome has polymorphisms in general and the precore mutations are complex.

OBJECTIVES

(1) To develop a reliable and ultrasensitive assay for the quantification of HBV G1896A and/or G1899A mutants. (2) To obtain preliminary data on the quantities of the precore mutants in patients.

STUDY DESIGN

A SimpleProbe real time PCR assay was developed to quantify the HBV precore mutants. Dual melting analysis and a primer-probe partial overlap approach were used to increase detection accuracy. A wild-type selective PCR blocker was also developed to increase mutant detection sensitivity.

RESULTS

The assay correctly identified the precore sequence from all 62 patient samples analyzed. More than 97% of precore sequences in the GenBank can be recognized. Mutant detection sensitivity reached 0.001% using a wild type-selective PCR blocker. At least one precore mutant can be detected from all 20 HBeAg-positive individuals who were negative for precore mutations by DNA sequencing.

CONCLUSIONS

The reliability of this ultrasensitive mutation quantification assay was demonstrated. The same approaches may be useful for the detection of other clinically significant mutations. Evolution of the precore mutants warrants further studies.

Epidemiological and clinical features of hepatitis B virus related liver failure in China

AIM: To examine the epidemiologic and clinical characteristics of hepatitis B virus (HBV) related liver failure in patients in China.

METHODS: This study was conducted with a retrospective design to examine 1066 patients with HBV-related liver failure in the southwest of China.

RESULTS: There were more male than female patients. Young and middle-aged people comprised most of the patients. Farmers and laborers comprised the largest proportion (63.09%). Han Chinese accounted for 98.12%, while minority ethnic groups only accounted for 0.88% of patients. A total of 43.47% patients had a family history of HBV-related liver failure and 56.66% patients had a history of drinking alcohol. A total of 42.59% patients with HBV-related liver failure had definite causes. With regard to the clinical manifestation of HBV-related liver failure, the symptoms were: hypodynamia, anorexia and abdominal distension. Total bilirubin (TBIL) and alanine aminotransferase (ALT) levels were altered in 46.23% of patients with evident damage of the liver. Univariate logistic regression analysis showed that the patients’ prognoses were correlated with ALT, aspartate aminotransferase, albumin, TBIL, prothrombin activity (PTA), and alpha-fetoprotein levels, and drinking alcohol, ascites, hepatorenal syndrome, infection and ≥ 2 complications. Multifactor logistic regression analysis showed that the activity of thrombinogen and the number of complications were related to the prognosis.

CONCLUSION: Alcohol influences the patients’ prognosis and condition. PTA and complications are independent factors that can be used for estimating the prognosis of HBV-related liver failure.

Natural history of chronic hepatitis B in Euro-Mediterranean and African countries

Data derived from population, case-control, and cohort studies conducted in several Euro-Mediterranean and African countries disclose impressive similarities in the age and modes of hepatitis B virus (HBV) transmission and in the prevalence, duration, and outcome of the four phases of the natural history of chronic infection. Perinatal HBV infection is rare while the vast majority of chronic infections originate from horizontal HBV transmission to infants and children. HBeAg loss and seroconversion to anti-HBe occur in a few years time, usually during the second decade of life. HBeAg-negative/anti-HBe-positive chronic hepatitis B (CHB), predominates in these countries being 7-9 times more frequent than HBeAg-positive CHB. The predominance of HBeAg-negative CHB is largely linked to the molecular characteristics of HBV genotype D prevailing in European and African countries of the Mediterranean basin and of genotype E and subgenotype A1 that prevail in the other parts of Africa. The molecular characteristics of the African subgenotype A1 differ from those of European subgenotype A2 explaining the fact that patients infected subgenotype A1 demonstrate an earlier loss of HBeAg and seroconversion to anti-HBe during the natural course of HBV infection compared to those infected with subgenotype A2. It is proposed that the molecular characteristics of HBV genotypes and subgenotypes prevailing in Euro-Mediterranean and African countries acting in concert with host and environmental factors largely determine the natural history of chronic HBV infection and its significant differences from countries of HBV genotype C and B and of subgenotype Ae predominance. The knowledge of the natural history of chronic HBV infection in Euro-Mediterranean and African countries combined with wide screening programs for prompt recognition and treatment of chronic HBV infection both in its HBeAg-positive and -negative immune reactive phases can be expected to increase the efficacy of current and future therapeutic strategies.

Viral level is an indicator of long-term outcome of hepatitis B virus e antigen-negative carriers with persistently normal serum alanine aminotransferase levels

The association between viral level and the long-term outcomes of hepatitis B virus (HBV) carriers who test negative for hepatitis B virus e antigen (HBeAg) but have persistently normal serum alanine aminotransferase levels (PNALT) remains unclear. We examined hepatocarcinogenesis, hepatitis reactivation, predictive factors and the time course of HBV DNA levels during follow-up in 104 HBeAg-negative Japanese carriers with PNALT. During a mean follow-up period of 6.4 ± 3.4 years, 5 patients (4.8%) had hepatocarcinogenesis and 14 (13.5%) had hepatitis reactivation. At 5 and 10 years, the cumulative rates of hepatocarcinogenesis were 2.4% and 9.9%, while those of hepatitis activation were 13.7% and 15.5%, respectively. An HBV DNA level of ≥5 log10  copies/mL was the sole predictor of hepatocarcinogenesis with a univariate analysis. An HBV DNA level of ≥5 log10  copies/mL and an alanine aminotransferase (ALT) level of >20 to ≤40 IU/L were independent predictors of hepatitis reactivation in a Cox model. Because there was no association between hepatocarcinogenesis and ALT activity, the HBV DNA level was considered an essential predictor. In addition, the baseline HBV DNA level was related to the future level and was not subject to wide fluctuations. Our results showed that an HBV DNA level of ≥5 log10  copies/mL predicts subsequent hepatocarcinogenesis and hepatitis reactivation in HBeAg-negative carriers with PNALT. As the baseline HBV DNA level reflects the future level, appropriate clinical management according to the viral level is expected to decrease future risk.

Long-term effects of lamivudine treatment in Japanese chronic hepatitis B patients

AIM: To analyze the association between the emergence of tyrosine-methionine-asparatate-asparatate (YMDD) mutants (reverse transcription; rtM204I/V) and deterioration of liver function during long-term lamivudine treatment of Japanese patients with chronic hepatitis B virus (HBV) infection.

METHODS: The data of 61 consecutive Japanese patients with chronic hepatitis B who underwent continuous lamivudine treatment for more than 24 mo and had a virological response were analyzed. Analysis of YMDD mutants was done by real-time polymerase chain reaction with LightCycler probe hybridization assay for up to 90 mo (mean, 50.8 mo; range, 24-90 mo).

RESULTS: A mixed mutant-type (YMDD + tyrosine-isoleucine-asparatate-asparatate: YIDD or tyrosine-valine-asparatate-asparatate: YVDD) or a mutant-type (YIDD or YVDD) were found in 57.4% of 61 patients at 1 year, 78.7% of 61 patients at 2 years, 79.6% of 49 patients at 3 years, 70.5% of 34 patients at 4 years, 68.4% of 19 patients at 5 years, 57.1% of 14 patients at 6 years, and 33.3% of 6 patients at 7 years. Of the 61 patients, 56 (92%) had mixed mutant- or a mutant-type. Only 5 (8%) had no mutants at each observation point. Virological breakthrough was found in 26 (46.4%) of 56 patients with YMDD mutants, 20 of whom had a hepatitis flare-up: the remaining 30 (53.6%) had neither a virological breakthrough nor a flare-up. All 20 patients who developed a hepatitis flare-up had a biochemical and virological response after adefovir was added to the lamivudine treatment.

CONCLUSION: Our results suggest that it is possible to continue lamivudine treatment, even after the emergence of YMDD mutants, up to the time that the patients develop a hepatitis flare-up.