Clinical significance and evolution of core promoter and precore mutations in HBeAg-positive patients with HBV genotype B and C: a longitudinal study

Detection of Immune Escape and Basal Core Promoter/Precore Gene Mutations in Hepatitis B Virus Isolated from Asymptomatic Hospital Attendees in Two Southwestern States in Nigeria

Several mutations in the surface (S), basal core promoter (BCP), and precore (PC) genes of the hepatitis B virus have been linked to inaccurate diagnosis and the development of immune escape mutants (IEMs) of the infection, which can lead to chronic infection. Understanding the prevalence and spread of these mutations is critical in the global effort to eliminate HBV. Blood samples were collected from 410 people in Osun and Ekiti states, southwest Nigeria, between 2019 and 2021. Participants were drawn from a group of asymptomatic people who were either blood donors, outpatients, or antenatal patients with no record of HBV infection at the medical outpatients' unit of the hospital. DNA was extracted from plasma using a Qiagen DNEasy kit, followed by nested PCR targeting HBV S and BCP/PC genes. The Sanger sequencing method was used to sequence the positive PCR amplicons, which were further analyzed for IEMs, BCP, and PC mutations. HBV-DNA was detected in 12.4% (51/410) of individuals. After DNA amplification and purification, 47.1% (24) of the S gene and 76.5% (39) of the BCP/PC gene amplicons were successfully sequenced. Phylogenetic analysis showed that all the HBV sequences obtained in this study were classified as HBV genotype E. Mutational analysis of the major hydrophilic region (MHR) and a-determinant domain of S gene sequences revealed the presence of three immune escape mutations: two samples harbored a T116N substitution, six samples had heterogenous D144A/N/S/H substitution, and one sample had a G145E substitution, respectively. The BCP/PC region analysis revealed a preponderance of major BCP mutants, with the prevalence of BCP double substitutions ranging from 38.5% (A1762T) to 43.6% (G1764A). Previously reported classical PC mutant variants were observed in high proportion, including G1896A (33.3%) and G1899A (12.8%) mutations. This study confirms the strong presence of HBV genotype E in Nigeria, the ongoing circulation of HBV IEMs, and a high prevalence of BCP/PC mutants in the cohorts. This has implications for diagnosis and vaccine efficacy for efficient management and control of HBV in the country.

A review of epidemiology and clinical relevance of Hepatitis B virus genotypes and subgenotypes

BACKGROUND

Hepatitis B virus (HBV) infection is a global public health burden, affecting nearly 300 million people around the world. Due to HBV population is considered to be represented as a viral quasispecies with genetic diversity, some reports showed that different genotypes of HBV have different viral effects, though the emergence of antiviral drugs that effectively inhibit viral replication, however, HBV infection has still not been eradicated and further research is needed.

SUMMARY

HBV has been classified into at least ten genotypes (A-J)  and more than 40 subgenotypes based on an intergroup or intragroup nucleotide difference across the whole genome, respectively. Inter genotypic recombinants were also observed during the HBV evolution. HBV genotypes and subgenotypes have distinct ethno-geographical distributions, as well as evident differences in their biological characteristics. HBV genotypes and subgenotypes also have close association with disease severity, long-term clinical outcomes, and response to antiviral therapy.

KEYMESSAGES

In this review, we up-dated the epidemiological characteristics, clinical features and prognosis of HBV infection with dissimilar genotype/subgenotypes, to better understanding and developing individualized prevention and treatment strategies.

Associations of HBV Genotype B vs C Infection With Relapse After Cessation of Entecavir or Tenofovir Therapy

BACKGROUND & AIMS

We compared rates of relapse of hepatitis B virus (HBV) infection between patients with HBV genotype B vs genotype C infection after cessation of entecavir or tenofovir disoproxil fumarate (TDF) therapy. All patients included in the study were HB e antigen (HBeAg)-negative.

METHODS

We performed a retrospective study of 460 HBeAg-negative patients without cirrhosis in Taiwan who had stopped entecavir or TDF treatment for at least 12 months; data were collected from 2007 through 2016. All patients fulfilled the stopping criteria proposed by the APASL 2012 guidelines. Patients were evaluated every 1-3 months during the first 6 months after stopping therapy and then every 3 months until their last hospital visit; HB surface antigen (HBsAg) was measured in serum samples collected before treatment, after 12 months of treatment, and at the end of treatment. Virologic relapse was defined as a serum level of HBV DNA >2000 IU/mL after the cessation of treatment; clinical relapse was defined as increase in alanine aminotransferase more than 2-fold the upper limit of normal (40 U/L) and level of HBV DNA >2000 IU/mL after stopping treatment.

RESULTS

Significantly higher proportions of patients with HBV genotype B infection had virologic and clinical relapse and retreatment than patients with HBV genotype C infection, among all patients and among patients matched by propensity sore. Patients who discontinued TDF therapy had significantly higher rates and earlier times of virologic and clinical relapse than patients who discontinued entecavir therapy, among all patients and propensity score-matched patients. Multivariate analysis showed that TDF therapy, old age, HBV genotype B, and higher end of treatment HBsAg level were independently associated with virologic and clinical relapse. Five-year rates of virologic and clinical relapse were low (19.2% and 15.4%, respectively) in patients with a combination of end of treatment level of HBsAg of 100 IU/mL or less and HBV genotype C infection. Rates of off-therapy HBsAg loss, development of hepatocellular carcinoma, and hepatic decompensation did not differ significantly between patients with HBV genotypes B vs C infection or between the entecavir vs TDF groups.

CONCLUSIONS

Higher proportions of HBeAg-negative patients with HBV genotype B infection have virologic and clinical relapse and retreatment than patients with HBV genotype C infection, after cessation of entecavir or TDF therapy.

Pre-S/Surface and Core Promoter/Precore Mutations in Chronic Hepatitis B Patients with Severe Acute Exacerbation

BACKGROUND

The role of pre-S/surface and basal core promoter/precore (BCP/PC) mutations in chronic hepatitis B (CHB) patients with severe acute exacerbation (SAE) remains unclear.

AIMS

To investigate the role of pre-S/surface and BCP/PC mutations in CHB patients with SAE and mortality.

METHODS

A total of 114 CHB patients with spontaneous SAE [alanine aminotransferase (ALT) ≥ 400 U/L] and hepatic decompensation were analyzed along with 114 patients with moderate liver inflammation (ALT: 80-400 U/L without hepatic decompensation) who were matched with the SAE patients in regard to age, sex, HBeAg, and cirrhosis.

RESULTS

Compared with patients with moderate liver inflammation, those with SAE had a higher rate of genotype B. Multivariate analysis showed that the independent factors for SAE were V14G/A and L21S in surface genes, codons 109-119 deletions in pre-S1 genes, M1V/T/I in pre-S2 genes, and C1766T/T1768A and C1913A/G mutations in BCP/PC genes. However, these gene variants or mutations were not significant predictors of mortality in patients with SAE. Of the 114 SAE patients, 17 died at week 24 of nucleoside analog treatment. Cox regression analysis showed that independent predictors for mortality at week 24 of treatment in SAE patients were higher international normalized ratio, the presence of ascites, and T1753C/A/G mutations. The SAE patients with T1753C/A/G mutations had a higher rate of acute-on-chronic liver failure (P = 0.006) and higher MELD score (P = 0.018) than those without T1753C/A/G mutations.

CONCLUSIONS

The variants or mutations in pre-S/surface and BCP/PC regions might play important roles and could predict mortality in SAE patients.

Clinical features of hepatitis B e-antigen positive chronic hepatitis B patients co-existing precore and/or basal core promoter mutations

Aim: Characterize the clinical features of treatment-naive hepatitis B e-antigen (HBeAg)-positive chronic hepatitis B (CHB) patients harboring either precore (PC) or basal core promoter (BCP; PC/BCP) mutations. Methods: Alanine aminotransferase, HBsAg, HBV-DNA, HBV genotypes, PC/BCP mutations and liver stiffness measurement were assessed for 186 treatment-naive HBeAg-positive CHB patients. Results: PC/BCP mutations were found in 40.31% of the treatment-naive HBeAg-positive CHB patients. Patients with PC/BCP mutations showed significantly higher alanine aminotransferase and liver stiffness measurement levels. The serum HBsAg and HBV DNA levels in patients with BCP mutations were significantly lower than those in patients with wild-type virus. PC/BCP mutations were more prevalent in patients in immune clearance phase than those in immune tolerance phase. Conclusion: The emergences of PC/BCP mutations possibly indicate that HBeAg positive patients are experiencing the phase of immune clearance.

Applications of next-generation sequencing analysis for the detection of hepatocellular carcinoma-associated hepatitis B virus mutations

BACKGROUND

Next-generation sequencing (NGS) is a powerful and high-throughput method for the detection of viral mutations. This article provides a brief overview about optimization of NGS analysis for hepatocellular carcinoma (HCC)-associated hepatitis B virus (HBV) mutations, and hepatocarcinogenesis of relevant mutations.

MAIN BODY

For the application of NGS analysis in the genome of HBV, four noteworthy steps were discovered in testing. First, a sample-specific reference sequence was the most effective mapping reference for NGS. Second, elongating the end of reference sequence improved mapping performance at the end of the genome. Third, resetting the origin of mapping reference sequence could probed deletion mutations and variants at a certain location with common mutations. Fourth, using a platform-specific cut-off value to distinguish authentic minority variants from technical artifacts was found to be highly effective. One hundred and sixty-seven HBV single nucleotide variants (SNVs) were found to be studied previously through a systematic literature review, and 12 SNVs were determined to be associated with HCC by meta-analysis. From comprehensive research using a HBV genome-wide NGS analysis, 60 NGS-defined HCC-associated SNVs with their pathogenic frequencies were identified, with 19 reported previously. All the 12 HCC-associated SNVs proved by meta-analysis were confirmed by NGS analysis, except for C1766T and T1768A which were mainly expressed in genotypes A and D, but including the subgroup analysis of A1762T. In the 41 novel NGS-defined HCC-associated SNVs, 31.7% (13/41) had cut-off values of SNV frequency lower than 20%. This showed that NGS could be used to detect HCC-associated SNVs with low SNV frequency. Most SNV II (the minor strains in the majority of non-HCC patients) had either low (< 20%) or high (> 80%) SNV frequencies in HCC patients, a characteristic U-shaped distribution pattern. The cut-off values of SNV frequency for HCC-associated SNVs represent their pathogenic frequencies. The pathogenic frequencies of HCC-associated SNV II also showed a U-shaped distribution. Hepatocarcinogenesis induced by HBV mutated proteins through cellular pathways was reviewed.

CONCLUSION

NGS analysis is useful to discover novel HCC-associated HBV SNVs, especially those with low SNV frequency. The hepatocarcinogenetic mechanisms of novel HCC-associated HBV SNVs defined by NGS analysis deserve further investigation.

Deep sequencing shows that HBV basal core promoter and precore variants reduce the likelihood of HBsAg loss following tenofovir disoproxil fumarate therapy in HBeAg-positive chronic hepatitis B

OBJECTIVE

Hepatitis B e antigen (HBeAg) seroconversion and hepatitis B surface antigen (HBsAg) loss are important clinical outcomes for patients with chronic hepatitis B (CHB) treated with antiviral therapy. To date, there have been few studies that have evaluated viral sequence markers predicting serological response to nucleos(t)ide analogue (NA) treatment.

DESIGN

We used next-generation sequencing (NGS) and quantitative HBV serology (HBeAg and HBsAg) to identify viral sequence markers associated with serological response to long-term tenofovir disoproxil fumarate therapy among HBeAg-positive patients. In the GS-US-174-0103 study, approximately half the patients seroconverted to anti-HBe by week 192 and 11% of patients exhibited HBsAg loss, the closest outcome to functional cure. The frequency of HBV variants that have previously been associated with HBV clinical outcomes was evaluated. HBV viral diversity in baseline sequences generated by NGS was calculated using Shannon entropy.

RESULTS

NGS analysis of HBV sequences from 157 patients infected with genotypes A to D showed the frequency of variants in the basal core promoter (BCP) and precore (PC) regions varied by genotype and that these mutations were associated with the absence of HBsAg loss. This was the case even when mutations were present at frequencies below the threshold of detection by population sequencing. Increased viral diversity across the HBV genome as determined by NGS was also associated with reduced likelihood of HBsAg loss.

CONCLUSION

Patients with detectable BCP and/or PC variants and higher viral diversity have a lower probability of HBsAg loss during long-term NA therapy. Strategies to achieve functional cure of HBV infection through combination therapy should consider using NGS to stratify patients according to BCP/PC sequence. Consideration should also be given to earlier initiation of therapy prior to the emergence of BCP/PC variants.

TRIAL REGISTRATION NUMBER

NCT00116805; Post result.

Hepatitis B virus sequencing and liver fibrosis evaluation in HIV/HBV co-infected Nigerians

OBJECTIVES

Molecular characteristics of hepatitis B virus (HBV), such as genotype and genomic mutations, may contribute to liver-related morbidity and mortality. The association of these characteristics with liver fibrosis severity in sub-Saharan Africa is uncertain. We aimed to characterise molecular HBV features in human immunodeficiency virus (HIV)/HBV co-infected Nigerians and evaluate associations between these characteristics and liver fibrosis severity before and after antiretroviral therapy (ART) initiation.

METHODS

HIV/HBV co-infected Nigerians underwent liver fibrosis estimation by transient elastography (TE) prior to and 36 months after ART initiation. Basal core promoter/precore (BCP/PC) and preS1/preS2/S regions of HBV were sequenced from baseline plasma samples. We evaluated associations between HBV mutations and liver fibrosis severity by univariate and multivariable regression.

RESULTS

At baseline, 94 patients underwent TE with median liver stiffness of 6.4 (IQR 4.7-8.7) kPa. Patients were predominantly infected with HBV genotype E (45/46) and HBe-antigen negative (75/94, 79.8%). We identified BCP A1762T/G1764A in 15/35 (43%), PC G1896A in 20/35 (57%), 'a' determinant mutations in 12/45 (26.7%) and preS2 deletions in 6/16 (37.5%). PreS2 mutations were associated with advanced fibrosis in multivariable analysis. At follow-up, median liver stiffness was 5.2 (IQR 4.1-6.6) kPa. No HBV molecular characteristics were associated with lack of fibrosis regression, although HIV virologic control, body mass index (BMI) and baseline CD4+ T-cell count were associated with a decline in fibrosis stage.

CONCLUSION

Frequent BCP/PC and preS1/preS2/S mutations were found in ART-naïve HIV/HBV co-infected Nigerians. Median liver stiffness declined after initiation of ART, regardless of pre-ART HBV mutational pattern or virologic characteristics.

Clinical Features of Chronic Hepatitis B in Treatment-naive Asian Patients With Positive HBeAg and Coexisting Precore and/or Basal Core Promoter Mutations

BACKGROUND

Precore or/and basal core promoter (PC/BCP) mutations are frequently detected in hepatitis B e antigen (HBeAg)-negative patients, but little is known about their clinical significance in HBeAg-positive patients.

AIM

To characterize and report the clinical features of treatment-naive chronic hepatitis B patients who are HBeAg positive and harbor PC and/or BCP mutations.

PATIENTS AND METHODS

Consecutive treatment-naive patients with chronic hepatitis B between 2004 and 2014 were enrolled. Clinical characteristics were compared based on the stratification of HBeAg status and the presence of PC/BCP mutations. In addition, subset analysis in HBeAg-positive cohort was performed to compare clinical features of patients with and without PC/BCP mutations RESULTS:: Of the 267 patients enrolled from 3 centers, 177 were HBeAg positive and 90 HBeAg negative. When compared with HBeAg-negative patients, HBeAg-positive patients were significantly younger in mean age (37.93 vs. 44.40; P<0.001), had higher levels of median ALT (51 vs. 30.5 U/mL; P<0.001), higher levels of mean HBV DNA (7.50±1.48 vs. 5.10±1.44 log10 copies/mL; P<0.001), and lower frequency of detectable PC/BCP mutations (60.45% vs. 93.33%; P<0.001), but had significantly higher frequency of BCP when mutations were detected (37.85% vs. 22.22%; P=0.013). Among HBeAg-positive patients, when compared with patients with wild type, those with PC/BCP mutations were significantly older (30.63 vs. 42.71; P<0.001), had higher median ALT levels (29.5 vs. 73 U/mL; P<0.001), but there was no significant association with mean HBV DNA levels (7.96 vs. 7.20 log10 copies/mL; P=0.865) or HBV genotype (P=1.000). In the multivariate analysis, only age and ALT were independently associated with PC/BCP mutations in HBeAg-positive patients, but there was no association with HBV genotype or DNA.

CONCLUSIONS

PC/BCP mutants were frequent (up to 60%) in treatment-naive HBeAg-positive patients and were associated with distinct clinical characteristics when compared with patients with wild type or HBeAg negative. Future large studies are needed to substantiate the long-term clinical outcomes when PC/BCP mutations are detected in HBeAg-positive patients as it may impact the natural history or treatment response in such patients.

Mutation Changes in the preC/Core Promoter in HBeAg-Positive Patients With Chronic Hepatitis B During Interferon Therapy

To study the changes in 3 mutations related with hepatitis B e antigen (HBeAg) in patients with HBeAg-positive chronic hepatitis B (CHB) during interferon therapy.HBeAg seroconversion is a major therapeutic milestone for patients with HBeAg-positive CHB. The precore mutation G1896A and the basal core promoter mutations A1762T/G1764A are 3 important mutations that affect the expression of HBeAg; however, the change of these 3 mutations in CHB patients during interferon therapy has not yet been evaluated.Sixty-four treatment-naive patients with HBeAg-positive CHB were treated with interferon for 48 weeks and followed up for 24 weeks. Serum samples were collected from all of the participants at different time points and then subjected to viral DNA extraction. The precore and basal core promoter sequences were determined using nested PCR and direct sequencing. The treatment outcomes were confirmed both at the end of therapy and the follow-up period, and the results were compared between patients with mutant and wild-type virus.No significant difference in HBeAg loss and HBeAg seroconversion was observed between patients with mutant versus wild-type virus although the portion of patients who achieved HBeAg loss/seroconversion with mutant virus was a little higher than in patients with wild-type virus. Once a mutation exists, it is not replaced with the wild-type sequence during interferon therapy and follow-up; moreover, our results show that mutants stably coexist with the wild-type virus during interferon therapy.This study shows the changes in 3 mutations affecting the expression of HBeAg during interferon therapy. However, additional studies with a larger sample size and more sensitive detection methods are needed to uncover the underlying mechanism and clinical significance of these results.

The incidence rate over 10 years of naturally occurring, cancer related mutations in the basal core promoter of hepatitis B virus

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The annual incidence rate of the basal core promoter (BCP) double mutations is 3.8%.

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The incidence rate tends to decrease with age and the peak appeared early in the life.

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Nucleotide (nt) 1762 is the favoured site of the first mutation.

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Viruses with a single mutation at nt 1762 or 1764 are more prone to develop double mutations.

Cross-sectional analyses showed that the prevalence of basal core promoter (BCP) double mutations (nt 1762T, 1764A) of hepatitis B virus (HBV) gradually increases with age. We aimed to determine the incidence rate of the mutations over 10 years. Study subjects were selected from the Long An cohort established in 2004, including 59 with HBV with single mutations at nt 1762 or 1764 in the BCP and 342 with wild type BCP sequences at baseline. Their serum samples for analysis were obtained at the 3rd and 10th annual visits, respectively. The results showed that the annual incidence rate of BCP double mutations is 3.8% (95% confidence interval [CI]: 1.4–6.2) and tends to decrease with age. The peak incidence is in the 30–34 years age-group. The incidence rate in HBeAg positive individuals (5.5%) is significantly higher than in those without HBeAg (3.4%) (P < 0.05). The incidence rate is significantly higher in genotype C (4.8%) than in genotype B (2.8%) or I (3.1%). The incidence rate of the mutations (6.8%) developing from a single mutation at nt 1762 or 1764 is significantly higher than that (3.8%) from the wild type sequence (P < 0.005). The difference in incidence of single mutations between nt 1762 (0.7%) and 1764 (0.03%) is significant (P < 0.05). In conclusion, the incidence rate of BCP double mutations tends to decrease with age after the age of 35 years. Viruses with a single mutation at nt 1762 or 1764 are more prone to develop double mutations. Nt 1762 is the more common site of the first mutation.

Precore/basal core promoter mutants quantification throughout phases of hepatitis B virus infection by Simpleprobe

AIM: To investigate precore/basal core promoter (PC/BCP) mutants throughout hepatitis B virus (HBV) infection and to determine their relationship to hepatitis B early antigen (HBeAg) titers.

METHODS: We enrolled 191 patients in various stages of HBV infection at the Huashan Hospital and the Taizhou Municipal Hospital from 2010 to 2012. None of the patients received antiviral therapy. HBV DNA from serum, was quantified by real-time PCR. The HBV genotype was determined by direct sequencing of the S gene. We used the Simpleprobe ultrasensitive quantitative method to detect PC/BCP mutants in each patient. We compared the strain number, percentage, and the changes in PC/BCP mutants in different phases, and analyzed the relationship between PC/BCP mutants and HBeAg by multiple linear regression and logistic regression.

RESULTS: Patients with HBV infection (n = 191) were assigned to groups by phase: Immune tolerance (IT) = 55, Immune clearance (IC) = 67, Low-replicative (LR) = 49, and HBeAg-negative hepatitis (ENH) = 20. Of the patients (male, 112; female, 79) enrolled, 122 were HBeAg-positive and 69 were HBeAg-negative. The median age was 33 years (range: 18-78 years). PC and BCP mutation detection rates were 84.82% (162/191) and 96.86% (185/191), respectively. In five HBeAg-negative cases, we detected double mutation G1896A/G1899A. The logarithm value of PC mutant quantities (log₁₀ PC) significantly differed in IT, IC, and LR phases, as well as in the ENH phase (F = 49.350, P < 0.001). The logarithm value of BCP mutant quantities (log₁₀ BCP) also differed during the four phases (F = 25.530, P < 0.001). Log₁₀ PC and log₁₀ BCP values were high in the IT and IC phases, decreased in the LR phase, and increased in the ENH phase, although the absolute value at this point remained lower than that in the IT and IC phases. PC mutant quantity per total viral load (PC%) and BCP mutant quantity per total viral load (BCP%) differed between phases (F = 20.040, P < 0.001; F = 10.830, P < 0.001), with PC% and BCP% gradually increasing in successive phases. HBeAg titers negatively correlated with PC% (Spearman’s rho = -0.354, P < 0.001) and BCP% (Spearman’s rho = -0.395, P < 0.001). The negative correlation between PC% and HBeAg status was significant (B = -5.281, P = 0.001), but there was no such correlation between BCP% and HBeAg status (B = -0.523, P = 0.552).

CONCLUSION: PC/BCP mutants become predominant in a dynamic and continuous process. Log₁₀ PC, log₁₀ BCP, PC% and BCP% might be combined to evaluate disease progression. PC% determines HBeAg status.

High risk of hepatitis B virus reactivation in nucleos(t)ide analogue-induced hepatitis B e antigen seroconverters older than 40 years

BACKGROUND

A recent study showed that chronic hepatitis B virus (HBV) carriers with nucleos(t)ide analogue (NA)-induced hepatitis B antigen (HBeAg) seroconversion occurring before the age of 30 years have a higher risk of HBV reactivation.

AIM

To compare the risk of HBV reactivation and HBeAg seroreversion between patients with spontaneous and NA-induced HBeAg seroconversion.

METHODS

A total of 135 and 251 non-cirrhotic patients with NA-induced and spontaneous HBeAg seroconversion, respectively, were analyzed.

RESULTS

NA-induced HBeAg seroconverters faced higher risks of HBV reactivation and HBeAg seroreversion than spontaneous HBeAg seroconverters (P < 0.001). In spontaneous HBeAg seroconverters, age at HBeAg seroconversion, sex, HBV DNA levels before HBeAg seroconversion, HBV genotype C, and pre-S deletions were independent predictors of HBV reactivation. In NA-induced HBeAg seroconverters, only age at baseline was an independent predictor of HBV reactivation. To determine whether the difference in the incidence of HBV reactivation or HBeAg seroreversion between two groups was age-specific, we analyzed these patients according to their age at HBeAg seroconversion (20-29, 30-39, and ≥40 years). Our data showed that NA-induced HBeAg seroconversion was an independent predictor of HBV reactivation and HBeAg seroreversion than spontaneous HBeAg seroconversion in patients older than 40 years at HBeAg seroconversion, but not in patients between 20-29 and 30-39 years of age.

CONCLUSIONS

NA-induced HBeAg seroconverters are associated with higher risks of HBV reactivation and HBeAg seroreversion compared to spontaneous HBeAg seroconverters, especially in patients who are older than 40 years at HBeAg seroconversion.

Entecavir vs. lamivudine in chronic hepatitis B patients with severe acute exacerbation and hepatic decompensation

BACKGROUND & AIMS

We compared the mortality and treatment response between lamivudine (LAM) and entecavir (ETV) in chronic hepatitis B (CHB) patients with severe acute exacerbation and hepatic decompensation.

METHODS

From 2003 to 2010 (the LAM group) and 2008 to 2010 (the ETV group), 215 and 107 consecutive CHB naïve patients with severe acute exacerbation and hepatic decompensation treated with LAM and ETV respectively, were recruited.

RESULTS

At baseline, the LAM group had higher AST levels and end-stage liver disease (MELD) scores, and lower albumin levels than the ETV group. Univariate analysis showed that the LAM group had a higher rate of overall (p=0.02) and liver-related mortality (p=0.052) at week 24 than the ETV group, including in patients with acute-on-chronic liver failure. Multivariate analysis showed that MELD scores, ascites, and hepatic encephalopathy were independent factors for overall and liver-related mortality at week 24. ETV or LAM treatment was not an independent factor for mortality in all patients or patients with acute-on-chronic liver failure. The best cut-off value of MELD scores were 24 for 24-week liver-related mortality. The ETV group achieved better virological response (HBV DNA <300 copies/ml) than the LAM group at week 24 (p=0.043) and 48 (p=0.007). The T1753C/A mutation was also an independent predictor associated with overall and liver-related mortality at week 24.

CONCLUSIONS

The choice between ETV and LAM was not an independent factor for mortality in CHB patients with acute exacerbation and hepatic decompensation. Patients with ascites, hepatic encephalopathy, and MELD scores ⩾24 were associated with poor outcome and should be considered for liver transplantation.

Patients with interferon-induced HBeAg seroconversion have a higher risk of HBV reactivation and HBeAg seroreversion

PURPOSE

It remains unclear whether chronic hepatitis B patients who undergo interferon (IFN)-induced hepatitis B e antigen (HBeAg) seroconversion have a higher risk of hepatitis B virus (HBV) reactivation and HBeAg seroreversion than those with spontaneous HBeAg seroconversion.

METHODS

A total of 80 and 251 non-cirrhotic patients with interferon-induced and spontaneous HBeAg seroconversion, respectively, were analyzed.

RESULTS

Compared to spontaneous HBeAg seroconverters, more IFN-induced HBeAg seroconverters were males (p = 0.004). For all patients, the IFN-induced HBeAg seroconverters faced a higher risk of HBV reactivation and HBeAg seroreversion than spontaneous HBeAg seroconverters (p < 0.001). For spontaneous HBeAg seroconverters, age at HBeAg seroconversion, male sex, HBV genotype C, and pre-S deletions were independent predictors of HBV reactivation. For IFN-induced HBeAg seroconverters, older age at baseline and HBV genotype C were independent predictors of HBV reactivation. To determine whether the difference in the rates of HBV reactivation or HBeAg seroreversion between two groups was age-dependent, patients were grouped and analyzed according to their age at HBeAg seroconversion (20-30, 31-39, ≥40 years). IFNs treatment was an independent factor in HBV reactivation and HBeAg seroreversion only in the groups of patients 31-39 and ≥40 years of age, but not in the group of patients 20-30 years of age.

CONCLUSIONS

IFN-induced rather than spontaneous HBeAg seroconversion was associated with higher risk of HBV reactivation and HBeAg seroreversion, especially in patients who were older than 30 years at HBeAg seroconversion.

New perspective on the natural course of chronic HBV infection

Chronic hepatitis B virus (HBV) infection is a significant threat to public health and an enormous burden on society. Mechanisms responsible for chronic HBV infection remain poorly understood. A better understanding of the natural course of chronic HBV infection may shed new light on the mechanisms underlying this disease and help in designing new antiviral strategies. Natural course of chronic HBV infection is conventionally viewed as an uninterrupted process that is usually marked by HBV e antigen (HBeAg) seroconversion or characterized by different phases associated with assumed host responses to HBV infection. However, none of these descriptions captures or highlights the core events that determine the natural course of chronic HBV infection. In this review, we briefly present the current knowledge on this subject and explain the significance and implication of events that occur during infection. A pre-core mutant becomes predominant in the viral population following elimination of the wild-type virus in duck hepatitis B virus-chronically infected animals. The coupled events in which first there is viral clearance that clears wild-type virus and then there is the reinfection of wild-type virus cleared livers with mutant virus are highly relevant to understanding of the natural course of chronic HBV infection under both treated and untreated conditions. In our new perspective, a general natural course of chronic HBV infection comprises cycles of viral clearance and reinfection, and such cycles prolong the chronic HBV infection course. Reviewing published data on the natural course of chronic HBV infection can reduce the possibility of missing important points in the initial data interpretation.

Association of a potential functional pre-miR-218 polymorphism and its interaction with hepatitis B virus mutations with hepatocellular carcinoma risk

BACKGROUND & AIMS

MicroRNA-218 (miR-218) can function as a tumour suppressor and inactivate cancer-promoting inflammation. However, role of miR-218 on hepatocellular carcinoma (HCC) remains unclear. To determine the contribution of miR-218 genetic predisposition and its interaction with hepatitis B virus (HBV) mutations to HCC risk.

METHODS

rs11134527 located at putative promoter region of pre-miR-218 was genotyped in 1012 healthy controls, 302 hepatitis B surface antigen (HBsAg) seroclearance subjects and 2011 subjects with chronic HBV infection (1021 with HCC) using quantitative PCR. HBV mutation was determined by sequencing.

RESULTS

rs11134527 variant genotypes in dominant model was associated with HCC risk compared with all HCC-free subjects [odds ratio (OR) = 1.22, 95% confidence interval (CI) = 1.04-1.43], HCC-free HBsAg-positive subjects (OR = 1.23, 95% CI = 1.02-1.50) and HBsAg seroclearance subjects (OR = 1.45, 95% CI = 1.08-1.96), adjusting for age and gender, and also associated with the generation of HBV preS deletion in men (adjusted OR = 1.85, 95% CI = 1.23-2.76). In multivariate regression analyses, rs11134527 in dominant model was associated with HCC risk (OR = 1.50, 95% CI = 1.05-2.13), whereas its multiplicative interaction with viral mutation T1674C/G was inversely associated with HCC risk (OR = 0.44, 95% CI = 0.21-0.96), adjusting for covariates including HBV mutations in the enhancer II-precore region; its interaction with HBV preS1 start codon mutation was associated with HCC risk (OR = 4.44, 95% CI = 1.27-15.55), adjusting for covariates including HBV mutations in the preS region.

CONCLUSION

rs11134527 may be a novel genetic risk factor of HCC in HBV-exposed subjects, can facilitate HBV preS deletion generation and predispose the host to the effect of T1674C/G and preS1 start codon mutation in hepatocarcinogenesis.

Development of an electrochemical sensing technique for rapid genotyping of hepatitis B virus

OBJECTIVE

To develop a convenient; sensitive; accurate; and economical technique for genotyping of hepatitis B viruses (HBVs).

METHODS

The mercapto-modified B1; B2; C1; and C2-specific genotyping probes consisted of two probes for each HBV genotype that served as a double verification system. These probes were fixed on the surface of No. 1; 2; 3; and 4 gold electrodes; respectively; via Au-S bonds. Different charge generated by the binding of RuHex to phosphate groups of the DNA backbone before and after hybridization was used for distinguishing the different genotypes.

RESULTS

During hybridization with genotype B; the charges detected at the No. 1 and 2 electrodes were significantly increased; while the charge at the No. 3 and 4 electrodes did not change significantly. During hybridization with genotype C; the charges detected at No. 3 and 4 electrodes were significantly increased; while the signals remained unchanged at the No. 1 and 2 electrodes. During hybridization with mixed genotypes (B and C); the charges detected at all four electrodes were significantly increased. The linear range of detection was 10(-7) to 10(-10) mol/L and the sensitivity for detecting mixed B (10%) or C (10%).

CONCLUSIONS

Rapid genotyping of HBVs based on electrochemical sensing is simple, has good specificity; and can greatly reduce the cost. This method can be used for sensitive detection of mixed B and C HBV genotypes.

Quasispecies structure, cornerstone of hepatitis B virus infection: Mass sequencing approach

Hepatitis B virus (HBV) is a DNA virus with complex replication, and high replication and mutation rates, leading to a heterogeneous viral population. The population is comprised of genomes that are closely related, but not identical; hence, HBV is considered a viral quasispecies. Quasispecies variability may be somewhat limited by the high degree of overlapping between the HBV coding regions, which is especially important in the P and S gene overlapping regions, but is less significant in the X and preCore/Core genes. Despite this restriction, several clinically and pathologically relevant variants have been characterized along the viral genome. Next-generation sequencing (NGS) approaches enable high-throughput analysis of thousands of clonally amplified regions and are powerful tools for characterizing genetic diversity in viral strains. In the present review, we update the information regarding HBV variability and present a summary of the various NGS approaches available for research in this virus. In addition, we provide an analysis of the clinical implications of HBV variants and their study by NGS.

Influencing Factors on the Outcome and Prognosis of Patients With HBV Infction: Seven Years Follow-up

BACKGROUND

Hepatitis B virus (HBV) is one of the most common chronic viral infections in the world. Iran has a low to intermediate HBV prevalence and approximately 1.5 million people are living with HBV infection. The impact of HBV in Iran is unknown and given the very low levels of alcohol consumption, this region provides an opportunity to examine the impact of isolated chronic HBV infection.

OBJECTIVES

To examine and evaluate outcome and prognosis of HBV in Iran.

PATIENTS AND METHODS

A longitudinal cohort study dating from 2003-2010 was performed. The patients were assessed six months after their first visit and then during periodic visits for the subsequent seven years. The patients' medical history, route of diagnosis of infection, family history, and liver diseases status including: carrier state of HBV, chronic HBV, cirrhosis, and HCC were recorded. Descriptive and analytic statistics were performed, using SPSS software version 18.

RESULTS

275 HBsAg positive patients, who had completed a 7 year follow up period, were selected. The annual incidence rate for chronic hepatitis B in inactive carrier states and cirrhosis were 0.46% and 0.2% respectively. Over seven years, the rate of inactive carriers decreased by eight percent (They turned into chronic HBV or became HBSAg negative). No significant association was found between HBSAg seroclearance, HBeAg seroconversion and the outcome in the end of each year of follow up. Different treatment regimens did not have any statistically significant difference regarding HBeAg seroconversion. There was no significant association between the outcome and different habitual characteristics, especially smoking, as well as family history on HBsAg, HBsAb, HBeAg, and Anti-HBeAg. Values of platelets and ALT showed a significant change during the follow ups. Annual incidence rate of HCC in the present study was in the range of other studies.

CONCLUSIONS

These data confirm and extend data from other populations showing a low incidence of significant change in chronic HBV infection in short term with good responses to currently available therapeutics.

Precore and basal core promoter mutations in Asian American patients with hepatitis B e antigen-positive chronic hepatitis B

BACKGROUND

Prior studies have shown that precore mutations abolish and basal core promoter (BCP) mutations down-regulate hepatitis B e antigen (HBeAg) production. Thus, the presence of precore and BCP mutations in HBeAg-positive patients indicates an infection with a mixed viral population of wild-type and precore and/or BCP mutant hepatitis B virus (HBV). To date, there has been limited study of the prevalence and clinical significance of precore and BCP mutations in patients with HBeAg-positive chronic hepatitis B.

AIM

To determine the prevalence, predictors and clinical characteristics of mixed wild-type and precore/BCP HBV infection, through a cross-sectional study, in a US cohort of patients with chronic hepatitis B.

METHODS

We conducted a retrospective study of 828 chronic hepatitis B patients with HBV genotype and mutation panel testing seen at three US gastroenterology and liver clinics from June 2005 to September 2009.

RESULTS

A majority of our patients (92.3%) were either Vietnamese or Chinese American. In the HBeAg-positive cohort, 17% of patients had precore mutations only, 28% had BCP mutations only and 5% had both BCP and precore mutations. On multivariate analyses, HBV genotype C, increasing age, lower HBV DNA level and an ALT quotient >2 were independent predictors for the presence of precore and/or BCP mutations.

CONCLUSIONS

The current distinction and management recommendations for HBeAg-positive vs. HBeAg-negative patients with chronic hepatitis B should be reassessed. Additional biomarkers and treatment endpoints should be studied for their usefulness in predicting continued viral suppression after treatment discontinuation.

T1846 and A/G1913 are associated with acute on chronic liver failure in patients infected with hepatitis B virus genotypes B and C

The aim of this study was to determine whether mutations in the hepatitis B virus (HBV) genome are associated with the onset of acute on chronic liver failure (ACLF). For the longitudinal study, full-length HBV genomes were cloned and sequenced from four ACLF patients and compared with sequences from matching samples collected before ACLF. For the cross-sectional study, 166 serum samples were obtained, including 49 samples from patients with ACLF. The results of longitudinal study showed that C53T, A1846T, and G1896A were the most common mutations in association with ACLF. In the cross-sectional study 61.2% patients with ACLF presented with T1846, which was higher than patients with chronic hepatitis B (CHB) (11.1%), liver cirrhosis (LC) (31.1%), and hepatocellular carcinoma (HCC) (33.3%). Prevalence of A/G1913 was 42.9% in patients with ACLF, also higher than patients with CHB (2.2%), LC (17.8%), and HCC (11.1%). There were no differences in HBV genotype and patients' HBeAg status among patients with ACLF, LC, and HCC. However, prevalence of T1846 was much higher in patients infected with genotype B (57.1%) than genotype C (30.4%). A/G1913 was higher in HBeAg negative patients (28%) than HBeAg positive patients (13.2%). Results of a multivariable analysis showed that T1846 and A/G1913 were independent factors for ACLF (OR = 3.373 and 4.244, respectively). Interestingly, T1846 destroys an ATG codon of a small open reading frame in the preC region, which may increase core protein expression. We conclude that T1846 and A/G1913 in the preC/C gene are closely associated with ACLF.

Hepatitis B virus basal core promoter mutations A1762T/G1764A are associated with genotype C and a low serum HBsAg level in chronically-infected HBeAg-positive Chinese patients

The present study was aimed to obtain baseline information of basal core promoter A1762T/G1764A and precore G1896A mutations of hepatitis B virus (HBV) in 192 HBeAg-positive chronically-infected Chinese patients, who were potential candidates for antiviral treatment. The detection of these mutations (including minor mutant subpopulations) was achieved by direct sequencing, whose sensitivity for minor mutant subpopulations identification was confirmed by clone sequencing. Patients enrolled were infected with either genotype B (46.35%) or C (53.65%) HBV identified by routine tests in our laboratory. The A1762T/G1764A or G1896A mutations were detected in 125specimens (125/192, 65.10%), in which 77 (77/125, 61.60%) existed as subpopulations. The A1762T/G1764A mutations were found to be more prevalent in genotype C than that in genotype B HBV [62.14% (64/103) vs. 20.22% (18/89), P<0.0001]. There is no statistically significant link between G1896A and genotypes. The emergence of A1762T/G1764A mutations was also found to be associated with an older age, an elevated ALT/AST level, and a lower HBsAg level in serum [wild-type vs. mutant: 4.57 (3.46-5.42) vs. 3.93 (2.51-5.36), P<0.0001]. In conclusion, HBV basal core promoter mutations A1762T/G1764A are associated with genotype C and a low serum HBsAg level in chronically-infected HBeAg-positive Chinese patients.

Combining the HBsAg decline and HBV DNA levels predicts clinical outcomes in patients with spontaneous HBeAg seroconversion

PURPOSE

The aim was to investigate whether the quantitation of the hepatitis B surface antigen (HBsAg) and hepatitis B virus (HBV) DNA levels can predict HBV reactivation and advanced liver disease after spontaneous hepatitis B e antigen (HBeAg) seroconversion.

METHODS

A total of 121 patients who experienced spontaneous HBeAg seroconversion were included in this longitudinal study. Serial HBsAg and HBV DNA levels were measured before and after HBeAg seroconversion.

RESULTS

Of the 121 patients, 32 experienced HBV reactivation and six achieved an HBsAg loss after HBeAg seroconversion during the follow-up period. The decline in the HBsAg level was considerably more pronounced in patients without HBV reactivation when compared to those with HBV reactivation (p = 0.016). Multivariate analysis revealed that the age of >40 years at HBeAg seroconversion, male sex, and HBsAg decline, and HBV DNA levels at month 12 after HBeAg seroconversion were independent factors for the development of HBeAg-negative hepatitis. All the six patients who achieved HBsAg loss had HBsAg level of <1,000 IU/mL at month 12 after HBeAg seroconversion (p < 0.001). The risk of HBeAg-negative hepatitis, cirrhosis, and HCC was substantially increased in patients who had a combination of both, i.e., no decline in the HBsAg level and HBV DNA level of >10(4) copies/mL at month 12 after HBeAg seroconversion.

CONCLUSIONS

Combining HBsAg reduction and HBV DNA levels at month 12 after HBeAg seroconversion was a useful marker to predict clinical outcomes in spontaneous HBeAg seroconverters. HBsAg level of <1,000 IU/mL at month 12 after HBeAg seroconversion could predict the HBsAg loss after HBeAg seroconversion.

Combination and evolution of HBV mutant strains in the HBeAg-positive status predict clinical outcomes after HBeAg seroconversion

PURPOSE

We investigated whether the combined presence and evolution of hepatitis B virus (HBV) mutant strains in the hepatitis B e antigen (HBeAg)-positive status can predict clinical outcomes after HBeAg seroconversion.

METHODS

One hundred and eighty-six patients with spontaneous HBeAg seroconversion were enrolled into this longitudinal study. The sequences of pre-S, core promoter, and precore regions were determined at study entry and at the visit immediately before HBeAg seroconversion.

RESULTS

Age ≥40 years at HBeAg seroconversion, male sex, and higher HBV DNA levels at entry were independent predictors for HBeAg-negative chronic hepatitis B (CHB). Patients with combined mutations of pre-S deletions and T1762/A1764 had a significantly increased risk of cirrhosis and hepatocellular carcinoma (HCC) compared to patients with the wild type at both genomic regions. Combinations of pre-S deletions and T1762/A1764 were found on the same HBV genome by cloning analysis of full-length HBV genomes. Patients with a persistent presence of pre-S deletions and T1762/A1764 mutations, and new development of pre-S deletions in the HBeAg-positive status were significantly at an increased risk of HBeAg-negative CHB, cirrhosis, and HCC after HBeAg seroconversion than those with a persistent presence of the wild type at both genomic regions. After adjusting the other risk factors, the evolution of pre-S deletions was an independent predictor for cirrhosis [hazard ratio (HR): 1.52, 95 % confidence interval (CI) 1.02-2.25] and HCC (HR: 4.0, 95 % CI 1.6-10.1).

CONCLUSIONS

The combined presence and evolution of pre-S deletions and T1762/A1764 in the HBeAg-positive status was a useful factor significantly predictive of clinical outcomes in patients with spontaneous HBeAg seroconversion.

Hepatitis B virus gene mutations in liver diseases: a report from New Delhi

OBJECTIVES

The study was designed to characterize the surface, core promoter, precore/core region sequences for the presence of mutations in hepatitis B virus (HBV) associated with different liver diseases.

METHODS

567 HBV associated patients with different liver diseases were enrolled in this study. All samples were analyzed for HBV surface, core promoter, precore/core region mutations and genotypes using PCR and direct sequencing.

RESULTS

HBV genotype D (72.8%) was the predominant type followed by genotype A (27.2%). The serum viral load of HBV was highest in HBsAg carriers group and lowest in patients with hepatocellular carcinoma. 17.9% patients with cirrhosis and 24.6% hepatocellular carcinoma cases were ADV-resistant with rtA181T/V mutations in the S-gene. A1896T was found more frequently in fulminant hepatic failure compared to acute viral hepatitis patients (p = 0.038). T1753V mutation was significantly higher in patients with cirrhosis of liver (34.6%) than in chronic hepatitis (18.9%) and hepatocellular carcinoma patients (21.2%; p = 0.001). T1762/A1764 mutation was observed in all the groups. C1914G core gene mutation was associated with the hepatocellular carcinoma (32.2%) compared to other groups. HBV genotype D predominated in comparison to genotype A. An increased frequency of precore mutation and BCP double mutations amongst the population studied was also observed.

CONCLUSION

Mutations such as T1762/A1764, T1753V and C1914G were usually associated with advanced forms of liver disease and had an increased risk of HCC. The nucleotide variability in the basal core promoter and precore regions possibly plays a role in the progression of HBV disease. Prospective studies on the sequence variations of the preC/C region of the HBV genome and the molecular mechanisms in relation to progression of liver disease would aid in better understanding of the biological significance of HBV strains in India.

The relationship between core promoter mutation of hepatitis B virus, viral load and hepatitis B e antigen status in chronic hepatitis B patients

The aim of this study is to detect the possible association of hepatitis B virus (HBV) core mutation, hepatitis B e antigen (HBeAg) status and the viral load in chronic hepatitis B (CHB) patients. Sixty-six patients with CHB were enrolled. Hepatitis markers and hepatitis C virus antibody (HCV-Ab) were tested using micro particle enzyme immunoassay kits. Viral load was measured by real-time polymerase chain reaction (PCR) and the mutation was analyzed by nested PCR followed by restriction fragment length polymorphism. Most of CHB patients were HBeAg (-ve). The HBeAg status did not have an influence on the presence or absence of T1762/A1764 mutation. HBV-DNA serum level was not significantly different in patients with core mutation and patients without core mutation in HBeAg (-ve) group, while in HBeAg (+ve) group HBV-DNA serum level was significantly higher in patients with core mutation. This study reports the predominance of HBeAg (-ve) and HBV core promoter mutation.

Genomic analysis of hepatitis B virus reveals antigen state and genotype as sources of evolutionary rate variation

Hepatitis B virus (HBV) genomes are small, semi-double-stranded DNA circular genomes that contain alternating overlapping reading frames and replicate through an RNA intermediary phase. This complex biology has presented a challenge to estimating an evolutionary rate for HBV, leading to difficulties resolving the evolutionary and epidemiological history of the virus. Here, we re-examine rates of HBV evolution using a novel data set of 112 within-host, transmission history (pedigree) and among-host genomes isolated over 20 years from the indigenous peoples of the South Pacific, combined with 313 previously published HBV genomes. We employ Bayesian phylogenetic approaches to examine several potential causes and consequences of evolutionary rate variation in HBV. Our results reveal rate variation both between genotypes and across the genome, as well as strikingly slower rates when genomes are sampled in the Hepatitis B e antigen positive state, compared to the e antigen negative state. This Hepatitis B e antigen rate variation was found to be largely attributable to changes during the course of infection in the preCore and Core genes and their regulatory elements.

Quantitative dynamics of hepatitis B basal core promoter and precore mutants before and after HBeAg seroconversion

BACKGROUND & AIMS

Hepatitis B e antigen (HBeAg) seroconversion is an important clinical and virological "landmark" during chronic hepatitis B virus (HBV) infection. Mutant viruses carrying the precore G1896A and/or the basal core promoter (BCP) A1762T/G1764A mutations are associated with HBeAg seroconversion. However, the exact role of these mutants in HBeAg seroconversion remains unclear, partly because the evolution of these mutant viruses before and after seroconversion has not been well studied.

METHODS

Using our novel mutant quantification methods, the percentage of the mutant viruses was analyzed both cross-sectionally and longitudinally, before and after seroconversion.

RESULTS

Cross-sectional analysis showed that the percentage of both precore and BCP mutants gradually increased with age in the HBeAg-positive population. Follow-up of 18 HBeAg-positive patients revealed that the mutant percentage may stay low and stable for many years, followed by a steady increase in the percentage of G1896A and/or A1762T/G1764A mutants, from <10% to 50-100%, within about 3 years prior to seroconversion. In all cases, increase of mutant percentage was preceded or accompanied by elevated serum alanine aminotransferase. After the seroconversion, the mutant percentage could remain high or decrease significantly, sometimes to below 20%.

CONCLUSIONS

Levels of G1896A and A1762T/G1764A mutants (of genotypes B and C) in the HBeAg-positive patients may predict the time of HBeAg seroconversion. The dominance of these mutants in the HBeAg-positive phase is more likely the result of immune selection rather than the enhanced replication capability of the mutants. However, anti-HBe antibody may not be a major selection force for these mutants.

[Mutations in precore/basal core promoter regions and viral polymerase in patients with chronic hepatitis B]

BACKGROUND

Variations of C gene give rise to precore and basal core mutations, which influence HBeAg expression The antiviral treatment failure is due to the presence of variations in the gene P, which cause mutations in the viral polymerase.

METHODS

We performed genotyping of HBV P gene by sequencing, and gene C in patients with chronic hepatitis B over a period of five years.

RESULTS

A total of 75% of the patients had some mutation in precore or in basal core promoter regions, and 37% demonstrated resistance mutations to antiviral treatment. The most frequent genotypes were A and D.

CONCLUSIONS

The presence of mutations in core/precore regions in patients with chronic hepatitis has led to tighter control of these patients. Detecting for resistance should be done as quickly as possible before there is an increase in viral load.

Precore/core promoter mutations and hepatitis B virus genotype in hepatitis B and C dually infected patients treated with interferon-based therapy

We studied the prevalence and distribution of precore/basal core promoter (BCP) mutations and hepatitis B virus (HBV) genotypes in HBV/hepatitis C virus (HCV) dually-infected patients, and evaluated their impact on long-term HBV response of interferon (IFN)-based therapy. The HBV genotypes and sequences of the precore/BCP regions were determined in 180 HBV/HCV dually-infected patients and were compared with 90 age, sex and hepatitis B e antigen-matched chronic hepatitis B controls. Serum HBV DNA and hepatitis B surface antigen (HBsAg) were assessed every 3-6 months after therapy with IFN or pegylated-IFN plus ribavirin in 135 dually-infected patients with active hepatitis C. Dually-infected patients had a higher prevalence of genotype C HBV (P=0.022) and a lower frequency of G1896A mutation (P=0.004) as compared with controls. Among dually-infected patients, genotype C was associated with a higher frequency of A1762T/G1764A mutation (P<0.001), but with lower HBV DNA (P<0.001) and a lower frequency of A1752T/G (P=0.008), C1799G (P<0.001) and G1896A mutation (P<0.001) than genotype B. Based on Cox proportional hazards model, young age (hazard ratio (HR)=0.952, P=0.001), sustained virological response to HCV (HR=4.638, P=0.044), C1766T mutation (HR=5.216, P=0.003) and A1846T mutation (HR=2.332, P=0.031) correlated with HBV DNA reactivation (⩾2000IU/ml) after therapy. Age (HR=1.068, P=0.020), G1896A mutation (HR=0.140, P=0.01) and A1846T mutation (HR=0.086, P=0.018) were associated with HBsAg seroclearance independently. In conclusion, specific mutations in the precore/BCP regions could be useful in predicting long-term HBV response in HBV/HCV dually-infected patients treated with IFN-based therapy.

Hepatitis B virus core promoter mutations G1613A and C1653T are significantly associated with hepatocellular carcinoma in genotype C HBV-infected patients

Background

Hepatitis B virus (HBV) is a major cause of hepatocarcinogenesis.

To identify mutations relevant to hepatocellular carcinoma (HCC) development, we compared the full genome sequences of HBV from the sera of patients with and without HCC.

Methods

We compared the full genome sequences of HBV isolates from 37 HCC patients (HCC group 1) and 38 patients without HCC (non-HCC group 1). We also investigated part of the core promoter region sequences from 40 HCC patients (HCC group 2) and 68 patients without HCC. Of the 68 patients who initially did not have HCC, 52 patients remained HCC-free during the follow-up period (non-HCC group 2), and 16 patients eventually developed HCC (pre-HCC group 2). Serum samples collected from patients were subjected to PCR, and the HBV DNA was directly sequenced.

Results

All patients had genotype C. A comparison of the nucleotide sequences of the HBV genome between HCC group 1 and non-HCC group 1 revealed that the prevalence of G1613A and C1653T mutations in the core promoter region was significantly higher in the HCC group. These mutations tended to occur simultaneously in HCC patients. Multivariate analysis with group 2 revealed that the presence of HCC was associated with aging and the double mutation. Future emergence of HCC was associated with aging and the presence of a single G1613A mutation.

Conclusions

G1613A and C1653T double mutations were frequently found in patients with HCC. A single G1613A mutation was associated with future emergence of HCC. These mutations may serve as useful markers in predicting HCC development.

A336C/A336T/T337C variations in HBV core gene and spontaneous hepatitis B e antigen loss in chronic hepatitis B patients

BACKGROUND

A336C/A336T/T337C variations in HBV core gene were demonstrated to relate to the decreases in serum HBV DNA levels and HBV replication in chronic hepatitis B patients. Usually the drastic decrease in serum HBV DNA levels correlates with spontaneous HBeAg loss during the course of chronic HBV infection. The aim of the present study was to investigate whether there was correlation between A336C/A336T/T337C variations and spontaneous HBeAg loss

METHODOLOGY/PRINCIPAL FINDINGS

A modified PCR-RFLP assay and ELISA were adopted to determine A336C/A336T/T337C variations and serum HBeAg levels in chronic hepatitis B patients without any antiviral therapy, respectively, whereas G1896A variation and HBV genotype were detected using Taqman-PCR assay. RFLP pattern C, E, G, C/G mixture and a new pattern C' were found in this study. A336C/A336T/T337C variations occurred in 40/166(24.1%) chronic hepatitis B patients. Chi-square test showed that C336/T336/C337 variants was more frequent in chronic hepatitis B patients with A1896 variants than those with the wild type G1896 (χ2 = 4.7, P = 0.03), and moreover, patients with C336/T336/C337 variants had a significantly lower HBeAg-positive percentage than those with the wild type A336/T337. Binary logistic regression identified genotype B (OR = 4.1, 95%CI = 1.8-9.2, P = 0.001), the presence of C336/T336/C337 variants (OR = 3.2, 95%CI = 1.2-8.5, P = 0.02) and A1896 variants (OR = 7.8, 95%CI = 3.3-18.5, P < 0.001) as independent factors associated with spontaneous HBeAg loss.

CONCLUSION/SIGNIFICANCE

A336C/A336T/T337C were naturally occurring polymorphisms in HBV core gene, and moreover, the presence of C336/T336/C337 variants was first demonstrated to be an independent factor associating with spontaneous HBeAg loss in chronic hepatitis B patients.

Hepatitis B virus genotype B results in better immediate, late and sustained responses to peginterferon-alfa in hepatitis-B-e-antigen-positive patients

BACKGROUND AND AIMS

This study investigated outcome predictors in hepatitis-B-e-antigen (HBeAg)-positive chronic hepatitis B patients treated with peginterferon alfa-2a.

METHODS

A total of 88 HBeAg-positive patients receiving peginterferon alfa-2a for 6 months and followed up for at least 24 weeks were prospectively analyzed. Precore and core promoter genes of hepatitis B virus (HBV) were sequenced from the serial serum samples of 88 patients.

RESULTS

After 24 weeks of follow up, 38.6% and 28.4% of patients achieved HBeAg clearance and combined response, respectively. Multivariate analysis disclosed that pretreatment HBeAg sample to cut-off (S/Co) ratio ≤ 200, alanine aminotransferase > 200 IU/mL, HBV genotype B and T1846 were independent factors for HBeAg clearance, and HBeAg S/Co ratio ≤ 200 and HBV genotype B were major determinants for combined response. HBeAg S/Co ratio ≤ 10 at week 12 of therapy was the useful factor for treatment response and had a greater power (P = 0.012) to predict HBeAg clearance than HBV DNA. Patients with HBeAg clearance had a higher frequency of A1896 mutation at baseline and during therapy than those without HBeAg clearance, and the frequency of A1896 decreased during treatment. During follow up, delayed HBeAg seroconversion and reactivation of HBV after HBeAg clearance were observed in eight non-responders and 20 patients with HBeAg clearance, respectively. HBV genotype B was a significant factor to predict both responses.

CONCLUSIONS

Pretreatment HBeAg S/Co ratio ≤ 200 and HBV genotype B were major determinants for treatment response to peginterferon. Genotype-B-infected patients had higher probability of delayed HBeAg clearance and sustained response. Rapid decrease of HBeAg titer was useful on treatment predictor.

HBV mutations in untreated HIV-HBV co-infection using genomic length sequencing

HIV infection has a significant impact on the natural progression of hepatitis B virus (HBV) related liver disease. In HIV-HBV co-infected patients, little is known about mutations in the HBV genome, which can influence severity of liver disease. The aim of this study was to characterize and to determine the frequency of known clinically significant mutations in the HBV genomes from HIV-HBV co-infected patients and from HBV mono-infected patients. To accomplish this, genomic length HBV sequencing was performed in highly-active anti-retroviral therapy (HAART)-naïve HIV-HBV co-infected patients (n=74) and in anti-HBV therapy-naïve HBV mono-infected patients (n=55). The frequency of HBV mutations differed between the co-infected and mono-infected patients when comparing patients with the same genotype. BCP mutations A1762T and G1764A were significantly more frequent in HBV genotype C mono-infection and the -1G frameshift was significantly more frequent in co-infection and was only observed in HBV genotype A co-infection. PreS2 deletions were observed more frequently in the setting of co-infection. Further work is needed to determine if these mutational patterns influence the differences in liver disease progression in HIV-HBV co-infected and HBV mono-infected patients.

Factors associated with progression to hepatocellular carcinoma and to death from liver complications in patients with HBsAg-positive cirrhosis

BACKGROUND AND AIMS

Hepatitis B viral markers and liver tests were used as predictors for development of hepatocellular carcinoma and progression to end-stage liver disease in 128 cirrhosis patients with hepatitis B.

RESULTS

During a median follow-up of 63.5 months, 28 patients (21.9%) developed HCC and 36 (28.1%) died from non-HCC liver deaths. By multivariate analysis, independent predictors of HCC development and their hazard ratios were high alfa-fetoprotein (HR2.83, 95% CI 1.60-5.00, P = 0.0003), negative HBeAg (HR2.33, 95% CI 1.04-5.29, P = 0.04), and low alanine aminotransferase value (HR1.42, 95% CI 1.08-1.89, P = 0.02). Independent predictors of non-HCC liver deaths were HBeAg positivity (HR3.39, 95% CI 1.16-9.93, P = 0.02), decrease albumin (HR1.61, 95% CI 0.99-2.63, P = 0.05), decrease platelet count (HR2.54, 95% CI 1.03-6.25, P = 0.04), high ALT value (HR1.22, 95% CI 1.03-1.43, P = 0.02), and onset of encephalopathy (HR3.34, 95% CI 1.21-9.27, P = 0.02).

CONCLUSIONS

HBeAg negativity, elevated AFP, and low ALT values predicted HCC development, while HBeAg positivity, abnormal liver tests, and low platelet counts identified patients with non-HCC liver deaths.

The role of HBV genotype, core promoter and precore mutations in advanced liver disease in renal transplant recipients

BACKGROUND/AIMS

In renal transplant recipients (RTRs), chronic hepatitis B virus (HBV) infection may lead to poor outcomes. This study aimed to investigate the role of the HBV genotype, core promoter and precore mutations in advanced liver disease in RTRs.

METHODS

We retrospectively reviewed 51 RTRs positive for hepatitis B surface antigen (HBsAg). HBV genotype determination and direct sequencing of core promoter and precore regions were performed using the baseline and end-of-follow-up sera post-renal transplantation.

RESULTS

Alanine Transaminase (ALT) and HBV DNA levels were elevated after transplantation (66%). HBV genotypes B and C were found in 45 (88%) and 6 (12%) patients, respectively. There was no significant association of cirrhosis development with ALT, and hepatitis B-e antigen (HBeAg) levels, type of immunosuppressant, HBV genotype, T1762/A1764 and A1896 mutations, and duration of follow-up, except endpoint HBV DNA levels (> or =10(5)copies/ml). High T1762/A1764 mutation rates were associated with high HBV DNA levels (P=0.036) at the endpoint.

CONCLUSIONS

HBV DNA replication was enhanced in RTRs with T1762/A1764 mutation. Increased serum HBV DNA levels were associated with cirrhosis development. T1762/A1764 mutation and cirrhosis development did not show significant correlation because of small sample size and/or interventional anti-viral therapies during follow-up.

Association of baseline viral factors with response to lamivudine therapy in chronic hepatitis B patients with high serum alanine aminotransferase levels

BACKGROUND

With the exception of alanine aminotransferase (ALT) level, baseline factors predictive of therapeutic response to lamivudine in patients with hepatitis B e antigen (HBeAg)-positive chronic hepatitis B (CHB) remain unknown. We thus studied the influence of pre-therapy viral factors on end-of-treatment responses to lamivudine.

METHODS

A total of 116 treatment-naive HBeAg-positive CHB patients who had pre-therapy ALT level >5x the upper limit of normal (ULN) and received lamivudine for 12-18 months were enrolled. HBeAg seroclearance and combined HBeAg seroclearance, ALT normalization and undetectable hepatitis B virus DNA at the end of therapy were defined as primary and secondary endpoints, respectively. Pre-therapy viral factors including viral load, genotype, precore (PC) stop codon status, basal core promoter status and pre-S deletion were determined to correlate with therapeutic endpoints.

RESULTS

The frequency of patients with detectable PC stop codon mutation (G1896A), basal core promoter mutation (A1762T/G1764A) and pre-S deletion at baseline was 22.4%, 21.6% and 12.1%, respectively. After the end of 12-18 months of lamivudine therapy, the overall HBeAg seroclearance rate was 56.0%. Patients with HBeAg seroclearance had a higher prevalence of baseline PC stop codon mutation than those without (30.8% versus 11.8%; P=0.015). By using multivariate analyses, the odds ratio of patients with the PC stop codon mutation to develop HBeAg seroclearance was 3.33 (P=0.024). The presence of the PC stop codon mutation also correlated with the combined response.

CONCLUSIONS

For lamivudine-treated HBeAg-positive CHB patients with pre-therapy ALT levels >5xULN, the PC stop codon mutation could predict a higher HBeAg seroclearance rate at the end of 12-18 months of therapy.

Clinical, virologic and phylogenetic features of hepatitis B infection in Iranian patients

AIM: To characterize the clinical, serologic and virologic features of hepatitis B virus (HBV) infection in Iranian patients with different stages of liver disease.

METHODS: Sixty two patients comprising of 12 inactive carriers, 30 chronic hepatitis patients, 13 patients with liver cirrhosis and 7 patients with hepatocellular carcinoma (HCC) were enrolled in the study. The HBV S, C and basal core promoter (BCP) regions were amplified and sequenced, and the clinical, serologic, phylogenetic and virologic characteristics were investigated.

RESULTS: The study group consisted of 16 HBeAg-positive and 46 HBeAg-negative patients. Anti-HBe-positive patients were older and had higher levels of ALT, ASL and bilirubin compared to HBeAg-positive patients. Phylogenetic analysis revealed that all patients were infected with genotype D (mostly ayw2). The G1896A precore (PC) mutant was detected in 58.1% patients. HBeAg-negative patients showed a higher rate of PC mutant compared to HBeAg-positive patients (χ² = 9.682, P = 0.003). The majority of patients with HCC were HBeAg-negative and were infected with PC mutant variants. There was no significant difference in the occurrence of BCP mutation between the two groups, while the rate of BCP plus PC mutants was higher in HBeAg-negative patients (χ² = 4.308, P = 0.04). In the HBV S region, the genetic variability was low, and the marked substitution was P120T/S, with a rate of 9.7% (n = 6).

CONCLUSION: In conclusion, HBV/D is the predominant genotype in Iran, and the nucleotide variability in the BCP and PC regions may play a role in HBV disease outcome in HBeAg-negative patients.