Low HBeAg serum levels correlate with the presence of the double A1762T/G1764A core promoter mutation and a positive response to interferon in patients with chronic hepatitis B virus infection

Next generation sequencing identifies baseline viral mutants associated with treatment response to pegylated interferon in HBeAg-positive chronic hepatitis B

Current data of hepatitis B virus (HBV) variants associated with treatment outcome identified by next generation sequencing (NGS) are limited. This study was aimed at determining the role of baseline sequence variations in the enhancer II (EnhII), basal core promotor (BCP) and pre-core (PC) regions of HBV genotype C in patients treated with pegylated interferon (PEG-IFN). Patients with HBeAg-positive chronic hepatitis B (CHB) treated with 48-week PEG-IFN were enrolled. Combined response (CR) at week 96 was defined by HBeAg seroconversion plus HBV DNA < 2000 IU/mL and HBsAg < 1000 IU/mL. Pre-treatment viral mutations were characterized by Sanger sequencing and NGS (Miseq Illumina platform). Among 47 patients (32 male, mean age 32.4 years), CR was achieved in 12 (25.5%) individuals. Overall, NGS was superior to Sanger sequencing in detecting mutations (61.7% vs. 38.3%, P < 0.001). Based on NGS, the prevalence of T1753V (T1753C/A/G) and A1762T/G1764A variants were significantly lower in responders compared to non-responders (8.3% vs. 51.4%, P = 0.009 and 33.3% vs. 68.6%, P = 0.032, respectively). No significant difference between groups was found regarding C1653T and G1896A mutants. The absence of T1753V and A1762T/G1764A mutations were factors associated with CR (OR 11.65, 95%CI 1.36-100.16, P = 0.025, and OR 4.36, 95%CI 1.08-17.63, P = 0.039, respectively). The existence of pre-treatment T1753V, A1762T/G1764A mutations and their combination yielded negative predictive values of 94.7%, 85.7% and 93.8%, respectively. The presence of HBV mutants in the BCP region determined by NGS at baseline was associated with poor treatment outcome in patients with HBeAg-positive CHB receiving PEG-IFN.

Deep sequencing identifies hepatitis B virus core protein signatures in chronic hepatitis B patients

BACKGROUND

We aimed to identify HBc amino acid differences between subgroups of chronic hepatitis B (CHB) patients.

METHODS

Deep sequencing of HBc was performed in samples of 89 CHB patients (42 HBeAg positive, 47 HBeAg negative). Amino acid types were compared using Sequence Harmony to identify subgroup specific sites between HBeAg-positive and -negative patients, and between patients with combined response and non-response to peginterferon/adefovir combination therapy.

RESULTS

We identified 54 positions in HBc where the frequency of appearing amino acids was significantly different between HBeAg-positive and -negative patients. In HBeAg negative patients, 22 positions in HBc were identified which differed between patients with treatment response and those with non-response. The fraction non-consensus sequence on selected positions was significantly higher in HBeAg-negative patients, and was negatively correlated with HBV DNA and HBsAg levels.

CONCLUSIONS

Sequence Harmony identified a number of amino acid changes associated with HBeAg-status and response to peginterferon/adefovir combination therapy.

Viral minority variants in the core promoter and precore region identified by deep sequencing are associated with response to peginterferon and adefovir in HBeAg negative chronic hepatitis B patients

BACKGROUND AND AIM

Precore (PC) and basal core promoter (BCP) mutations are associated with responses to interferon-based treatment in HBeAg-positive chronic hepatitis B (CHB) patients. Here, we identify viral minority variants in these regions and assess association with response to peginterferon-alfa (Peg-IFN) and adefovir combination therapy.

PATIENTS AND METHODS

Ultra-deep pyrosequencing analysis of the BCP and PC region was performed for 89 CHB patients (42 HBeAg-positive; 47 HBeAg-negative), at baseline and during treatment. Specifically, associations of individual positions with the HBeAg-negative phenotype were studied, as well as the association of the most prevalent mutations with combined response in HBeAg-positive and -negative patients at week 72 (HBeAg negativity, HBV-DNA <2000 IU/mL and ALT normalization at 24 weeks of treatment-free follow-up).

RESULTS

The mutations most strongly correlated with the HBeAg-negative phenotype were at positions 1762/1764 and 1896/1899 in the BCP and PC region, respectively. No major changes in nucleotide composition of these positions were observed during treatment. In HBeAg-negative patients, a combined presence of 1764A and 1896A was correlated with lower ALT levels (p = 0.004), whereas the presence of 1899A was correlated with higher age (p = 0.030), lower HBV-DNA level (p = 0.036), and previous IFN therapy (p = 0.032). The presence of 1764A/1896A or the absence of 1899A at baseline, was associated with lower response rates, after adjustment for HBV genotype (p = 0.031 and p = 0.017) and HBsAg level (p = 0.035 and p = 0.022).

CONCLUSION

We identified novel correlations between common BCP and PC variants with response to Peg-IFN and adefovir in HBeAg-negative patients. Ultimately, this may guide the selection of those patients most likely to benefit from Peg-IFN-based treatment.

Identification of hepatitis B virus A1762T/G1764A double mutant strain in patients in Southern Brazil

Infection by hepatitis B virus (HBV) is a worldwide public health problem. Chronic HBV infection with high viral replication may lead to cirrhosis and/or hepatocellular carcinoma. Mutant HBV strains, such as the HBV A1762T/G1764A double mutant, have been associated with poor prognosis and higher risk of the patient for developing cirrhosis and/or hepatocellular carcinoma. This study analyzed the presence of the HBV A1762T/G1764A double mutant in patients with chronic HBV and its association with clinical parameters such as viral load, aminotransferases, and HBV antigens. A total of 49 patients with chronic hepatitis B were included in the study, and the HBV A1762T/G1764A double mutant strain was detected in four samples (8.16%) by polymerase chain reaction followed by restriction fragment length analysis (PCR-RFLP). The viral load was not significantly different between patients with or without the double mutant strain (p=0.43). On the other hand, carriers of the HBV A1762T/G1764A double mutant had higher levels of ALT (p=0.0028), while AST levels did not differ between groups (p=0.051). In this study, 75% of the samples with the HBV A1762T/G1764A double mutation were HBeAg negative and anti-HBe positive, reflecting seroconversion even though they still displayed high viral loads. Our study has shown that the HBV A1762T/G1764A double mutant strain circulates in Brazilian patients, and is associated with elevated levels of ALT and HBeAg seroconversion.

Quantification of hepatitis B surface antigen and E antigen: correlation between Elecsys and architect assays

Quantification of hepatitis B surface antigen (HBsAg) and hepatitis B e antigen (HBeAg) and their change model during treatment are emerging as a useful tool for assessing the outcome of hepatitis B virus (HBV) infection and predicting the efficacy of antiviral therapy. The aim of this study was to compare the performance of the Elecsys and Architect assays for HBsAg and HBeAg quantification. Quantification of HBsAg and HBeAg, determined by these two assays, were assessed in 1292 sera from patients with chronic hepatitis B(CHB). HBeAg quantification in serum was performed by calibrating the results through HBeAg Paul-Ehrlich international (PEI) reference standard. The HBV genotype was determined by direct sequencing and phylogenetic analysis. Of 1292 samples, the distribution of genotype was 514 (39.78%) genotype B, 776 (60.06%) genotype C, 2 (0.16%) genotype D. The results of HBsAg and HBeAg quantification between the Architect and Elecsys assays were significantly correlated (HBsAg: r = 0.939; HBeAg: r = 0.987), independent of HBV genotype and treatment phase. The mean differences between the two methods (the log10 [Elecsys] - the log10 [Architect]) were 0.075 log10  IU/mL and -0.149 log10 PE IU/mL in quantifying HBsAg and HBeAg, respectively. This study demonstrates a high correlation between the Elecsys and the Architect assays in quantifying HBsAg and HBeAg, regardless of HBV genotype. Both the two assays can be used to monitor the HBsAg and HBeAg levels in patients with chronic hepatitis B.

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.

Prediction of response to treatment of chronic hepatitis B with pegylated interferon in the Philippines

The response marker for interferon has not been investigated fully for hepatitis B viruses (HBVs) in the Philippines where novel subtypes B5 and C5 were recognized recently. The prediction parameters for interferon treatment were assessed, with emphasis on the mutation patterns in the basal core promoter and precore regions in patients with chronic hepatitis B. Seventeen HBeAg-positive patients were stratified according to response to treatment with pegylated interferon based on HBe seroconversion and HBV load. Intra-patient distributions of wild-type strains (A1762, G1764) and variants (T1762, A1764) were analyzed using HBV-DNA amplification and subsequent molecular cloning. The rate of variants (T1762, A1764) harbored by a patient was higher among responders (41.2% and 31% per person on average) than among non-responders (2.4% and 2.4%) to treatment with pegylated interferon at the baseline, respectively (P < 0.05). The rate of variants (T1762, A1764) harbored by responders (41.2% and 31%) decreased to 1.7% and 1.7%, and wild-type strains (A1762, G1764) conversely became majority (98.3% and 98.3%) after treatment with pegylated interferon, respectively. HBV strains harbored by two of six responders and a patient with lower baseline load (1.0 x 10(4) copies/ml) showed genotype shift from A to other genotypes, where genotype A disappeared preferentially after the loss of HBeAg and genotypes B and C formed a major population. These results suggest that the HBV variants (T1762, A1764) and HBV genotype A in the Philippines have an advantage in the response to pegylated interferon. These results warrant a large-scale examination for further precise prediction of the response to treatment with interferon.

Genetic Variability of Hepatitis B virus and Response to Antiviral Therapy

Hepatitis B virus (HBV) infection is a global health issue. Effective and individualized treatment of chronic hepatitis B to prevent progression to end-stage liver diseases and hepatocellular carcinoma is needed. HBV can be classified into eight genotypes (A–H) on the basis of genome sequence divergence. In addition, several naturally occurring HBV mutants have also been identified. The epidemiology of HBV genotypes and their implications for response to antiviral therapy have become increasingly recognized. Recent studies suggested that responses to standard interferon treatment in patients with genotype A or B are better than those with genotype C or D; however, conflicting results exist regarding the response to pegylated interferon. The influence of dose and duration on interferon-based therapy remains to be clarified. In addition to genotype, naturally occurring mutations such as precore and core promoter mutations have also attracted much attention, because they have been shown to affect the disease progression of HBV-related chronic liver disease and possibly the response to antiviral therapy. Here, we review the differences in antiviral theraputic response among HBV genotypes and discuss the role of precore or core promoter mutations in response to antiviral therapy.

Heterogeneity analysis of the hepatitis B virus genome in intrauterine infection

There are many factors leading to intrauterine infection with hepatitis B virus (HBV). These factors include viral structure, HBV mutations, HBV DNA level, placenta barrier, immune status of the mother, and susceptibility of the fetus. The purpose of this study was to investigate the possible relationship between intrauterine infection with and HBV mutations of the genome of the virus. In this study, HBsAg-positive mothers were divided into two groups: intrauterine infection group and non-infection group according to whether the newborn infants were infected or not. The intrauterine infection group included four pairs of mother and their newborn infants infected in utero, and non-infection group included five HBsAg-positive mothers. HBV sequences from the two groups were analyzed and compared. The predominant strains in the mothers and infants from the intrauterine infection group were not completely consistent. This suggested that both HBV predominant strains and minority strains in the mothers could infect their infants through intrauterine transmission. Some HBV mutations probably related to intrauterine infection were examined and it was found that the frequencies of mutations were low in isolates of the virus of infants from the intrauterine infection group and high in the non-infection group. These results suggest that some strains of HBV from the mother may be transmitted selectively to the fetus in utero because of viral heterogeneity. The strains without screened mutations such as P21L in the pre-S1 region may infect the fetus more readily.

Chronic Hepatitis B and Viral Genotype: The Clinical Significance of Determining HBV Genotypes

The global health challenge posed by the hepatitis B virus (HBV) centres around the widespread distribution and the serious complications as a result of persistent infection with the virus. As with other chronic diseases mediated by pathogens such as human immunodeficiency virus (HIV) and hepatitis C virus (HCV), clinicians are searching for epidemiological, pathological and viral characteristics of HBV infection that may lead to more effective management of patients with chronic infection. Unlike HCV, the role of HBV genotype in disease progression, severity, response to therapy and drug resistance is still under investigation and just beginning to be clarified. This review examines the potential role of HBV genotype determination in the clinic with emphasis on how this genetic information may used to provide effective management for the treatment of patients with chronic hepatitis B.

Three-phase sequential combined treatment with lamivudine and interferon in young patients with chronic hepatitis B

Alpha-interferon (IFN) or lamivudine monotherapy are ineffective in treating chronic HBeAg positive patients with high viral load and low alanine aminotransferase (ALT) levels. We investigated whether priming lamivudine treatment might enhance the antiviral and immunostimulant action of lamivudine/IFN combination in young tolerant patients. Eleven chronic HBeAg positive patients received: 100 mg/day lamivudine for 3 months followed by IFN 5 MU/m2/tiw with lamivudine 100 mg/day for 6 months and then lamivudine alone 100 mg/day for 9 months. Quantitative hepatitis B virus (HBV)-DNA was evaluated during treatment and core-promoter, precore and polymerase HBV mutants were detected by direct sequencing at the end of therapy. Serum HBV-DNA levels dropped during lamivudine monotherapy and in combination with IFN. After IFN withdrawal, viraemia transiently increased to high levels in five of 11 (45%) patients who showed rt M204V/I lamivudine mutant resistant. Two patients cleared HBeAg without anti-HBe seroconversion. One patient presented core-promoter (A1762T/G1764A) and precore stop codon mutations. Hence, three-phase sequential combined lamivudine/IFN treatment reduced HBV-DNA serum level, but did not lead to HBeAg and HBV-DNA clearance in these highly viraemic, normal ALT patients. Lamivudine/IFN combination did not prevent the emergence of YMDD lamivudine resistance. New schedules of antiviral treatments must be evaluated in this population at risk of disease progression.

In vitro resistance to interferon of hepatitis B virus with precore mutation

AIM: Chronic hepatitis B virus (HBV) infection is predominantly treated with interferon alpha (IFN-α), which results in an efficient reduction of the viral load only in 20-40% of treated patients. Mutations at HBV precore prevail in different clinical status of HBV infection. The roles of precore mutation in the progression of chronic hepatitis and interferon sensitivity are still unknown. The aim of this study was to explore if there was any relationship between HBV precore mutation and sensitivity to interferon in vitro.

METHODS: HBV replication-competent recombinant constructs with different patterns of precore mutations were developed. Then the recombinants were transiently transfected into hepatoma cell line (Huh7) by calcium phosphate transfection method. With or without IFN, viral products in culture medium were collected and quantified 3 d after transfection.

RESULTS: We obtained 4 recombinant constructs by orientation-cloning 1.2-fold-overlength HBV genome into pUC18 vector via the EcoRI and Hind III and PCR mediated site-directed mutagenesis method. All the recombinants contained mutations within precore region. Huh7 cells transfected with recombinants secreted HBsAg and HBV particles into the cell culture medium, indicating that all the recombinants were replication-competent. By comparing the amount of HBV DNA in the medium, we found that HBV DNA in medium reflecting HBV replication efficiency was different in different recombinants. Recombinants containing precore mutation had fewer HBV DNAs in culture medium than wild type. This result showed that recombinants containing precore mutation had lower replication efficiency than wild type. HBV DNA was decreased in pUC18-HBV1.2-WT recombinants after IFN was added while others with precore mutations were not, indicating that HBV harboring precore mutation was less sensitive to IFN in cell culture system.

CONCLUSION: These data indicate that HBV harboring precore mutation may be resistant to IFN in vitro.