HBV pre-core mutant in genotype-D infected children is selected during HBeAg/anti-HBe seroconversion and leads to HBeAg negative chronic hepatitis B in adulthood

HBeAg-Negative/Anti-HBe-Positive Chronic Hepatitis B: A 40-Year-Old History

Hepatitis B “e” antigen (HBeAg) negative chronic hepatitis B (CHB), 40 years since discovery in the Mediterranean area, has become the most prevalent form of HBV-induced liver disease worldwide and a major health care burden caused by HBV infection. A great deal of knowledge accumulated over the last decades provides consistent evidence on the bimodal dynamics of the expression of structural and non-structural forms of the viral core proteins which associate with different virologic and clinic–pathologic outcomes of HBV infection. In absence of serum HBeAg, the presence and persistence of HBV replication causes and maintains virus-related liver injury. Thus, in clinical practice it is mandatory to screen HBV carriers with HBeAg-negative infection for the early diagnosis of HBeAg-negative CHB since antiviral therapy can cure HBV-induced liver disease when started at early stages.

Combining the HBcrAg decline and HBV mutations predicts spontaneous HBeAg seroconversion in chronic hepatitis B patients during the immune clearance phase

OBJECTIVE

To assess predictive ability of hepatitis B virus (HBV) markers and genome mutations for spontaneous hepatitis B e antigen (HBeAg) seroconversion.

METHODS

A total of 113 chronic hepatitis B (CHB) patients were followed up for 76 weeks without antiviral treatment. Baseline basal core promoter (BCP) and precore mutations were detected and serum hepatitis B surface antigen (HBsAg), HBeAg, hepatitis B core-related antigen (HBcrAg) and HBV DNA levels were serially quantified.

RESULTS

Eighteen patients experienced spontaneous HBeAg seroconversion (Group A), and the left 95 patients did not experience spontaneous HBeAg seroconversion (Group B). At week 28, HBsAg (P=0.03) and HBcrAg (P=0.01) levels were significantly different between Group A and B. Reduced HBsAg (P=0.02) and HBcrAg (P<0.01) levels from baseline to week 28 were significantly different between two groups. Multivariate logistic regression showed that lower HBcrAg (OR=1.02, P=0.03) levels at week 28, and HBcrAg levels with sharp decrease at week 28 (OR=0.19, P=0.02) were related with spontaneous HBeAg seroconversion. The areas under the receiver operating characteristic curve (AUROC) showed that reduction in HBcrAg levels from baseline to week 28 (0.93, P=0.001, 95% CI: 0.74-1.08) have excellent prediction value. The mutation frequencies of A1574T (51.11% vs 18.18%, P=0.001), G1862A (30.00% vs 13.03%, P=0.001), G1896A (27.22% vs 5.45%, P=0.001) and C1913G (32.78% vs 12.73%, P=0.001) in Group A were significantly higher than Group B.

CONCLUSIONS

Baseline A1574T, G1862A, G1896A and C1913G mutations and HBcrAg levels with sharp decrease at week 28 were associated with spontaneous HBeAg seroconversion. This article is protected by copyright. All rights reserved.

Low-level viremia in nucleoside analog-treated chronic hepatitis B patients

ABSTRACT

Low-level viremia (LLV) was defined as persistent or intermittent episodes of detectable hepatitis B virus (HBV) DNA (<2000 IU/mL, detection limit of 10 IU/mL) after 48 weeks of antiviral treatment. Effective antiviral therapies for chronic hepatitis B (CHB) patients, such as entecavir (ETV), tenofovir disoproxil fumarate (TDF), and tenofovir alafenamide (TAF), have been shown to inhibit the replication of HBV DNA and prevent liver-related complications. However, even with long-term antiviral therapy, there are still a number of patients with persistent or intermittent LLV. At present, the research on LLV to address whether adversely affect the clinical outcome is limited, and the follow-up treatment for these patients is open to question. At the same time, the mechanism of LLV is not clear. In this review, we summarize the incidence of LLV, the association between LLV and long-term outcomes, possible mechanisms, and management strategies in these patient populations.

Do the circulating Pre-S/S quasispecies influence hepatitis B virus surface antigen levels in the HBeAg negative phase of HBV infection?

BACKGROUND

Virus, host factors and their interplay influence Hepatitis B surface Antigen serum levels during Hepatitis B Virus (HBV) infection course and treatment.

AIM

To study the Pre-S/S circulating quasispecies in a cohort of untreated, HBeAg negative, genotype-D, HBsAg carriers.

METHODS

We studied 260 carriers: 71 with HBeAg negative infection (ENI; HBV-DNA ≤2000 IU/mL); 42 Grey Zone (GZ; HBV-DNA ≤20 000 IU/mL); 82 chronic hepatitis (CH) and 65 cirrhosis (CI) (HBV-DNA > 20 000 IU/mL). Population sequencing was applied to identify Pre-S/S gene mutations responsible for any amino acid substitution or potential biological/antigenic implications (M-muts) on HBsAg.

RESULTS

HBsAg serum levels were lower in ENI + GZ than in CH + CI (2.61 [-1.10/4.06] vs 3.62 [2.41/4.92] log₁₀ IU/mL, P < 0.001) and in CI than CH (3.48 [2.41/4.38] vs 3.66 [2.57/4.92] log₁₀ IU/mL, P < 0.001). M-muts were found in 73 (28.1%) cases: 5 (7.0%) ENI, 3 (7.1%) GZ, 26 (31.7%) CH, 39 (60.0%) CI (P < 0.001) and mostly in Pre-S2 (17.6%) than Pre-S1 (5.8%) and Small-S (10.8%; P < 0.001). Overall HBsAg serum levels were higher in carriers with M-muts (3.56 [0.95/4.38] vs 3.17 [-1.10/4.92] log₁₀ IU/mL, P < 0.001), but comparable in carriers with or without M-mut when considering separately ENI + GZ (2.84 [0.95/3.89] vs 2.61 [-1.10/4.06] log₁₀ IU/mL, P = 0.330] and CH + CI (3.57 [2.67/4.38] vs 3.63 [2.41/4.92] log₁₀ IU/mL, P = 0.37). Infection phase (β: 0.422, P < 0.001), age (β: -0.260, P < 0.001), ALT (β: -0.103, P = 0.045), liver stiffness (β: -0.118, P = 0.039) and HBV-DNA (β: 0.384, P < 0.001), but not M-mut were independently associated with HBsAg serum levels.

CONCLUSIONS

In HBeAg negative, genotype-D, carriers Pre-S/S heterogeneity increases with severity of liver disease, but does not influence HBsAg serum levels, that in low viraemic carriers are associated with an effective control of HBV.

In silico Analysis of Genetic Diversity of Human Hepatitis B Virus in Southeast Asia, Australia and New Zealand

The extent of whole genome diversity amongst hepatitis B virus (HBV) genotypes is not well described. This study aimed to update the current distribution of HBV types and to investigate mutation rates and nucleotide diversity between genotypes in Southeast Asia, Australia and New Zealand. We retrieved 930 human HBV complete genomes from these regions from the NCBI nucleotide database for genotyping, detection of potential recombination, serotype prediction, mutation identification and comparative genome analyses. Overall, HBV genotypes B (44.1%) and C (46.2%) together with predicted serotypes adr (36%), adw2 (29%) and ayw1 (19.9%) were the most commonly circulating HBV types in the studied region. The three HBV variants identified most frequently were p.V5L, c.1896G>A and double mutation c.1762A>T/c.1764G>A, while genotypes B and C had the widest range of mutation types. The study also highlighted the distinct nucleotide diversity of HBV genotypes for whole genome and along the genome length. Therefore, this study provided a robust update to HBV currently circulating in Southeast Asia, Australia and New Zealand as well as an insight into the association of HBV genetic hypervariability and prevalence of well reported mutations.

Conservative Evolution of Hepatitis B Virus Precore and Core Gene During Immune Tolerant Phase in Intrafamilial Transmission

Hepatitis B virus (HBV) is characterized with high mutations, which is attributed to the lack of proof-reading of the viral reverse transcriptase and host immune pressure. In this study, 31 HBV chronic carriers from 14 families were enrolled to investigate the evolution of the same original HBV sources in different hosts. Sequences of pre-C and C (pre-C/C) genes were analyzed in eight pairs of HBV-infected mothers with longitudinal sera (at an interval of 6.0-7.2 years) and their children (5.5-6.7 years old), and in 15 adults (21-78 years old) from six families with known intrafamilial HBV infection. The pre-C/C sequences had almost no change in eight mothers during 6.0-7.2 years and their children who were in immune tolerant phase. The pre-C/C sequences from the 15 adults of six families, mostly in the immune-clearance phase or the low replicative phase, showed various diversified mutations between individuals from each family. Compared to a reference stain (GQ205441) isolated nearby, the pre-C/C in individuals in immune tolerant phase showed 98.56%-99.52% homology at nucleotide level and 99.5%-100% homology at amino acid level. In contrast, multiple mutations were developed in the immune-clearance phase or the low replicative phase, affecting immune epitopes in core gene and G1896 in pre-C gene. The results indicate that the evolution of new HBV variants is not mainly resulted from the spontaneous error rate of viral reverse transcription, but from the host immune pressure.

High mutation prevalence of precore and basal core promoter in pregnant women who underwent spontaneous HBeAg seroconversion within one year postpartum

BACKGROUND

Seroconversion of hepatitis B e antigen (HBeAg) is a critical event in the natural course of hepatitis B virus (HBV) infection.

AIM

We herein characterize the virological factors associated with postpartum spontaneous HBeAg seroconversion.

METHODS

A total of 214 pregnant women positive for both hepatitis B surface antigen (HBsAg) and HBeAg were followed up at 7-12 months postpartum.

RESULTS

Of the subjects, 26 (12.1%) achieved spontaneous HBeAg seroconversion. Receiver operating curve analysis indicated that HBV DNA level <1.0 × 10⁷ IU/mL, HBsAg <1.0 × 10⁴ IU/mL and HBeAg <7.36 × 10² S/CO each independently predicted HBeAg seroconversion within 12 months postpartum. At delivery, 73.1% (19/26) women with postpartum HBeAg seroconversion had precore (PC) and/or basal core promoter (BCP) mutations, higher than that (5/36, 13.9%) in the women without postpartum seroconversion. Binary logistic regression analysis indicated that the presence of mutations in PC, BCP, and both PC and BCP at delivery was associated with an increased likelihood (OR = 13.286, 16. 238, and 22.143 respectively, all P < 0.05) to undergo postpartum spontaneous HBeAg seroconversion.

CONCLUSION

These results suggest that quantitative determination of virological markers and sequencing PC and BCP can predict spontaneous HBeAg seroconversion, which could be valuable in deciding antiviral therapy against HBV.