Distinct patterns of serum hepatitis B core-related antigen during the natural history of chronic hepatitis B

A critique and systematic review of the clinical utility of hepatitis B core-related antigen

BACKGROUND & AIMS

Hepatitis B core-related antigen (HBcrAg) is a new biomarker for chronic hepatitis B (CHB) whose performance has not been critically or systematically appraised. Herein, we performed a systematic review to determine its clinical utility.

METHODS

We evaluated the biological pathway of HBcrAg and performed a systematic review of PubMed for clinical trials, cohort studies, and case-control studies that evaluated the clinical utility of HBcrAg. The effectiveness of HBcrAg in predicting HBV-specific clinical events (e.g. HBeAg seroconversion, phases of CHB, HBsAg loss, treatment response, and relapse after stopping therapy) was examined using receiver-operating characteristic curves. The correlation coefficients of HBcrAg with HBV DNA, quantitative HBsAg (qHBsAg), HBV RNA, and cccDNA were summarised from published studies. Median values were used as estimates.

RESULTS

HBcrAg consists of three precore/core protein products: HBcAg, HBeAg, and a 22 kDa precore protein. HBcrAg assays have been associated with false-positive rates of 9.3% and false-negative rates of between 12-35% for CHB. The new iTACT-HBcrAg is more sensitive but does not reduce the false-positive rate. A PubMed search found 248 papers on HBcrAg, of which 59 were suitable for analysis. The clinical performance of HBcrAg was evaluated using AUROC analyses, with median AUROCs of 0.860 for HBeAg seroconversion, 0.867 for predicting HBeAg(-) hepatitis, 0.645 for HBsAg loss, 0.757 for treatment response, and 0.688 for relapse after stopping therapy. The median correlation coefficient (r) was 0.630 with HBV DNA, 0.414 with qHBsAg, 0.619 with HBV RNA and 0.550 with cccDNA. Correlation decreased during antiviral therapy, but combined biomarkers improved performance.

CONCLUSIONS

HBcrAg has a mixed performance and has a poor correlation with HBsAg loss and antiviral therapy, hence HBcrAg results should be interpreted with caution.

IMPACT AND IMPLICATIONS

Hepatitis B core-related antigen (HBcrAg) has been used to assess management of patients with chronic hepatitis B (CHB) without a systematic and critical Sreview of its performance. Our finding that HBcrAg had a false-positive rate of 9% and a false-negative rate of 12-35% raises concerns, although larger studies are needed for validation. A systematic review showed that the performance of HBcrAg was variable depending on the CHB endpoint; it was excellent at predicting HBeAg seroconversion and HBeAg-negative chronic hepatitis (vs. chronic infection), which should be its main use, but it was poor for relapse after stopping antiviral therapy and for HBsAg loss. HBcrAg results should be interpreted with considerable caution, particularly by physicians, researchers, guideline committees and agencies that approve diagnostic tests.

Histologic changes in immune-tolerant patients with chronic hepatitis B: a systematic review and meta-analysis

The serological diagnostic criteria for the immune-tolerant (IT) phase have not been strictly defined and it is hard to determine an accurate rate for significant histologic changes among IT patients. The aim of this study was to establish a baseline rate of significant histologic changes and to determine the main characteristics of IT patients. We systematically searched PubMed, Embase, and Web of Science. Studies reporting liver biopsy results (inflammation grade or fibrosis stage) for adults with chronic hepatitis B virus (HBV) infection in the IT phase diagnosed by serological criterion were included to pool the rate of significant histologic changes. Studies that enrolled subjects with confirmed chronic HBV infection in the IT phase diagnosed by serological and liver biopsy criteria (dual criteria) were included to pool the mean values of main characteristics among IT patients. Of 319 studies screened, 15 were eventually included in the meta-analysis. The pooled rates of significant liver fibrosis and inflammatory activity for 10 studies were 10% (95% confidence interval [CI] 0.06-0.18) and 16% (95% CI 0.07-0.31), respectively. The pooled mean values of age, alanine aminotransferase level, HBV DNA level, and HBsAg level for another 5 studies with IT patients diagnosed by dual criteria were 30.7 years (95% CI 27.31-34.09), 26.64 IU/mL (95% CI 24.45-28.83), 8.41 log₁₀ cp/mL (95% CI 7.59-9.23), and 4.24 log₁₀ IU/mL (95% CI 3.67-4.82), respectively. Significant histologic changes were not rare events among IT patients. Strictly defined serological diagnostic criteria for the IT phase are warranted.

Correlations between serum hepatitis B core-related antigen and hepatitis B surface antigen in patients with hepatitis B cirrhosis and a hepatitis B virus-DNA-negative status: a retrospective study

OBJECTIVE

This study aimed to examine the correlations between serum hepatitis B core-related antigen (HBcrAg) and hepatitis B surface antigen (HBsAg) titers in patients with hepatitis B cirrhosis and a hepatitis B virus (HBV)-DNA-negative status.

METHODS

We retrospectively analyzed the data and blood samples of patients who were diagnosed with HBV liver cirrhosis and an HBV-DNA negative status. These patients were hospitalized between October 2018 and October 2019 at one hospital.

RESULTS

A total of 180 patients were included. The median (interquartile range) HBsAg and HBcrAg concentrations were 2.77 log₁₀ IU/mL (1.60-3.15) and 3.96 log₁₀ U/mL (2.70-4.97), respectively. A non-linear significant relationship was found between HBsAg and HBcrAg concentrations. The inflection point was 0.58. The effect size and confidence interval on the left and right sides of the inflection point were 0.10 (-0.23-0.42) and 0.62 (0.46-0.78), respectively. When HBsAg concentrations were ≥0.58 log₁₀ IU/mL, HBsAg concentrations were positively correlated with HBcrAg concentrations. When HBsAg concentrations increased by 1 log₁₀ IU/mL, HBcrAg concentrations increased by 0.62 log₁₀ U/mL (95% confidence interval: 0.46, 0.78).

CONCLUSIONS

There might be a non-linear relationship between HBcrAg and HBsAg concentrations in patients with hepatitis B cirrhosis and an HBV-DNA-negative status.

Quantitative HBsAg versus HBV DNA in Predicting Significant Hepatitis Activity of HBeAg-Positive Chronic HBV Infection

(1) Background: As specialparameters in predicting significant hepatitis activity of hepatitis B e antigen (HBeAg)-positive chronic hepatitis B virus (HBV) infection, the quantitative standard of HBV DNA has not been agreed and that of hepatitis B surface antigen(HBsAg) has not been formed. Our objective is to evaluate the validity of HBsAg and HBV DNA in predicting the significant hepatitis activity of HBeAg-positive patients. (2) Methods: A population of 516 patients with HBeAg-positive chronic HBV infection was enrolled. Serum ALT was measured using an Abbott Architect c16000 autoanalyzer; diagnoses of liver pathological grade and stage referred to the Scheuer standard. Three levels of significant hepatitis activity were preset, which were successively “ALT ≥ 20 IU/L or Grade > G1 or Stage > S1”, “ALT ≥ 30 IU/L or Grade > G1 or Stage > S1” and “ALT ≥ 40 IU/L or Grade > G1 or Stage > S1”. (3) Results: A subpopulation of 288 patients with possible high HBV replication was selected based on locally weighted scatterplot smoothing regression curves between ALT and HBsAg, HBeAg and HBV DNA. In the subpopulation with possible high HBV replication, areas under receiver operating characteristic curves of HBsAg for predicting the three levels of significant hepatitis activity were successively 0.868, 0.839 and 0.789, which were all significantly greater than those of HBV DNA, as those were successively 0.553, 0.550 and 0.574 (p = 0.0002, p < 0.0001 and p < 0.0001). With the standard of HBsAg ≤ 4.699 log₁₀ IU/mL, the sensitivity and specificity of HBsAg for predicting the three levels of significant hepatitis activity were successively 75.81% and 81.82%, 79.23% and 78.57% and 80.82% and 67.44%. (4) Conclusion: Quantitative HBsAg instead of HBV DNA is valuable in predicting significant hepatitis activity of HBeAg-positive chronic HBV infection.

Probing the spatiotemporal patterns of HBV multiplication reveals novel features of its subcellular processes

Through evolution, Hepatitis B Virus (HBV) developed highly intricate mechanisms exploiting host resources for its multiplication within a constrained genetic coding capacity. Yet a clear picture of viral hitchhiking of cellular processes with spatial resolution is still largely unsolved. Here, by leveraging bDNA-based fluorescence in situ hybridization (FISH) combined with immunofluorescence, we developed a microscopic approach for multiplex detection of viral nucleic acids and proteins, which enabled us to probe some of the key aspects of HBV life cycle. We confirmed the slow kinetics and revealed the high variability of viral replication at single-cell level. We directly visualized HBV minichromosome in contact with acetylated histone 3 and RNA polymerase II and observed HBV-induced degradation of Smc5/6 complex only in primary hepatocytes. We quantified the frequency of HBV pregenomic RNAs occupied by translating ribosome or capsids. Statistics at molecular level suggested a rapid translation phase followed by a slow encapsidation and maturation phase. Finally, the roles of microtubules (MTs) on nucleocapsid assembly and virion morphogenesis were analyzed. Disruption of MTs resulted in the perinuclear retention of nucleocapsid. Meanwhile, large multivesicular body (MVB) formation was significantly disturbed as evidenced by the increase in number and decrease in volume of CD63⁺ vesicles, thus inhibiting mature virion secretion. In conclusion, these data provided spatially resolved molecular snapshots in the context of specific subcellular activities. The heterogeneity observed at single-cell level afforded valuable molecular insights which are otherwise unavailable from bulk measurements.

HBV is a hepatotropic, enveloped virus with a partially double-stranded relaxed circular DNA genome. Studies on the molecular biology of HBV mainly rely on biochemical extraction and bulk quantification methods. Detailed spatiotemporal information on virus components in subcellular context is still lacking. Here, we re-evaluated the reproduction schemes of HBV by fluorescence in situ hybridization (FISH). We visualized cccDNA minichromosome formation in an epigenetic context, identified pgRNA associated with actively translating ribosomes and capsids. Moreover, the active participation of microtubules in nucleocapsid transport and MVB-mediated virion secretion was identified. These observations have broad implications for understanding the HBV replication cycle and may facilitate the identification of novel antiviral targets.

Quantitative serum HBV markers in predicting phases of natural history of chronic HBV infection

BACKGROUND

Clinical importance of commercially available quantitative HBV markers has not been fully investigated.

OBJECTIVE

To choice and to evaluate clinically valuable HBV markers for predicting phases of natural history with chronic HBV infection.

METHODS

472 naïve patients with chronic HBV infection were enrolled, in which 21 and 220 were confirmed as HBeAg-positive inactive and active hepatitis (EPIH and EPAH), respectively, and 106 and 125 were confirmed as HBeAg-negative inactive and active hepatitis (ENIH and ENAH), respectively. HBsAg, HBcrAg and anti- HBc were measured using chemiluminescent immunoassay, and HBV DNA was measured using PCR-fluorescence probing assay.

RESULTS

There were all statistical differences in medians of HBsAg, anti-HBc, HBcrAg and HBV DNA between EPIH and EPAH and between ENIH and ENAH (all P < 0.01). According to binary logistic stepwise regressions, HBsAg and anti-HBc were preferred variables for predicting EPAH, and HBcrAg and HBV DNA were preferred variables for predicting ENAH. Based on normalization for coefficients of preferred variables entering regression equations, a handy model of MEPAH for predicting EPAH and of MENAH for predicting ENAH was constructed, respectively. Area under receiver operating characteristic curves of MEPAH and MENAH for predicting EPAH and ENAH were 0.882 and 0.931, respectively. With standard of MEPAH ≤ 5.997 and MENAH > 10.535, sensitivity or specificity of which for predicting EPAH and ENAH were about 81.0 % and 87.0 %, respectively.

CONCLUSION

HBsAg and anti-HBc for predicting EPAH and HBcrAg and HBV DNA for predicting ENAH are dependable markers; MEPAH for predicting EPAH and MENAH for predicting ENAH have very good performance.

Hepatitis B Core-Related Antigen as Surrogate Biomarker of Intrahepatic Hepatitis B Virus Covalently-Closed-Circular DNA in Patients with Chronic Hepatitis B: A Meta-Analysis

Hepatitis B virus (HBV) covalently-closed-circular (ccc)DNA is the key molecule responsible for viral persistence within infected hepatocytes. The evaluation of HBV cccDNA is crucial for the management of patients with chronic HBV infection and for the personalization of treatment. However, the need for liver biopsy is the principal obstacle for the assessment of intrahepatic HBV cccDNA. In the last decade, several studies have investigated the performance of hepatitis B core-related antigen (HBcrAg) as a surrogate of HBV cccDNA amount in the liver. In this meta-analysis, we collected 14 studies (1271 patients) investigating the correlation between serum HBcrAg and intrahepatic HBV cccDNA. Serum HBcrAg showed a high correlation with intrahepatic HBV cccDNA (r = 0.641, 95% confidence interval (CI) 0.510–0.743, p < 0.001). In a head-to-head comparison, we observed that the performance of HBcrAg was significantly superior to that of hepatitis B surface antigen (r = 0.665 vs. r = 0.475, respectively, p < 0.001). Subgroup analysis showed that the correlation between HBcrAg and intrahepatic HBV cccDNA was high, both in hepatitis B e antigen-positive and -negative patients (r = 0.678, 95% CI 0.403–0.840, p < 0.001, and r = 0.578, 95% CI 0.344–0.744, p < 0.001, respectively). In conclusion, the measurement of serum HBcrAg qualifies as a reliable non-invasive surrogate for the assessment of an intrahepatic HBV cccDNA reservoir.

Clinical relevance of the in situ assay for HBV DNA: a cross-sectional study in patients with chronic hepatitis B

Aims

The visualisation of HBV DNA in liver sections of patients with chronic hepatitis B (CHB) in our previous report uncovered a mosaic distribution of viral antigens and nucleic acids. Here we aim to further explore the clinical utility of the in situ hybridisation (ISH) assay for HBV DNA.

Method

ISH of HBV DNA along with immunohistochemistry (IHC) of HBsAg, HBcAg and routine histopathology analysis was performed in 313 treatment-naive patients with CHB. Serum HBcrAg and HBcAb titre were also measured in addition to basic biochemical and virological parameters.

Results

The ISH of HBV DNA, HBsAg and HBcAg showed 95.2%, 97.1% and 42.8% positive rate, respectively. The staining pattern of HBV DNA differs significantly with that of HBsAg. Intrahepatic HBV DNA exhibited high-level of correlations with viral load, HBcrAg and HBsAg titre. In HBeAg-negative patients, higher intrahepatic HBV DNA is associated with histological evidence of liver inflammation and fibrosis, whereas no such trend was observed in HBeAg-positive patients. Finally, a triple staining protocol that combined the detection of HBV DNA, HBsAg and collagen fibre was developed to enable better evaluation of viral replication and antigen expression in the context of disease progression.

Conclusions

The ISH assay for HBV DNA reflects the vigour of intrahepatic viral replication. It is complementary to the routine IHC assay for viral antigens and also related to the histopathological progression of liver diseases. The application of the HBV DNA ISH assay may help a better evaluation of virological and pathological condition of patients with CHB.

Quantitative Anti-HBc in Liver Pathological States in Patients with Chronic Hepatitis B Virus Infection

Background

Changes of hepatitis B core antigen antibody (anti-HBc) in liver pathological involvement in patients with chronic hepatitis B virus (HBV) infection have not been investigated in detail. This study aimed to explore evolving patterns of anti-HBc following liver pathological states and to investigate validities of anti-HBc for predicting liver pathological states.

Methods

254 HBeAg-positive and 237 HBeAg-negative patients with chronic HBV infection were enrolled. Liver pathological diagnoses referred to Scheuer standard, and anti-HBc was measured using chemiluminescence microparticle immunoassay.

Results

Anti-HBc was significantly positively correlated with pathological grades and stages in both HBeAg-positive (r_s = 0.312, P < 0.0001, and r_s = 0.268, P < 0.0001) and HBeAg-negative (r_s = 0.270, P < 0.0001, and r_s = 0.147, P=0.0237) patients. The medians of anti-HBc in pathological grades of G1, G2, and G3 and stages of S1, S2, S3, and S4 in HBeAg-positive patients were all significantly lower than those in HBeAg-negative patients (all P < 0.005). The areas under receiver-operating characteristic curves (95% confidence interval) of anti-HBc for predicting pathological grades ≥G2 and ≥G3, and stages ≥S2 and =S4 in HBeAg-positive patients were 0.683 (0.622–0.740) and 0.662 (0.601–0.720), and 0.627 (0.564–0.687) and 0.683 (0.622–0.740), respectively, and in HBeAg-negative patients were 0.681 (0.618–0.740) and 0.702 (0.639–0.760), and 0.569 (0.503–0.633) and 0.630 (0.565–0.691), respectively.

Conclusion

Following hepatic aggravation of necroinflammation and progression of fibrosis, anti-HBc increases gradually in HBeAg-positive patients and continues to increase gradually in HBeAg-negative patients, which is a useful but unsatisfactory marker for monitoring pathological states.

Non-invasive biomarkers for chronic hepatitis B virus infection management

Chronic hepatitis B virus (HBV) infection remains a major health burden with over 250 million cases worldwide. This complex infection can lead to chronic hepatitis, liver cirrhosis and hepatocellular carcinoma. Complete recovery is seldom achieved due to the persistence in infected hepatocytes of covalently closed circular (ccc)DNA, which is not targeted by current antiviral therapies. Routine circulating biomarkers used for clinical monitoring of patients do not accurately reflect the cccDNA pool and transcriptional activity. New biomarkers, such as serum HB core-related Ag and circulating HBV RNAs, are under development. In this review, we discuss surrogate non-invasive biomarkers for evaluating intrahepatic cccDNA abundance and transcriptional activity. We also present their relevance for improving the classification of patients with regards to their natural history and for evaluating novel compounds to assess target engagement and to define new virological endpoints.

Relationship between hepatitis B core-related antigen levels and sustained HBeAg seroconversion in patients treated with nucleo(s)tide analogues

Hepatitis B e antigen (HBeAg) seroconversion experienced during nucleo(s)tide analogue (NUC) therapy is often not sustained. We aimed to study whether hepatitis B core-related antigen (HBcrAg) levels predict sustained HBeAg seroconversion in patients treated with NUCs. We studied HBeAg-positive patients treated with NUCs for at least 6 months. We quantified HBcrAg at baseline and at the time of HBeAg seroconversion and studied the relationship with HBeAg seroconversion and subsequent relapse. HBcrAg was quantified at baseline in 196 patients; levels varied significantly by HBV genotype and correlated with HBsAg, HBV DNA and HBeAg. Baseline HBcrAg levels were lower in patients who achieved HBeAg seroconversion than in those who did not; the unadjusted hazard ratio (HR) was 0.802 (95% CI: 0.656-0.980, P = 0.031); and this association was not sustained in multivariate analysis. HBcrAg remained detectable in all patients at the time of HBeAg seroconversion. Higher HBcrAg at the time of seroconversion was an independent predictor of relapse (adjusted HR: 1.855 (95% CI: 1.099-3.133, P = 0.021), and none of the patients with HBcrAg < 4.90 log U/mL experienced relapse. Baseline HBcrAg is not an independent predictor of HBeAg seroconversion during NUC therapy. HBcrAg remains detectable in patients after HBeAg seroconversion. Patients with lower levels at the time of seroconversion have a higher probability of sustained HBeAg seroconversion.