The Role of Hepatitis B Core-Related Antigen

High end-of-treatment hepatitis B core-related antigen levels predict hepatitis flare after stopping nucleot(s)ide analogue therapy

BACKGROUND AND AIMS

Accurate biomarkers to predict outcomes following discontinuation of nucleos(t)ide analogue (NA) therapy are needed. We evaluated serum hepatitis B core-related antigen (HBcrAg) level as a biomarker for predicting outcomes after NA discontinuation.

METHODS

Patients with HBeAg-negative chronic hepatitis B (CHB) without cirrhosis were enrolled in a prospective trial evaluating clinical outcomes until 96 weeks after NA discontinuation. End of treatment (EOT) and off-treatment levels of serum HBcrAg, HBsAg, HBV RNA and HBV DNA were used to predict key clinical outcomes including hepatitis flare (ALT ≥5 × ULN and HBV DNA > 2000 IU/mL). The SCALE-B score was calculated for the purposes of model validation.

RESULTS

HBcrAg was tested amongst 65 participants. The median age was 54 years, 54% were male and 83% were Asian. HBcrAg was detectable in 86% patients. HBcrAg level ≥4 log U/mL at EOT was predictive of hepatitis flare [8/10 (80%) vs. 17/55 (31%), p = .001]. The presence of either HBcrAg ≥4 log U/mL or detectable HBV RNA at EOT predicted for both biochemical relapse and hepatitis flare. The SCALE-B model at EOT predicted for virological relapse, biochemical relapse, hepatitis flare and HBsAg loss in this cohort. An increase in the serum HBcrAg level off-treatment was also associated with hepatitis flare. No participant with EOT HBcrAg level ≥4 log U/mL achieved HBsAg loss.

CONCLUSIONS

High levels of serum HBcrAg predict for hepatitis flare after stopping NA therapy and low likelihood of HBsAg loss at week 96. People with high levels of serum HBcrAg are not suitable candidates for NA discontinuation.

Two Concepts of Hepatitis B Core-Related Antigen Assay: A Highly Sensitive and Rapid Assay or an Effective Tool for Widespread Screening

Hepatitis B core-related antigen (HBcrAg) reflects the activity of intrahepatic covalently closed circular DNA. HBcrAg can be detected even in chronic hepatitis B patients in whom serum HBV DNA or hepatitis B surface antigen is undetectable. The HBcrAg measurement system was developed based on two concepts. One is a fully-automated and highly-sensitive HBcrAg assay (iTACT-HBcrAg) and the other is a point-of-care testing (POCT) that can be used in in resource-limited areas. iTACT-HBcrAg is an alternative to HBV DNA for monitoring HBV reactivation and predicting the development of hepatocellular carcinoma. This validated biomarker is available in routine clinical practice in Japan. Currently, international guidelines for the prevention of mother-to-child transmission recommend anti-HBV prophylaxis for pregnant women with high viral loads. However, over 95% of HBV-infected individuals live in countries where HBV DNA quantification is widely unavailable. Given this situation, a rapid and simple HBcrAg assay for POCT would be highly effective. Long-term anti-HBV therapy may have potential side effects and appropriate treatment should be provided to eligible patients. Therefore, a simple method of determining the indication for anti-HBV treatment would be ideal. This review provides up-to-date information regarding the clinical value of HBcrAg in HBV management, based on iTACT-HBcrAg or POCT.

Hepatitis B core-related antigen dynamics and risk of subsequent clinical relapses after nucleos(t)ide analog cessation

BACKGROUND/AIMS

Finite nucleos(t)ide analog (NA) therapy has been proposed as an alternative treatment strategy for chronic hepatitis B (CHB), but biomarkers for post-treatment monitoring are limited. We investigated whether measuring hepatitis B core-related antigen (HBcrAg) after NA cessation may stratify the risk of subsequent clinical relapse (CR).

METHODS

This retrospective multicenter analysis enrolled adults with CHB who were prospectively monitored after discontinuing entecavir or tenofovir with negative HBeAg and undetectable HBV DNA at the end of treatment (EOT). Patients with cirrhosis or malignancy were excluded. CR was defined as serum alanine aminotransferase > two times the upper limit of normal with recurrent viremia. We applied time-dependent Cox proportional hazard models to clarify the association between HBcrAg levels and subsequent CR.

RESULTS

The cohort included 203 patients (median age, 49.8 years; 76.8% male; 60.6% entecavir) who had been treated for a median of 36.9 months (interquartile range [IQR], 36.5-40.1). During a median post-treatment follow-up of 31.7 months (IQR, 16.7-67.1), CR occurred in 104 patients with a 5-year cumulative incidence of 54.8% (95% confidence interval [CI], 47.1-62.4%). Time-varying HBcrAg level was a significant risk factor for subsequent CR (adjusted hazard ratio [aHR], 1.53 per log U/mL; 95% CI, 1.12-2.08) with adjustment for EOT HBsAg, EOT anti-HBe, EOT HBcrAg and time-varying HBsAg. During follow-up, HBcrAg <1,000 U/mL predicted a lower risk of CR (aHR, 0.41; 95% CI, 0.21-0.81).

CONCLUSION

Dynamic measurement of HBcrAg after NA cessation is predictive of subsequent CR and may be useful to guide post-treatment monitoring.

Gene-Editing and RNA Interference in Treating Hepatitis B: A Review

The hepatitis B virus (HBV) continues to cause substantial health and economic burdens, and its target of elimination may not be reached in 2030 without further efforts in diagnostics, non-pharmaceutical prevention measures, vaccination, and treatment. Current therapeutic options in chronic HBV, based on interferons and/or nucleos(t)ide analogs, suppress the virus replication but do not eliminate the pathogen and suffer from several constraints. This paper reviews the progress on biotechnological approaches in functional and definitive HBV treatments, including gene-editing tools, i.e., zinc-finger proteins, transcription activator-like effector nucleases, and CRISPR/Cas9, as well as therapeutics based on RNA interference. The advantages and challenges of these approaches are also discussed. Although the safety and efficacy of gene-editing tools in HBV therapies are yet to be demonstrated, they show promise for the revitalization of a much-needed advance in the field and offer viral eradication. Particular hopes are related to CRISPR/Cas9; however, therapeutics employing this system are yet to enter the clinical testing phases. In contrast, a number of candidates based on RNA interference, intending to confer a functional cure, have already been introduced to human studies. However, larger and longer trials are required to assess their efficacy and safety. Considering that prevention is always superior to treatment, it is essential to pursue global efforts in HBV vaccination.

Long-Term Hepatitis B Surface Antigen Profile and Seroclearance Following Antiviral Treatment: A Single-Center, Real-World Cohort Study

Hepatitis B surface antigen (HBsAg) seroclearance, an indicator of recovery from hepatitis B virus (HBV) infection, is uncommon in long-term nucleos(t)ide analog (NUC) therapy. We compared the incidence of HBsAg seroclearance in patients with and without NUC discontinuation to identify predictors of HBsAg seroclearance. This retrospective study enrolled adult patients with a chronic HBV infection followed for ≥12 months after NUC discontinuation (finite group) and those treated with NUCs for >3 years (non-finite group). Demographic, clinical, and laboratory data were analyzed. The study cohort included 978 patients, including 509 and 469 patients in the finite and non-finite groups, respectively. Cumulative HBsAg seroclearance incidence was significantly higher in the finite group than in the non-finite group (p = 0.006). The 5- and 10-year cumulative HBsAg seroclearance incidence were 6.6% and 18.9% in the finite group and 3% and 14.6% in the non-finite group, respectively. The likelihood of HBsAg seroclearance was higher in those with end of treatment (EOT) HBsAg levels of <100 IU/mL and in those without clinical relapse (CR). The cumulative 3-year CR incidence was 16.8%. The incidence of liver decompensation and hepatocellular carcinoma were 4.1 and 0.4 per 1000 person-years, respectively. The hepatocellular carcinoma incidence did not significantly differ between the finite and non-finite groups (p = 0.941). In conclusion, higher HBsAg seroclearance incidence in patients receiving finite therapy, and the increased likelihood of HBsAg seroclearance in those with EOT HBsAg levels of <100 IU/mL and in those without CR should be considered during decision-making of treatment options.

The Epidemiology, Transmission, Genotypes, Replication, Serologic and Nucleic Acid Testing, Immunotolerance, and Reactivation of Hepatitis B Virus

The epidemiology of Hepatitis B virus (HBV) has drastically changed in recent decades due to public health initiatives, including universal infant vaccination programs,urbanization driving global travel, and migration patterns. Despite screening of pregnant women and newborns significantly reducing the rate of perinatal transmission in certain parts of the world, other, perhaps more uncommon, routes (e.g., parenteral) have led to outbreaks in specific areas affected by the opioid epidemic and injection drug use. Although our current understanding of the effect of genetic variants of HBV is lacking, we review current knowledge and patterns of genetic variants with geographical predominance, pathophysiology, and clinical manifestations. Serologic and molecular markers are used to screen, identify phase and activity of infection, and monitor response to antivirals and/or reactivation. This review will provide the most up-to-date summary of the epidemiology, transmission, genotype, replication, and current methods of screening to follow the various phases of HBV, including immunotolerance and reactivation.

Hepatitis B core-related antigen: A novel and promising surrogate biomarker to guide anti-hepatitis B virus therapy

The current requirement for biomarkers to detect hepatitis B virus (HBV) infection is polarized. One is a fully-automated and highly sensitive measurement system; the other is a simple system for point-of-care testing (POCT) in resource-limited areas. Hepatitis B core-related antigen (HBcrAg) reflects intrahepatic covalently closed circular DNA and serum HBV DNA. Even in patients with undetectable serum HBV DNA or HBsAg loss, HBcrAg may remain detectable. Decreased HBcrAg levels are associated with reduction of the occurrence of hepatocellular carcinoma (HCC) in chronic hepatitis B. Recently, a fully-automated, novel high-sensitivity HBcrAg assay (iTACT-HBcrAg, cut-off value: 2.1 logIU/mL) has been developed. This attractive assay has been released in Japan very recently. iTACT-HBcrAg can be useful for monitoring HBV reactivation and prediction of HCC occurrence, as an alternative to HBV DNA. Moreover, monitoring HBcrAg may be suitable for determining the therapeutic effectiveness of approved drugs and novel drugs under development. Presently, international guidelines recommend anti-HBV prophylaxis for pregnant women with high viral loads to prevent mother-to-child transmission of HBV. However, >95% of HBV-infected individuals live in countries where HBV DNA quantification is not available. Worldwide elimination of HBV needs the scaling-up of examination and medication services in resource-limited areas. Based on this situation, a rapid and easy HBcrAg assay as a POCT is valuable. This review provides the latest information regarding the clinical use of a new surrogate marker, HBcrAg, in HBV management, based on iTACT-HBcrAg or POCT, and introduces novel agents targeting HBV RNA/protein.

Kinetics of HBcrAg and HBsAg using highly sensitive iTACT assays in chronic hepatitis B patients with HBsAg seroclearance

Two novel assays have been developed, iTACT-hepatitis B core-related antigen (iTACT-HBcrAg) and iTACT-hepatitis B surface antigen (iTACT-HBsAg) assays. We investigated the longitudinal profiles of iTACT-HBcrAg- and -HBsAg in patients with HBsAg seroclearance (SC) (<0.05 IU/mL). This study comprises 60 HBV-infected patients with HBsAg SC, 27 in chronic hepatitis/liver cirrhosis (CH/LC) group and 33 in inactive carrier (IC) group. Longitudinal profiles of iTACT-HBcrAg and -HBsAg were examined using stored serum samples. The median period from HBsAg SC to iTACT-HBcrAg loss or to the last observation was longer in the CH/LC group than the IC group (39 vs. -3 months, p = 0.004), but this tendency was not observed in that by iTACT-HBsAg. Comparing the times of iTACT-HBcrAg and -HBsAg loss, the rate of patients who lost HBcrAg first was significantly higher in the IC group (p = 0.008). The cumulative incidence rate of iTACT-HBcrAg loss after HBsAg SC was higher in the IC group that the CH/LC group (p = 0.002). Patients in the CH/LC group had higher rates of detectable iTACT-HBcrAg than those in the IC group after HBsAg SC, suggesting that the presence of HBcrAg possibly contribute to the progression of chronic hepatitis B.

HIV-HBV Coinfection-Current Challenges for Virologic Monitoring

HIV-HBV coinfected patients have higher rates of liver-related morbidity, hospitalizations, and mortality compared to HBV or HIV mono-infected ones. Clinical studies have shown an accelerated progression of liver fibrosis and an increased incidence of HCC, resulting from the combined action of HBV replication, immune-mediated hepatocytolysis, and HIV-induced immunosuppression and immunosenescence. Antiviral therapy based on dually active antiretrovirals is highly efficient, but late initiation, global disparities in accessibility, suboptimal regimens, and adherence issues may limit its impact on the development of end-stage liver disease. In this paper, we review the mechanisms of liver injuries in HIV-HBV coinfected patients and the novel biomarkers that can be used for treatment monitoring in HIV-HBV coinfected persons: markers that assess viral suppression, markers for liver fibrosis evaluation, and predictors of oncogenesis.

What will it take to cure hepatitis B?

The current treatment of chronic HBV infection, pegylated interferon-α (pegIFNα) and nucleos(t)ide analog (NA), can suppress HBV replication, reverse liver inflammation and fibrosis and reduce the risks of cirrhosis, HCC, and HBV-related deaths, but relapse is common when the treatment is stopped before HBsAg loss. There have been major efforts to develop a cure for HBV, defined as sustained HBsAg loss after a finite course of therapy. This requires the suppression of HBV replication and viral protein production and the restoration of immune response to HBV. Direct-acting antivirals targeting virus entry, capsid assembly, viral protein production and secretion are in clinical trials. Immune modulatory therapies to stimulate adaptive or innate immunity and/or to remove immune blockade are being tested. NAs are included in most and pegIFNα in some regimens. Despite the combination of 2 or more therapies, HBsAg loss remains rare in part because HbsAg can be derived not only from the covalently closed circular DNA but also from the integrated HBV DNA. Achievement of a functional HBV cure will require therapies to eliminate or silence covalently closed circular DNA and integrated HBV DNA. In addition, assays to differentiate the source of circulating HBsAg and to determine HBV immune recovery, as well as standardization and improvement of assays for HBV RNA and hepatitis B core-related antigen, surrogate markers for covalently closed circular DNA transcription, are needed to accurately assess response and to target treatments according to patient/disease characteristics. Platform trials will allow the comparison of multiple combinations and channel patients with different characteristics to the treatment that is most likely to succeed. Safety is paramount, given the excellent safety profile of NA therapy.

HB Surface Antigen Level as a Useful Predictor for the Treatment Response to Tenofovir Alafenamide in Nucleoside Analogue Naïve Chronic Hepatitis B

AIM

To elucidate factors contributing to hepatitis B virus (HBV)-DNA clearance following tenofovir alafenamide (TAF) therapy in nucleoside analogue (NA) naïve patients with chronic hepatitis B (CHB) (n=92, 11 cirrhotic cases).

PATIENTS AND METHODS

The time interval between the start of TAF therapy and first confirmed undetectable HBV-DNA after TAF therapy was calculated. Univariate and multivariate analyses of factors related to undetectable HBV-DNA after TAF therapy were performed.

RESULTS

HB envelop antigen seropositivity was found in 12 patients (13.0%). The cumulative undetectable HBV-DNA rate at 1- and 2- year was 74.9% and 90.9%. In the multivariate Cox regression analysis of the undetectable HBV-DNA after TAF therapy, HBsAg level >1,000 IU/ml (p=0.0082, HBsAg level <100 IU/ml as a reference standard) was an independent predictor of the undetectable HBV-DNA after TAF therapy.

CONCLUSION

Baseline higher HBsAg level can be an adverse predictor for the undetectable HBV-DNA after TAF therapy in NA naïve CHB patients.

Research progress on detection methods for hepatitis B virus covalently closed circular DNA

Hepatitis B virus (HBV) infection remains a serious global public health problem, and HBV covalently closed circular DNA (cccDNA) in the nucleus of infected cells cannot be eliminated by current treatments and is a major factor in the persistence and recurrence of hepatitis B. Efficient and scientific detection methods are important for clinical monitoring of cccDNA and targeted drug development. Western blotting is the gold standard for the quantitative detection of cccDNA, but it is time-consuming and complex. In recent years, new detection technologies have been continuously updated. There are new developments and breakthroughs in both next-generation polymerase chain reaction (PCR) and non-PCR methods such as in situ hybridization. Some HBV-related markers (such as hepatitis B core-related antigen) have also been shown to be closely related to cccDNA, and they can be used as surrogate markers to indirectly reflect cccDNA content. In this paper, the main detection methods of cccDNA and their improvements are reviewed, the advantages and limitations of these methods are analysed and summarized, and future development directions are proposed.

Baseline and on-treatment HBcrAg levels as predictors of HBeAg seroconversion in chronic hepatitis B patients treated with antivirals

HBeAg seroconversion is an important treatment endpoint. We aimed to identify predictors of seroconversion using serum HBsAg and hepatitis B core-related antigen (HBcrAg) in HBeAg-positive patients treated with nucleos(t)ide analogs (NAs). Data and samples from 70 HBeAg-positive patients treated with entecavir or tenofovir between January 2007 and December 2017 were retrospectively analysed. The mean follow-up period was 11 years. The predictive power for HBeAg seroconversion of HBcrAg levels at baseline and 2 years after antiviral therapy was determined using receiver operating curve analysis. Twenty-one patients (30%) achieved HBeAg seroconversion at a mean of 28 (range, 12-84) months after antiviral treatment. The median baseline HBcrAg and HBsAg levels were 6.9(5.7-7.0) vs. 5.8(5.5-6.5) log₁₀ U/mL (p = .006), 4.9(4.5-5.1) vs. 4.5(4.1-5.0) log₁₀ IU/mL (p = .044) in the no seroconversion group and seroconversion group, respectively. In the multivariate analysis, the serum HBcrAg levels at baseline and 2 years after antiviral therapy were predictive factors for HBeAg seroconversion ([HR]; 0.326; [CI], 0.111-0.958; p = .042 and HR, 0.4555; CI, 0.211-0.984; p = .045). HBcrAg levels≤6.5log₁₀ U/mL at baseline and ≤5.3log₁₀ U/mL at 2 years after antiviral therapy had sensitivities of 53.1% and 69.8%, specificities of 95.2% and 70.6%, positive predictive values of 82.6% and 50.0%, and negative predictive values of 82.6% and 84.5%, respectively, with AUROCs of 0.712 (95%CI, 0.596-0.830) and 0.745 (95%CI, 0.599-0.891) for predicting HBeAg seroconversion. In chronic hepatitis B patients treated with NAs, HBcrAg levels≤6.5log₁₀ U/mL at baseline and ≤5.3log₁₀ U/mL at 2 years after antiviral therapy were useful predictive factors of HBeAg seroconversion.

Clinical usefulness of a novel high-sensitivity hepatitis B core-related antigen assay to determine the initiation of treatment for HBV reactivation

BACKGROUNDS

A fully automated, novel, high-sensitivity hepatitis B core-related antigen assay (iTACT-HBcrAg) has been developing. The purpose of this study is to evaluate the efficacy of measuring HBcrAg, using that assay, to diagnose HBV reactivation in a multi-center setting, compared with ultra-high-sensitivity HBsAg (iTACT-HBsAg) and HBV DNA assays.

METHODS

Forty-four patients with HBV reactivation from 2008 to 2020 were enrolled in four hospitals. Serial serum specimens from the patients were assessed retrospectively for their HBcrAg levels by iTACT-HBcrAg (lower limit of detection; 2.0 log U/mL) and HBsAg levels by iTACT-HBsAg (lower limit of detection; 0.0005 IU/mL); these were compared to the HBV DNA levels. HBV reactivation was defined as detection of serum HBV DNA, including unquantifiable detection.

RESULTS

At HBV reactivation and/or thereafter, HBV DNA levels were quantified (≥ 1.3 log IU/mL) in the sera of 27 patients, and were below the level of quantification (< 1.3 log IU/mL) in the sera of 17 patients. Of the 27 patients with HBV reactivation and whose serum HBV DNA was quantified, the sera of 26 and 24 patients (96.3% and 88.9%) were positive by iTACT-HBcrAg and iTACT-HBsAg, respectively. HBcrAg was detectable by iTACT-HBcrAg before HBV DNA was quantifiable in 15 of the 27 patients. Of the 11 patients with HBV reactivation and undetectable HBcrAg by iTACT-HBcrAg at HBV reactivation and/or thereafter, 10 had unquantifiable HBV DNA and none developed HBV reactivation-related hepatitis.

CONCLUSIONS

The iTACT-HBcrAg assay is useful for monitoring HBV reactivation to determine the initiation of treatment with nucleos(t)ide analogues.

Standardized Hepatitis B Virus RNA Quantification in Untreated and Treated Chronic Patients: a Promising Marker of Infection Follow-Up

The measurement and interpretation of HBV DNA and RNA levels in HBV infected patients treated with antiviral therapy supports the objective of HBV disease management. Here, we quantified circulating HBV RNA through a standardized and sensitive assay in follow-up samples from both naive and treated patients as a marker of infection evolution. HBV DNA (HBV DNA for use in Cobas 6800/8800 Automated Roche Molecular Systems), RNA (Roche HBV RNA Investigational Assay for use in the Cobas 6800/8800; Roche), HBeAg and HBsAg (Elycsys HBsAg chemiluminescence immunoassay by Cobas 8000; Roche), and core-related antigen (Lumipulse G chemiluminescence assay; Fujirebio) levels were measured in cohorts of untreated or nucleos(t)ide treated, HBV-infected subjects in an outpatient hospital setting. HBV DNA levels in untreated people were 3.6 log10 higher than corresponding RNA levels and were stable over 5 years of observation. While only five of 52 treated patients had DNA levels below the lower limit of quantification (10 IU/mL) at the end of follow-up, 13 had HBV RNA levels persistently above this limit, including eight with undetectable DNA. In samples with undetectable core-related antigen we observed a median HBsAg titer 2.7-fold higher than in samples with undetectable RNA (adjusted P = 0.012). Detectable HBV RNA with undetectable HBV DNA was a negative predictor of HBsAg decrease to a level ≤100 IU/mL (P = 0.03). In naive patients the difference between HBV DNA and RNA was higher than previously reported. HBV RNA rapidly decreased during treatment. However, in some cases, it was detectable even after years of effective therapy, being a negative predictor of HBsAg decrease. The investigational RNA assay for use on the Cobas 6800/8800 instruments is a sensitive and standardized method that could be applied in general management of HBV infection. IMPORTANCE This study focused on the quantification of circulating HBV RNA by using a standardized and sensitive assay. Thanks to this system we observed a higher difference between circulating HBV DNA and RNA than previously reported. In treated patients, HBV RNA decreased together with DNA, although some patients presented detectable levels even after years of successful antiviral treatment, suggesting a persistent viral transcription. Of note, the detection of viral RNA when HBV DNA is undetectable was a negative predictor of HBsAg decrease to a level ≤100 IU/mL. This assay could be extremely helpful in HBV patients management to study viral transcription and to identify those treated patients that may achieve sustained viral suppression.

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.

Current laboratory tests for diagnosis of hepatitis B virus infection

BACKGROUND

Hepatitis B virus (HBV) has a long history in human infectious diseases. HBV infection can progress chronically, leading to cancer. After introduction of a vaccine, the overall incidence rate of HBV infection has decreased, although it remains a health problem in many countries.

PURPOSE

The aim of this review was to summarise current diagnostic efforts for HBV infection and future HBV diagnosis perspectives.

METHODS

We reviewed and summarised current laboratory diagnosis related with HBV infection in clinical practice.

RESULTS

There have been various serologic- and molecular-based methods to diagnose acute or chronic HBV infection. Since intrahepatic covalently closed circular DNAs (cccDNAs) function as robust HBV replication templates, cure of chronic HBV infection is limited. Recently, new biomarkers such as hepatitis B virus core-related antigen (HBcrAg) and HBV RNA have emerged that appear to reflect intrahepatic cccDNA status. These new biomarkers should be validated before clinical usage.

CONCLUSION

An effective diagnostic approach and current updated knowledge of treatment response monitoring are important for HBV infection management. Brand new ultrasensitive and accurate immunologic methods may pave the way to manage HBV infection in parallel with immunotherapy era.

How to interpret viral markers in the management of chronic hepatitis B infection

BACKGROUND

Hepatitis B virus (HBV) infection is a global public health issue with several unsolved clinical challenges. As multiple new drugs are under development, HBV markers are gaining importance for both diagnostic and prognostic purposes.

OBJECTIVES

This review summarizes the most important data on the usefulness of HBV markers in the natural history of this infection, and in predicting clinical and treatment outcomes.

SOURCES

Selected peer-reviewed publications on HBV markers published between January 2009 and July 2021.

CONTENT

In addition to the classical markers (e.g. HBV-DNA), newer ones, such as quantitative HBsAg, HBcrAg, HBV-RNA and quantitative anti-HBc, have proven useful for predicting events within the natural history of HBV infection, the development of complications (e.g. hepatocellular carcinoma) and the response to antiviral therapy. Most data regarding the response to treatment have been related to nucleos(t)ide analogues, whereas evidence on new therapeutic agents, such as capsid assembly modulators or small interference RNAs, is promising, but still scarce.

IMPLICATIONS

Knowledge on the use of viral markers is a key factor for optimizing the clinical appraisal of HBV infection. The new markers have an enhanced ability to predict clinical outcomes. Further studies should expand the current evidence on the use of markers in relation to antiviral agents currently under evaluation. Wide availability of these markers in regions with a high incidence of HBV infection is of paramount importance.

Serum hepatitis B core-related antigen as a surrogate marker of hepatitis B e antigen seroconversion in chronic hepatitis B

BACKGROUND

Quantitative hepatitis B core-related antigen (qHBcrAg) has a better correlation with intrahepatic hepatitis B virus (HBV) covalently closed circular DNA (cccDNA) than HBV DNA or hepatitis B e antigen (HBeAg), but data are still lacking for its clinical application.

AIM

The aim was to investigate serum qHBcrAg levels in patients with chronic hepatitis B and assess the correlation of serum qHBcrAg with pregenomic RNA (pgRNA), cccDNA, and HBeAg seroconversion.

METHODS

This study was a secondary analysis of patients who underwent percutaneous liver biopsy between July 2014 and June 2019 in two multicenter randomized controlled clinical trials of peginterferon vs nucleos(t)ide analog (NUC)-based therapy (NCT03509688 and NCT03546530). Serum qHBcrAg, pgRNA, HBV DNA, hepatitis B core antigen, HBeAg, liver cccDNA, and HBV DNA were measured. The correlations of serum qHBcrAg with other biomarkers were analyzed.

RESULTS

A total of 139 patients were included. The mean qHBcrAg levels were 5.32 ± 1.18 log₁₀ U/mL at baseline and decreased during treatment (all P < 0.0001). Serum qHBcrAg levels were positively correlated with pgRNA (r = 0.597, P < 0.0001) and cccDNA (r = 0.527, P < 0.0001) levels. The correlation of serum qHBcrAg level and intrahepatic HBV DNA levels at baseline was weak but significant (r = 0.399, P < 0.0001). HBcrAg predicted HBeAg seroconversion, with areas under the receiver operating characteristics curve of 0.788 at 24 wk and 0.825 at 48 wk. Log HBcrAg at wk 24 and 48 was independently associated with HBeAg seroconversion [odds ratio (OR) = 2.402, 95% confidence interval (CI): 1.314-4.391, P = 0.004; OR = 3.587, 95%CI: 1.315-9.784, P = 0.013].

CONCLUSION

Serum HBcrAg levels were correlated with HBV virological markers and could be used to predict HBeAg seroconversion.

Approaches to quantifying Hepatitis B Virus covalently closed circular (ccc)DNA

Chronic hepatitis B is a major cause of liver disease worldwide and is currently incurable. Hepatitis B virus (HBV) covalently closed circular (ccc) DNA is a key form of the virus responsible for its persistence and is the transcriptional template for all viral transcripts. The field is focussed on methods to clear HBV cccDNA but this been limited by technical difficulties in its quantification due to: identical sequence to other forms of HBV DNA; low copy number per cell; and high resistance to denaturation by heat, leading to difficulty using polymerase chain reaction or hybridization methods for detection. A number of assays have been developed in order to overcome these hurdles either directly or detecting cccDNA levels indirectly via its transcriptional products. In this review, we summarize the approaches to cccDNA quantification that are currently used, and outline key open questions in the cccDNA biology field which remain to be answered due to the limitations of current methods.

Hepatitis B Core-Related Antigen and New Therapies for Hepatitis B

The hepatitis B core-related antigen (HBcrAg) is an unprecedented novel HBV biomarker that plays an essential role in reflecting covalently closed circular DNA (cccDNA) in chronic hepatitis B (CHB) because its levels correlate with intrahepatic cccDNA and serum HBV DNA. In this review, we describe the clinical application of serum HBcrAg in CHB patients, with a particular focus on new therapies targeting intrahepatic HBV replication. (1) HBcrAg can be detected in clinical cases where serum HBV DNA is undetectable during anti-HBV therapy. (2) A highly sensitive HBcrAg assay (iTACT-HBcrAg) may be useful for monitoring HBV reactivation, as an alternative to HBV DNA. (3) Decreased HBcrAg levels have been significantly associated with promising outcomes in CHB patients, reducing the risk of progression or recurrence of hepatocellular carcinoma. Additionally, we focus on and discuss several drugs in development that target HBV replication, and monitoring HBcrAg may be useful for determining the therapeutic efficacies of such novel drugs. In conclusion, HBcrAg, especially when measured by the recently developed iTACT-HBcrAg assay, may be the most appropriate surrogate marker, over other HBV biomarkers, to predict disease progression and treatment response in CHB patients.

Novel strategies for the early diagnosis of hepatitis B virus reactivation

Hepatitis B virus (HBV) reactivation under systemic chemotherapy or immunosuppressive therapy is a serious complication among HBV-resolved patients. Some medications, such as more than 2 weeks of corticosteroid therapy, can influence HBV reactivation; therefore, screening tests that measure hepatitis B surface antigen (HBsAg), hepatitis B core antibody, and hepatitis B surface antibody before therapy are required. Additionally, because HBV reactivation has been reported in patients positive for HBsAg treated with immune checkpoint inhibitors (ICIs), the prophylactic administration of nucleos(t)ide analogues prior to administering ICIs is recommended for HBsAg-positive patients. Under these circumstances, highly sensitive novel biomarkers are expected to be used for the early diagnosis of HBV reactivation. A fully automated high-sensitivity HBsAg assay (detection limit: 5 mIU/ml) by Lumipulse HBsAg-HQ, with 10-fold higher sensitivity than that of conventional assays, is currently used. Furthermore, ultra-sensitive HBsAg assays using a semi-automated immune complex transfer chemiluminescence enzyme immunoassay (ICT-CLEIA; detection limit: 0.5 mIU/ml) have been developed. Recently, a fully automated, novel high-sensitivity hepatitis B core-related antigen assay (iTACT-HBcrAg; cut-off value: 2.1 Log U/mL) has been developed and reported. The utility of ICT-CLEIA and iTACT-HBcrAg for the diagnosis of HBV reactivation appears comparable to the use of HBV DNA. In this review, we provide the latest information related to medications that influence HBV reactivation and recently developed novel biomarkers that predict and monitor HBV reactivation.

Serum PreS1 and HBsAg ratio reflects liver fibrosis and predicts the development of hepatocellular carcinoma in chronic hepatitis B patients

While the preS1 region of the large hepatitis B surface protein plays an essential role in hepatitis B virus (HBV) infection, the effect of preS1 on liver fibrosis and hepatocarcinogenesis in chronic hepatitis B (CHB) patients is not well known. In this study, we measured serum preS1 levels by chemiluminescent immunoassay technology in 690 CHB patients and evaluated the correlation between serum preS1 levels and HBV, liver function markers and liver inflammation, fibrosis assessed by histological findings. Predictive factors for hepatocellular carcinoma (HCC) development in patients who had no previous history of HCC at the time of preS1 level measurement were also analysed. Median hepatitis B surface antigen (HBsAg) and preS1 levels were 3.08 log IU/mL and 98 ng/mL, respectively. PreS1 values were significantly correlated with serum HBsAg (p <0.001), hepatitis B core-related antigen (HBcrAg) (p <0.001) and HBV DNA levels (p <0.01). PreS1 values were also significantly correlated with serum alanine aminotransferase levels (p <0.001) and were significantly higher in patients who had higher grading of liver inflammatory activity (p <0.05). HBsAg level was correlated, but preS1/HBsAg ratio reflected liver fibrosis staging more directly than HBsAg alone. Multivariate analysis identified age ≥53 years (hazard ratio [HR], 18.360 for <53 years; p = 0.021) and preS1/HBsAg ratio ≥0.12 (HR, 6.205 for <0.12; p = 0.040) as significant and independent factors for HCC development in CHB patients. The preS1/HBsAg ratio directly reflects liver fibrosis, and the ratio might be a predictive marker for HCC development in CHB patients.

Clinical efficacy of a novel, high-sensitivity HBcrAg assay in the management of chronic hepatitis B and HBV reactivation

BACKGROUND & AIMS

A fully automated, novel high-sensitivity hepatitis B core-related antigen assay (iTACT-HBcrAg) has been developed. We demonstrate the clinical utility of iTACT-HBcrAg for monitoring chronic hepatitis B (CHB) and for the early detection of HBV reactivation.

METHODS

After fundamental assessments, the clinical performance of iTACT-HBcrAg was compared with other HBV markers. i) Serial sera, available from 161 HBeAg-negative patients with CHB and persistently undetectable HBV DNA, were measured by iTACT-HBcrAg and a conventional HBcrAg assay (G-HBcrAg). ii) Serial sera from 13 HBV-reactivated patients were measured by iTACT-HBcrAg and an ultra-high-sensitivity HBsAg immune complex transfer-chemiluminescent enzyme immunoassay (lower limit of detection; 0.0005 IU/ml, ICT-CLEIA) to compare HBV DNA detection. iii) To elucidate the various HBcrAg components detected by iTACT-HBcrAg, OptiPrep density gradient centrifugation analysis was performed on sera obtained before and after HBV reactivation.

RESULTS

The analytical performance of iTACT-HBcrAg was satisfactory. The sensitivity of iTACT-HBcrAg (2.1 Log U/ml) was approximately 10-fold greater than that of G-HBcrAg (2.8 Log U/ml). i) HBcrAg was detectable in the sera of 97.5% (157/161) of patients with CHB by iTACT-HBcrAg, of whom 75.2% (121/161) had ≥2.8 Log U/ml HBcrAg and 22.4% (36/161) had 2.1-2.8 Log U/ml HBcrAg, which was undetectable by G-HBcrAg. ii) 9 and 2 of 13 HBV-reactivated patients were HBcrAg-positive by iTACT-HBcrAg before and at HBV DNA positivity, respectively; 7 and 4 were HBcrAg-positive by iTACT-HBcrAg before and at HBsAg-positivity by ICT-CLEIA, respectively. iii) The HBcrAg detected by iTACT-HBcrAg before HBV reactivation was contained in empty particles (22 KDa precore protein).

CONCLUSIONS

iTACT-HBcrAg could be used to better monitor responses to anti-HBV treatments in HBeAg-negative patients and for the early detection of HBV reactivation.

LAY SUMMARY

A fully automated, novel high-sensitivity hepatitis B core-related antigen assay (iTACT-HBcrAg) has been developed. iTACT-HBcrAg can be used to monitor HBeAg-negative patients with chronic hepatitis B, as well as for the early detection of HBV reactivation. iTACT-HBcrAg could be used as a general marker of disease progression and treatment response.

Mechanism of Hepatitis B Virus cccDNA Formation

Hepatitis B virus (HBV) remains a major medical problem affecting at least 257 million chronically infected patients who are at risk of developing serious, frequently fatal liver diseases. HBV is a small, partially double-stranded DNA virus that goes through an intricate replication cycle in its native cellular environment: human hepatocytes. A critical step in the viral life-cycle is the conversion of relaxed circular DNA (rcDNA) into covalently closed circular DNA (cccDNA), the latter being the major template for HBV gene transcription. For this conversion, HBV relies on multiple host factors, as enzymes capable of catalyzing the relevant reactions are not encoded in the viral genome. Combinations of genetic and biochemical approaches have produced findings that provide a more holistic picture of the complex mechanism of HBV cccDNA formation. Here, we review some of these studies that have helped to provide a comprehensive picture of rcDNA to cccDNA conversion. Mechanistic insights into this critical step for HBV persistence hold the key for devising new therapies that will lead not only to viral suppression but to a cure.

Baseline serum hepatitis B core antibody level predicts HBeAg seroconversion in patients with HBeAg-positive chronic hepatitis B after antiviral treatment

Antibody to hepatitis B core antigen (anti-HBc) is one of the most classical serological markers of HBV infection. This study aimed to investigate the association of serum anti-HBc and HBeAg seroconversion in patients with HBeAg-positive chronic hepatitis B (CHB) after antiviral treatment. Two hundred and seventeen HBeAg-positive CHB patients treated with entecavir (ETV) or tenofovir disoproxil fumarate (TDF) for 48 weeks were retrospectively enrolled. Serological response (SR) is defined as HBeAg seroconversion at 48 weeks of antiviral treatment. Serum anti-HBc level was measured using the Abbott ARCHITECT assay. After 48 weeks of antiviral treatment, twenty-two (10.1 %) patients achieved SR. Baseline level of serum anti-HBc in the SR patients (11.8 S/CO) was significantly higher than patients with non-SR (9.6 S/CO, P < 0.001). The median anti-HBc level was significantly declined after 48 weeks of antiviral therapy (9.9 vs. 8.9 S/CO, P < 0.001). Multivariate logistic regression analysis showed baseline of serum anti-HBc was an independent predictor of SR (odds ratio [OR]: 1.462, 95 % confidence interval [CI] 1.170-1.825, P = 0.001). The area under receiver operating characteristic curve (AUROC) of baseline anti-HBc level for predicting SR was 0.781 with the cut-off of 11.1 S/CO, with a sensitivity of 77.27 % and a specificity of 72.82 %. Our findings highlighted that baseline serum anti-HBc level is a promising indictor for predicting HBeAg seroconversion in HBeAg-positive CHB patients after antiviral treatment.

Screening for Hepatocellular Carcinoma in Chronic Hepatitis B: An Update

(1) Background: Hepatocellular carcinoma (HCC) is an important cause of mortality in individuals with chronic hepatitis B infection, with screening of high-risk groups recommended in all major international guidelines. Our understanding of the risk factors involved has improved over time, encouraging researchers to develop models that predict future risk of HCC development. (2) Methods: A literature search of the PubMed database was carried out to identify studies that derive or validate models predicting HCC development in patients with chronic hepatitis B. Subsequently, a second literature search was carried out to explore the potential role of novel viral biomarkers in this field. (3) Results: To date, a total of 23 models have been developed predicting future HCC risk, of which 12 have been derived from cohorts of treatment-naïve individuals. Most models have been developed in Asian populations (n = 20), with a smaller number in Caucasian cohorts (n = 3). All of the models demonstrate satisfactory performance in their original derivation cohorts, but many lack external validation. In recent studies, novel viral biomarkers have demonstrated utility in predicting HCC risk in patients with chronic hepatitis B, amongst both treated and treatment-naïve patients. (4) Conclusion: Several models have been developed to predict the risk of HCC development in individuals with chronic hepatitis B infection, but many have not been externally validated outside of the Asian population. Further research is needed to refine these models and facilitate a more tailored HCC surveillance programme in the future.

48 weeks outcome after cessation of nucleos(t)ide analogue therapy in chronic hepatitis B patients

INTRODUCTION AND OBJECTIVE

The aim of the present study was to investigate the significance of serum HBsAg levels in treatment cessation of nucleoside analogues (NAs) in patients with chronic hepatitis B (CHB) infection.

METHODS

In 158 CHB patients with long-term NAs treatment, 74 patients were in HBeAg negative and had a HBsAg level <1500IU/mL, 36 of whom were informed and consented to cease NAs. HBsAg, HBV DNA and liver function were examined in the 1st, 3rd, 6th, 9th and 12th month after treatment cessation.

RESULTS

The sustained response rate was 88.89% (32/36) within one year after NAs cessation. Sub-group analysis was based on HBsAg levels of patients with NAs cessation, there was no relapse case in 11 patients whose HBsAg <50IU/mL, and the negative predictive value (NPV) was 100%. Seroconversion of HBsAg occurred in 3 patients. 2 patients from 21 cases whose HBsAg was between 50IU/mL and 1000IU/mL relapsed. 2 of 4 patients whose in HBsAg >1000IU/mL relapsed. HBsAg of patients with a sustained response decreased slowly. In contrast, HBsAg levels increased gradually in relapsed patients, and the increase of HBsAg was precedent to relapses of HBV DNA and ALT. Multivariate analysis suggested that only HBsAg level showed a close correlation with HBV DNA relapses. ROC curve analysis suggested that the increase of HBsAg level in the 3rd and 6th month after NAs cessation had a great predictive value for relapses.

CONCLUSION

Monitoring of base line HBsAg level can predict outcomes of NAs cessation in HBeAg-negative chronic hepatitis B. HBsAg <50IU/mL has higher predictive values of better sustained responses in HBeAg-negative CHB patients.

Clinical Implications of Serum Hepatitis B Virus Pregenomic RNA Kinetics in Chronic Hepatitis B Patients Receiving Antiviral Treatment and Those Achieving HBsAg Loss

Serum hepatitis B virus (HBV) pregenomic RNA (pgRNA) is correlated with covalently closed circular DNA. We aimed to investigate the utility of serum HBV pgRNA in chronic hepatitis B patients receiving nucleos(t)ide analogue treatment and those achieving HBsAg loss. One hundred and eighty-five patients were enrolled for studying long-term HBV pgRNA kinetics during treatment. Twenty patients achieving HBsAg loss after treatment were enrolled for examining HBV pgRNA kinetics around HBsAg loss. HBV pgRNA significantly decreased in the high baseline HBV pgRNA (≥6 log copies/mL) group but significantly increased in the low baseline HBV pgRNA (<4 log copies/mL) group after 3-month entecavir treatment. Among the 20 patients achieving HBsAg loss, 13 (65%) patients had serum HBV pgRNA higher than the limit of detection (LOD, 1466 copies/mL) when they achieved HBsAg loss. Finally, all 20 patients had HBV pgRNA going below the LOD within 3 years after achieving HBsAg loss. In conclusion, baseline serum HBV pgRNA alone is insufficient for predicting the trajectory of HBV pgRNA. Most patients still had HBV pgRNA higher than the LOD when they achieved HBsAg loss. Further studies on HBV pgRNA kinetics around HBsAg loss would provide an enhanced basis for further applications of HBV pgRNA.

The Matching Status Between Donor and Recipient Hepatitis B Seroepidemiology Makes a Difference in Liver Transplantation for Hepatocellular Carcinoma

Antibody to hepatitis B core antigen (HBcAb) is known to be related with the prognosis for patients with hepatocellular carcinoma (HCC). This study aims to evaluate the prognostic capacity of HbcAb and other donor/recipient hepatitis B seroepidemiological indexes in transplantation for HCC.

Hepatitis B Core-Related Antigen: From Virology to Clinical Application

Hepatitis B core-related antigen (HBcrAg) is a composite measure of the serum levels of hepatitis B e antigen, hepatitis B core antigen, and a 22-kDa precore protein. It has been shown to reflect the level and transcriptional activity of covalently closed circular DNA in the liver. Longitudinal cohort studies have improved our understanding of the role of this novel viral marker in the natural history of chronic hepatitis B. HBcrAg kinetics reflect the response to peginterferon, and its role in defining guidelines for stopping peginterferon therapy has been evaluated. HBcrAg is a marker of intrahepatic viral activity, which may influence the risk of hepatocellular carcinoma. In this article, we review the virology and role of HBcrAg in defining phases of chronic hepatitis B. Furthermore, the function of HBcrAg in predicting treatment outcomes and its role in monitoring response to novel antiviral agents will be discussed.

Hepatitis B core-related antigen reflects viral replication and protein production in chronic hepatitis B patients

BACKGROUND

Hepatitis B core-related antigen (HBcrAg) is a promising disease-monitoring marker for chronic hepatitis B (CHB). We investigated correlations between HBcrAg with antiviral efficacy and virological and histological variables.

METHODS

One hundred and forty-five CHB patients from the mainland of China between August 2013 and September 2016 who underwent liver biopsy received entecavir therapy and had paired liver biopsy at 78 weeks. We analyzed correlations between HBcrAg and virological and histological variables in hepatitis B e antigen (HBeAg)-positive and HBeAg-negative patients. We also explored the predictors of HBeAg loss after 78 weeks of antiviral therapy. Pearson correlation analysis and logistic forward stepwise regression were the main statistic methods.

RESULTS

HBeAg-positive patients (n = 93) had higher baseline HBcrAg (median 7.4 vs. 5.3 log10 U/mL P < 0.001) and greater HBcrAg declines (median 1.6 vs. 0.9 log10 U/mL P = 0.007) than HBeAg-negative patients after 78 weeks of therapy. At baseline, HBcrAg correlated with hepatitis B virus (HBV) DNA in both HBeAg-positive (r = 0.641, P < 0.001) and -negative patients (r = 0.616, P < 0.001), with hepatitis B surface antigen (HBsAg) in HBeAg-positive patients (r = 0.495, P < 0.001), but not with anti-hepatitis B virus core antibody (anti-HBc). Weak correlations existed between HBcrAg, histology activity index (HAI; r = 0.232, P = 0.025), and Ishak fibrosis score (r = -0.292, P = 0.005) in HBeAg-positive patients. At 78 weeks, significant correlations existed only between HBcrAg and anti-HBc in HBeAg-positive (r = -0.263, P = 0.014) and HBeAg-negative patients (r = -0.291, P = 0.045). Decreased HBcrAg significantly correlated with reduced HBV DNA (r = 0.366, P = 0.001; r = 0.626, P < 0.001) and HBsAg (r = 0.526, P = 0.001; r = 0.289, P = 0.044) in HBeAg-positive and -negative patients, respectively, and with reduced HAI in HBeAg-positive patients (r = 0.329, P = 0.001). Patients with HBeAg loss (n = 29) showed a larger reduction in HBcrAg than those without (median 2.3 vs. 1.3 log10 U/mL, P = 0.001). In multivariate analysis, decreased HBcrAg was an independent predictor of HBeAg loss (P = 0.005).

CONCLUSIONS

HBcrAg reflects viral replication and protein production. Decreased HBcrAg could predict HBeAg loss after antiviral therapy.

TRIAL REGISTRATION

Clinical Trials.gov: NCT01962155; https://www.clinicaltrials.gov/ct2/show/NCT01962155?term=NCT01962155&draw=2&rank=1.

Total Antioxidant Capacity in HBV Carriers, a Promising Biomarker for Evaluating Hepatic Fibrosis: A Pilot Study

Oxidative stress plays a pivotal role in the progression of chronic hepatitis B; however, it is unclear whether the status of blood oxidative stress and antioxidant components differs depending on the degree of hepatic fibrosis. To explore the relationship between oxidative stress/antioxidant capacity and the extent of hepatic fibrosis, fifty-four subjects with liver fibrosis (5.5 ≤ liver stiffness measurement (LSM) score ≤ 16.0 kPa) by chronic hepatitis B virus (HBV) were analyzed. From the analysis of eight kinds of serum oxidative stress/antioxidant profiles and liver fibrosis degrees, the level of total antioxidant capacity (TAC) reflected a negative correlation with the severity of hepatic fibrosis (Pearson correlation, r = −0.35, p = 0.01). Moreover, TAC showed higher sensitivity (73.91%) than the aspartate transaminase (AST) to platelet ratio index (APRI, 56.52%) in the receiver operating characteristic (ROC) curves. Interestingly, the TAC level finely reflected the fibrosis degree in inactive carriers (HBV DNA < 2000 IU/mL), while the APRI did in active carriers (HBV DNA > 2000 IU/mL). In conclusion, TAC is a promising biomarker for evaluating the progression of liver fibrosis in patients with HBV, and this finding may indicate the involvement of TAC-composing factors in the pathogenesis of hepatic fibrosis in chronic HBV carriers.

Novel biomarkers for the management of chronic hepatitis B

Hepatitis B virus (HBV) cannot be eliminated completely from infected hepatocytes because of the presence of intrahepatic covalently closed circular DNA (cccDNA). As chronic hepatitis B (CHB) can progress to cirrhosis and hepatocellular carcinoma (HCC), it is important to manage CHB to prevent HCC development in high-risk patients with high viral replicative activity or advanced fibrosis. Serum biomarkers are noninvasive and valuable for the management of CHB. Hepatitis B core-related antigen (HBcrAg) correlates with serum HBV DNA and intrahepatic cccDNA. In CHB patients with undetectable serum HBV DNA or loss of HBsAg, HBcrAg still can be detected and the decrease in HBcrAg levels is significantly associated with hopeful outcomes. Therefore, HBcrAg can predict HCC occurrence or recurrence. Measurement of the Mac-2 binding protein glycosylation isomer (M2BPGi) has been introduced for the evaluation of liver fibrosis. Because elevated M2BPGi in CHB is related to liver fibrosis and the prediction of HCC development, monitoring its progression is essential. Because alpha fetoprotein (AFP) has insufficient sensitivity and specificity for early-stage HCC, a combination of AFP plus protein induced by vitamin K absence factor II, or AFP plus Lens culinaris agglutinin-reactive fraction of alpha-fetoprotein might improve the diagnosis of HCC development. Additionally, Dickkopf-1 and circulating immunoglobulin G antibodies are the novel markers to diagnose HCC or assess HCC prognosis. This review provides an overview of novel HBV biomarkers used for the management of intrahepatic viral replicative activity, liver fibrosis, and HCC development.

Novel Biomarkers of Hepatitis B and Hepatocellular Carcinoma: Clinical Significance of HBcrAg and M2BPGi

The hepatitis B virus (HBV) cannot be removed completely from infected hepatocytes, owing to the presence of intrahepatic covalently closed circular DNA (cccDNA). As chronic hepatitis B (CHB) can progress to cirrhosis and hepatocellular carcinoma (HCC), predicting HCC development in high-risk patients with high viral replicative activity or advanced fibrosis is important. Novel serological biomarkers reflect intrahepatic viral replicative activity or the progression of liver fibrosis, indicating non-invasive alternatives to liver biopsy: (1) Hepatitis B core-related antigen (HBcrAg) correlates with serum HBV DNA and intrahepatic cccDNA. In CHB patients, a decrease in HBcrAg is associated with favorable outcomes. HBcrAg can predict HCC occurrence or recurrence. (2) Measurement of the Mac-2 binding protein glycosylation isomer (M2BPGi) has been introduced for the evaluation of liver fibrosis. An increase in M2BPGi in CHB patients is related to the progression of liver fibrosis and high potential (risk) of HCC development. Here, we describe the clinical applications of HBcrAg and M2BPGi in CHB patients. Additionally, because new potential therapeutic agents that eliminate intrahepatic cccDNA are being developed, monitoring of HBcrAg or M2BPGi might be suitable for evaluating therapeutic effects and the clinical outcomes. In conclusion, these would be appropriate surrogate markers for predicting disease progression.

Novel Biomarkers of Hepatitis B and Hepatocellular Carcinoma: Clinical Significance of HBcrAg and M2BPGi

The hepatitis B virus (HBV) cannot be removed completely from infected hepatocytes, owing to the presence of intrahepatic covalently closed circular DNA (cccDNA). As chronic hepatitis B (CHB) can progress to cirrhosis and hepatocellular carcinoma (HCC), predicting HCC development in high-risk patients with high viral replicative activity or advanced fibrosis is important. Novel serological biomarkers reflect intrahepatic viral replicative activity or the progression of liver fibrosis, indicating non-invasive alternatives to liver biopsy: (1) Hepatitis B core-related antigen (HBcrAg) correlates with serum HBV DNA and intrahepatic cccDNA. In CHB patients, a decrease in HBcrAg is associated with favorable outcomes. HBcrAg can predict HCC occurrence or recurrence. (2) Measurement of the Mac-2 binding protein glycosylation isomer (M2BPGi) has been introduced for the evaluation of liver fibrosis. An increase in M2BPGi in CHB patients is related to the progression of liver fibrosis and high potential (risk) of HCC development. Here, we describe the clinical applications of HBcrAg and M2BPGi in CHB patients. Additionally, because new potential therapeutic agents that eliminate intrahepatic cccDNA are being developed, monitoring of HBcrAg or M2BPGi might be suitable for evaluating therapeutic effects and the clinical outcomes. In conclusion, these would be appropriate surrogate markers for predicting disease progression.