Hepatitis B surface antigen quantification: why and how to use it in 2011 - a core group report

Latest insights into the epidemiology, characteristics, and therapeutic strategies of chronic hepatitis B patients in indeterminate phase

As a hepatotropic virus, hepatitis B virus (HBV) can establish a persistent chronic infection in the liver, termed, chronic hepatitis B (CHB), which causes a series of liver-related complications, including fibrosis, cirrhosis, and hepatocellular carcinoma (HCC). HCC with HBV infection has a significantly increased morbidity and mortality, whereas it could be preventable. The current goal of antiviral therapy for HBV infection is to decrease CHB-related morbidity and mortality, and achieve sustained suppression of virus replication, which is known as a functional or immunological cure. The natural history of chronic HBV infection includes four immune phases: the immune-tolerant phase, immune-active phase, inactive phase, and reactivation phase. However, many CHB patients do not fit into any of these defined phases and are regarded as indeterminate. A large proportion of indeterminate patients are only treated with dynamic monitoring rather than recommended antiviral therapy, mainly due to the lack of definite guidelines. However, many of these patients may gradually have significant liver histopathological changes during disease progression. Recent studies have focused on the prevalence, progression, and carcinogenicity of indeterminate CHB, and more attention has been given to the prevention, detection, and treatment for these patients. Herein, we discuss the latest understanding of the epidemiology, clinical characteristics, and therapeutic strategies of indeterminate CHB, to provide avenues for the management of these patients.

Clinical outcome after cessation of nucleos(t)ide analog treatment in chronic hepatitis B patients who achieved HBsAg seroclearance

BACKGROUND

We determined the long-term clinical outcome and the durability of treatment cessation after HBsAg seroclearance following nucleos(t)ide analog (NA) therapy in patients with chronic hepatitis B (CHB).

METHODS

We analyzed virological relapse (VR), HBsAg reversion, clinical relapse, and changes in HBsAg and HBcrAg levels by iTACT assay after treatment cessation of 90 CHB patients who achieved HBsAg seroclearance by NA treatment.

RESULTS

Median age of patients at treatment cessation was 57 years. Median duration of NA treatment and follow-up from cessation of NA were 9.25 and 5.2 years, respectively. Although VR occurred in 19 of 90 (21.1%) patients, HBV DNA levels of 18 patients had temporal elevations and sustained levels under the detection level thereafter. HBsAg reversion using Architect HBsAg QT assay occurred in six patients (6.7%) after cessation of NA. Five patients had temporal HBsAg level elevations and sustained levels under the detection level thereafter. One patient had virological and clinical relapse at 6 months after cessation of NA, and received NA re-treatment. HBsAg levels by iTACT assay from end of treatment (EOT) gradually decreased and in 18 of 28 (64%) patients reached an undetectable level at 5 years after EOT. In contrast, HBcrAg levels by iTACT assay slowly decreased, and in 8 of 29 patients (28%) reached an undetectable level at 5 years after EOT.

CONCLUSIONS

Patients receiving NA treatment who achieved HBsAg seroclearance as determined by HBsAg QT assay rarely experienced virological or clinical relapse after the cessation of treatment.

Advances in Cancer Vaccine Research

The use of cancer vaccines is considered a promising therapeutic strategy in clinical oncology, which is achieved by stimulating antitumor immunity with tumor antigens delivered in the form of cells, peptides, viruses, and nucleic acids. The ideal cancer vaccine has many advantages, including low toxicity, specificity, and induction of persistent immune memory to overcome tumor heterogeneity and reverse the immunosuppressive microenvironment. Many therapeutic vaccines have entered clinical trials for a variety of cancers, including melanoma, breast cancer, lung cancer, and others. However, many challenges, including single antigen targeting, weak immunogenicity, off-target effects, and impaired immune response, have hindered their broad clinical translation. In this review, we introduce the principle of action, components (including antigens and adjuvants), and classification (according to applicable objects and preparation methods) of cancer vaccines, summarize the delivery methods of cancer vaccines, and review the clinical and theoretical research progress of cancer vaccines. We also present new insights into cancer vaccine technologies, platforms, and applications as well as an understanding of potential next-generation preventive and therapeutic vaccine technologies, providing a broader perspective for future vaccine design.

Large spontaneous HBV DNA fluctuations and potential usefulness of a single-point measurement of combined HBV DNA and quantitative HBsAg for the exclusion of HBeAg-negative chronic hepatitis B: A prospective Tunisian cohort study

BACKGROUND AND STUDY AIM

During the natural course of HBeAg-negative chronic hepatitis B (CHB), fluctuations in hepatitis B virus (HBV) DNA and alanine aminotransferase (ALT) levels are often observed, making the classification of patients difficult. We aimed to describe spontaneous short-term HBV DNA level fluctuations and to assess the usefulness of qHBsAg in Tunisian patients with HBeAg-negative chronic HBV infection.

PATIENTS AND METHODS

We included 174 treatment-naive Tunisian patients with HBeAg-negative chronic HBeAg-negative HBV infection. A prospective 1-year follow-up was conducted with serial determinations of HBV DNA, ALT levels, and qHBsAg. The patients were classified into three groups: inactive carriers (G1), patients with negative HBeAg CHB (G2), and patients with an "indeterminate state" (G3). For the latter group, a liver biopsy was indicated.

RESULTS

Only genotype D was detected. During follow-up, 21.6% and 19.5% of patients with a low initial (<2,000 IU/ml) and intermediate viral load (2,000-20,000 IU/ml) experienced a subsequent increase in their HBV DNA levels above 2,000 and 20,000 IU/ml, respectively. Significant variations in viral load were observed in 61.1% of patients at 6-month intervals. Among the 174 patients, 89 (51.1%) belonged to G1, 33 (19%) to G2, and 52 (29.9%) to G3. Fourteen patients have undergone a liver biopsy, of whom seven showed moderate to severe liver disease. Combination of HBV DNA < 2,000 IU/ml and qHBsAg < 832 IU/ml excluded CHB in 98.4% of cases. A cutoff point for qHBsAg < 100 IU/ml associated with an annual decline of > 0.5 log 10 IU/ml is a good predictor marker of functional cure for hepatitis B.

CONCLUSIONS

This study highlights the large short-term fluctuations in HBV DNA in patients with HBeAg-negative chronic HBeAg-negative HBV infection with genotype D. Thus, using the cutoff value of 832 for qHBsAg combined with that of 2,000 for HBV DNA makes it possible to exclude CHB for most patients.

A role for immune modulation in achieving functional cure for chronic hepatitis B among current changes in the landscape of new treatments

INTRODUCTION

Chronic hepatitis B (CHB) is rarely cured using available treatments. Barriers to cure are: 1) persistence of reservoirs of hepatitis B virus (HBV) replication and antigen production (HBV DNA); 2) high burden of viral antigens that promote T cell exhaustion with T cell dysfunction; 3) CHB-induced impairment of immune responses.

AREAS COVERED

We discuss options for new therapies that could address one or more of the barriers to functional cure, with particular emphasis on the potential role of immunotherapy.

EXPERT OPINION/COMMENTARY

Ideally, a sterilizing cure for CHB would translate into finite therapies that result in loss of HBV surface antigen and eradication of HBV DNA. Restoration of a functional adaptive immune response, a key facet of successful CHB treatment, remains elusive. Numerous strategies targeting the high viral DNA and antigen burden and aiming to restore the host immune responses will enter clinical development in coming years. Most patients are likely to require combinations of several drugs, personalized according to virologic and disease characteristics, patient preference, accessibility, and affordability. The management of CHB is a global health priority. Expedited drug development requires collaborations between regulatory agencies, scientists, clinicians, and within the industry to facilitate testing of the best drug combinations.

Exploring FeLV-Gag-Based VLPs as a New Vaccine Platform-Analysis of Production and Immunogenicity

Feline leukemia virus (FeLV) is one of the most prevalent infectious diseases in domestic cats. Although different commercial vaccines are available, none of them provides full protection. Thus, efforts to design a more efficient vaccine are needed. Our group has successfully engineered HIV-1 Gag-based VLPs that induce a potent and functional immune response against the HIV-1 transmembrane protein gp41. Here, we propose to use this concept to generate FeLV-Gag-based VLPs as a novel vaccine strategy against this retrovirus. By analogy to our HIV-1 platform, a fragment of the FeLV transmembrane p15E protein was exposed on FeLV-Gag-based VLPs. After optimization of Gag sequences, the immunogenicity of the selected candidates was evaluated in C57BL/6 and BALB/c mice, showing strong cellular and humoral responses to Gag but failing to generate anti-p15E antibodies. Altogether, this study not only tests the versatility of the enveloped VLP-based vaccine platform but also sheds light on FeLV vaccine research.

Accuracy Validation of the Elecsys HBsAg II Quant Assay and Its Utility in Resolving Equivocal Qualitative HBsAg Results

Background and Objectives: There are reports of false qualitative HBsAg results, because of various causes, such as samples with low HBsAg concentrations that may produce false positives. The main aims of this study were to validate the analytical accuracy and to assess the utility of the Elecsys assay compared to that of the qualitative HbsAg assay as a screening test in resolving equivocal qualitative HbsAg results. Materials and Methods: The limit of blank (LoB), the limit of detection (LoD), the limit of quantification (LoQ), and linearity were estimated to validate the analytical accuracy of the Elecsys HBsAg II Quant assay. A total of 449 serum samples showing initial equivocal results (1–50 index) were evaluated by Elecsys HBsAg II Quant and ADVIA Centaur HBsAg II assays. Results: The LoQ of the assay was determined to be 0.050 IU/mL, as provided by the manufacturer. The Kappa agreement between the two assays was almost perfect, at 0.9669, despite seven discordant results. With a specificity of 100% at new cut-off index value ≥5.42, about 78 samples (17%, 78/449) with index value ≥5.42 were interpreted as positives without further duplicate tests, however the remaining 371 samples with index value <5.42 need to be confirmed with additional HBV marker assays. Conclusions: We confirm that the Elecsys HBsAg II Quant assay is accurate and sensitive for HBV infection and recommend it as an alternative confirmatory HBsAg assay for resolving equivocal qualitative HBsAg results.

Short-Term Peg-IFN α-2b Re-Treatment Induced a High Functional Cure Rate in Patients with HBsAg Recurrence after Stopping Peg-IFN α-Based Regimens

Little is known about the treatment of patients with hepatitis B surface antigen (HBsAg) recurrence after being clinically cured by peginterferon alpha(peg-IFN-α)-based regimens. This study aimed to investigate the efficacy and safety of peg-IFNα-2b in re-treating patients with HBsAg recurrence after stopping peg-IFN α-based regimens. In this two-center, prospective observational study, 33 patients with HBsAg recurrence after stopping peg-IFN α-based regimens were enrolled and re-treated with an individualized course of peg-IFN α-2b. The hepatitis B virus (HBV) vaccine could be injected immediately after HBsAg clearance, according to patients’ willingness. All patients were monitored and followed-up for 48 weeks after peg-IFN α-2b re-treatment stop. The primary endpoint was HBsAg clearance at the end of follow-up. At baseline, all patients had HBsAg levels of <10 IU/mL and undetectable HBV DNA, with the median HBsAg level of 1.66 (0.56−2.87) IU/mL. After a median of 24 (24−30) weeks of peg-IFN α-2b re-treatment, 87.9% (29/33) of the patients achieved HBsAg clearance again and 66.7% (22/33) of the patients achieved HBsAg seroconversion. At the end of follow-up, the HBsAg clearance and HBsAg seroconversion rates decreased to 78.8% (26/33) and 51.5% (17/33), respectively. Furthermore, 88.9% (16/18) of the patients with HBsAg clearance benefited from receiving the HBV vaccine therapy. Generally, both peg-IFN α-2b and HBV vaccine therapy were well tolerated. A high functional cure rate can be achieved by a short-course of peg-IFN α-2b re-treatment in patients with HBsAg recurrence after stopping peg-IFN α-based regimens. Furthermore, injecting HBV vaccine is beneficial after HBsAg clearance.

Can G-quadruplex become a promising target in HBV therapy?

The chronic infection with hepatitis B virus (HBV) is an important health problem that affects millions of people worldwide. Current therapies for HBV always suffer from a poor response rate, common side effects, and the need for lifelong treatment. Novel therapeutic targets are expected. Interestingly, non-canonical structures of nucleic acids play crucial roles in the regulation of gene expression. Especially the formation of G-quadruplexes (G4s) in G-rich strands has been demonstrated to affect many bioprocesses including replication, transcription, and translation, showing great potential as targets in anticancer and antiviral therapies. In this review, we summarize recent antiviral studies about G4s and discuss the potential roles of G4 structures in antiviral therapy for HBV.

An improved method for rapid identification of hook effect samples in HBsAg quantitative assay

Quantitative hepatitis B surface antigen assay is widely used for diagnosis of hepatitis B virus infection; however, specimens with high levels of the antigen can cause false-negative results (Hook effect), which needs to be resolved. The hook effect samples and non-hook effect samples were detected on the LiCA® 500 instrument using three methods, viz., 1, 2, and 3. Method 1, the currently used procedure, was performed in two steps with a total reaction time of 25 min in a final volume of 250 µL: first incubation was with two reagents for 15 min and then with one other reagent for 10 min. In Method 2, all three reagents were added in one step with a final volume of 250 µL, and the total reaction time was still 25 min. In Method 3, the improved method, all three reagents were added in one step while the final volume was only 130 µL and the total reaction time was only 1 min. Signal values of the non-hook effect samples obtained using Method 2 were significantly lower than those with Method 1, showing competitive inhibition. The hook effect samples tested with Method 2 approximated those obtained using Method 1. Method 3 took 1 min and differentiated hook effect samples successfully, similar to the results with Method 2 which took 25 min. Changing the timing of one reagent addition and incubation time in Method 3 provided a rapid and effective method for the identification of hook effect. The results were more clearly distinguishable due to the phenomenon of competitive inhibition. Method 3 can be considered an improvement on the chemiluminescence platform.

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.

Correlation between Results of Semi-Quantitative and Quantitative Tests for Hepatitis B Virus Surface Antigen among Patients Achieving Viral Suppression with Antiviral Treatment

Background: Hepatitis B virus (HBV) infection remains a threat to global public health. Serum hepatitis B surface antigen (HBsAg) has been used in screening for HBV infection. Quantitative HBsAg assays are useful for monitoring the natural history of HBV infection and its response to therapy. The aim of this study was to determine the relationship between quantitative (qHBsAg; IU/mL) and semi-quantitative (sqHBsAg; signal-to-cutoff ratio [S/Co]) HBsAg titers in patients with chronic hepatitis B (CHB). Methods: We retrospectively included 284 samples with HBV DNA < 20 IU/mL from patients who had simultaneous qHBsAg (using electrochemiluminescence assay) and sqHBsAg tests. Patients were grouped according to their serum HBV-envelope antigen (HBeAg) status (HBeAg-negative, n = 239 and HBeAg-positive, n = 45). The Spearman test was used to analyze the correlation between the quantitative and semi-quantitative assays. Results: There was a significant linear correlation between sqHBsAg and qHBsAg in the HBeAg-negative patients (qHBsAg [IU/mL] = 0.0094 × sqHBsAg [S/Co]1.323; adjusted R2 = 0.8445; p < 0.001). There was a substantial hook effect in the assays from the HBeAg-positive patients, so we performed a stratified analysis according to qHBsAg <1000 IU/mL or ≥1000 IU/mL and found a significant positive linear correlation between sqHBsAg S/Co and qHBsAg (qHBsAg [IU/mL] = 0.072 × sqHBsAg [S/Co]1.331; adjusted R2 = 0.7878; p < 0.001) in HBeAg-positive patients with qHBsAg titers of <1000 IU/mL and a significant negative correlation in HBeAg-positive patients with qHBsAg titers of ≥1000 IU/mL (qHBsAg [IU/mL] = 8.987 × 1014 × sqHBsAg [S/Co]−3.175; adjusted R2 = 0.6350; p < 0.001). Conclusions: There was a highly linear, positive correlation between qHBsAg and sqHBsAg in HBeAg-negative CHB patients. The hook effect led to a negative correlation in HBeAg-positive CHB patients with qHBsAg titers ≥1000 IU/mL.

Virological Treatment Monitoring for Chronic Hepatitis B

More than 250 million people worldwide are currently infected with hepatitis B, despite the effectiveness of vaccination and other preventive measures. In terms of treatment, new therapeutic approaches are rapidly developing, promising to achieve the elimination of infected cells and the complete cure of infection. The on-treatment monitoring of these innovative antiviral treatments will require the implementation of new virological tools. Therefore, new biomarkers are being evaluated besides the traditional virological and serological assays in order to obtain information on different steps of the viral replication cycle and to monitor response to therapy more accurately. The purpose of this work is to describe both standard and innovative tools for chronic hepatitis B treatment monitoring, and to analyse their potential and feasibility.

Comparison of the Effect of Entecavir and Tenofovir on Serum HBsAg Levels in Chronic HBe-Negative Hepatitis B Patients

Background: The quantification of hepatitis B surface antigen (qHBsAg) was proposed as a helpful tool to monitor treatment efficacy with nucleos(t)ide analogs (NA) in HB e antigen-negative chronic HB. Objectives: The present study aimed to assess the effect of entecavir (ETV) and tenofovir dipivoxil (TDF) on qHBsAg kinetics and estimate the time necessary to achieve HBsAg clearance with each of these drugs. Methods: The study was conducted on 93 patients, 54 and 39 of whom were treated with ETV and TDF for a median time of 42 months, respectively. The qHBsAg was measured in 6-month intervals with the Elecsys HBsAg II Quantitative assay. The estimated time to undetectable HBsAg was calculated using the best-fitted curve analysis. Results: There was a significant decrease in qHBsAg titers in 79 (84.9%) patients with no difference between ETV and TDF groups (P = 0.754). The median quantitative HBsAg drop was 2003 IU/mL (interquartile range: 638.1 - 5010). The HBsAg levels decreased by 40.3 ± 25.9% on average. The expected time required for HBsAg clearance was comparable in both groups, equaling 104 and 114 months for TDF and ETV, respectively. Conclusions: The HBsAg clearance can be achieved in a substantial proportion of patients after additional 5 years of treatment with NA. The potency of TDF and ETV in qHBsAg reduction is similar.

Molecular investigation of occult hepatitis B virus infection in a reference center in Northern Brazil

The goal of this study was to investigate the prevalence of occult HBV infection in a reference center for the Northern Brazil from 2005 to 2015 and to identify mutations associated with occult hepatitis B. Molecular analysis was performed on 110 serum samples in which anti-HBc was the only positive serological marker. Regions of the HBV genome were amplified by polymerase chain reaction to detect HBV DNA. A prevalence of 4.1% (793/18,889) for anti-HBc alone was identified. Molecular analysis revealed a prevalence of occult HBV infection of 0.04%. HBV DNA detected were identified in individuals who underwent hemodialysis, infected with the hepatitis C virus and from area of high endemicity for HBV. Direct DNA nucleotide sequencing and phylogenetic analysis identified that genotypes A and D and mutations E164D, I195M, P217L and P120S were associated with occult HBV infection in the S gene. This study contributed with epidemiological and molecular information on Northern Brazil samples with a suggestive profile of occult HBV infection in addition to reinforcing the importance of molecular diagnosis in this type of infection.

PAGE-B and REACH-B Predicts the Risk of Developing Hepatocellular Carcinoma in Chronic Hepatitis B Patients from Northeast, Brazil

This study aims to evaluate the accuracy of the PAGE-B and REACH-B scores in predicting the risk of developing HCC in patients with chronic hepatitis B regularly followed up at a reference service in the State of Maranhão. A historical, longitudinal, retrospective cohort study, carried out from the review of medical records of patients with chronic Hepatitis B. PAGE-B and REACH-B scores were calculated and the accuracy of the scores in predicting the risk of HCC in the studied population was evaluated. A total of 978 patients were included, with a median age of around 47 years, most of them female and not cirrhotic. HCC was identified in 34 patients. Thrombocytopenia, high viral load, male gender and age were associated with the occurrence of HCC. The ROC curve for the PAGE-B score showed a value of 0.78 and for the REACH-B score of 0.79. The cutoff point for PAGE-B was 11 points for greater sensitivity and for REACH-B 7.5 points considering greater sensitivity and 9.5 points considering greater specificity. PAGE-B and REACH-B scores were able to predict the risk of developing HCC in the studied population. The use of risk stratification scores is useful to reduce costs associated with HCC screening.

Kinetics of hepatitis B surface antigen in pregnant women with and without tenofovir disoproxil fumarate

Tenofovir disoproxil fumarate (TDF) is the preferred treatment to prevent mother-to-infant transmission in highly viremic HBV-infected women. Data on hepatitis B surface antigen (HBsAg) levels in pregnant women are lacking. We aimed to investigate prepartum and postpartum HBsAg kinetics and its correlation with HBV DNA in pregnant women. HBV-infected mothers with HBV DNA ≥7.5 log₁₀  IU/ml were tested for HBsAg and HBV DNA from baseline to 6 months postpartum. Of the 186 pregnant women with comparable baseline HBsAg and HBV DNA, 101 received TDF from the third trimester until 1 month postpartum. At delivery, TDF group had mildly lower HBsAg (4.32 ± 0.47 vs. 4.54 ± 0.35 log₁₀  IU/ml, p = .0004) and markedly lower HBV DNA (4.26 ± 0.97 vs. 8.11 ± 0.70 log₁₀  IU/ml, p < .0001) than the control group. In the TDF group, mean reduction of HBsAg and HBV DNA from baseline to delivery were 0.22 ± 0.38 and 3.96 ± 0.93 log₁₀  IU/ml. HBsAg reduction had a positive correlation (r = .309; p = .0017) with HBV DNA reduction, and was predictive of HBV DNA reduction ≥3 log₁₀  IU/ml (area under the receiver operating characteristic curve, 0.67; 95% confidence interval, 0.50-0.82). At 6 months postpartum, TDF and control group had comparable HBsAg and HBV DNA. In conclusion, HBsAg decreased slightly at delivery in pregnant women receiving TDF. For monitoring the effect of antiviral therapy during pregnancy, HBV DNA is a better marker than HBsAg. Our data provided valuable information regarding monitoring HBV-infected pregnant women using antiviral therapy.

O-glycosylated HBsAg peptide can induce specific antibody neutralizing HBV infection

BACKGROUND

Hepatitis B virus (HBV), which causes hepatitis, liver cirrhosis, and hepatocellular carcinoma, is a global human health problem. HBV contains three envelope proteins, S-, M-, and L-hepatitis B surface antigen (HBsAg). We recently found that O-glycosylated M-HBsAg, reactive with jacalin lectin, is one of the primary components of HBV DNA-containing virus particles. Thus, we aimed to analyze and target the glycosylation of HBsAg.

METHODS

HBsAg prepared from the serum of Japanese patients with HBV were analyzed using mass spectrometry. The glycopeptide modified with O-glycan was generated and used for immunization. The specificity of the generated antibody and the HBV infection inhibition activity was examined.

RESULTS

Mass spectrometry analysis revealed that T37 and/or T38 on M-HBsAg of genotype C were modulated by ±NeuAc(α2,3)Gal(β1,3)GalNAc. Chemically and enzymatically synthesized O-glycosylated peptide (Glyco-PS2) induced antibodies that recognize mainly PreS2 in M-HBsAg not in L-HBsAg, whereas the non-glycosylated peptide (PS2) induced antisera recognizing L-HBsAg but not O-glycosylated M-HBsAg. The removal of O-glycan from M-HBsAg partly decreased the reactivity of the Glyco-PS2 antibody, suggesting that peptide part was also recognized by the antibody. The antibody further demonstrated the inhibition of HBV infection in human hepatic cells in vitro.

CONCLUSIONS

Glycosylation of HBsAg occurs differently in different HBsAgs in a site-specific manner. The new Glyco-PS2 antibody, recognizing O-glycosylated M-HBsAg of genotype C, could inhibit HBV infection.

GENERAL SIGNIFICANCE

The detailed analysis of HBsAg identified different glycosylations of HBV surface. The glycosylated peptide based on mass spectrometry analysis showed higher potential to induce functional antibody against HBV.

Overt Acute Hepatitis B Deteriorates in Females: Destructive Immunity With an Exaggerated Interleukin-17 Pathway

Background and Aims

We previously showed that overt acute hepatitis B (AHB) was more severe in female patients. Using the same cohort and AHB mouse model, we examined the underlying mechanism.

Methods

Baseline biochemistry, virological and cytokine assays, and T helper (Th)1 and Th2 immune markers of 118 consecutive patients were analyzed. The decompensated livers of AHB and chronic hepatitis B (CHB) patients who underwent liver transplantation were analyzed immunohistochemically. B6 mice were hydrodynamically injected with pHBV1.3 plasmids.

Results

Decompensated AHB patients (n=41) were older, more often female, and had higher alanine aminotransferase (ALT), soluble programmed cell death protein 1 (sPD-1) levels, and neutrophil-lymphocyte ratios but lower rates of HBeAg positivity and quantitative HBsAg, interferon (IFN)-γ-inducible protein 10 (IP-10), IFN-γ, and interleukin-4 (IL-4) levels than the compensated patients. Female sex (95% CI OR=1.07~54.9), age (1.06~1.40), and ALT levels (1.001~1.004) were associated with hepatic decompensation. Higher sPD-1 but lower IFN-γ and IL-4 levels were observed in female patients. Compared to CHB, decompensated AHB livers had more IL-17-positive cells but fewer HBsAg-positive cells and lower CD4/CD8 ratios. Higher serum IL-17 levels were noted in the female AHB mice than those in the males.

Conclusions

Females predominated in decompensated AHB, in which downregulated IFN-γ and IL-4 with augmented hepatic IL-17-positive cell development indicated accelerating destructive immunity to enhance viral clearance. The early surge of serum IL-17 was confirmed in the female AHB mice. Targeting the pathway involving IFN-γ, IL-4, and IL-17 might prevent liver transplantation or fatality in decompensated AHB.

Silicon Nanowire Field-Effect Transistor as Label-Free Detection of Hepatitis B Virus Proteins with Opposite Net Charges

The prevalence of hepatitis B virus (HBV) is a global healthcare threat, particularly chronic hepatitis B (CHB) that might lead to hepatocellular carcinoma (HCC) should not be neglected. Although many types of HBV diagnosis detection methods are available, some technical challenges, such as the high cost or lack of practical feasibility, need to be overcome. In this study, the polycrystalline silicon nanowire field-effect transistors (pSiNWFETs) were fabricated through commercial process technology and then chemically functionalized for sensing hepatitis B virus surface antigen (HBsAg) and hepatitis B virus X protein (HBx) at the femto-molar level. These two proteins have been suggested to be related to the HCC development, while the former is also the hallmark for HBV diagnosis, and the latter is an RNA-binding protein. Interestingly, these two proteins carried opposite net charges, which could serve as complementary candidates for evaluating the charge-based sensing mechanism in the pSiNWFET. The measurements on the threshold voltage shifts of pSiNWFETs showed a consistent correspondence to the polarity of the charges on the proteins studied. We believe that this report can pave the way towards developing an approachable tool for biomedical applications.

JNJ-64794964 (AL-034/TQ-A3334), a TLR7 agonist, induces sustained anti-HBV activity in AAV/HBV mice via non-cytolytic mechanisms

JNJ-64794964 (JNJ-4964/AL-034/TQ-A3334), an oral toll-like receptor 7 agonist, is being investigated for the treatment of chronic hepatitis B (CHB), a condition with a high unmet medical need. The anti-hepatitis B (HBV) activity of JNJ-4964 was assessed preclinically in an adeno-associated virus vector expressing HBV (AAV/HBV) mouse model. Mice were treated orally with 2, 6 or 20 mg/kg of JNJ-4964 once-per-week for 12 weeks and then followed up for 4 weeks. At 6 mg/kg, a partial decrease in plasma HBV-DNA and plasma hepatitis B surface antigen (HBsAg) was observed, and anti-HBs antibodies and HBsAg-specific T cells were observed in 1/8 animals. At 20 mg/kg, plasma HBV-DNA and HBsAg levels were undetectable for all animals 3 weeks after start of treatment, with no rebound observed 4 weeks after JNJ-4964 treatment was stopped. High anti-HBs antibody levels were observed until 4 weeks after JNJ-4964 treatment was stopped. In parallel, HBsAg-specific immunoglobulin G-producing B cells and interferon-γ-producing CD4⁺ T cells were detected in the spleen. In 2/4 animals, liver HBV-DNA and HBV-RNA levels and liver hepatitis B core antigen expression dropped 4 weeks after JNJ-4964 treatment-stop. In these animals, HBsAg-specific CD8⁺ T cells were detectable. Throughout the study, normal levels of alanine aminotransferase were observed, with no hepatocyte cell death (end of treatment and 4 weeks later) and minimal infiltrations of B and T cells into the liver, suggesting induction of cytokine-mediated, non-cytolytic mechanisms.

Safety, tolerability, pharmacokinetics, and pharmacodynamics of oral JNJ-64794964, a TLR-7 agonist, in healthy adults

Background

This Phase I, two-part, first-in-human study assessed safety/tolerability and pharmacokinetics/pharmacodynamics of single-ascending doses (SAD) and multiple doses (MD) of the oral toll-like receptor-7 agonist, JNJ-64794964 (JNJ-4964) in healthy adults.

Methods

In the SAD phase, participants received JNJ-4964 0.2 ( N = 6), 0.6 ( N = 6), 1.25 ( N = 8) or 1.8 mg ( N = 6) or placebo ( N = 2/dose cohort) in a fasted state. Food effect was evaluated for the 1.25 mg cohort following ≥6 weeks washout. In the MD phase, participants received JNJ-4964 1.25 mg ( N = 6) or placebo ( N = 2) weekly (fasted) for 4 weeks. Participants were followed-up for 4 weeks.

Results

No serious adverse events (AEs) occurred. 10/34 (SAD) and 5/8 (MD) participants reported mild-to-moderate (≤Grade 2), transient, reversible AEs possibly related to JNJ-4964. Five (SAD) participants had fever/flu-like AEs, coinciding with interferon-α serum levels ≥100 pg/mL and lymphopenia (<1 × 109/L), between 24–48 h after dosing and resolving approximately 96 h after dosing. One participant (MD) had an asymptomatic Grade 1 AE of retinal exudates (cotton wool spots) during follow-up, resolving 6 weeks after observation. JNJ-4964 exhibited dose-proportional pharmacokinetics, with rapid absorption (tmax 0.5–0.75 h) and distribution, and a long terminal half-life (150–591 h). Overall, no significant differences in JNJ-4964 pharmacokinetic parameters were observed in the fed versus fasted state. JNJ-4964 dose-dependently and transiently induced cytokines with potential anti-HBV activity, including interferon-α, IP-10, IL-1 RA, and/or MCP-1, and interferon-stimulated genes (ISG15, MX1, and OAS1) in serum.

Conclusions

In healthy adults, JNJ-4964 was generally well-tolerated, exhibited dose-proportional pharmacokinetics and induced cytokines/ISGs, with possible anti-HBV activity.

Advances in Nanoparticle Drug Delivery Systems for Anti-Hepatitis B Virus Therapy: A Narrative Review

Chronic hepatitis B (CHB) is an infectious viral disease that is prevalent worldwide. Traditional nucleoside analogues, as well as the novel drug targets against hepatitis B virus (HBV), are associated with certain critical factors that influence the curative effect, such as biological stability and safety, effective drug delivery, and controlled release. Nanoparticle drug delivery systems have significant advantages and have provided a basis for the development of anti-HBV strategies. In this review, we aim to review the advances in nanoparticle drug delivery systems for anti-hepatitis B virus therapy by summarizing the relevant literature. First, we focus on the characteristics of nanoparticle drug delivery systems for anti-HBV therapy. Second, we discuss the nanoparticle delivery systems for anti-HBV nucleoside drugs, gene-based drugs, and vaccines. Lastly, we provide an overview of the prospects for nanoparticle-based anti-HBV agents.

Association between HBs Ag quantification and the risk of hepatocellular carcinoma in patients treated with tenofovir disoproxil fumarate or entecavir

This study evaluated the clinical implications of hepatitis B surface antigen quantification (qHBs Ag) in chronic hepatitis B (CHB) patients treated with entecavir (ETV) or tenofovir disoproxil fumarate (TDF) and identified the association between qHBs Ag and the risk of hepatocellular carcinoma (HCC) in these patients.Between January 2007 and December 2018, the qHBs Ag and clinical data of 183 CHB patients who initially received ETV (n = 45, 24.6%) or TDF (n = 138, 75.4%) were analyzed.The mean follow-up period of the 183 CHB patients was 45.3 months, of which 59 (32.2%) patients showed a reduction in qHBs Ag by >50% after 1 year of antiviral treatment (ETV or TDF). The HCC development (P = .179) or qHBs Ag reduction (P = .524) were similar in the ETV and TDF groups. Patients with a ≥50% decrease in qHBs Ag had a significantly lower incidence of HCC or decompensated cirrhosis complications (P = .005). Multivariate analysis showed that a >50% reduction of qHBs Ag (hazard ratio 0.085, P = .018) and the presence of cirrhosis (hazard ratio 3.32, P = .016) were independent factors predicting the development of HCC.Patients whose qHBs Ag value decreased >50% at 1 year after antiviral treatment for CHB showed a significant decrease in HCC or decompensated cirrhosis events. A reduction in qHBs Ag could be used as a predictive factor of HCC development or critical complications in CHB patients treated with TDF or ETV.

Clinical utility of quantifying hepatitis B surface antigen in African patients with chronic hepatitis B

The clinical utility of quantifying hepatitis B surface antigen (qHBsAg) levels in African subjects with chronic hepatitis B virus (HBV) infection has been poorly documented. From a multicentre cohort of 944 HBV-infected African patients, we aimed to assess whether qHBsAg alone can accurately identify i) those in a HBeAg-negative chronic HBV infection phase at low risk of liver disease progression and ii) those in need of antiviral therapy according to the 2017 EASL guidelines. We analysed 770 HBV mono-infected treatment-naïve patients, mainly males (61%) from West Africa (92%), median age 35 years (IQR: 30-44), median HBV DNA: 95.6 IU/ml (10.0-1,300.0), median qHBsAg 5,498 IU/ml (1,171-13,000) and HBeAg-pos 38 (5%). A total of 464/770 (60.2%) patients were classified as HBeAg-negative chronic infection (median age 36 years (31-46), median ALT 23 IU/l (18-28), median HBV-DNA 33.5 IU/ml (3.8-154.1), median LSM 4.8 kPa (4.1-5.8)) and qHBsAg levels had poor accuracy to identify these subjects with an AUROC at 0.58 (95%CI: 0.54-0.62), sensitivity 55.0% and specificity 55.6%; 118/770 (15.3%) patients were eligible for treatment according to the 2017 EASL criteria. qHBsAg correlated poorly with HBV DNA and had poor accuracy to select patients for antiviral therapy with an AUROC at 0.54 (0.49-0.60), sensitivity 46.6% and specificity 46.9%. In African treatment-naïve HBV-infected subjects, the clinical utility of qHBsAg to identify subjects in HBeAg-negative infection phase or subjects eligible for antiviral therapy seems futile. Whether qHBsAg levels can be used as a predictor of long-term liver complications in Africa needs to be further investigated.

The role of quantitative HBsAg in patients with HBV DNA between 2000-20,000 IU/ml

AIMS

We aimed to determine the contribution of quantitative HBsAg in differentiating chronic infections from chronic hepatitis in HBeAg negative patients with HBV DNA 2000-20,000 IU/ml.

MATERIAL AND METHODS

A total of 79 untreated HBeAg negative patients were included. Patients were divided into 3 groups based on HBV DNA levels: group 1 (HBV DNA ≤ 2000 IU/ml), group 2 (HBV DNA: 2000-20,000 IU/ml) and group 3 (HBV DNA > 20,000 IU/ml). We collected serum from all patients for quantitative HBsAg analysis. We compared serum quantitative HBsAg levels with biochemical parameters, HBV DNA and liver biopsy results.

RESULTS

In this study 46 patients were female and the mean age was 42 years. Serum quantitative HBsAg levels were found to be significantly lower in chronic infections compared with chronic hepatitis. There was a positive correlation between quantitative HBsAg and HBV DNA, ALT (alanine aminotransferase), HAI score (histological activity index), fibrosis score and disease stage. The cut-off level of quantitative HBsAg was determined as 4425 IU/ml to differentiate chronic infection from chronic hepatitis. With the test specificity of 95%, we found quantitative HBsAg cut-off values 1026 IU/ml and 20,346 IU/ml for the diagnosis of chronic infection and chronic hepatitis, respectively.

CONCLUSION

Our study suggests that the quantitative HBsAg ≤ 1000 IU/ml limit value might be used for the diagnosis of chronic infection not only in HBV DNA ≤ 2000 IU/ml but also in patients with HBV DNA between 2000-20,000 IU/ml. In addition, antiviral treatment could be considered in patients with quantitative HBsAg > 20,000 IU/ml and HBV DNA > 2000 IU/ml without further examinations such as liver biopsy.

Potential of ultra-highly sensitive immunoassays for hepatitis B surface and core-related antigens in patients with or without development of hepatocellular carcinoma after hepatitis B surface antigen seroclearance

AIMS

Hepatitis B surface antigen (HBsAg) seroclearance indicates a "functional cure" in chronic hepatitis B (CHB) virus infection. However, several cases of hepatocellular carcinoma (HCC) development have been reported after HBsAg seroclearance. We evaluated the potential of HBsAg and hepatitis B core-related antigen (HBcrAg), measured by the ultra-highly sensitive assays, in cases with HCC development after HBsAg seroclearance.

METHODS

We enrolled 17 patients with CHB who achieved HBsAg seroclearance, defined by the conventional assay using Architect HBsAg QT kit (five HCC patients and 12 non-HCC patients). HBsAg and HBcrAg were measured in their stored serum samples using ultra-highly sensitive assays featuring "immunoassay for total antigen including complex via pretreatment (iTACT)" technology.

RESULTS

All five patients who developed HCC were positive for HBsAg or HBcrAg by iTACT-HBsAg or iTACT-HBcrAg at all follow-up points. HBcrAg levels in the HCC group, using iTACT-HBcrAg, were significantly higher than those in the non-HCC group at HBsAg seroclearance (3.6 LogU/ml (2.8-4.2) versus 2.6 (<2.1-3.8), p = 0.020). The best cutoff value of iTACT-HBcrAg for predicting HCC development was 2.7 LogU/ml by receiver operating characteristic curve analysis. The prevalence of HBcrAg ≥2.7 in the HCC group was significantly higher than that in non-HCC group (100% [5/5] versus 33% [4/12], p = 0.029).

CONCLUSIONS

Residual low viral antigen might predict HCC development even if HBsAg seroclearance was achieved according to a conventional assay. The results suggest that iTACT assays of HBsAg and HBcrAg would be useful for monitoring CHB patients.

HBV-Integration Studies in the Clinic: Role in the Natural History of Infection

Hepatitis B virus (HBV) infection is a major global health problem causing acute and chronic liver disease that can lead to liver cirrhosis and hepatocellular carcinoma (HCC). HBV covalently closed circular DNA (cccDNA) is essential for viral replication and the establishment of a persistent infection. Integrated HBV DNA represents another stable form of viral DNA regularly observed in the livers of infected patients. HBV DNA integration into the host genome occurs early after HBV infection. It is a common occurrence during the HBV life cycle, and it has been detected in all the phases of chronic infection. HBV DNA integration has long been considered to be the main contributor to liver tumorigenesis. The recent development of highly sensitive detection methods and research models has led to the clarification of some molecular and pathogenic aspects of HBV integration. Though HBV integration does not lead to replication-competent transcripts, it can act as a stable source of viral RNA and proteins, which may contribute in determining HBV-specific T-cell exhaustion and favoring virus persistence. The relationship between HBV DNA integration and the immune response in the liver microenvironment might be closely related to the development and progression of HBV-related diseases. While many new antiviral agents aimed at cccDNA elimination or silencing have been developed, integrated HBV DNA remains a difficult therapeutic challenge.

Sensitivity and Specificity of Hepatitis B Virus Screening via Rapid Immunoassay Chromatographic Test

Introduction: In low-income and high hepatitis B and C virus burden countries like Pakistan, it is important to develop cheap yet efficient strategies in diagnosing as well as treating hepatitis. The aim of this study is to assess the sensitivity and specificity of serum hepatitis B surface antigen (HbsAg) via Rapid Immunoassay Chromatographic Test (RICT) for the screening of hepatitis B, compared to the gold standard laboratory-based method.

Methods: The study was conducted in the Hepatology Clinic of Civil Hospital, Sukkur. All records of the clinic from June 1, 2018, to December 31, 2018, were accessed for identification of the records in which hepatitis B screening via RICT and then confirmatory polymerase chair reaction (PCR) by gene amplification with forward and reverse primers was done.

Results: There were 151 samples in this study. There were 32 (94.1%) true-positive and three (5.8%) false-negative samples. There were two (2.5%) false-positive and 114 (97.4%) true-negative samples. The sensitivity of HbsAg detection via RICT for the screening of 1-1B V was 91.43%, specificity was 98.28% and the accuracy was 96.69%, compared to PCR.

Conclusion: The RICT method has high sensitivity and specificity. In low-income and high-hepatitis B virus-burden countries like Pakistan, it serves as a very efficient screening tool that is easy to use, cheaper in cost, and gives rapid and accurate results.

Recombinant Baculovirus-Produced Grass Carp Reovirus Virus-Like Particles as Vaccine Candidate That Provides Protective Immunity against GCRV Genotype II Infection in Grass Carp

Grass carp reovirus (GCRV) leads to severe hemorrhagic disease in grass carp (Ctenopharyngodon idella) and causes economic losses in grass carp aquaculture. Recent epidemiological investigations showed that GCRV genotype II is the dominant subtype in China. Therefore, it is very important to develop a novel vaccine for preventing diseases caused by GCRV genotype II. In this study, we employed a bac-to-bac expression system to generate GCRV-II-based virus-like particles (VLPs). Previous studies have shown that the structural proteins VP3, VP4, and VP38 encoded by the segments S3, S6, and S10 of type II GCRV are immunogenic. Hence, the GCRV-VLPs were produced by co-infection of sf9 cells with recombinant baculoviruses PFBH-VP3, PFBH-VP4, and PFBH-VP38. The expressions of VP3, VP4, and VP38 proteins in GCRV-VLPs were tested by IFA and Western blot analysis. By electron microscopic observations of ultrathin sections, purified VLPs showed that the expressed proteins are similar in shape to GCRV genotype II with a size range from 40 nm to 60 nm. The immunogenicity of GCRV-VLPs was evaluated by the injection immunization of grass carp. The analysis of serum-specific IgM antibody showed that grass carp immunized with GCRV-VLPs produced GCRV-specific antibodies. Furthermore, injection with GCRV-VLPs increased the expressions of immune-related genes (IgM, IFN, TLR3, TLR7) in the spleen and kidney. In addition, grass carp immunized with a GCRV-VLPs-based vaccine showed a relative percent survival rate (RPS) of 83.33% after challenge. The data in this study showed that GCRV-VLPs demonstrated an excellent immunogenicity and represent a promising approach for vaccine development against GCRV genotype II infection.

Amine-functionalized Cu-MOF nanospheres towards label-free hepatitis B surface antigen electrochemical immunosensors

Metal-organic framework (MOF) nanomaterials offer a wide range of promising applications due to their unique properties, including open micro- and mesopores and richness of functionalization. Herein, a facile synthesis via a solvothermal method was successfully employed to prepare amine-functionalized Cu-MOF nanospheres. Moreover, the growth and the morphology of the nanospheres were optimized by the addition of PVP and TEA. By functionalization with an amine group, the immobilization of a bioreceptor towards the detection of hepatitis B infection biomarker, i.e., hepatitis B surface antigen (HBsAg), could be realized. The immobilization of the bioreceptor/antibody to Cu-MOF nanospheres was achieved through a covalent interaction between the carboxyl group of the antibodies and the amino-functional ligand in Cu-MOF via EDC/NHS coupling. The amine-functionalized Cu-MOF nanospheres act not only as a nanocarrier for antibody immobilization, but also as an electroactive material to generate the electrochemical signal. The electrochemical sensing performance was characterized using cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and differential pulse voltammetry (DPV). The results showed that the current response proportionally decreased with the increase of HBsAg concentration. More importantly, the sensing performance of the amine-functionalized Cu-MOF nanospheres towards HBsAg detection was found to be consistent in real human serum media. This strategy successfully resulted in wide linear range detection of HBsAg from 1 ng mL-1 to 500 ng mL-1 with a limit of detection (LOD) of 730 pg mL-1. Thus, our approach provides a facile and low-cost synthesis process of an electrochemical immunosensor and paves the way to potentially utilize MOF-based nanomaterials for clinical use.

New Therapeutics for Hepatitis B: The Road to Cure

Chronic hepatitis B virus (HBV) infection impacts an estimated 257-291 million people globally. The current approach to treatment for chronic HBV infection is complex, reflecting a risk:benefit approach driven by the lack of an effective curative regimen. This complexity and the lack of a durable treatment response, necessitating indefinite treatment in the majority of cases, have resulted in low uptake of testing and treatment, particularly in regions where comprehensive primary care is lacking and access to affordable testing and treatment is limited. Multiple targeted therapies are now in early human study with the primary goal to achieve persistent HBV DNA and hepatitis B surface antigen suppression after a finite course of treatment, which is referred to as functional cure. This article summarizes the current therapies for HBV infection and discusses the limitations of these therapies, novel approaches to HBV cure, and therapeutic endpoints of clinical trials aimed to cure hepatitis B.

Final analysis of the international observational S-Collate study of peginterferon alfa-2a in patients with chronic hepatitis B

Background and aims

Sustained off-treatment immune control is achievable in a proportion of patients with chronic hepatitis B treated with peginterferon alfa-2a. We evaluated on-treatment predictors of hepatitis B surface antigen (HBsAg) clearance 3 years after peginterferon alfa-2a treatment and determined the incidence of hepatocellular carcinoma.

Methods

A prospective, international, multicenter, observational study in patients with chronic hepatitis B who have been prescribed peginterferon alfa-2a (40KD) in a real-world setting. The primary endpoint was HBsAg clearance after 3 years’ follow-up.

Results

The modified intention-to-treat population comprised 844 hepatitis B e antigen (HBeAg)-positive patients (540 [64%] completed 3 years’ follow-up), and 872 HBeAg-negative patients (614 [70%] completed 3 years’ follow-up). At 3 years’ follow-up, HBsAg clearance rates in HBeAg-positive and HBeAg-negative populations, respectively, were 2% (16/844) and 5% (41/872) in the modified intention-to-treat population and 5% [16/328] and 10% [41/394] in those with available data. In HBeAg-positive patients with data, Week 12 HBsAg levels <1500, 1500–20,000, and >20,000 IU/mL were associated with HBsAg clearance rates at 3 years’ follow-up of 11%, 1%, and 5%, respectively (Week 24 predictability was similar). In HBeAg-negative patients with available data, a ≥10% decline vs a <10% decline in HBsAg at Week 12 was associated with HBsAg clearance rates of 16% vs 4%. Hepatocellular carcinoma incidence was lower than REACH-B (Risk Estimation for Hepatocellular Carcinoma in Chronic Hepatitis B) model predictions.

Conclusions

Sustained off-treatment immune control is achieved with peginterferon alfa-2a in a real-world setting. HBsAg clearance 3 years after completion of peginterferon alfa-2a can be predicted on the basis of on-treatment HBsAg kinetics.

Quantitation of large, middle and small hepatitis B surface proteins in HBeAg-positive patients treated with peginterferon alfa-2a

BACKGROUND & AIMS

Hepatitis B virus (HBV) contains three viral surface proteins, large, middle and small hepatitis B surface protein (LHBs, MHBs, SHBs). Proportions of LHBs and MHBs are lower in patients with inactive vs active chronic infection. Interferon alfa may convert hepatitis B e antigen (HBeAg)-positive chronic hepatitis B (CHB) to an inactive carrier state, but prediction of sustained response is unsatisfactory. The aim of this study was to test the hypothesis that quantification of MHBs and LHBs may allow for a better prognosis of therapeutic response than total hepatitis B surface antigen (HBsAg) concentration.

METHODS

Hepatitis B surface proteins were measured before and during peginterferon alfa-2a therapy in serum from 127 Asian patients with HBeAg-positive CHB. Sustained response was defined as HBeAg seroconversion 24 weeks post-treatment.

RESULTS

Mean total HBs levels were significantly lower in responders vs nonresponders at all time points (P < .05) and decreased steadily during the initial 24 weeks treatment (by 1.16 vs 0.86 ng/mL in responders/nonresponders respectively) with unchanged relative proportions. Genotype B had a two-fold higher proportion of LHBs than genotype C (13% vs 6%). HBV DNA, HBeAg, HBsAg and HBs protein levels predicted response equally well but not optimally (area under the receiver operating characteristic curve values >0.70).

CONCLUSIONS

Hepatitis B surface protein levels differ by HBV genotype. However, quantification of HBs proteins has no advantage over the already established HBsAg assays to predict response to peginterferon alfa-2a therapy in HBeAg-positive patients.

Emerging tools in the changing landscape of chronic hepatitis B management

Introduction: The availability of a preventative vaccine, interferon, and nucleos(t)ide analogs have provided progress in the control of chronic hepatitis B (CHB). Despite this, it remains a major contributor to global morbidity and mortality. Developments in our understanding of the pathogenesis of CHB and the emergence of new therapies are paving the way, as we move toward HBV cure.Areas covered: We performed bibliographical searches of online databases to review the literature regarding conventional disease phases of CHB. We provide the latest evidence challenging the perception of the natural history of CHB, noting that previously considered quiescent disease phases may not represent benign disease states devoid of progression. We explore the use of potential novel immunological and viral tools which should enhance disease stratification and management decisions in the coming years. Finally, we discuss the timing of treatment and how this could be initiated earlier to improve treatment outcomes, preventing sequelae of chronic infection.Expert opinion: The treatment paradigm in CHB is set to change with multiple novel agents in early phase clinical trials with the aim of a functional cure. An improved understanding of disease pathogenesis and the timing of treatment will be critical to the success of new therapies.

Use of HBsAg quantification in the natural history and treatment of chronic hepatitis B

In patients with chronic hepatitis B (CHB) infection, it is important to monitor the natural history, assess treatment response, and predict the risk of liver-related complications. Quantification of serum hepatitis B surface antigen (HBsAg) has gained wide interests since the last decade. It is secreted from hepatocytes in both hepatitis B e antigen (HBeAg)-positive and HBeAg-negative phases of the disease, and can be transcribed and translated from different sources of viral genome [ccc DNA or integrated hepatitis B virus (HBV) DNA]. In untreated patients, it declines slowly through the natural course and remains stable for a long time after HBeAg seroconversion. In patients treated with nucleos(t)ide analogues (NA), it also declines very slowly, even though serum hepatitis B DNA has been rendered negative. Low serum HBsAg may predict either spontaneous or treatment-induced HBsAg seroclearance, and potentially selects out HBeAg-negative patients who can safely stop NA. High serum HBsAg is associated with high risk of hepatocellular carcinoma in untreated population, and predicts treatment failure in patients receiving pegylated interferon. These potential roles of HBsAg quantification are applicable to selected populations only. There is also a need for novel markers to study the effect of emerging antiviral therapies targeting various parts of the HBV cycle to reflect their distinct mechanistic effects. Several agents measuring HBsAg levels have shown rapid and significant decline. Ongoing studies are required to demonstrate the sustainability of HBsAg suppression by these novel agents.

Quantitative HBsAg levels do not identify hepatic fibrosis in HBeAg-negative chronic hepatitis B patients

BACKGROUND/AIMS

Quantitative serum hepatitis B surface antigen (qHBsAg) has been evaluated in limited patient groups as a marker of histological fibrosis. The accurate identification of inactive chronic hepatitis B virus (HBV) carriers from those with active carriers is difficult because of wide and frequent HBV DNA fluctuations. We aimed to assess the utility of qHBsAg in distinguishing histologically significant fibrosis in untreated HBeAg-negative chronic HBV patients.

PATIENTS AND METHODS

qHBsAg levels were measured at baseline as single-point quantification and correlated with virologic and biochemical profiles of consecutive carriers (median, 29; range, 12-110 months). HBeAg-negative patients (n = 75) with HBV DNA <2000 (n = 5), 2000-20,000 (n = 16) and >20,000 IU/mL (n = 54) were included and all had liver biopsy. A qHBsAg cutoff point of 1000 IU/mL was assessed to demonstrate whether it better delineated patients with non-significant histology (F0-1, inflammatory grade A0-1).

RESULTS

Mean age of the patients was 39.4 ± 11.4 years and 58 (77.3%) were male. Patients with qHBsAg levels >1000 IU/mL were more likely to be males (84.5%, P = 0.006) or with elevated AST (68.4%, P = 0.0002) and ALT levels (72.4%, P < 0.0001), higher HBV DNA (log₁₀ 6.4 ± 1.4, P < 0.0001) and those with F2-4 fibrosis (48.3%, P = 0.028). Serum log₁₀ qHBsAg were significantly lower in patients with HBV DNA <2000 (2.80 ± 1.47) and HBV DNA 2000-20,000 (2.71 ± 0.83) vs. >20,000 IU/mL (3.89 ± 0.61, P < 0.0001). Overall, qHBsAg were not different in patients with F0-1 (3.44 ± 0.91) and F2-4 fibrosis (3.74 ± 0.85, P = 0.161). Serum qHBsAg were higher in patients with significant (A2-3) inflammation (3.85 ± 0.72) compared to A0-1 (3.38 ± 0.95; P = 0.018). Serum qHBsAg demonstrated poor accuracy (AUROC, 0.61, P = 0.111) in identification of F2-4 fibrosis.

CONCLUSION

Serum qHBsAg levels do not help differentiate between those with HBV DNA <2000 or 2000 - 20,000 IU/mL or distinguish patients with significant fibrosis. Moreover, more than half of the patients with non-significant fibrosis have a qHBsAg level greater than 1000 IU/mL.

Toward a Functional Cure for Hepatitis B: The Rationale and Challenges for Therapeutic Targeting of the B Cell Immune Response

The central role of the cellular immune response in the control and clearance of the hepatitis B virus (HBV) infection has been well-established. The contribution of humoral immunity, including B cell and antibody responses against HBV, has been investigated for a long time but has attracted increasing attention again in recent years. The anti-HBs antibody was first recognized as a marker of protective immunity after the acute resolution of the HBV infection (or vaccination) and is now defined as a biomarker for the functional cure of chronic hepatitis B (CHB). In this way, therapies targeting HBV-specific B cells and the induction of an anti-HBs antibody response are essential elements of a rational strategy to terminate chronic HBV infection. However, a high load of HBsAg in the blood, which has been proposed to induce antigen-specific immune tolerance, represents a major obstacle to curing CHB. Long-term antiviral treatment by nucleoside analogs, by targeting viral translation by siRNA, by inhibiting HBsAg release via nucleic acid polymers, or by neutralizing HBsAg via specific antibodies could potentially reduce the HBsAg load in CHB patients. A combined strategy including a reduction of the HBsAg load via the above treatments and the therapeutic targeting of B cells by vaccination may induce the appearance of anti-HBs antibodies and lead to a functional cure of CHB.

A Global View to HBV Chronic Infection: Evolving Strategies for Diagnosis, Treatment and Prevention in Immunocompetent Individuals

Hepatitis B Virus (HBV) is a significant public health challenge. Around 250 million people live with chronic HBV infection. With a global approach to this issue, we focus on new perspective in diagnosis, management and prevention of HBV chronic infection. Precise diagnosis of HBV status is crucial to guide patient management. Although available drugs reduce the risk of liver disease progression, they are not able to definitely eradicate HBV, and new therapeutic options are urgently needed. Thus, prevention of HBV infection is still the most effective strategy to achieve the control of the disease. Key aspects of prevention programs include surveillance of viral hepatitis, screening programs and immunization strategies. In spite of the high success rate of licensed HBV vaccines, a need for improved vaccine persists, especially in order to provide coverage of current non-responders.

The enrichment of HBV immune-escape mutations during nucleoside/nucleotide analogue therapy

BACKGROUND

Drug-resistant HBV mutants frequently arise during nucleoside/nucleotide analogue (NA) therapy, while the resistance mutations on polymerase also have consequent changes in the S protein. The enrichment of immune-escape mutations was negatively correlated with hepatitis B surface antigen (HBsAg) clearance under NA therapy. This study aims to characterize the variability of HBV polymerase and surface antigen in patients with virological breakthrough under NA therapy.

METHODS

From 2012 to 2014, serum samples were collected from 156 patients with chronic hepatitis B infection, who had experienced NA therapy for at least 24 weeks and displayed virological breakthrough, while 165 HBV carriers without NA treatment were also enrolled. HBV DNA was quantified and polymerase reverse transcriptase domain was amplified and sequenced.

RESULTS

A total of 97 patients in the NA treatment group had resistance mutations, with rtM204I/V/S being the most common substitution (78 of 97), while no resistance mutations were detected in the treatment-naive group. Various escape mutations were detected, and the detection rate was significantly higher in the NA treatment group (38, 24.4%) than that of treatment-naive group (18, 10.9%; P<0.05). Except for the combination of sP120T+sA128V, other double combinations (n=11) were only detected in the NA treatment group, and nine of these combinations in the treatment group were detected in HBV variants without antiviral resistance mutations.

CONCLUSIONS

Antiviral resistance mutations were selected by a long duration of NA therapy. Virological breakthrough was not only attributed to the emergence of resistance mutations, but may also be associated with the enrichment of immune-escape mutations.

Discovery of New Hepatitis B Virus Capsid Assembly Modulators by an Optimal High-Throughput Cell-Based Assay

In this article, a simple and effective high-throughput screening (HTS) assay was developed to identify anti-HBV compounds by using a HepAD38 luciferase reporter (HepAD38-luc) cell line that can effectively exclude the false positive hit compounds targeted on the tetracycline off (tet-off) regulation system. Through screening in-house chemical libraries, N-phenylpiperidine-3-carboxamide derivatives, represented by 1 and 2, were identified, while the other false positive hits (i.e., quinoxaline (3) and benzothiazin (4) derivatives) were simultaneously excluded. Compounds 1 and 2 exhibit strong inhibitory activity against HBV replication in both HepAD38 and HepG2.2.15 cells. Further studies revealed that 1 and 2 reduced extracellular HBV DNA, HBeAg, and intracellular HBV intermediates, including total DNA, RNA, and precore RNA of HBV. Size-exclusion chromatography (SEC) and electron microscopy (EM) investigations demonstrated that 1 and 2 remarkably induced the formation of morphologically intact capsids and accelerated the dynamics of capsid assembly, suggesting that both 1 and 2 were type I capsid assembly modulators (CAMs).

Serum hepatitis B core-related antigen is an effective tool to categorize patients with HBeAg-negative chronic hepatitis B

The discrimination between active chronic hepatitis B (CHB) and the clinically quiescent infection (CIB) is not always easy, as a significant portion of patients falls in a "grey" zone. Hepatitis B core-related antigen (HBcrAg) is a now quantifiable serological marker with potential applications in diagnosis and therapy monitoring. The aim of the present study was to evaluate the HBcrAg serum levels in HBeAg-negative HBV infection, and its ability in identifying the clinical profile, in comparison with HBsAg serum levels. HBcrAg was retrospectively assessed on serum samples from a population of treatment-naive HBeAg-negative patients by ChemiLuminescent Enzyme Immunoassay (CLEIA). HBsAg and HBV-DNA data were collected. Serological data were associated to clinical profile, defined in the subsequent follow-up of at least 1 year. In the overall population of 160 HBeAg-negative patients, HBcrAg results weakly correlated with qHBsAg levels (Spearman r = 0.471, P < 0.0001) and correlated closely with HBV-DNA (Spearman r = 0.746, P < 0.0001). HBcrAg levels were significantly higher in 85 CHB patients relative to 75 CIB carriers. A value of 2.5 logU/mL produced the optimal cut-off to identify CIB patients, with diagnostic accuracy comparable to HBsAg levels. In long-term clinical evaluation, a single measurement of HBcrAg at the established cut-off was optimally consistent with clinical outcome. Conversely, the HBsAg cut-off performed well in the true quiescent phase and less in more difficult-to-categorize patients. In conclusion, single-point use of HBcrAg serum levels provides an accurate identification of CIB and represents a useful tool for patient classification.

Serum hepatitis B core-related antigen (HBcrAg) correlates with covalently closed circular DNA transcriptional activity in chronic hepatitis B patients

BACKGROUND & AIMS

It has been proposed that serum hepatitis B core-related antigen (HBcrAg) reflects intrahepatic covalently closed circular (ccc)DNA levels. However, the correlation of HBcrAg with serum and intrahepatic viral markers and liver histology has not been comprehensively investigated in a large sample. We aimed to determine if HBcrAg could be a useful therapeutic marker in patients with chronic hepatitis B.

METHODS

HBcrAg was measured by chemiluminescent enzyme immunoassay in 130 (36 hepatitis B e antigen [HBeAg]+ and 94 HBeAg-) biopsy proven, untreated, patients with chronic hepatitis B. HBcrAg levels were correlated with: a) serum hepatitis B virus (HBV)-DNA, quantitative hepatitis B surface antigen and alanine aminotransferase levels; b) intrahepatic total (t)HBV-DNA, cccDNA, pregenomic (pg)RNA and cccDNA transcriptional activity (defined as pgRNA/cccDNA ratio); c) fibrosis and necroinflammatory activity scores.

RESULTS

HBcrAg levels were significantly higher in HBeAg+ vs. HBeAg- patients and correlated with serum HBV-DNA, intrahepatic tHBV-DNA, pgRNA and cccDNA levels, and transcriptional activity. Patients who were negative for HBcrAg (<3 LogU/ml) had less liver cccDNA and lower cccDNA activity than the HBcrAg+ group. Principal component analysis coupled with unsupervised clustering identified that in a subgroup of HBeAg- patients, higher HBcrAg levels were associated with higher serum HBV-DNA, intrahepatic tHBV-DNA, pgRNA, cccDNA transcriptional activity and with higher fibrosis and necroinflammatory activity scores.

CONCLUSIONS

Our results indicate that HBcrAg is a surrogate marker of both intrahepatic cccDNA and its transcriptional activity. HBcrAg could be useful in the evaluation of new antiviral therapies aiming at a functional cure of HBV infection either by directly or indirectly targeting the intrahepatic cccDNA pool.

LAY SUMMARY

Hepatitis B virus causes a chronic infection which develops into severe liver disease and liver cancer. The viral covalently closed circular DNA (cccDNA) is responsible for the persistence of the infection in hepatocytes. To better manage patient treatment and follow-up, and to develop new antiviral treatments directly targeting the intrahepatic pool of cccDNA, serum surrogate markers reflecting the viral activity in the liver are urgently needed. In this work, we demonstrate that quantification of hepatitis B core-related antigen in serum correlates with cccDNA amount and activity and could be used to monitor disease progression.

Current state-of-the-art pharmacotherapy for the management of hepatitis B infection

INTRODUCTION

Hepatitis B virus (HBV) infection remains a global challenge with several hundred million infected individuals. Disease activity can be controlled, and adverse outcomes prevented when treatment can be provided. Frequently life-long therapy is required instead of defined treatment periods such as with the case of Hepatitis C Virus (HCV) infection.

AREAS COVERED

In this review, the authors provide an overview of current start of the art therapy for HBV and indicate where variation from the current guidelines could be considered. Certain patients may be eligible for treatment with suboptimal therapies when their baseline viral load is low. Identifying ideal candidates for interferon therapy will result in good sustained responses for some patients.

EXPERT OPINION

The biggest challenge remains linking patients to care and therapy. Patients can nowadays be sufficiently treated before the disease advances to a more progressed phase. However, future therapies must be extremely safe and ideally limit the required treatment period. Given Hepatitis D Virus's dependence on HBV and being a disease with an unmet clinical need, HDV may be the best target group for the development of a functional cure for hepatitis B.

HBV preS deletion mapping using deep sequencing demonstrates a unique association with viral markers

Aim

Deletions are observed frequently in the preS1/S2 region of hepatitis B virus (HBV) genome, in association with liver disease advancement. However, the most significant preS1/S2 region and its influences on viral markers are unclear.

Methods

The preS1/S2 HBV regions of 90 patients without antiviral therapy were subjected to deep sequencing and deleted regions influencing viral markers were investigated.

Results

From the deletion frequency analysis in each patient, deletions were observed most frequently in the preS2 codon 132–141 region. When the patients were divided into three groups (0–0.1%: n = 27, 0.1%-10%: n = 34, 10–100%: n = 29), based on the deletion frequency, FIB-4 (p < 0.01), HBV DNA (p < 0.01), HBcrAg (p < 0.01) and preS1/S2 start codon mutations (p < 0.01, both) were significantly associated with the deletion. When clinical and viral markers were investigated by multivariate analysis for their association with the deletion, FIB-4 (p < 0.05), HBcrAg (p < 0.05), and preS1 start codon mutation (p < 0.01) were extracted as independent variables. When the influence of the preS codon 132-141deletions on HBsAg and HBcrAg, relative to HBV DNA, was investigated, the HBsAg/HBV DNA ratio was lower (0–10% vs. 10%-100%, p<0.05), while the HBcrAg/HBV DNA rati o was higher (0–0.1% vs. 10%-100%, p<0.05) in the presence of the preS codon 132-141deletions.

Conclusion

The preS codon.132-141 deletions have a significant influence on the clinical characteristics and viral markers, even when present as a minor population. Importantly, the preS codon 132–141 deletions have a clear influence on the viral life cycle and pathogenesis.

Magnetic digital microfluidics on a bioinspired surface for point-of-care diagnostics of infectious disease

Magnetic digital microfluidics uses magnetic force to manipulate droplets on a Teflon-coated substrate through the added magnetic particles. To achieve a wide range of droplet manipulation, hydrophilic patterns, known as surface energy traps, are introduced onto the Teflon-coated hydrophobic substrate. However, the Teflon-coated substrate is difficult to modify because it is nonwettable, and existing techniques for patterning surface energy traps have many limitations. Inspired by the mussel adhesion mechanism, we use polydopamine, a bioinspired substance that adheres strongly to almost any materials, to pattern surface energy traps on the Teflon-coated substrate with a great ease. We have optimized the polydopamine coating protocol and characterized the surface properties of the polydopamine surface energy traps. Droplet operations including particle extraction, liquid dispensing, liquid shaping, and cross-platform transfer have been demonstrated on the polydopamine surface energy trap-enabled magnetic digital microfluidic platform in both single-plate and two-plate configurations. Furthermore, the detection of hepatitis B surface antigen using ELISA has been demonstrated on the new magnetic dgitial microfluidic platform. This new bioinspired magnetic digital microfluidic platform is easy to fabricate and operate, showing a great potential for point-of-care applications.

Lamivudine plus tenofovir versus lamivudine plus adefovir for the treatment of hepatitis B virus in HIV-coinfected patients, starting antiretroviral therapy

Background

Combination of tenofovir disoproxil fumarate (TDF), lamivudine (3TC) and efavirenz (EFV) is preferred in the treatment of HIV/hepatitis B virus (HBV) coinfection. We postulated that a HBV active nucleoside reverse transcriptase (RT) inhibitor/nucleotide RT inhibitor backbone of adefovir dipivoxil (ADV) +3TC would be as effective as TDF +3TC for the Indian population.

Objective

ADV + 3TC could be an alternative option for these HIV/HBV coinfected individuals, preserving the dually active TDF + 3TC as second-line nucleoside backbone following failure of the first-line ART.

Materials and Methods

This randomised control trial (CTRI/2012/03/002471) was carried out at the ART Centre of Calcutta School of Tropical Medicine, India. Seventy-eight (39 on each arm) treatment-naïve HIV/HBV coinfected patients were randomised to receive either the combination of lamivudine + tenofovir + EFV or lamivudine + adefovir + zidovudine + EFV and followed up for 120 weeks.

Results

Median age of the study participants was 36 years (21-62), majority were male (61/78; 78.2%) and heterosexually (39/78; 50%) infected. Baseline characteristics were identical in both arms. There was no statistically significant difference in median aspartate aminotransferase (37 vs. 29.5 U/L), alanine aminotransferase (ALT) (36 vs. 34.5 U/L), ALT normalisation rate (80 vs. 70%), AST to platelet ratio index (0.45 vs. 0.33), CD4 count (508 vs. 427 cells/mm³), HBV DNA suppression (81.8 vs. 70%), hepatitis B e antigen loss (9 vs. 5%), hepatitis B surface antigen seroclearance rate (6.06 vs. 18.75%) and death (3 vs. 3) at 120 weeks between TDF (n = 33) and ADV (n = 32), respectively.

Conclusions

Adefovir plus lamivudine is an effective alternative of tenofovir plus lamivudine in long-term HBV treatment outcome in HIV/HBV coinfected patients.