The role of quantitative hepatitis B surface antigen revisited

Baseline HBsAg levels associated with HBsAg loss in HBeAg-negative chronic hepatitis B infection with persistently normal alanine aminotransferase

BACKGROUND

We aimed to assess the long-term outcomes of e antigen-negative chronic hepatitis B (CHB) infection with low hepatitis B virus (HBV) DNA level (< 200 IU/mL) and persistently normal alanine aminotransferase (PNALT) and to explore the factors associated with the results.

METHODS

This retrospective cohort study enrolled consecutive baseline CHB patients with PNALT from January 2005 to June 2008. In total, 252 e antigen-negative CHB patients with PNALT and low HBV DNA level (< 200 IU/mL) were enrolled, of whom 188 were eligible for this analysis. Among the 188 patients, 131 were followed up more than twice per year and 57 were followed up at least once per year, with a median follow-up period of 102 (73-123) months.

RESULTS

Of 188 patients, 16 had HBV DNA level of > 200 IU/mL and PNALT, 164 had HBV DNA level of < 200 IU/mL and PNALT and 8 had HBV DNA level of > 200 IU/mL and elevated ALT level, of which 3 used an antiviral drug during follow-up. Twelve of 164 experienced HBsAg loss. Cox regression analysis suggested that baseline HBsAg levels were associated with HBsAg loss in patients after follow-up, especially the baseline HBsAg levels of < 200 IU⁄mL, which is a risk factor for HBsAg loss. The AUC of baseline HbsAg level in the e antigen-negative CHB group was 0.772 (cutoff value 426, P < 0.001). The cumulative probability of HBsAg loss in the HBsAg < 400 IU/L group was 20% (7/35), which ws higher than that in the HBsAg ≥ 400 IU/L group (3.88%; 5/129; X2 = 11.75, P = 0.0006).

CONCLUSION

The e antigen-negative CHB infection with low HBV DNA level (< 200 IU/mL) and PNALT will progress to chronic hepatitis, although the probability of its occurrence is low. Spontaneous HBsAg loss may not occur frequently because the manifested cumulative probability of HBsAg loss was higher in the HBsAg < 400 IU/L group than in the HBsAg ≥ 400 IU/L group.

Pregenomic RNA: How to assist the management of chronic hepatitis B?

Pregenomic RNA (pgRNA) is an emerging serological marker for chronic hepatitis B virus (HBV) infection. While pgRNA is principally the template for viral proteins and viral DNAs, additional novel functions for the serum pgRNA have recently been described. These results extend for pgRNA a regulatory function in the viral life cycle and potentially a role in pathogenesis. Here, we review the diverse roles of pgRNA in HBV replication and pathogenesis, emphasizing how the unique structure of this RNA is key to its various functions. We focus in particular on the role of HBV pgRNA in guiding antiviral therapy including nucleot(s)ide analog interruption and role as a marker of cure with new curative therapies. We also briefly allude to the emerging niche for new direct-acting or indirect-acting antivirals targeting pgRNA.

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 Virus RNA: A New Potential Biomarker for Chronic Hepatitis B Virus Infection

Chronic hepatitis B infection is one of the major etiological causes of liver failure, cirrhosis, and hepatocellular carcinoma (HCC) worldwide. This condition cannot be completely cured by currently available drugs due to the persistent existence of hepatitis B virus (HBV) covalently closed circular DNA (cccDNA), the bona fide transcription template for HBV RNAs, in infected hepatocytes. Because quantifying cccDNA per se requires an invasive procedure, serum biomarkers reflecting intrahepatic cccDNA activity are warranted. Recently, a growing body of research suggests that the circulating HBV RNA may serve as a serum biomarker for HBV infection, treatment, and prognosis. In order to delineate the molecular and clinical characteristics of serum HBV RNA, we systematically reviewed the available literature on serum HBV RNA dating back to the early 1990s. In this review, we summarize the reported serum HBV RNA quantification methods and discuss the potential HBV RNA species in patient serum. We also compare the reported correlations of serum HBV RNA with other serological markers, including HBV DNA, hepatitis B surface antigen, e antigen, and core-related antigen, as well as their correlations with intrahepatic cccDNA, to assess their potential in clinical applications. Future directions for serum HBV RNA research are also discussed.

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.

Variants of hepatitis B virus surface antigen observed during therapy with nucleic acid polymer REP 2139-Ca have no influence on treatment outcome and its detection by diagnostic assays

The treatment of patients suffering from HBeAg-positive chronic hepatitis B with REP 2139-Ca resulted in potent reductions in HBsAg and HBV DNA, seroconversion to anti-HBs and the establishment of functional control of infection. In this cohort of 12 patients, we investigated whether differences between HBsAg sequences might explain the lack of response to REP 2139-Ca observed in 3 of 12 patients. We also assessed if the reduction or complete loss of HBsAg in serum observed during therapy were caused by mutations in the "a" determinant preventing the detection of HBsAg by standard diagnostic assays. The complete pre-S/S open reading frame (ORF) was sequenced and pre-S1, pre-S2 and S amino acid sequences were analysed. We found no major differences between pre-S1, pre-S2 and S sequences in responders and nonresponders correlated with low reduction in HBsAg. In addition, we found no mutations in the "a" determinant that would significantly affect the reactivity of HBsAg in diagnostic assays. These results demonstrate that the amino acid sequence of complete pre-S/S ORF has no direct influence on response to REP 2139-Ca therapy.

Okuda lecture: Challenges of hepatitis B in the era of antiviral therapy

Nucleos(t)ide analogs (NAs) are effective, safe, and convenient antiviral therapy to suppress replication of hepatitis B virus, which can be translated into improved long-term outcome of chronic hepatitis B patients. The current recommended first-line NAs, namely, entecavir and tenofovir, are largely free from problems of drug resistance. Nonetheless, there are still a few challenges in the era of NA. First, the risk of hepatocellular carcinoma can only be reduced but not eliminated, particularly among cirrhotic patients. For cirrhotic patients who have persistent low-level viremia on NA, that is, partial responders, the risk of hepatocellular carcinoma is higher than those with complete viral suppression. The best strategy to manage partial responders to entecavir or tenofovir is uncertain. Second, immune-tolerant patients are very difficult to treat with NA. A significant proportion of immune-tolerant patients will have detectable viremia despite a few years of continuous NA treatment, and the rate of hepatitis B e-antigen seroconversion is very low. Third, most patients need long-term treatment as NA cannot eliminate covalently closed circular DNA in the hepatocytes. Some patients can consider stop NA according to treatment guidelines, but viral and clinical relapses often occur after treatment cessation. There is no concrete consensus on when one should stop NA in a hepatitis B e-antigen-negative patient among different treatment guidelines. New biomarkers such as hepatitis B surface antigen level can be used to select patients to stop NA, but the data are still preliminary.

Automated Diagnosis of Hepatitis B Using Multilayer Mamdani Fuzzy Inference System

In this research, a new multilayered mamdani fuzzy inference system (Ml-MFIS) is proposed to diagnose hepatitis B. The proposed automated diagnosis of hepatitis B using multilayer mamdani fuzzy inference system (ADHB-ML-MFIS) expert system can classify the different stages of hepatitis B such as no hepatitis, acute HBV, or chronic HBV. The expert system has two input variables at layer I and seven input variables at layer II. At layer I, input variables are ALT and AST that detect the output condition of the liver to be normal or to have hepatitis or infection and/or other problems. The further input variables at layer II are HBsAg, anti-HBsAg, anti-HBcAg, anti-HBcAg-IgM, HBeAg, anti-HBeAg, and HBV-DNA that determine the output condition of hepatitis such as no hepatitis, acute hepatitis, or chronic hepatitis and other reasons that arise due to enzyme vaccination or due to previous hepatitis infection. This paper presents an analysis of the results accurately using the proposed ADHB-ML-MFIS expert system to model the complex hepatitis B processes with the medical expert opinion that is collected from the Pathology Department of Shalamar Hospital, Lahore, Pakistan. The overall accuracy of the proposed ADHB-ML-MFIS expert system is 92.2%.

Effect of hepatitis B virus (HBV) surface-gene variability on markers of replication during treated human immunodeficiency virus-HBV infection in Western Africa

BACKGROUND & AIMS

Replication markers exhibit substantial variation during chronic hepatitis B virus (HBV) infection, part of which can be explained by mutations on the surface (S) gene. We aimed to identify S-gene mutations possibly influencing the quantification of HBV replication markers (MUPIQH) in HBV genotype E infection, common to Western Africa.

METHODS

Seventy-three antiretroviral treatment (ART)-naïve human immunodeficiency virus (HIV)-HBV co-infected patients from Côte d'Ivoire, initiating anti-HBV-containing ART, had available HBV S-gene sequences. S-gene MUPIQHs were screened at ART initiation based on lower HBV-DNA or HBsAg quantification (qHBsAg) compared to wildtype. Their association with HBV virological response and qHBsAg slope during treatment was evaluated.

RESULTS

Genotype E was predominant (95.9%). At ART initiation, median HBV-DNA was 7.27 log₁₀ copies/mL (IQR = 5.26-8.33) and qHBsAg 4.08 log₁₀ IU/mL (IQR = 3.49-4.61). Twelve S-gene MUPIQHs were identified among 21 patients (28.8%): sS140L (n = 4), sD144A (n = 1), sS167L (n = 2), sS174N (n = 6), sP178Q (n = 2), sG185L (n = 2), sW191L (n = 2), sP203Q/R (n = 2), sS204N/I/R/K/T/G (n = 7), sN207T (n = 2), sF212C (n = 1) and sV224A/Y (n = 7). MUPIQHs at positions s185+s191+s224 and s178+s204 were within highly covarying networks of S-gene mutations. Older age (P = 0.02), elevated transaminases (P = 0.03) and anti-hepatitis B "e" antibody-positive serology (P = 0.009) were significantly associated with prevalent MUPIQHs at ART initiation. During treatment, baseline MUPIQHs were not associated with time-to-undetectable HBV-DNA (P = 0.7) and qHBsAg levels decreased at similar rates between those with vs without MUPIQHs (P = 0.5).

CONCLUSION

Several novel S-gene mutations were associated with reductions in replication markers among West African co-infected patients. These mutations, however, do not affect response during antiviral treatment. Their diagnostic and clinical consequences need clarification.

Hepatitis B Treatment: What We Know Now and What Remains to Be Researched

Chronic hepatitis B virus (HBV) infection remains a major global health burden. Currently, two types of treatment, interferons (IFNs) and nucleos(t)ide analogues (NAs), have been approved. These treatments are effective in suppressing HBV replication and in decreasing the risk of developing cirrhosis, liver failure, hepatocellular carcinoma (HCC), and death. However, these treatments do not eliminate the virus, and the risk of HCC remains. This review article summarizes current knowledge about the safety, efficacy, and clinical indications of hepatitis B treatment. It also discusses limitations of existing treatment, gaps in knowledge, and feasibility of a hepatitis B cure.

New and Old Biomarkers for Diagnosis and Management of Chronic Hepatitis B Virus Infection

Tests to detect the presence and activity of hepatitis B virus (HBV) are the cornerstones of diagnosis and management. Assays that detect or measure serum levels of HB surface antigen, HB surface antibody, and HB core antibody are used to identify patients with exposure to HBV, whereas other tests provide information on the level of virus replication, presence of specific variants, and presence of virus reservoirs. Newer diagnostic tests, used only in research settings so far, aim to quantify levels of intrahepatic HBV replication. Other tests have been developed to detect HBV infection in resource-limited settings. We review point-of-care tests (essential in global screening efforts), standard diagnostic tests used in routine clinical management, and newer tests that might be used in clinical trials of agents designed to cure HBV infection.

Switching to peginterferon for chronic hepatitis B patients with hepatitis B e antigen seroconversion on entecavir - A prospective study

Nucleos(t)ide analogues (NA) are effective in suppressing hepatitis B virus (HBV) replication, but most patients require long-term treatment. This study aimed to investigate switching to peginterferon as a strategy to stop NA. Hepatitis B e antigen (HBeAg)-positive chronic hepatitis B patients who developed HBeAg seroconversion during NA treatment were studied. All patients received open-label peginterferon alfa-2a 180 μg/wk for 48 weeks, and NA was stopped at week 4 of peginterferon treatment. The primary endpoint was sustained response, which was defined as negative HBeAg, positive anti-HBe and HBV DNA <2000 IU/mL at week 72. Other secondary endpoints including HBsAg loss at week 72 were also studied. Forty-one patients treated with entecavir for 56 ± 23 months were recruited. Sustained response was achieved in 30 patients (73%, 95% confidence interval 58%-84%). At week 72, 31 (76%) patients had HBeAg seroconversion, 56 (23%) patients had undetectable HBV DNA, 31 (76%) patients had normal ALT, and 6 patients (15%) had HBsAg loss. Baseline HBsAg level was the best predictor for both sustained response and HBsAg loss; the best HBsAg cut-off for sustained response was <1500 IU/mL and that for HBsAg loss was <500 IU/mL by receiver operating characteristic curve analysis. Twenty-two of 25 (88%) patients with baseline HBsAg <1500 IU/mL had sustained response. Five of 10 (50%) patients with baseline HBsAg <500 IU/mL developed HBsAg loss. Switching to peginterferon can be considered as a treatment option in NA-treated patients with HBeAg seroconversion, particularly among those with lower HBsAg levels.

Management of Hepatitis B Virus Infection: 2018 Guidelines from the Canadian Association for the Study of Liver Disease and Association of Medical Microbiology and Infectious Disease Canada

Hepatitis B virus (HBV) infection is an important public health problem in Canada. In keeping with evolving evidence and understanding of HBV pathogenesis, the Canadian Association for the Study of Liver Disease periodically publishes HBV management guidelines. The goals of the 2018 guidelines are to (1) highlight the public health impact of HBV infection in Canada and the need to improve diagnosis and linkage to care, (2) recommend current best-practice guidelines for treatment of HBV, (3) summarize the key HBV laboratory diagnostic tests, and (4) review evidence on HBV management in special patient populations and include more detail on management of HBV in pediatric populations. An overview of novel HBV tests and therapies for HBV in development is provided to highlight the recent advances in HBV clinical research. The aim and scope of these guidelines are to serve as an up-to-date, comprehensive resource for Canadian health care providers in the management of HBV infection.

HIV, HCV and HBV: A Review of Parallels and Differences

Elimination of the three blood-borne viruses-human immunodeficiency virus (HIV), hepatitis B (HBV) and hepatitis C (HCV)-as public health issues may be plausible in the near future. Spectacular advances have been made with the introduction of highly effective antiviral agents into clinical practice, and prevention strategies are available for all three infections. Effective disease control, laid out by WHO global strategies, is currently feasible for all three viruses. However, for worldwide elimination of these viruses, effective vaccines are required that are currently only available for HBV. In this review differences and parallels among HIV, HCV and HBV will be discussed with a focus on virologic and therapeutic issues, and prospects for the future of HBV will be presented.

Performance of Hepatitis B Core-Related Antigen Versus Hepatitis B Surface Antigen and Hepatitis B Virus DNA in Predicting HBeAg-positive and HBeAg-negative Chronic Hepatitis

BACKGROUND

We examined changes in hepatitis B core-related antigen (HBcrAg) during the four sequential phases of chronic hepatitis B virus (HBV) infection: hepatitis B e antigen (HBeAg)-positive chronic infection (EPCI) and hepatitis (EPCH), followed by HBeAg-negative chronic infection (ENCI) and hepatitis (ENCH). We compared the performance of serum HBcrAg, hepatitis B surface antigen (HBsAg), and HBV DNA in predicting EPCH and ENCH.

METHODS

We enrolled 492 consecutive patients: 49 with EPCI, 243 with EPCH, 101 with ENCI, and 99 with ENCH. HBcrAg was detected by chemiluminescent enzyme immunoassays. HBsAg and HBeAg were detected by chemiluminescent microparticle immunoassays. HBV DNA was detected by real-time PCR. Predictive performance of HBcrAg, HBsAg, and HBV DNA was evaluated using ROC curves.

RESULTS

Areas under ROC curves (AUCs) of HBcrAg, HBsAg, and HBV DNA for predicting EPCH were 0.738, 0.812, and 0.717, respectively; optimal cutoffs were ≤1.43×10⁵ kU/mL, ≤1.89×10⁴ IU/mL, and ≤3.97×10⁷ IU/mL, with sensitivities and specificities of 66.3% and 77.6%, 65.0% and 93.9%, and 60.5% and 79.6%, respectively. AUCs of HBcrAg, HBsAg, and HBV DNA for predicting ENCH were 0.887, 0.581, and 0.978, respectively; optimal cutoffs were >26.8 kU/mL, >2.29×10² IU/mL, and >8.75×10³ IU/mL, with sensitivities and specificities of 72.7% and 95.1%, 86.9% and 39.6%, and 89.9% and 92.1%, respectively.

CONCLUSIONS

HBsAg and HBV DNA were the best predictors of EPCH and ENCH, respectively. HBcrAg is an important surrogate marker for predicting EPCH and ENCH.

Application strategies of serum HBV DNA detection in HBV infection patients: A retrospective study of 5611 specimens

The detection of hepatitis B virus (HBV) DNA plays a critical role in determining the level of viral replication in HBV-infected patients. However, how to select appropriate HBV DNA detection method, low-sensitivity (ls) and hypersensitivity (hs) remains unclear. In this study, hepatitis B surface antigen (HBsAg), hepatitis B e-antigen (HBeAg), alanine transaminase (ALT), aspartate transaminase (AST), and hs HBV DNA titers in serum of 5611 cases with suspected HBV infection were reviewed. Besides, the dynamic changes of HBV DNA and HBsAg in 85 chronic hepatitis B (CHB) patients receiving peginterferon α (PegIFNα) or entecavir (ETV) were observed. The results showed the positive rate of HBV DNA was 32.8%, of which low viral load (20 to 500 IU/mL) accounted for 51.8%. In the 5611 cases, when the HBsAg was less than 1000 IU/mL, the proportion of low viral load was 76.3%. Moreover, in patients receiving antiviral treatment, when HBsAg was less than 2000 IU/mL (PegIFNα) or HBsAg was less than 3500 IU/mL (ETV), the proportion of patients with low viral load was 79.5% or 78.0%, respectively. We developed a strategy of serum HBV DNA detection in HBV-infected patients. When HBsAg was negative, HBV DNA detection should be unnecessary. When HBsAg was 0.05 to 1000 IU/mL, hs HBV DNA should be detected in patients with abnormal level of ALT, AST, or HBeAg. While HBsAg was greater than or equal to 1000 IU/mL, ls HBV DNA was recommended. Moreover, the cutoff value of HBsAg increased during antiviral therapy of CHB patients. In conclusion, hs HBV DNA is of great value in HBV-infected patients with low viral load. HBV DNA detection methods should be selected reasonably according to the levels of HBsAg, HBeAg, ALT, and AST.

New viral biomarkers for Hepatitis B: Are we able to change practice?

The management of chronic hepatitis B virus (HBV) infection is challenged by its varying natural course and its stealthy nature. Not all HBV-infected patients will develop complications of infection; however, it is of utmost importance to identify patients who are at risk and require antiviral treatment and/or close surveillance. Hepatic inflammation and quantification of HBV DNA have guided treatment decisions in the last decade, and these guided interventions have been shown to reduce liver-related complications and death. Data on the quantification of additional HBV markers such as hepatitis B surface antigen (HBsAg), hepatitis B core-related antigen (HBcrAg) and hepatitis B virus RNA (HBV RNA) have accumulated in recent years. Here, we review the current evidence of how to use these markers and discuss open issues that require additional research.

Improvements in the management of chronic hepatitis B virus infection

The primary goals of managing chronic hepatitis B (CHB) are prevention of liver-related complications and reduction of mortality. Universal vaccination has dramatically reduced the incidence of new infection, but the management of existing CHB patients are still challenging. Areas covered: This review compares the similarities and differences among the latest published regional guidelines on the indications and choices of antiviral therapy. We have summarized advances in virological biomarkers and non-invasive tests for liver fibrosis in disease assessment. Benefits and remaining challenges of current standard of care by peginterferon and nucleos(t)ide analogs (NA) have been presented. Data on combination therapy of peginterferon and NA in seeking functional cure of the disease is also critically discussed. We have also described the improvement in the management of CHB at pregnancy and prophylaxis in patients on chemotherapy and immunosuppressants. Expert commentary: Controversies exist in the assessment of disease activity for selection patients for treatment as well as on the use of tenofovir alafenamide as a safe and cost-effective alternative to tenofovir disoproxil fumarate. Though combination therapy of peginterferon and NA has induced HBsAg seroclearance in a small proportion of patients, peginterferon is not preferred in the future trend of drug development.

Clinical Implications of Hepatitis B Virus RNA and Covalently Closed Circular DNA in Monitoring Patients with Chronic Hepatitis B Today with a Gaze into the Future: The Field Is Unprepared for a Sterilizing Cure

. Chronic hepatitis B virus (HBV) infection has long remained a critical global health issue. Covalently closed circular DNA (cccDNA) is a persistent form of the HBV genome that maintains HBV chronicity. Decades of extensive research resulted in the two therapeutic options currently available: nucleot(s)ide analogs and interferon (IFN) therapy. A plethora of reliable markers to monitor HBV patients has been established, including the recently discovered encapsidated pregenomic RNA in serum, which can be used to determine treatment end-points and to predict the susceptibility of patients to IFN. Additionally, HBV RNA splice variants and cccDNA and its epigenetic modifications are associated with the clinical course and risks of hepatocellular carcinoma (HCC) and liver fibrosis. However, new antivirals, including CRISPR/Cas9, APOBEC-mediated degradation of cccDNA, and T-cell therapies aim at completely eliminating HBV, and it is clear that the diagnostic arsenal for defining the long-awaited sterilizing cure is missing. In this review, we discuss the currently available tools for detecting and measuring HBV RNAs and cccDNA, as well as the state-of-the-art in clinical implications of these markers, and debate needs and goals within the context of the sterilizing cure that is soon to come.

Natural history of serum HBV-RNA in chronic HBV infection

Virus-like particles encapsulating HBV-RNA represent a serum biomarker for assessing viral replication activity in clinical practice. However, baseline levels of serum HBV-RNA and their associations with viral replicative intermediates and liver disease in phases of chronic hepatitis B remain unknown. In this cross-sectional study, 102 patients were categorized into immune-tolerant (IT), HBeAg-positive immune active (HBeAg+IA), inactive carrier (IC) and HBeAg-negative immune active (HBeAg-IA) phases. HBV-RNA in serum samples and in 66 paired liver biopsies were quantified and correlated with serum ALT levels, histopathological scores and the levels of other viral replicative intermediates. Mean levels of serum HBV-RNA differed among phases, with the highest levels among IT (6.78 ± 0.83 log₁₀ copies mL^-1 ) patients, followed by HBeAg+IA (5.73 ± 1.16 log₁₀ copies mL^-1 ), HBeAg-IA (4.52 ± 1.25 log₁₀ copies mL^-1 ) and IC (2.96 ± 0.40 log₁₀ copies mL^-1 ) patients. Serum HBV-RNA levels correlated with HBV DNA in all phases, although correlations with other viral replicative intermediates weakened or disappeared when cases were stratified into phases. Distinct compositions of viral products were found among phases: the ratio of HBsAg to serum HBV-RNA was highest in IC patients, while the ratio of serum HBV-RNA to intrahepatic HBV-RNA and the ratio of intrahepatic HBV-DNA to intrahepatic HBV-RNA were significantly higher in IT patients. In conclusion, baseline levels of HBV-RNA and the composition of viral replicative intermediates differ significantly across the natural course of chronic HBV infection. These findings shed light on the nature of viral replication and pathogenesis of disease among different phases of chronic HBV infection.

Entecavir or tenofovir monotherapy prevents HBV recurrence in liver transplant recipients: A 5-year follow-up study after hepatitis B immunoglobulin withdrawal

BACKGROUND

Recent data suggest that oral third-generation nucleos(t)ide analogs (NA) monoprophylaxis following hepatitis B immunoglobulin (HBIg) withdrawal may be effective to prevent HBV reinfection after liver transplantation (LT).

PATIENTS AND METHODS

Between 01/2010 and 03/2012, all HBV monoinfected and HBV/HDV co-infected LT patients followed in our centre withdrew HBIg ± NA and were commenced on either ETV or TDF as monotherapy.

RESULTS

Seventy-seven patients were included in the study (55% TDF, 45% ETV). Group A comprised 69 HBV monoinfected patients and Group B 8 HBV/HDV co-infected patients. After HBIg withdrawal, Groups A and B patients were followed for 69 (range 13-83) months and 61 (range 31-78) months, respectively. No Group B patients had HBsAg or HBV DNA recurrence, while 6 (9%) Group A patients became HBsAg-positive after a median of 18 (range 1-40) months. The cumulative 5-year incidence of HBsAg recurrence was 9%. All 6 patients demonstrated undetectable HBV-DNA levels and stable graft function during 30 months of additional follow-up. In 3/6 patients, seroconversion was transitory, while the remaining 3 showed HBsAg levels <0.13 IU/mL over the entire period of observation. Pre-LT HCC emerged as the strongest predictor of HBsAg recurrence.

CONCLUSION

HBIG can be safely discontinued in HBsAgpositive LT recipients and replaced by ETV or TDF monotherapy.

HBsAg and HBcrAg as predictors of HBeAg seroconversion in HBeAg-positive patients treated with nucleos(t)ide analogues

HBeAg seroconversion marks an important spontaneous change and treatment end-point for HBeAg-positive patients and is a pre-requisite for HBsAg loss or functional cure. In this retrospective analysis, we aimed to identify predictors of seroconversion using serum quantitative HBsAg and HBcrAg, in HBeAg-positive patients treated with nucleos(t)ide analogues (NA). Data and samples from 118 HBeAg-positive adults (genotypes A-G) started on NA between Jan 2005 and Sept 2016 were retrospectively analysed at several time-points. The predictive power of on-treatment levels of HBsAg and HBcrAg was determined using receiver operating curve (ROC) analysis and cut-off values determined by maximized Youden's index. About 36.4% of patients achieved HBeAg seroconversion after a median of 39 months' treatment. On treatment kinetics of HBV DNA, HBsAg and HBcrAg differed between HBeAg seroconverters and nonseroconverters. A combination of HBsAg and HBcrAg had the greatest predictive value for HBeAg seroconversion: at 6 months, HBsAg of 3.9 log₁₀  IU/mL and HBcrAg of 5.7 log₁₀ U/mL had a sensitivity of 71.4%, specificity of 79.5%, positive predictive value (PPV) of 65.2% and negative predictive value (NPV) of 83.8%, with AUROC of 0.769 (0.668, 0.869; 95%CI), and at 12 months, HBsAg 3.8 log₁₀  IU/mL and HBcrAg 5.5 log₁₀ U/mL had a sensitivity of 73.7%, specificity of 79.5%, PPV of 63.6% and NPV of 86.1%, with AUROC 0.807 (0.713, 0.901; 95% CI). In conclusion, our results may be used to identify patients who are unlikely to achieve treatment end-points, which will be important as the future management of chronic hepatitis B looks to therapies that offer functional cure.

Serum biomarkers for diagnosis and monitoring viral hepatitis and hepatocellular carcinoma

INTRODUCTION

Chronic liver disease due to viral hepatitis continues to be a major global health concern. Timely diagnosis and treatment will prevent cirrhosis, risk of hepatocellular carcinoma (HCC), and requirement for liver transplantation. Numerous serum biomarkers are available for viral hepatitis that are helpful in diagnosis, measuring severity, progression of disease, evaluating the best therapeutic options, and monitoring antiviral treatment response. Determining the clinical use of available diagnostic tests can be challenging for the health care provider. Areas covered: This review article attempts to summarize the established and emerging serological markers for diagnosis and managing viral hepatitis. The literature search was performed in February 2018 and included MEDLINE and Embase databases for recent relevant literature on biomarkers for viral hepatitis. Expert Commentary: Despite the discovery of several candidate biomarkers, translating these to clinical practice in viral hepatitis and HCC remains challenging. While limited availability of the new biomarkers in prevalent geographic areas and significant cost remain major obstacles, there have been exciting developments in this field. Understanding the detection limits and sensitivity of these markers and translating them into clinical use is important in management of viral hepatitis and complications of liver disease such as cirrhosis and hepatocellular cancer.

Noninvasive Biomarkers in Assessment of Liver Fibrosis in Patients with HBeAg Negative Chronic Hepatitis B

BACKGROUND

Liver biopsy for evaluation of liver fibrosis has several adverse effects, for which reason noninvasive tests have been developed.

AIM

To evaluate the usefulness of noninvasive biomarkers, qHBsAg and HBV DNA levels in predicting liver fibrosis in patients with hepatitis Be antigen (HBeAg) negative chronic hepatitis B (CHB).

MATERIAL AND METHODS

This prospective study included 50 patients with HBeAg negative CHB. All patients underwent laboratory and serology testing, quantification of HBV DNA and HBs antigen. The liver stiffness was measured with elastography. The patients were analysed for APRI and FIB-4, quantitative hepatitis Bs antigen and HBV DNA.

RESULTS

Logistic regression analysis showed that greatest significance in predicting liver fibrosis has FIB-4 (Wald = 3.24, P = 0.07), followed by HBV DNA ≥ 2 000 IU/ml ≤ 20 000 IU/ml (Wald = 2.86, P = 0.09), qHBsAg (Wald = 2.17, P = 0.14), HBV DNA > 20 000 IU/ml (Wald = 0.58, P = 0.45), APRI (Wald = 0.04, P = 0.84).

CONCLUSION

the FIB-4 index has the greatest value in predicting liver fibrosis while APRI has the lowest; the more advanced liver disease is associated with lower serum level of quantitative HBs antigen. Combination of noninvasive blood biomarkers and imaging tests can provide better diagnostic accuracy and exclude the need for liver biopsy.

Hepatitis B virus infection

Hepatitis B virus (HBV) is a hepatotropic virus that can establish a persistent and chronic infection in humans through immune anergy. Currently, 3.5% of the global population is chronically infected with HBV, although the incidence of HBV infections is decreasing owing to vaccination and, to a lesser extent, the use of antiviral therapy to reduce the viral load of chronically infected individuals. The course of chronic HBV infection typically comprises different clinical phases, each of which potentially lasts for decades. Well-defined and verified serum and liver biopsy diagnostic markers enable the assessment of disease severity, viral replication status, patient risk stratification and treatment decisions. Current therapy includes antiviral agents that directly act on viral replication and immunomodulators, such as interferon therapy. Antiviral agents for HBV include reverse transcriptase inhibitors, which are nucleoside or nucleotide analogues that can profoundly suppress HBV replication but require long-term maintenance therapy. Novel compounds are being actively investigated to achieve the goal of HBV surface antigen seroclearance (functional cure), a serological state that is associated with a higher remission rate (thus, no viral rebound) after treatment cessation and a lower rate of cirrhosis and hepatocellular carcinoma. This Primer addresses several aspects of HBV infection, including epidemiology, immune pathophysiology, diagnosis, prevention and management.

High serum levels of pregenomic RNA reflect frequently failing reverse transcription in hepatitis B virus particles

Background

Hepatocytes infected by hepatitis B virus (HBV) produce different HBV RNA species, including pregenomic RNA (pgRNA), which is reverse transcribed during replication. Particles containing HBV RNA are present in serum of infected individuals, and quantification of this HBV RNA could be clinically useful.

Methods

In a retrospective study of 95 patients with chronic HBV infection, we characterised HBV RNA in serum in terms of concentration, particle association and sequence. HBV RNA was detected by real-time PCR at levels almost as high as HBV DNA.

Results

The HBV RNA was protected from RNase and it was found in particles of similar density as particles containing HBV DNA after fractionation on a Nycodenz gradient. Sequencing the epsilon region of the RNA did not reveal mutations that would preclude its binding to the viral polymerase before encapsidation. Specific quantification of precore RNA and pgRNA by digital PCR showed almost seven times lower ratio of precore RNA/pgRNA in serum than in liver tissue, which corresponds to poorer encapsidation of this RNA as compared with pgRNA. The serum ratio between HBV DNA and HBV RNA was higher in genotype D as compared with other genotypes.

Conclusions

The results suggest that HBV RNA in serum is present in viral particles with failing reverse transcription activity, which are produced at almost as high rates as viral particles containing DNA. The results encourage further studies of the mechanisms by which these particles are produced, the impact of genotype, and the potential clinical utility of quantifying HBV RNA in serum.

Electronic supplementary material

The online version of this article (10.1186/s12985-018-0994-7) contains supplementary material, which is available to authorized users.

What is changed in HBV molecular epidemiology in Italy?

Hepatitis B virus (HBV) infection represents the most common cause of chronic liver diseases worldwide. Consequently, to the introduction of the universal HBV vaccination program, the prevalence of hepatitis B surface antigen was markedly reduced and less than 1% of the population of Western Europe and North America is chronically infected. To date, despite great advances in therapeutics, HBV chronic infection is considered an incurable disease. Ten hepatitis B virus genotypes (A-J) and several subgenotypes have been identified so far, based on intergroup divergences of 8% and 4%, respectively, in the complete viral genome. HBV-D genotype has been found throughout the world, with highest prevalence in the Mediterranean area. In the present review, several articles concerning HBV epidemiology, and phylogeny in Italy have been analyzed, mainly focusing on the changes occurred in the last decade.

Increased NK Cell Function After Cessation of Long-Term Nucleos(t)ide Analogue Treatment in Chronic Hepatitis B Is Associated With Liver Damage and HBsAg Loss

BACKGROUND

Treatment with nucleos(t)ide analogues (NA) suppresses hepatitis B virus (HBV) DNA but rarely leads to functional cure of chronic hepatitis B (CHB). Following NA cessation, some hepatitis B e antigen (HBeAg)-negative CHB patients experience hepatitis B s antigen (HBsAg) loss. Cellular immune responses, including natural killer (NK) cell responses, explaining virological events following NA treatment cessation remain elusive.

METHODS

In a single-center prospective trial, 15 HBeAg-negative CHB patients on long-term NA treatment underwent structured NA cessation and were studied longitudinally. The NK cell compartment was assessed using high-dimensional flow cytometry and correlated with the clinical course.

RESULTS

Unsupervised stochastic neighbor embedding analysis revealed NA-treated CHB patients to have a significantly affected NK cell compartment compared to controls. Cessation of NA treatment resulted in minor phenotypic alterations, but it significantly augmented NK cell natural cytotoxicity responses in the CHB patients. This increased NK cell functionality correlated with alanine aminotransferase flares in the patients and was particularly enhanced in patients experiencing HBsAg seroclearance at long-term follow-up.

CONCLUSIONS

Increased NK cell function is associated with active hepatitis and HBsAg seroclearance following structured NA cessation. This adds to our knowledge of the immunological events that develop following cessation of NA treatment in CHB.

[Personalized treatment of viral hepatitis of the present and the future : Hepatitis B, C, delta, and E]

Precision medicine is also possible for infectious diseases as shown for the treatment of chronic viral hepatitis, especially if different options are available. In hepatitis B virus (HBV) infection, treatment indication as well as the choice of treatment and the decisions to stop treatment are based on viral markers and alanine aminotransferase (ALT) level. Future therapies for HBV infection aiming for functional cure or even virus elimination may be even more personalized and have to take into account the immune status of a given patient. Such treatment modalities might also increase the chance for successful treatment of chronic hepatitis delta where treatment options are still very limited. Some new therapeutic concepts targeting host receptors or host enzymes are promising, but may require individualized approaches. Chronic hepatitis C is a good example for precision medicine based on viral and host factors. However, the main reason for individualized direct-acting antiviral (DAA) treatment is to save costs. As DAAs are effective in more than 95% of patients, elimination of HCV seems to be possible at the level of a given country or even on a global scale. However, owing to high reinfection rates in high-risk groups and limited availability of antiviral therapy in many high endemic countries, it must still be decided whether an HCV vaccine or pre-exposure prophylaxis is required to achieve this goal. Hepatitis E is an emerging topic as this is the most frequent acute hepatitis virus infection. It can result in a chronic infection in immunosuppressed individuals. Treatment options are still limited and individualized management is based on tailoring immunosuppressive therapy and therapy with ribavirin. Thus, personalized therapy of hepatitis E virus infection is still limited.

Impact of integrated viral DNA on the goal to clear hepatitis B surface antigen with different therapeutic strategies

A hallmark of hepatitis B virus (HBV) infection is the presence of hepatitis B surface antigen (HBsAg) in the serum of patients. Sustained loss of HBV DNA and HBsAg from the blood are main goals for treatment, and considered as functional cure. It is rarely achieved with long-term nucleoside analogue treatment though, both because cccDNA, the template for viral replication, is not completely cleared, and probably also because hepatocytes with HBV DNA integrated into their chromosomes persist and continue to produce large amounts of HBsAg. Therefore, loss of HBsAg requires that both cccDNA and integrated DNA are cleared or their expression blocked. Recent data indicate that this may be achieved in some patients by stopping nucleoside analogue treatment, and that HBsAg-levels can be reduced by using specific interfering RNA. In the future, targeted degradation or disruption of HBV DNA might be possible using genome editing techniques such as CRISPR/Cas9.

Clinical utility of hepatitis B surface antigen kinetics in treatment-naïve chronic hepatitis B patients during long-term entecavir therapy

AIM

To investigate the utility of hepatitis B surface antigen (HBsAg) kinetics in chronic hepatitis B patients during long-term entecavir treatment.

METHODS

This retrospective study included treatment-naïve chronic hepatitis B patients who received at least 2 years of consecutive entecavir treatment. Patients were followed up at three to six month intervals with liver biochemistry, hepatitis B virus DNA, and abdominal sonography. In hepatitis B e antigen (HBeAg)-positive patients, HBeAg levels were assessed every three to six month until results became negative. Serum HBsAg levels were determined at the baseline, one-year and five-year time points. Liver cirrhosis was diagnosed through liver biopsy, imaging examinations, or clinical findings of portal hypertension. Hepatocellular carcinoma was diagnosed by histological examination or dynamic image studies.

RESULTS

A total of 211 patients were enrolled. The median treatment time was 5.24 (2.00-9.62) years. Multivariate analysis showed that lower baseline HBsAg levels were associated with an earlier virological response, earlier hepatitis B e antigen (HBeAg) seroconversion, and earlier biochemical response in HBeAg-positive patients (cut-off value: 4 log IU/mL) and an earlier virological response in HBeAg-negative non-cirrhotic patients (cut-off value: 2.4 log IU/mL). Although HBsAg levels decreased slowly during long-term entecavir treatment, higher HBsAg decrease rates were found in the first year for HBeAg-positive non-cirrhotic patients, and patients with higher baseline HBsAg levels. More favorable clinical outcomes were not observed by a rapid HBsAg decline per se, but depended on lower baseline HBsAg levels.

CONCLUSION

Baseline HBsAg can be used to predict treatment responses. HBsAg levels and decrease rates should be considered together according to disease status while interpreting HBsAg changes.

Hepatitis B: Who and when to treat?

As current treatment options almost never achieve eradication of hepatitis B virus (HBV), the most realistic goal for HBV treatment is persistent inhibition of viral replication and ALT normalization. Thus, the decision to start treatment should be based on careful patient selection and individualized decisions. Treatment is generally indicated in chronic hepatitis B patients with HBV DNA >2000 IU/mL, elevated ALT and/or at least moderate histological lesions, while all patients with cirrhosis and detectable HBV DNA should be treated. Patients with HBV DNA >20 000 IU/mL and ALT >2xULN (upper limit of normal), HBV DNA >2000 IU/mL and liver stiffness >9 or >12 kPa in case of normal or ≤5xULN, HBV DNA >2000 IU/mL and a family history of cirrhosis and/or HCC as well as HBeAg-positive patients with HBV DNA >20 000 IU/mL and over 30 years old can begin treatment whatever the liver histology. Moreover, patients with HBV DNA >2000 IU/mL and at least moderate histological lesions can begin treatment whatever the ALT levels. Prophylactic treatment is indicated in HBV-related liver transplantation patients to prevent recurrence, in the last trimester of pregnancy in women with high viraemia to prevent vertical transmission and in patients receiving immunosuppression/chemotherapy to prevent the reactivation of HBV. Treatment is also indicated in patients with co-infections, extrahepatic manifestations and severe acute hepatitis B, or healthcare workers with viraemia. These treatment indications can only change if HBV eradication or at least HBsAg clearance can be achieved in the future in a significant proportion of patients.

Can quantitative hepatitis B surface antigen levels predict the severity of liver disease in genotype E Patients?

The utility of quantitative Hepatitis B surface antigen (qHBsAg) level as a marker of chronic hepatitis B (CHB)-related liver damage is not fully delineated, but is becoming increasingly relevant. Quantitative HBsAg levels are linked with progression of liver disease in HBeAg-negative genotype B and C patients, but it is not clear whether this is consistent across all HBV genotypes. In this single-centre, cross-sectional observational study, we evaluated whether qHBsAg levels can predict the severity of liver disease in genotype E patients. Demographic characteristics, viral, biochemical markers and qHBsAg levels were assessed at time of liver biopsy [all HBV DNA>2000 IU/mL and/or abnormal alanine transaminase (ALT)]. Patients were divided into three groups according to the severity of fibrosis on biopsy: mild (F0-1), moderate (F2-4), severe (F5-6) liver disease and into two groups according to the NI grading, low (NI 0-3) and high inflammation (NI ≥4). A total of 259 HBeAg-negative CHB treatment-naive genotype E patients were studied. The median age of this cohort was 38 years, and 61% were males. Advanced (severe) fibrosis patients had higher ALT, HBV DNA, and lower HBsAg level and qHBsAg/DNA ratio. Patients with NI ≥4 had higher ALT, HBV DNA, but lower qHBsAg/DNA ratio. There was no correlation between HBsAg and HBV DNA levels. Quantitative HBsAg levels were lower in more advanced liver fibrosis. There was no correlation between qHBsAg and HBV DNA levels. This may reflect discordance between viral replication and transcriptional activity or differential HBsAg expression in HBeAg-negative genotype E patients with advanced liver disease.

Pronounced decline of serum HBsAg in chronic hepatitis B patients with long-term effective nucleos(t)ide analogs therapy

AIMS

This study aims to investigate the kinetics of serum HBsAg levels in chronic hepatitis B patients with long-term nucleos(t)ide analogs (NAs) therapy.

METHODS

This was a retrospective clinical study. Serum HBsAg in serial samples of 94 patients, who received at least 8 years of NAs therapy, were measured using Elecsys® HBsAg II Quant Assay.

RESULTS

In this cohort, serum HBsAg levels reduced from 3.80 log10 IU/mL at baseline to 2.72 log10 IU/mL at year 8 (p < .001), and the percentage of patients with HBsAg <1000 IU/mL increased from 14.9% at baseline to 55.3% at year 8 (p < .001). The reduction of serum HBsAg did not differ significantly between patients stratified by baseline virological parameters and type of antiviral agents. But as compared to patients without HBeAg seroconversion, HBsAg levels were significant lower in patients with HBeAg seroconversion (3.19 vs. 2.47 log10 IU/mL at year 8, p = .001). As compared to patients with slow (0-1 log10 IU/mL) or steady HBsAg(≤0 log10 IU/mL) decline at year 1, patients with a rapid HBsAg (≥1 log10 IU/mL) decline had a significantly lower HBsAg levels from year 2 to 8. However, Cox regression analysis showed that only absolute HBsAg levels at year 1 was an independent predictor of subsequent HBsAg <1000 IU/mL at year 8 of antiviral therapy(HR 0.242, p = .004).

CONCLUSION

Pronounced HBsAg declines could be achieved in patients after long-term effective therapy with NAs, and on-treatment low serum HBsAg level at year 1 might be a predictor of serum HBsAg <1000 IU/mL at year 8.

Potential use of serum HBV RNA in antiviral therapy for chronic hepatitis B in the era of nucleos(t)ide analogs

Although the efficacy of nucleos(t)ide analogue (NA) has been confirmed for treatment of chronic hepatitis B, long-term therapy has been recommended due to the high frequency of off-therapy viral DNA rebound and disease relapse. In this review, the RNA virion-like particles of hepatitis B virus (HBV) are integrated into the life cycle of HBV replication, and the potential significance of serum HBV RNA is systematically described. The production of HBV RNA virion-like particles should not be blocked by NA; in this regard, serum HBV RNA is found to be a suitable surrogate marker for the activity of intrahepatic covalently closed circular DNA (cccDNA), particularly among patients receiving NA therapy. Therefore, the concept of virological response is redefined as persistent loss of serum HBV DNA and HBV RNA. In contrast to hepatitis B surface antigen (HBsAg) that can originate from either the cccDNA or the integrated HBV DNA fragment, serum HBV RNA, with pregenomic RNA origination, can only be transcribed from cccDNA. Therefore, the loss of serum HBV RNA would likely be a promising predicator for safe drug discontinuation. The clinical status of consistent loss of serum HBV RNA accompanied with low serum HBsAg levels might be implicated as a "para-functional cure," a status nearly close to the functional cure of chronic hepatitis B, to distinguish the "functional cure" characterized as serum HBsAg loss with or without anti-HBs seroconversion.

Negative Correlation of Serum Hepatitis B Surface Antigen and Hepatitis B e Antigen Levels with the Severity of Liver Inflammation in Treatment-naïve Patients with Chronic Hepatitis B Virus Infection

BACKGROUND

Estimating the grades of liver inflammation is critical in the determination of antiviral therapy in patients chronically infected with hepatitis B virus (HBV). The aim of this study was to investigate the correlation of serum levels of hepatitis B surface antigen (HBsAg) and hepatitis B e antigen (HBeAg) with the liver inflammation grades in treatment-naïve patients with chronic HBV infection.

METHODS

We retrospectively enrolled 584 treatment-naïve HBeAg-positive patients who underwent liver biopsy in Ditan Hospital from January 2008 to January 2016. Based on the severity of liver inflammation, the patients were divided into minimal, mild, and moderate groups. SPSS software was used for statistical analysis of all relevant data.

RESULTS

The liver histological examinations showed that 324, 194, and 66 patients had minimal, mild, and moderate liver inflammation, respectively. The median age of the three groups was 30, 33, and 38 years, respectively (Χ2 = 26.00, P < 0.001). The median HBsAg levels in minimal, mild, and moderate inflammation groups were 4.40, 4.16, and 3.67 log U/ml, respectively, and the median HBeAg levels in the three groups were 3.12, 2.99, and 1.86 log sample/cutoff, respectively; both antigens tended to decrease as the grade of inflammation increased (Χ2 = 99.68 and Χ2 = 99.23, respectively; both P < 0.001). The cutoff values of receiver operating characteristic curve in the age, HBsAg and HBeAg levels were 36 years, 4.31 log U/ml, and 2.86 log S/CO, respectively, l to distinguish minimal grade and other grades of treatment-naïve HBeAg-positive patients with chronic HBV infection.

CONCLUSIONS

Serum HBsAg and HBeAg quantitation might gradually decrease with aggravated liver inflammation and the corresponding cutoff values might help us to distinguish minimal grades and other grades and detect those who do not need antiviral therapy in treatment-naïve HBeAg-positive patients with chronic HBV infection.

HBsAg mRNA degradation induced by a dihydroquinolizinone compound depends on the HBV posttranscriptional regulatory element

In pursuit of novel therapeutics targeting the hepatitis B virus (HBV) infection, we evaluated a dihydroquinolizinone compound (DHQ-1) that in the nanomolar range reduced the production of virion and surface protein (HBsAg) in tissue culture. This compound also showed broad HBV genotype coverage, but was inactive against a panel of DNA and RNA viruses of other species. Oral administration of DHQ-1 in the AAV-HBV mouse model resulted in a significant reduction of serum HBsAg as soon as 4 days following the commencement of treatment. Reduction of HBV markers in both in vitro and in vivo experiments was related to the reduced amount of viral RNA including pre-genomic RNA (pgRNA) and 2.4/2.1 kb HBsAg mRNA. Nuclear run-on and subcellular fractionation experiments indicated that DHQ-1 mediated HBV RNA reduction was the result of accelerated viral RNA degradation in the nucleus, rather than the consequence of inhibition of transcription initiation. Through mutagenesis of HBsAg gene sequences, we found induction of HBsAg mRNA decay by DHQ-1 required the presence of the HBV posttranscriptional regulatory element (HPRE), with a 109 nucleotides sequence within the central region of the HPRE alpha sub-element being the most critical. Taken together, the current study shows that a small molecule can reduce the overall levels of HBV RNA, especially the HBsAg mRNA, and viral surface proteins. This may shed light on the development of a new class of HBV therapeutics.

Hepatitis B s antigen kinetics during treatment with nucleos(t)ides analogues in patients with hepatitis B e antigen-negative chronic hepatitis B

BACKGROUND/AIMS

Serum hepatitis B s antigen (HBsAg) levels might be used as a predictor of virological breakthrough or of sustained off-treatment virological response in hepatitis B e antigen (HBeAg)-negative chronic hepatitis B (CHB) patients. We evaluated the changes of HBsAg in those patients under nucleos(t)ide analogue(s) [NA(s)] therapy for ≥12 months.

METHODS

We included 99 HBeAg-negative CHB patients treated with low-genetic barrier NA(s) for a mean of 66 months (lamivudine: 66, adefovir: 6, lamivudine plus adefovir: 11 and telbivudine: 16) and 86 HBeAg-negative CHB patients treated under entecavir or tenofovir for a mean of 30 months as the comparison group.

RESULTS

Compared to baseline, HBsAg levels decreased by a median of 162, 1525, 943, 1545, 2163 and 3859 IU/mL at 6, 12, 24, 36, 48 and 60 months of therapy with low-genetic barrier NA(s) respectively. The 6-, 12-, 24-, 36-, 48- and 60-month cumulative rates of HBsAg<100 IU/mL were 2%, 3%, 3%, 5%, 5% and 5%, and <1000 IU/mL 6%, 9%, 15%, 19%, 24% and 61% respectively. Baseline HBsAg levels were the only significant variable associated with the time to HBsAg drop <1000 IU/mL. HBsAg loss occurred in 3.0% of patients. The high-genetic barrier NAs were not found to offer a greater or faster HBsAg decline.

CONCLUSIONS

In HBeAg-negative CHB patients, long-term therapy with low-genetic barrier NA(s) decreases serum HBsAg levels, but the rate of decline is slow. Lower baseline HBsAg levels are significantly associated with on-therapy HBsAg drop <1000 IU/mL. Serum HBsAg decline is similar during therapy with low- or high-genetic barrier NAs.

Diagnostic accuracy of tests to detect hepatitis B surface antigen: a systematic review of the literature and meta-analysis

BACKGROUND

Chronic Hepatitis B Virus (HBV) infection is characterised by the persistence of hepatitis B surface antigen (HBsAg). Expanding HBV diagnosis and treatment programmes into low resource settings will require high quality but inexpensive rapid diagnostic tests (RDTs) in addition to laboratory-based enzyme immunoassays (EIAs) to detect HBsAg. The purpose of this review is to assess the clinical accuracy of available diagnostic tests to detect HBsAg to inform recommendations on testing strategies in 2017 WHO hepatitis testing guidelines.

METHODS

The systematic review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines using 9 databases. Two reviewers independently extracted data according to a pre-specified plan and evaluated study quality. Meta-analysis was performed. HBsAg diagnostic accuracy of rapid diagnostic tests (RDTs) was compared to enzyme immunoassay (EIA) and nucleic-acid test (NAT) reference standards. Subanalyses were performed to determine accuracy among brands, HIV-status and specimen type.

RESULTS

Of the 40 studies that met the inclusion criteria, 33 compared RDTs and/or EIAs against EIAs and 7 against NATs as reference standards. Thirty studies assessed diagnostic accuracy of 33 brands of RDTs in 23,716 individuals from 23 countries using EIA as the reference standard. The pooled sensitivity and specificity were 90.0% (95% CI: 89.1, 90.8) and 99.5% (95% CI: 99.4, 99.5) respectively, but accuracy varied widely among brands. Accuracy did not differ significantly whether serum, plasma, venous or capillary whole blood was used. Pooled sensitivity of RDTs in 5 studies of HIV-positive persons was lower at 72.3% (95% CI: 67.9, 76.4) compared to that in HIV-negative persons, but specificity remained high. Five studies evaluated 8 EIAs against a chemiluminescence immunoassay reference standard with a pooled sensitivity and specificity of 88.9% (95% CI: 87.0, 90.6) and 98.4% (95% CI: 97.8, 98.8), respectively. Accuracy of both RDTs and EIAs using a NAT reference were generally lower, especially amongst HIV-positive cohorts.

CONCLUSIONS

HBsAg RDTs have good sensitivity and excellent specificity compared to laboratory immunoassays as a reference standard. Sensitivity of HBsAg RDTs may be lower in HIV infected individuals.