Hepatitis B core-related antigen as a promising serological marker for monitoring hepatitis B virus cure

Hepatitis B virus(HBV)infection is a global health concern.The current sequen-tial endpoints for the treatment of HBV infection include viral suppression,hepatitis B e antigen(HBeAg)seroconversion,functional cure,and covalently closed circular DNA(cccDNA)clearance.Serum hepatitis B core-related antigen(HBcrAg)is an emerging HBV marker comprising three components:HBeAg,hepatitis B core antigen,and p22cr.It responds well to the transcriptional activity of cccDNA in the patient's liver and is a promising alternative marker for serolo-gical testing.There is a strong correlation,and a decrease in its level corresponds to sustained viral suppression.In patients with chronic hepatitis B(CHB),serum HBcrAg levels are good predictors of HBeAg seroconversion(both spontaneous and after antiviral therapy),particularly in HBeAg-positive patients.Both low baseline HBcrAg levels and decreasing levels early in antiviral therapy favored HBsAg seroconversion,which may serve as a good surrogate option for treatment endpoints.In this review,we summarize the role of serum HBcrAg in the treat-ment of CHB.Therefore,long-term continuous monitoring of serum HBcrAg levels contributes to the clinical management of patients with CHB and optimizes the choice of treatment regimen,making it a promising marker for monitoring HBV cure.

On-treatment monitoring of liver fibrosis with serum hepatitis B core-related antigen in chronic hepatitis B

BACKGROUND Non-invasive evaluation for liver fibrosis is clinically important,especially in patients with undetectable hepatitis B virus(HBV)DNA treated with nucleoside analogs.AIM To clarify the monitoring power of hepatitis B core-related antigen(HBcrAg)for hepatic histologic changes in patients with chronic hepatitis B(CHB)treated with entecavir.METHODS This prospective multicenter study used multiple ordinal and multivariate logistics regression analysis to assess variables associated with Ishak fibrosis score and regression for fibrosis regression,respectively,in 403 CHB patients,including 374 with entecavir for 72 weeks(291 underwent paired liver biopsy)and 29 as controls.RESULTS Level of HBcrAg correlated negatively with liver fibrosis staging(γ=-0.357,P<0.001)in hepatitis B e antigen(HBeAg)-positive patients,and positively with liver fibrosis staging in HBeAg-negative patients.Higher HBcrAg concentration was associated with younger age,HBeAg positive status,high HBV DNA loads,high level of hepatitis B surface antigen(HBsAg)and higher necroinflammation,but not with HBV genotype.Serum concentration of HBcrAg,basal core promoter/precore(BCP/PC)mutant,quantitation of HBsAg(qHBsAg)and platelet counts were independently associated with Ishak fibrosis score on multiple ordinal regression.HBV DNA was undetectable in 88.37%of patients treated with entecavir at week 72,while their level of HBcrAg was still detectable.A greater reduction in post-treatment HBcrAg concentration was associated with the regression of hepatic fibrosis and histological improvement.HBcrAg concentration>6.33 log IU/mL at baseline and logarithmic reduction>1.03 log IU/mL at week 72 were associated with a higher chance of regression of liver fibrosis and histological improvement,respectively.CONCLUSION HBcrAg level is associated with liver fibrosis progression.HBcrAg is an excellent monitor of hepatic histological changes,especially in CHB patients treated with nucleoside analogs.

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

BACKGROUND Quantitative hepatitis B core-related antigen(qHBcrAg)has a better correlation with intrahepatic hepatitis B virus(HBV)covalently closed circular DNA(cccDNA)than HBV DNA or hepatitis B e antigen(HBeAg),but data are still lacking for its clinical application.AIM The aim was to investigate serum qHBcrAg levels in patients with chronic hepatitis B and assess the correlation of serum qHBcrAg with pregenomic RNA(pgRNA),cccDNA,and HBeAg seroconversion.METHODS This study was a secondary analysis of patients who underwent percutaneous liver biopsy between July 2014 and June 2019 in two multicenter randomized controlled clinical trials of peginterferon vs nucleos(t)ide analog(NUC)-based therapy(NCT03509688 and NCT03546530).Serum qHBcrAg,pgRNA,HBV DNA,hepatitis B core antigen,HBeAg,liver cccDNA,and HBV DNA were measured.The correlations of serum qHBcrAg with other biomarkers were analyzed.RESULTS A total of 139 patients were included.The mean qHBcrAg levels were 5.32±1.18 log10 U/mL at baseline and decreased during treatment(all P<0.0001).Serum qHBcrAg levels were positively correlated with pgRNA(r=0.597,P<0.0001)and cccDNA(r=0.527,P<0.0001)levels.The correlation of serum qHBcrAg level and intrahepatic HBV DNA levels at baseline was weak but significant(r=0.399,P<0.0001).HBcrAg predicted HBeAg seroconversion,with areas under the receiver operating characteristics curve of 0.788 at 24 wk and 0.825 at 48 wk.Log HBcrAg at wk 24 and 48 was independently associated with HBeAg seroconversion[odds ratio(OR)=2.402,95%confidence interval(CI):1.314-4.391,P=0.004;OR=3.587,95%CI:1.315-9.784,P=0.013].CONCLUSION Serum HBcrAg levels were correlated with HBV virological markers and could be used to predict HBeAg seroconversion.

Hepatitis B surface antigen and hepatitis B core-related antigen kinetics after adding pegylated-interferon to nucleos(t)ids analogues in hepatitis B e antigen-negative patients

BACKGROUND Hepatitis B e antigen-negative chronic hepatitis B patients under nucleos(t)ids analogues(NAs)rarely achieve hepatitis B surface antigen(HBsAg)loss.AIM To evaluate if the addition of pegylated interferon(Peg-IFN)could decrease HBsAg and hepatitis B core-related antigen(HBcrAg)levels and increase HBsAg loss rate in patients under NAs therapy.METHODS Prospective,non-randomized,open-label trial evaluating the combination of Peg-IFN 180μg/week plus NAs during forty-eight weeks vs NAs in monotherapy.Hepatitis B e antigen-negative non-cirrhotic chronic hepatitis B patients of a tertiary hospital,under NAs therapy for at least 2 years and with undetectable viral load,were eligible.Patients with hepatitis C virus,hepatitis D virus or human immunodeficiency virus co-infection and liver transplanted patients were excluded.HBsAg and HBcrAg levels(log10 U/mL)were measured at baseline and during ninety-six weeks.HBsAg loss rate was evaluated in both groups.Adverse events were recorded in both groups.The kinetic of HBsAg for each treatment group was evaluated from baseline to weeks 24 and 48 by the slope of the HBsAg decline(log10 IU/mL/week)using a linear regression model.RESULTS Sixty-five patients were enrolled,61%receiving tenofovir and 33%entecavir.Thirty-six(55%)were included in Peg-IFN-NA group and 29(44%)in NA group.After matching by age and treatment duration,baseline HBsAg levels were comparable between groups(3.1 vs 3.2)(P=0.25).HBsAg levels at weeks 24,48 and 96 declined in Peg-IFN-NA group(-0.26,-0.40 and-0.44)and remained stable in NA group(-0.10,-0.10 and-0.10)(P<0.05).The slope of HBsAg decline in Peg-IFN-NA group(-0.02)was higher than in NA group(-0.00)(P=0.015).HBcrAg levels did not change.Eight(22%)patients discontinued Peg-IFN due to adverse events.The HBsAg loss was achieved in 3(8.3%)patients of the Peg-IFN-NA group and 0(0%)of the NA group.CONCLUSION The addition of Peg-IFN to NAs caused a greater and faster decrease of HBsAg levels compared to NA therapy.Side effects of Peg-IFN can limit its use in clinical practice.

Hepatitis B core-related antigen:Are we near a treatment endpoint?

Different serological and virological markers in chronic hepatitis B patients guide staging of viral infection,and initiation and response to therapy.Due to the persistence of intrahepatic covalently closed circular DNA(cccDNA)in the hepatocyte nucleus,hepatitis B is not curable.Even after undetectable hepatitis B virus DNA levels,the persistence of hepatitis B surface antigen and novel markers such as hepatitis B core-related antigen(HBcrAg)indicate the persistence of intrahepatic cccDNA.In this study,HBcrAg levels at baseline and after 24 and 48 wk of antiviral therapy predicted hepatitis B e antigen seroconversion.Due to the poor sensitivity of assays and detectable levels in HBsAg-negative patients,the long-term utility of HBcrAg needs future research.

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

Background:Hepatitis B core-related antigen(HBcrAg)is a promising disease-monitoring marker for chronic hepatitis B(CHB).We investigated correlations between HBcrAg with antiviral efficacy and virological and histological variables.Methods:One hundred and forty-five CHB patients from the mainland of China between August 2013 and September 2016 who underwent liver biopsy received entecavir therapy and had paired liver biopsy at 78 weeks.We analyzed correlations between HBcrAg and virological and histological variables in hepatitis B e antigen(HBeAg)-positive and HBeAg-negative patients.We also explored the predictors of HBeAg loss after 78 weeks of antiviral therapy.Pearson correlation analysis and logistic forward stepwise regression were the main statistic methods.Results:HBeAg-positive patients(n=93)had higher baseline HBcrAg(median 7.4 vs.5.3 log10 U/mL P<0.001)and greater HBcrAg declines(median 1.6 vs.0.9 log10 U/mL P=0.007)than HBeAg-negative patients after 78 weeks of therapy.At baseline,HBcrAg correlated with hepatitis B virus(HBV)DNA in both HBeAg-positive(r=0.641,P<0.001)and-negative patients(r=0.616,P<0.001),with hepatitis B surface antigen(HBsAg)in HBeAg-positive patients(r=0.495,P<0.001),but not with anti-hepatitis B virus core antibody(anti-HBc).Weak correlations existed between HBcrAg,histology activity index(HAI;r=0.232,P=0.025),and Ishak fibrosis score(r=-0.292,P=0.005)in HBeAg-positive patients.At 78 weeks,significant correlations existed only between HBcrAg and anti-HBc in HBeAg-positive(r=-0.263,P=0.014)and HBeAg-negative patients(r=-0.291,P=0.045).Decreased HBcrAg significantly correlated with reduced HBV DNA(r=0.366,P=0.001;r=0.626,P<0.001)and HBsAg(r=0.526,P=0.001;r=0.289,P=0.044)in HBeAg-positive and-negative patients,respectively,and with reduced HAI in HBeAg-positive patients(r=0.329,P=0.001).Patients with HBeAg loss(n=29)showed a larger reduction in HBcrAg than those without(median 2.3 vs.1.3 log10 U/mL,P=0.001).In multivariate analysis,decreased HBcrAg was an independent predictor of HBeAg loss(P=0.005).Conclusions:HBcrAg reflects viral replication and protein production.Decreased HBcrAg could predict HBeAg loss after antiviral therapy.Trial registration:Clinical Trials.gov:NCT01962155;https://www.clinicaltrials.gov/ct2/show/NCT01962155?term=NCT01962155&draw=2&rank=1.

Progression and status of antiviral monitoring in patients with chronic hepatitis B:From HBsAg to HBV RNA

As alternative indexes of hepatitis B virus(HBV),co-valently closed circular DNA(cccDNA) transcriptional activity,hepatitis B surface antigen(HBsAg),hepatitis B core-related antigen(HBcrAg),and peripheral blood RNA known as pgRNA,have been advocated as novel serum markers for prediction of prognosis and treatment response in chronic hepatitis B(CHB). Since the availability of commercial quantitative assays of HBsAg in 2011,HBsAg has been widely used for predicting treatment response of patients with CHB. Patients who received interferon therapy have shown a sharper reduction of HBsAg level than those who received nucleoside drug(NAs) therapy. Upon peginterferon treatment,sustained responders have presented a larger reduction of HBsAg level than the non-responders. An absence of HBsAg decline,together with < 2 log reduction in HBV DNA at week 12,can serve as a stopping rule in HBsAg-negative patients infected with genotype D HBV. A sharp reduction of HBs Ag titer in the NAs therapy is a predictor of HBsAg clearance in long-term treatment. HBcrAg,which consists of three species of related proteins sharing an identical 149 amino acid sequence,including HbcAg,hepatitis B e antigen(HBeAg),and a truncated 22-kDa precore protein,is still detectable in situations where serum HBV DNA levels become undetectable or HBsAg loss is achieved. Therefore,HBcrAg remains a measurable serum marker to correlate with cccDNA in this situation. The decline in HBcrAg has been observed with NAs therapy and the pattern of decline might provide prognostic information on the risk of HBV posttreatment reactivation. Peripheral blood RNA,which is known as pgRNA,directly derives from cccDNA and reflects intrahepatic cccDNA level. Quantitative pgRNA has been suggested to be helpful in CHB management. However,commercial quantitative assays are lacking. Additionally,the use of simultaneous and continuous clearance of HBV RNA and HBV DNA in serum has been suggested to be a safe stopping rule of NAs therapy for patients with CHB. However,clinical studies of large sample sizes are needed to prove the feasibility andsignificance of using serum HBV RNA as the assessment standard of antiviral therapy in CHB and the safety of the stopping rule in clinics.

Mutations of pre-core and basal core promoter before and after hepatitis B e antigen seroconversion

AIM: To investigate the role of pre-core and basal core promoter(BCP) mutations before and after hepatitis Be antigen(HBe Ag) seroconversion.METHODS: The proportion of pre-core(G1896A) and basal core promoter(A1762T and G1764A) mutant viruses and serum levels of hepatitis B virus(HBV) DNA, hepatitis B surface antigen(HBs Ag), and HB core-related antigen were analyzed in chronic hepatitis B patients before and after HBe Ag seroconversion(n = 25), in those who were persistently HBe Ag positive(n = 18), and in those who were persistently anti-HBe positive(n = 43). All patients were infected with HBV genotype C and were followed for a median of 9 years.RESULTS: Although the pre-core mutant became predominant(24% to 65%, P = 0.022) in the HBe Ag seroconversion group during follow-up, the proportion of the basal core promoter mutation did not change. Median HBV viral markers were significantly higher in patients without the mutations in an HBe Ag positive status(HBV DNA: P = 0.003; HBs Ag: P < 0.001; HB core-related antigen: P = 0.001). In contrast, HBV DNA(P = 0.012) and HBs Ag(P = 0.041) levels were significantly higher in patients with the pre-core mutation in an anti-HBe positive status.CONCLUSION: There is an opposite association of the pre-core mutation with viral load before and after HBe Ag seroconversion in patients with HBV infection.

ACE Score Identifies HBeAg-negative Inactive Carriers at a Single-point Evaluation,Regardless of HBV Genotype

Background and Aims:Hepatitis B virus(HBV)biomark-ers have been used for a better categorization of patients,even though the lack of simple algorithms and the impact of genotypes limit their application.Our aim was to assess the usefulness of noninvasive markers for the identification of HBV inactive carriers(ICs)in a single-point evaluation and to design a predictive model for their identification.Meth-ods:This retrospective-prospective study included 343 consecutive HBeAg-negative individuals.Clinical,analytical,and virological data were collected,and a liver biopsy was performed if needed.Subjects were classified at the end of follow-up as ICs,chronic hepatitis B and gray zone.A pre-dictive model was constructed,and validated by 1000-boot-strap samples.Results:After 39 months of follow-up,298 subjects were ICs,36 were chronic hepatitis B CHB,and nine were gray zone.Eighty-nine(25.9%)individuals re-quired a liver biopsy.Baseline HBV DNA hazard ratio(HR)6.0,p<0.001),HBV core-related antigen(HBcrAg)(HR 6.5,p<0.001),and elastography(HR 4.6,p<0.001)were inde-pendently associated with the IC stage.The ACE score(HBV DNA,HBcrAg,elastography),obtained by bootstrapping,yielded an area under the receiver operating characteris-tics(AUROC)of 0.925(95%CI:0.880-0.970,p<0.001)for identification of ICs.The AUROC for genotype D was 0.95,0.96 for A,0.90 for E,and 0.88 for H/F.An ACE score of<1 had a positive predictive value of 99.5%,and a score≤12 points had a diagnostic accuracy of 93.8%.Conclusions:Low baseline HBV DNA,HBcrAg,and liver stiffness were in-dependently associated with the IC phase.A score including those variables identified ICs at a single-point evaluation,and might be applied to implement less intensive follow-up strategies.

Stopping nucleos(t)ide analog treatment in chronic hepatitis B-Who and when?

Nucleos(t)ide analogs(NAs)are one of the first-line treatments for chronic hepatitis B(CHB)infection.NAs are highly efficient in suppressing viral replication but are associated with a low rate of hepatitis B surface antigen(HBsAg)seroclearance and a high risk of post-treatment virologic relapse.As a result,the optimal timing of NA cessation remains unclear,and long-term treatment is often needed.While international guidelines suggest that NA can be discontinued in hepatitis B e antigen(HBeAg)-positive patients who achieve HBeAg seroconversion with undetectable hepatitis B virus(HBV)DNA levels,the recommendations for discontinuing NA treatment in HBeAg-negative patients remain controversial.Furthermore,there is no consensus regarding in whom and when to restart treatment among patients with hepatitis relapse after stopping NA therapy.Recent studies suggest that virologic markers such as HBsAg and hepatitis B core-related antigen(HBcrAg)titers may be useful to guide when to stop NAs in CHB,since both markers appear to correlate with intrahepatic covalently closed circular HBV DNA levels.However,additional studies are required to refine their use.