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  • Review Article
  • OPEN ACCESS

An Ideal Hallmark Closest to Complete Cure of Chronic Hepatitis B Patients: High-sensitivity Quantitative HBsAg Loss

  • Zi-Long Wang#,
  • Jia-Rui Zheng#,
  • Rui-Feng Yang,
  • Lin-Xiang Huang,
  • Hong-Song Chen and
  • Bo Feng* 
 Author information  Cite
Journal of Clinical and Translational Hepatology   2023;11(1):197-206

doi: 10.14218/JCTH.2022.00289

Abstract

In the era of antiviral therapy, the main goal of treatment has shifted from the persistent inhibition of hepatitis B virus (HBV) replication to the pursuit of serological clearance of HBs surface antigen (HBsAg). Based on the life cycle of HBV, HBsAg originates from covalently closed circular DNA (cccDNA) and integrated HBV DNA, thus reflecting their transcriptional activity. Complete HBsAg loss may mean elimination or persistent inactivity of the HBV genome including cccDNA and integrated HBV DNA. HBsAg loss improves the recovery of abnormal immune function, which in turn, may further promote the clearance of residual viruses. Combined with functional cure and the great improvement of clinical outcomes, the continuous seroclearance of high-sensitivity quantitative HBsAg may represent the complete cure of chronic hepatitis B (CHB). For many other risk factors besides HBV itself, patients with HBsAg loss still need regular monitoring. In this review, we summarized the evolution of CHB treatment, the origin of serum HBsAg, the pattern of HBsAg seroclearance, and the effect of HBsAg loss on immune function and disease outcomes. In addition, we discuss the significance of high-sensitivity HBsAg detection and its possibility as a surrogate of complete cure.

Graphical Abstract

Keywords

Hepatitis B virus, Chronic hepatitis B, HBsAg, Immunoassay, Functional cure, Complete cure, Biomarker

Introduction

Despite the widespread use of the hepatitis B vaccine and antiviral drugs, chronic hepatitis B virus (HBV) infection remains a threat to human health and is the principal cause of liver cirrhosis and hepatocellular carcinoma (HCC). The latest data show that the global prevalence of HBsAg in the whole population is 3.9% and there are around 290 million HBsAg-positive people worldwide.1 In 2016, a plan to eliminate viral hepatitis as a public health threat by 2030 was formulated by the World Health Organization (WHO). This plan aimed to reduce the new infection rate of HBV by 90% and the HBV related mortality by 65% in 2030 compared with the same period in 2015.2 However, according to the current progress rate, with the global cumulative rate of diagnosis and treatment of hepatitis B in 2020 being 12.7% and 8%, respectively, this goal will be met after 2051.3 To achieve this goal as soon as possible, early diagnosis, active standardization of antiviral treatment, and ultimately, working toward a cure are the most effective strategies. Therefore, it is important to find the ideal biomarker of cure.

Continuous HBsAg seroclearance as a marker of hepatitis B cure

History of anti-HBV regimens

Since the introduction of lamivudine in clinical practice in 1998, effective treatment of chronic hepatitis B (CHB) has been an era of antiviral treatment with other nucleos(t)ide analogues (NAs) that were subsequently developed one after another. In 2005, pegylated interferon-alpha (PegIFNα) was approved for the management of CHB patients, thus forming two categories of anti-HBV drugs.4 At present, the goal of CHB treatment is to maximize the persistent inhibition of HBV replication, which ultimately lowers the occurrence of liver cirrhosis, decompensation, and HCC.5,6 Unfortunately, a few patients develop end-stage liver diseases despite treatment. A South Korean study analyzed 3,156 treatment-naïve CHB patients treated with entecavir (ETV) or tenofovir dipivoxil (TDF), and found that 285 patients (9.0%) developed liver cancer during a median follow-up of 58.3 months. The cumulative incidence rates of HCC at 3, 5, and 7 years ere 5.3%, 9.3%, and 13.8%. There were no significant differences in the incidence of HCC per 100 person-years 5 years before and 5 years after treatment with NAs. No significant differences were observed in the incidence of HCC in high-, middle-, and low-risk groups determined by their modified platelet age gender-HBV (mPAGE-B) scores 5 years before and 5 years after treatment. Prolonging the duration of oral NAs had no significant influence on the overall incidence of HCC after achieving a complete virological response. After long-term NA treatment, the risk of HCC in CHB patients was still present, suggesting that treatment should not be limited to long-term inhibition of the virus, but also to pursue a higher level of efficacy.7

Evolution of hepatitis B cure marked by continuous HBsAg seroclearance

In 2009, Ning et al.8 initiated the first clinical study on HBsAg clearance, by transitioning the treatment from ETV to PegIFNα-2a in CHB patients who were HBeAg positive. All patients treated with ETV and those with HBV DNA ≤1,000 copies/mL and HBeAg <100 PEIU/mL were randomly divided to switching to PegIFN or continuing ETV for 48 weeks. HBsAg loss was 8.5% and 0% in the PegIFN and continuous ETV groups, respectively. For patients with negative HBV DNA, negative HBeAg, and HBsAg <1,500 IU/mL, the rate of HBsAg loss was as high as 22.2%. Subsequently, more studies on NAs sequenced or combined with PEG-IFNα were performed to explore and improve the clinical cure rate.9,10 The definition of clinical cure in the CHB guidelines in China in 2015 was based on those study findings.11 For some suitable patients, the clinical cure of CHB, that is, the continuous virological response and HBsAg loss after treatment is stopped, should be pursued as far as possible.

In 2014, The French National Agency for Research on AIDS and Viral Hepatitis proposed an HBV cure program.12 To guide clinical trials of a hepatitis B cure, a workshop was held in 2016 to develop a common perspective on the endpoints of CHB treatment, which was that a functional cure indicated by continuous HBsAg loss could be achieved with currently available treatment regimens. An HBV functional cure was proposed and defined as sustained HBV DNA and HBsAg seroclearance with or without positive hepatitis B surface antibodies (anti-HBs) after a finite course of treatment.13 The term functional cure was mentioned in both the HBV guidelines of the European Association for the Study of the Liver (EASL) in 2017 and the American Association for the Study of Liver Diseases (AASLD) in 2018.5,6 In 2019, the EASL and the AASLD jointly organized a conference on HBV treatment endpoint to develop a consensus on HBV cures (Fig. 1).14 A complete cure for HBV infection is difficult because of the limited treatment options. Thus, the current study focuses on varying degrees of functional cure. Antiviral drugs target HBV reverse transcriptase activity and cannot directly act on cccDNA, which makes them fail to eliminate cccDNA. Therefore, the elimination of cccDNA from infected cells has provided future research directions for drug research and development, which is an idealistic functional cure that we have been long pursuing. Realistic functional cure was defined as undetectable HBV DNA and HBsAg with detectable cccDNA and integrated HBV DNA, as already suggested by its name. That cure is currently an attainable goal for us. An attainable partial functional cure was defined as undetectable HBV DNA with positive HBsAg after completing a short course of therapy. The clearance of HBsAg is the ideal endpoint, thus we need to seek comprehensively inhibition of viral DNA replication.

Characteristics and evolution of the biomarkers defining various hepatitis B cures.
Fig. 1  Characteristics and evolution of the biomarkers defining various hepatitis B cures.

Partial functional cure: undetectable HBV DNA with positive HBsAg after completing a short course of therapy. Realistic functional cure: undetectable HBV DNA and HBsAg with detectable cccDNA and integrated HBV DNA. Idealistic functional cure: undetectable HBV DNA and HBsAg with undetectable integrated HBV DNA. Complete cure, sustained serum HBsAg loss with undetectable cccDNA and integrated HBV DNA; HBsAg, HBV surface antigen; cccDNA, covalently closed circular DNA; Inactive cccDNA, transcriptional activity decreases or even disappears; HBV DNA, serum HBV DNA. cccDNA, covalently closed circular DNA; HBsAg, HBV surface antigen.

In the same year, Chinese experts released a consensus on the roadmap to a functional cure for CHB.15 The WHO highlighted that progress in curing hepatitis B is required to achieve the 2030 objective of eliminating viral hepatitis and continued investment in a functional cure for hepatitis B research is insured as one of priorities in 2021.16 Of course, complete cure, that is the elimination of integrated HBV DNA and covalently closed circular DNA (cccDNA), is the ultimate goal we pursue, and it may require combination therapy with potent NAs and at least one immunomodulator,17 or even triple combination therapies of inhibiting HBV replication, reducing antigen levels, and stimulating immune function.18

Origin and degradation of serum HBsAg

Serum HBsAg originates from cccDNA and integrated HBV DNA. The former may exist in a condensed state which is transcriptionally inactive or a relaxed state which is transcriptionally active.19 Infectious HBV particles and noninfectious subviral particles (SVPs) are formed and released into the blood (Fig. 2). The latter is linear HBV DNA that is integrated into different parts of the hepatocyte chromosome. Because of the lack of a normal circular structure, the integrated DNA can only express S- and M-HBsAg, and the spherical SVPs that are released into the blood cannot form pregenomic RNA (pgRNA) and other viral proteins.20,21 Around 99.99% of HBsAg in the blood exists in SVPs.22 For CHB patients with a complete virological response or negative HBeAg, most of the serum HBsAg comes from integrated HBV DNA rather than cccDNA.23 Transcriptionally active integrated HBV DNA is present in the entire liver and forms widespread HBsAg independent of HBV replication.24

A marker of complete cure of chronic hepatitis B: HBsAg loss by high-sensitivity assay.
Fig. 2  A marker of complete cure of chronic hepatitis B: HBsAg loss by high-sensitivity assay.

Serum HBsAg originates from cccDNA and integrated HBV DNA. cccDNA serves as a transcription template to produce infectious HBV particles and noninfectious SVPs and releases them into the blood. In addition, integrated HBV DNA is also a replication template of S- and M-HBsAg, and only spherical SVPs can release into the blood. cccDNA, covalently closed circular DNA; HBsAg, HBV surface antigen; HBcrAg, hepatitis B core-related antigen; SVP, subviral particle; rcDNA, relaxed circular DNA; ds DNA, double-stranded DNA.

Infected hepatocytes regulate the secretion of HBsAg through a variety of degradation pathways, such as endoplasmic reticulum-mediated proteolysis and autophagy. In addition, the unique proteolytic mechanism of proteasome, ubiquitin, and proteome-independent processes is also involved in the degradation of M- and L-HBsAg.25,26 The infection of hepatocytes is accompanied by an increase in the activity of the degradation pathways, indicating that HBsAg renewal is involved in the production of SVP and virus.

Patterns and epidemiology of continuous HBsAg seroclearance

Spontaneous HBsAg seroclearance is rarely reported, with a rate of only about 1% per year.27 A study including 1,076 CHB patients reported cumulative rates of spontaneous HBsAg seroclearance of 8.1% and 44.7% after 10 years and 25 years, respectively.28 Prospective follow-up of a cohort of 1,240 patients with negative HBeAg and who were not treated for 5.5 years found that the crude incidence rate of HBsAg loss was 1.6 per 100 person-years. HBsAg seroclearance was also found to be highly associated with older age, nonasian race, inactive HBsAg carrier, HBV genotype A, lower HBV DNA, and quantitative HBsAg levels.29

NAs suppress HBV DNA rather than directly acting on cccDNA. Consequently, it is very difficult for NAs to prevent the production of HBV particles and their antigens. A recent large multicenter cohort study that enrolled 4,769 CHB patients showed that the 10-year cumulative loss rate of HBsAg was only 2% during 26,614 person-years of ETV or TDF therapy.30 Although stopping NAs following the withdrawal criteria of the guidelines has the risk of virological relapse, clinical relapse, or exacerbation of the liver disease, it may benefit from HBsAg loss.31,32 A study including 1,216 CHB patients with undetectable HBV DNA and HBeAg who did not complete long-term NA therapy reported that after an average follow-up of nearly 2 years, 98 patients (8.1%) achieved HBsAg loss. The predictors of HBsAg loss were found to be race, HBV genotype, and viral antigen level at treatment cessation.33 Based on the findings, the Asian Pacific Association for the Study of the Liver (APASL) developed a guideline for stopping NAs that recommended withdrawal of NAs to obtain HBsAg clearance in patients who had negative HBeAg and relatively low HBsAg levels.34

Although the ability of PegIFNα to inhibit HBV DNA is much weaker than that of NAs, the former promotes the decline of HBsAg level more significantly, with a 3–7% clearance rate of HBsAg after 48 weeks of treatment.6 A real-world study divided 330 CHB patients into three groups: PegIFNα + TDF, PegIFNα, and TDF monotherapy. At 72 weeks, the incidence of HBsAg loss was 11.5%, 5.7%, and 0%, respectively.35 A meta-analysis indicated that the initial combination (PegIFNα + NA) significantly increased the clearance rate of HBsAg compared with NA monotherapy (relative risk: 15.59, 95% CI: 3.22–75.49). However, there was no significant difference observed between the initial combination and PegIFNα monotherapy.36 HBsAg clearance continued to increase with the prolongation of PegIFNα withdrawal time. Moreover, in inactive HBsAg carriers for whom antiviral therapy was recommended, PegIFNα induced a high HBsAg clearance rate, especially in patients with low baseline HBsAg levels.37

Effect of continuous HBsAg seroclearance on immune function

HBV infection results from the interaction between HBV and the host. Immunological liver injury is the main pathogenesis of hepatitis B. The immune response generated by the host is closely associated with outcomes of the natural history of CHB and acute HBV infection. HBV antigens, especially HBsAg, are major contributors to the immunopathogenesis of CHB, and the chronicity of HBV infection is related to the exhaustion of T and B cell responses.38,39 Theoretically, the disappearance of HBsAg should improve recovery from abnormal immune function, which is also one of the manifestations of functional cure, and in turn promotes the clearance of residual viruses, including cccDNA and integrated HBV DNA.

Host cellular immune function, especially HBV-specific CD4+ and CD8+ T cells, has a critical impact on the clearance of HBV and the prognosis of hepatitis B infection.40,41 The continuous loss of HBsAg and the appearance of HBsAb indicate a successful immune response to HBV and mark the complete and sustained control of infection.42,43 Boni et al.43 compared HBV-specific T cell responses in patients who were given NA with those who experienced other forms of HBV control by measuring intracellular levels of cytokines including interleukin-2 (IL-2), interferon-gamma (IFNγ), and tumor necrosis factor α (TNFα). They found that the T cell response in patients with HBsAg loss was stronger than that in patients with persistent HBsAg. Compared with those of HBsAg-positive patients, CD4+ and CD8+ T cells had a more active phenotype in NA-induced HBsAg clearance and presented higher proliferation 12 weeks after stopping NA treatment44 A longitudinal study found that patients with negative HBsAg presented definite CD4+ and CD8+ T cell phenotypic characteristics compared with those with persistent HBsAg, and these changes in T cell phenotypes were related to IFNα treatment. Furthermore, the study identified HBsAg quantification combined with CTLA-4, CD95, and CD107a expression on CD4+ T cells, and TIM-3 and HLA-DR expression on CD8+ T cells as potential predictors for HBsAg clearance within 12 months in CHB patients.45

A humoral immune response based on neutralizing antibodies to inhibit and eliminate HBV infection has recently attracted more attention.46 In CHB patients, the differentiation ability of B cells in vivo is significantly enhanced, but proliferation is significantly reduced.47,48 There have been few studies on the effect of HBsAg reduction or loss on B cells. A study that recruited 63 treatment-naïve CHB patients and 46 patients with HBsAg loss induced by antiviral treatment found that compared with HBsAg-positive patients, HBsAg-negative patients had more naïve B cells and plasmablasts and fewer memory B cells. The dominant B cell epitopes (S76 and S78) in patients with negative HBsAg may be significant candidates for treatment to achieve a functional cure.49 During PegIFNα treatment, the proportion of total B cells and plasma B cells in the HBsAg-negative group was higher than that in the HBsAg-positive group, when other factors including age, sex, and treatment duration were completely matched.50

Durability of HBsAg seroclearance

Functional cure is more reflected in the recovery of liver function, especially the specific immune function against HBV, through the maximum long-term suppression of HBV replication, without emphasis on the elimination of integrated HBV DNA and cccDNA. At present, the gap between functional cure and complete cure is still very large. In addition to the detection of integrated HBV DNA and cccDNA, the duration of functional cure after drug withdrawal and the improvement of long-term outcomes are also very important as these can reflect complete cure to some degree (Table 1).51–70

Table 1

Summary of durability and outcomes of HBsAg seroclearance

First authorYearCountry or regionDesignCumulative cases of HBsAg seroclearanceLongest or average follow-up of HBsAg seroclearanceRecurrence of HBsAg, %Incidence of HCC, %Deaths or liver transplantation, %Notes
Spontaneous HBsAg seroclearance
  Yip TC512021HK, ChinaRetrospective5,9174.3 (2.2–7.6) years7.0%1.64%NRNR
  Park Y522021KoreaRetrospective9844.8 years (0.5–17.8)NR1.22%NRNR
  Choi J532021KoreaRetrospective1,6245.6 (2.8–9.6) years1.23%2.16%2.28%Risk factors of HCC and clinical events: older age, male sex, and cirrhosis
  Song C542019ChinaProspective652NRNR1.23%NRNR
  Zhu L552018ChinaProspective348NRNR0.29%NRNR
  Chen YC562016Taiwan, ChinaRetrospective312107 monthsNR1.28%0%NR
  Lim TH572016New ZealandProspective14572 months (0–300)NR0%0%NR
  Ari A582016TurkeyRetrospective84NRNR0%NRNR
NAs induced HBsAg seroclearance
  Yip TC512021HK, ChinaRetrospective1,2074.3 (2·2–7·6) years7.7%1.32%NRNR
  Choi J532021KoreaRetrospective3484.6 (2.4–7.8) years5.46%4.02%5.75%Risk factors of HCC and clinical events: older age, male sex, and cirrhosis
  Kim MA592020KoreaRetrospective27626.9 (12.2–49.2) months3.6%2.9%NRNR
  Yip TC602019HK, ChinaRetrospective3764.8 (2.8–7.0) years1.4%0.5%0%NR
  Suarez E612019SpainRetrospective6937.8 (23.8–54.6) months1.5%1.5%0%NR
  Sun Y622019ChinaRetrospective54NRNR0%NRNR
  Chi H632017MulticenterRetrospective701.6 (0.5–2.7) years3.7%0%0%NR
  Chen YC562016Taiwan, ChinaRetrospective110107 monthsNR0.91%0.91%NR
IFNα or combined with NAs induced HBsAg seroclearance
  Li MH642022ChinaProspective23148 weeks8.2%0%NR
  Chen J652021ChinaProspective4824 weeks6.25%0%0%PegIFNα add on NAs
  Wu F662021ChinaProspective6848 weeks, follow-up 24 weeksNR0%0%IFNα monotherapy, Inactive HBV carriers
  Pan CQ672021ChinaProspective37696 weeks17.3%0.3%0%258 IFN monotherapy, 118 IFN add on NA
  Wu Y682020Chinaretrospective238160 weeks (21–597)5.88%0%0%IFN monotherapy, or IFN + NA
  Choi HS692020CanadaRetrospective6511.5 (6.6–19.0) years1.96%4.44%8.89%IFNα
  Li MH702019ChinaProspective17648 weeks13.37%0.58%0%118 IFN monotherapy, 58 IFN add on NAs

HCC, hepatocellular carcinoma; HBV, hepatitis B virus; NAs, nucleos(t)ide analogues; IFNα, interferon α; PegIFNα, pegylated interferon α; NR, not reported.

Wu et al.68 analyzed 238 cases with HBsAg clearance who were treated with IFNα/PegIFNα alone or combined with NAs. The cumulative recurrence rates at 26, 52, 78, 104, and 597 weeks were 0.84%, 6.29%, 6.88%, 8.18%, and 9.66%, respectively, of which 83% (15/18) recurred within 52 weeks after drug withdrawal. A prospective study enrolled 176 CHB patients who underwent IFN alone or combined NAs treatment and achieved HBsAg clearance. The study found that at 48 weeks of follow-up, 86.63% (149/172) had maintained HBsAg seroclearance.70 Lok et al.71 followed 55 PegIFNα or NAs treated patients with HBsAg clearance in three clinical studies for an average of 96 weeks. They found that 82% of the patients maintained HBsAg clearance.71 In another study, 104 HBeAg-positive children 2–16 years of age with CHB who completed at least 36 weeks of PegIFNα and were followed up for 104 weeks. The HBsAg clearance rates were 48.1% at the end of treatment and 53.8% at follow-up. The continuous response incidence of HBsAg clearance was as high as 94%.72 Long-term follow-up studies in Hong Kong, China and the National Institutes of Health also found that the clinical cure rate of patients with HBsAg clearance can be maintained at more than 95%, whether it is spontaneous clearance or clearance after drug treatment.73,74 A recent meta-analysis reported that CHB patients had a durable negative HBsAg response after HBsAg seroclearance.75

Effect of continuous HBsAg seroclearance on disease outcomes

Outcomes of CHB patients with HBsAg seroclearance are summarized in Table 1. A retrospective cohort study enrolled 4,568 CHB patients with HBsAg clearance, of which 793 had received NAs and 60 had received interferon (IFN) treatment. During a median follow-up of 3.4 years, 54 patients (2.9%) developed liver cancer, including 49 patients with spontaneous clearance of HBsAg and five men over 50 years of age old treated with NA. None of the patients treated with PegIFNα had liver cancer within 5 years. The cumulative incidence rates of HCC were 0.9%, 1.3%, and 1.5% at 1, 3, and 5 years, respectively. In patients with HBsAg clearance, age, and sex were two independent predictors of the risk of HCC. After HBsAg loss, the 5-year cumulative incidence of HCC was 0% in women and 0.7 % in men at ≤50 years of age and 1.0% and 2.5%, respectively in those >50 years of age.76 The same team also analyzed 7,124 CHB patients with HBsAg loss. Spontaneous clearance and NA-induced clearance occurred in 5,917 and 1,207, respectively. After an average follow-up of 4.3 years, the incidence of HCC was 1.6% and 1.3%, respectively, with no significant difference.76

A systematic review included a total of 188,316 CHB patients and showed that the total incidence rate of end-stage liver disease in the HBsAg clearance and HBsAg-persistent groups was 0.19 and 2.45 per 1,000 person-years, respectively. In addition, the incidence of decompensation, HCC, liver transplantation, and all-cause death per 1,000 person-years in the HBsAg clearance and HBsAg-persistent groups was 1.37 and 3.65, 0.14 and 1.81, 1.57 and 12.71, respectively. The combined relative risk of end-stage liver disease, decompensation, HCC, liver transplantation, and all-cause death in the HBsAg clearance group was 0.31, 0.28, 0.30, and 0.22, respectively. The findings suggest that the clinical outcomes of CHB patients after HBsAg seroclearance were significantly improved. Stratified analysis of various treatment regimens (e.g. IFN, NAs, or IFN + NAs) did not find significant differences in the risk of endpoint events among the subgroups.77 Another meta-analysis also found that the risk of HCC was very low in CHB patients with HBsAg clearance, especially in those treated with IFN.78 Patients with HBsAg loss had a lower risk of hepatic decompensation, incident cirrhosis, overall mortality, and liver-related mortality compared with those with no HBsAg loss.

HBsAg is better than other new biomarkers as an indicator of clinical cure

Serum HBV RNA is mainly derived from pgRNA without initiation of reverse transcription in the nucleocapsid that results in HBV RNA virus-like particles.79 This is of great significance in drug withdrawal management, optimizing antiviral strategy, and predicting outcomes of CHB patients. However, HBV RNA only indicates the presence and transcriptional activity of cccDNA. It does not reflect the active state of integrated HBV DNA (Fig. 2). Therefore, when studying the association between HBsAg and serum HBV RNA, it was found that the relation between serum HBsAg and serum HBV RNA was significant only in treatment-naïve CHB patients with positive HBeAg.80,81 In CHB patients with negative HBeAg and those treated with NAs or IFN, the correlation was extensively weakened or was not significant.80,82 In addition, the detection methods of HBV RNA are not standardized and are easily affected by HBV pgRNA splice variants and HBV DNA.

Hepatitis B core-related antigen (HBcrAg) consists of three antigens encoded by HBV pre-C/C region genes, including HBV core antigen, HBeAg, and precore/core protein with a relative molecular weight of 22 KD (Fig. 2). Its quantitative level is important in guiding the management of chronic HBV infection. As a marker of cccDNA and HBV translation, serum HBcrAg correlates well with the transcriptional activity of intrahepatic cccDNA and thus can monitor the efficacy of the new HBV regimens targeting cccDNA.83

Lim et al.84 studied 114 HBeAg-negative patients who were treated with PegIFNα for and evaluated the value of quantitative HBsAg, HBV RNA, and quantitative HBcrAg in predicting HBsAg clearance. Quantitative HBsAg was better than both HBcrAg and HBV RNA whose baseline AUCs were 0.916, 0.649, and 0.542, respectively. Based on the kinetics of these markers, only quantitative HBsAg had a good relationship with HBsAg clearance, HBV RNA had a low correlation, and HBcrAg did not change significantly.

Based on the HBV life cycle and the origin of various markers, HBsAg reveals the transcriptional activity of both integrated HBV DNA and cccDNA, unlike HBV RNA and HBcrAg (Fig. 2). Therefore, the continuous negative HBsAg is closer to complete cure of CHB. Theoretically, the current regimens pursuing clinical cure are mainly based on IFNα. IFNα can act on cccDNA and is even regarded as one of the most promising drugs in the elimination of HBV cccDNA.85 Additionally, IFNα regulates the transcription of cccDNA by the epigenetic modifications of the histones and indirectly targets cccDNA through APOBEC3 family proteins.86–88

Management of patients with continuous HBsAg seroclearance

The incidence of cirrhosis and end-stage liver diseases is significantly reduced. However, the risk of HCC still exists in CHB patients who achieve a functional cure.88 A meta-analysis showed that 1.86% of patients developed HCC within 19.6 to 336 months after HBsAg clearance compared with 6.56% of patients with positive HBsAg in the control group.89 Aside from HBV factors, HCC was related to age, sex, family history, liver cirrhosis, treatment regimens (NAs or IFNα induced HBsAg seroclearance), HBV DNA integration, co-infection, obesity, diabetes, and other complications.90,91 Male sex, a history of cirrhosis, and a family history of HCC are related to a higher incidence of HCC after HBsAg clearance.90 A recent study from South Korea retrospectively analyzed 831 CHB patients who reached HBsAg loss and found that the age of HBsAg loss, underlying liver cirrhosis, family history of HCC, and excessive drinking were independent predictors of HCC. A prediction model of HCC after HBsAg seroclearance was constructed based on those parameters.92 Therefore, HCC surveillance should continue even after HBsAg clearance. In particular, patients with a long duration of infection, liver cirrhosis, a first-degree family member with HCC,5 or other risk factors should be targeted for close HCC surveillance after HBsAg loss.

Necessity of high-sensitivity HBsAg detection and its possible use as a marker of complete cure

Serum HBsAg originates from cccDNA and integrated HBV DNA fragments. Commercially available HBsAg test kits can check out not only total forms of HBsAg such as Dane particles and spherical and filamentous HBsAg, but also detect integrated HBV DNA and cccDNA.93 Theoretically, continuous HBsAg seroclearance indicates that the activities of cccDNA and the integrated HBV DNA are inhibited.

In the livers of CHB patients with HBsAg seroclearance, integrated HBV DNA and cccDNA can still be detected. HBV DNA can also be found in the blood or liver of patients with occult HBV infection (OBI). Wong et al.91 collected liver tissues from 90 HCC HbsAg-negative patients with HBV DNA, cccDNA, and integrative HBV DNA in DNA of liver cells. They found cccDNA in 29 and integrated HBV DNA in 42 of the 62 HCC patients with concomitant OBI. However, the presence of low-level HBsAg cannot be excluded in those patients. A study enrolled 114 CHB patients with undetectable HBsAg by conventional enzyme immunoassay (EIA) and detected HBsAg in half the patients with a high-sensitivity HBsAg assay with a lower limit of quantitation of 0.005 IU/mL.94 In another study, the Architect HBsAg Next qualitative assay (Abbott Laboratories, Abbott Park, IL, USA) was used to measure HBsAg in 800 CHB patients who had HBsAg loss by conventional assays. HBsAg was detected in 59/800 (7.3%) patients with HBsAg clearance. At <3, 3–5, 5–8, 8–11, and >11 years after HBsAg seroclearance, HBsAg was detected in 27.8%, 8.2%, 6.9%, 3.8%, and 1.9% samples, respectively.95 Therefore, in patients with OBI and serum negative HBV DNA, high-sensitivity quantitative HBsAg may detect HBV protein synthesis. The lower limit of detection (LLOD) is between 0.03 and 0.05 IU/mL in conventional commercially available assays. A highly sensitive quantitative HBsAg assay detects serum HBsAg at 0.005 IU/mL with an automated chemiluminescent enzyme immunoassay system (Lumipulse G1200; Fujirebio, Inc., Tokyo, Japan). Moreover, highly sensitive quantitative HBsAg assays detects antigen-antibody complexes in addition to free HBsAg proteins, even mutant HBsAg.96 Across HBV genotypes A to H and common mutants, the Architect HBsAg Next qualitative assay has a consistent sensitivity.97 The ultra-sensitive quantitative HBsAg assay has an LLOD of 0.0005 IU/mL which is 100-fold lower than those of conventional HBsAg assays.98

After a functional cure, HBsAg may be present at low or very low levels that are related to the recurrence and progression of liver disease after drug withdrawal. Seventeen CHB patients with HBsAg seroclearance confirmed with a conventional assay (Architect HBsAg QT kit; Abbott Laboratories) were tested with an ultra-sensitive assay that had a sensitivity of 0.0005 IU/mL, and three of five patients in the HCC group and 12 in the non-HCC group were found to be HBsAg positive for up to 1 year.98 Therefore, detection by high-sensitivity or ultra-sensitive quantitative HBsAg is important for the determination of a real cure. Functional cure means the elimination or persistent inactivation of cccDNA. Persistent HBsAg loss can also reflect marked reduction or clearance of integrated HBV DNA.99 Characteristics of conventional and high-sensitive HBsAg quantitative assays are summarized in Table 2.95,97,100 In addition, HBsAg loss can likely stimulate and restore HBV-specific immune responses that promote complete resolution of HBV infection.101 Combined with the persistence of functional cure and the great improvement of clinical outcome of liver disease, the continuous seroclearance of high-sensitivity or ultra-sensitive quantitative HBsAg likely reflects a complete cure of CHB, which is similar to the treatment of chronic hepatitis C virus (HCV) infection. Although the possibility of HCC may still happen, especially in those who have HCV related cirrhosis, it does not hinder the perspective of complete cure.

Table 2

Characteristics of HBsAg quantitative and HQ-HBsAg assays

AssaySupplierPrincipleTechnology (tracer)PretreatmentReaction sample volumeAssay durationLinear range (analytical sensitivity)On-board dilutionTraceability (NIBSC code)
Abbott Architect HBsAg97Architect i2000SRSandwich principle, capture mAbs, and polyclonal detection antibodiesCMIA (acridinium)None75 µL29 m0.05–250 IU/mL (0.05 IU/mL)1:500 with recalcified negative human plasmaWHO first international standard, subtype ad (80/549)
Roche HBsAg II QuantMolecular E170Sandwich principle, two capture mAbs, and a mixture of mAbs and polyclonal antibodiesECLIA (ruthenium)None50 µL18 m0.05–130 IU/mL (0.05 IU/mL)1:400 with buffered negative human serumWHO second international standard, subtype adw2, genotype A (00/588)
Fujirebio Lumipulse G HBsAg-QuantLumipulse G1200Sandwich principle, two capture mAbs and two detections mAbsCLEIA (AMPPD)Yes, to disrupt viral particles and dissociate HBsAg from HBsAg-anti-HBs complexes100 µL29 m0.005–150 IU/mL (0.005 IU/mL)1:100, 1:200 or 1:1000 with NaCl and Tris bufferWHO second international standard, subtype adw2, genotype (00/588)
Architect HBsAg Next qualitative assay95Architect i2000SRSandwich principle, two monoclonal antibodies solid-phase, and a goat polyclonal antibody conjugateOne-step CMIANone75 µLNR0.0052– IU/mL (0.0052 IU/mL)NRWHO second international standard (00/588) a consistent sensitivity across major HBV genotypes A to H and common mutants
iTACT-HBsAg100LUMIPULSE PRESTO II (Fujirebio, Inc.)Sandwich principleICT-CLEIAYes, to inactivate anti-HBs, releases the antigen from the immune complexes, and to disassociate the antigen polymers into monomers50 µL20 m0.0005–113 IU/mL (0.0005 IU/mL)NRNR

CMIA, chemiluminescent microparticle immunoassay; ECLIA, electrochemiluminescence immunoassay; CLEIA, chemiluminescent enzyme immunoassay; iTACT, immunoassay for total antigen including complex via pretreatment; ICT-CLEIA, immune complex transfer - chemiluminescent enzyme immunoassay; NR, not reported.

Conclusions and perspectives

In the last 20 years, significant progress has been made in the antiviral treatment of hepatitis B, which has evolved from persistent inhibition of HBV replication to the pursuit of seroclearance of HBsAg, that is, a functional cure. A complete cure likely means persistent inactivity of cccDNA and integrated HBV DNA rather than complete elimination of the HBV genome. HBsAg reveals the transcriptional activity of both cccDNA and integrated HBV DNA, and to some degree, the continuing seroclearance of high-sensitivity or ultra-sensitive quantitative HBsAg may represent a complete cure of CHB. Alternatively, HBV antigens, especially HBsAg, are involved in the immunopathogenesis of hepatitis B. Thus, HBsAg loss can significantly recover abnormal immune function, which in turn, may further facilitate the clearance of residual viruses conversely, including cccDNA and integrated HBV DNA. Some remaining issues need to be addressed. First, it is unclear whether the continuous HBsAg loss means that cccDNA and integrated HBV DNA are completely inactive, resulting in the inability of HBsAg expression, or most of them are eliminated. Second, more and more new drugs that inhibit HBV and improve host immune response are in the process of clinical trials.99,102 The effectiveness and safety of these novel drugs, as well as the best treatment strategy in complete cure, still need a lot of exploration. HBsAg cannot reflect the efficacy of some new drugs that inhibit or scavenge cccDNA because the integrated HBV DNA can still express HBsAg. Third, more HBsAg mutants were detected in the patients with HCC/cirrhosis than in the asymptomatic carriers.103 Although a panel of antibodies has been optimized specifically for HBsAg mutants, qualitative immunoassays may produce false-negative results for HBV with mutant surface antigen. And last, for many risk factors of hepatitis B related HCC, even if HBsAg is serologically cleared, there is still the possibility of end-stage liver disease including HCC. Therefore, regular monitoring is still warranted. The clinical significance of trace amounts of HBsAg needs to be further studied.

Abbreviations

cccDNA: 

covalently closed circular DNA

CHB: 

chronic hepatitis B

ETV: 

entecavir

HBcrAg: 

Hepatitis B core-related antigen

HBsAg: 

hepatitis B virus surface antigen

HBV: 

hepatitis B virus

HCC: 

hepatocellular carcinoma

IFNγ: 

interferon-gamma

IL-2: 

interleukin-2

LLOD: 

the lower limit of detection

NAs: 

nucleos(t)ide analogues

OBI: 

occult HBV infection

PegIFNα: 

pegylated interferon-alpha

TDF: 

tenofovir dipivoxil

TNFα: 

tumor necrosis factor α

Declarations

Funding

The work was supported in part by a grant from the National Major Project for Infectious Diseases Prevention and Treatment (No. 2017ZX10302201-004-001, 2017ZX10203202-003-003).

Conflict of interest

The authors have no conflict of interests related to this publication.

Authors’ contributions

Study concept and design (BF), acquisition, analysis and interpretation of data, drafting of the manuscript (ZLW, JRZ), critical revision of the manuscript for important intellectual content (RFY, LXH), and study supervision (HSC). All authors have made a significant contribution to this study and have approved the final manuscript.

References

  1. Polaris Observatory Collaborators. Global prevalence, treatment, and prevention of hepatitis B virus infection in 2016: a modelling study. Lancet Gastroenterol Hepatol 2018;3(6):383-403 View Article PubMed/NCBI
  2. WHO global health sector strategy on viral hepatitis 2016-2021. 2016. Available from: https://www.emcdda.europa.eu/drugs-library/who-global-health-sector-strategy-viral-hepatitis-2016-2021_en
  3. Regions Dashboard - CDA Foundation. 2020. Available from: https://cdafound.org/polaris-regions-dashboard/
  4. Schinazi RF, Ehteshami M, Bassit L, Asselah T. Towards HBV curative therapies. Liver Int 2018;38(Suppl 1):102-114 View Article PubMed/NCBI
  5. Terrault NA, Lok ASF, McMahon BJ, Chang KM, Hwang JP, Jonas MM, et al. Update on prevention, diagnosis, and treatment of chronic hepatitis B: AASLD 2018 hepatitis B guidance. Hepatology 2018;67(4):1560-1599 View Article PubMed/NCBI
  6. European Association for the Study of the Liver. EASL 2017 Clinical Practice Guidelines on the management of hepatitis B virus infection. J Hepatol 2017;67(2):370-398 View Article PubMed/NCBI
  7. Kim SU, Seo YS, Lee HA, Kim MN, Lee EJ, Shin HJ, et al. Hepatocellular Carcinoma Risk Steadily Persists over Time Despite Long-Term Antiviral Therapy for Hepatitis B: A Multicenter Study. Cancer Epidemiol Biomarkers Prev 2020;29(4):832-837 View Article PubMed/NCBI
  8. Ning Q, Han M, Sun Y, Jiang J, Tan D, Hou J, et al. Switching from entecavir to PegIFN alfa-2a in patients with HBeAg-positive chronic hepatitis B: a randomised open-label trial (OSST trial). J Hepatol 2014;61(4):777-784 View Article PubMed/NCBI
  9. Lu J, Zhang S, Liu Y, Du X, Ren S, Zhang H, et al. Effect of Peg-interferon α-2a combined with Adefovir in HBV postpartum women with normal levels of ALT and high levels of HBV DNA. Liver Int 2015;35(6):1692-1699 View Article PubMed/NCBI
  10. Brouwer WP, Xie Q, Sonneveld MJ, Zhang N, Zhang Q, Tabak F, et al. Adding pegylated interferon to entecavir for hepatitis B e antigen-positive chronic hepatitis B: A multicenter randomized trial (ARES study). Hepatology 2015;61(5):1512-1522 View Article PubMed/NCBI
  11. Hou JL, Lai W, Chinese Society of Hepatology, Chinese Medical Association; Chinese Society of Infectious Diseases, Chinese Medical Association. The guideline of prevention and treatment for chronic hepatitis B: a 2015 update. Zhonghua Gan Zang Bing Za Zhi 2015;23(12):888-905 View Article PubMed/NCBI
  12. Zeisel MB, Lucifora J, Mason WS, Sureau C, Beck J, Levrero M, et al. Towards an HBV cure: state-of-the-art and unresolved questions—report of the ANRS workshop on HBV cure. Gut 2015;64(8):1314-1326 View Article PubMed/NCBI
  13. Lok AS, Zoulim F, Dusheiko G, Ghany MG. Hepatitis B cure: From discovery to regulatory approval. J Hepatol 2017;67(4):847-861 View Article PubMed/NCBI
  14. Cornberg M, Lok AS, Terrault NA, Zoulim F, 2019 EASL-AASLD HBV Treatment Endpoints Conference Faculty. Guidance for design and endpoints of clinical trials in chronic hepatitis B - Report from the 2019 EASL-AASLD HBV Treatment Endpoints Conference‡. J Hepatol 2020;72(3):539-557 View Article PubMed/NCBI
  15. Ning Q, Wu D, Wang GQ, Ren H, Gao ZL, Hu P, et al. Roadmap to functional cure of chronic hepatitis B: An expert consensus. J Viral Hepat 2019;26(10):1146-1155 View Article PubMed/NCBI
  16. Global progress report on HIV vhasti. 2021. Available from: https://www.who.int/publications/i/item/9789240027077
  17. Kim SW, Yoon JS, Lee M, Cho Y. Toward a complete cure for chronic hepatitis B: Novel therapeutic targets for hepatitis B virus. Clin Mol Hepatol 2022;28(1):17-30 View Article PubMed/NCBI
  18. Fung S, Choi HSJ, Gehring A, Janssen HLA. Getting to HBV cure: The promising paths forward. Hepatology 2022;76(1):233-250 View Article PubMed/NCBI
  19. Levrero M, Pollicino T, Petersen J, Belloni L, Raimondo G, Dandri M. Control of cccDNA function in hepatitis B virus infection. J Hepatol 2009;51(3):581-592 View Article PubMed/NCBI
  20. Tu T, Budzinska MA, Shackel NA, Urban S. HBV DNA Integration: Molecular Mechanisms and Clinical Implications. Viruses 2017;9(4):E75 View Article PubMed/NCBI
  21. Ishii T, Tamura A, Shibata T, Kuroda K, Kanda T, Sugiyama M, et al. Analysis of HBV Genomes Integrated into the Genomes of Human Hepatoma PLC/PRF/5 Cells by HBV Sequence Capture-Based Next-Generation Sequencing. Genes (Basel) 2020;11(6):E661 View Article PubMed/NCBI
  22. Vaillant A. HBsAg, Subviral Particles, and Their Clearance in Establishing a Functional Cure of Chronic Hepatitis B Virus Infection. ACS Infect Dis 2021;7(6):1351-1368 View Article PubMed/NCBI
  23. Wooddell CI, Yuen MF, Chan HL, Gish RG, Locarnini SA, Chavez D, et al. RNAi-based treatment of chronically infected patients and chimpanzees reveals that integrated hepatitis B virus DNA is a source of HBsAg. Sci Transl Med 2017;9(409):eaan0241 View Article PubMed/NCBI
  24. Meier MA, Calabrese D, Suslov A, Terracciano LM, Heim MH, Wieland S. Ubiquitous expression of HBsAg from integrated HBV DNA in patients with low viral load. J Hepatol 2021;75(4):840-847 View Article PubMed/NCBI
  25. Lazar C, Uta M, Petrescu SM, Branza-Nichita N. Novel function of the endoplasmic reticulum degradation-enhancing α-mannosidase-like proteins in the human hepatitis B virus life cycle, mediated by the middle envelope protein. Cell Microbiol 2017;19(2):e12653 View Article PubMed/NCBI
  26. Lin Y, Wu C, Wang X, Kemper T, Squire A, Gunzer M, et al. Hepatitis B virus is degraded by autophagosome-lysosome fusion mediated by Rab7 and related components. Protein Cell 2019;10(1):60-66 View Article PubMed/NCBI
  27. Zhou K, Contag C, Whitaker E, Terrault N. Spontaneous loss of surface antigen among adults living with chronic hepatitis B virus infection: a systematic review and pooled meta-analyses. Lancet Gastroenterol Hepatol 2019;4(3):227-238 View Article PubMed/NCBI
  28. Chu CM, Liaw YF. HBsAg seroclearance in asymptomatic carriers of high endemic areas: appreciably high rates during a long-term follow-up. Hepatology 2007;45(5):1187-1192 View Article PubMed/NCBI
  29. Terrault NA, Wahed AS, Feld JJ, Cooper SL, Ghany MG, Lisker-Melman M, et al. Incidence and prediction of HBsAg seroclearance in a prospective multi-ethnic HBeAg-negative chronic hepatitis B cohort. Hepatology 2022;75(3):709-723 View Article PubMed/NCBI
  30. Hsu YC, Yeh ML, Wong GL, Chen CH, Peng CY, Buti M, et al. Incidences and Determinants of Functional Cure During Entecavir or Tenofovir Disoproxil Fumarate for Chronic Hepatitis B. J Infect Dis 2021;224(11):1890-1899 View Article PubMed/NCBI
  31. Kuo YH, Wang JH, Hung CH, Lu SN, Hu TH, Chen CH. Combining end-of-treatment HBsAg and baseline hepatitis B core-related antigen reduce HBV relapse rate after tenofovir cessation. Hepatol Int 2021;15(2):301-309 View Article PubMed/NCBI
  32. Broquetas T, Hernandez JJ, Garcia-Retortillo M, Canillas L, Puigvehí M, Cañete N, et al. On-therapy HBsAg kinetics can predict HBsAg loss after nucleos(t)ide analogues interruption in HBeAg-negative patients. The cup is half full and half empty. Dig Liver Dis 2022;54(8):1044-1051 View Article PubMed/NCBI
  33. Sonneveld MJ, Chiu SM, Park JY, Brakenhoff SM, Kaewdech A, Seto WK, et al. Probability of HBsAg loss after nucleo(s)tide analogue withdrawal depends on HBV genotype and viral antigen levels. J Hepatol 2022;76(5):1042-1050 View Article PubMed/NCBI
  34. Kao JH, Jeng WJ, Ning Q, Su TH, Tseng TC, Ueno Y, et al. APASL guidance on stopping nucleos(t)ide analogues in chronic hepatitis B patients. Hepatol Int 2021;15(4):833-851 View Article PubMed/NCBI
  35. Hu C, Song Y, Tang C, Li M, Liu J, Liu J, et al. Effect of Pegylated Interferon Plus Tenofovir Combination on Higher Hepatitis B Surface Antigen Loss in Treatment-naive Patients With Hepatitis B e Antigen -positive Chronic Hepatitis B: A Real-world Experience. Clin Ther 2021;43(3):572-581.e3 View Article PubMed/NCBI
  36. Liu J, Wang T, Zhang W, Cheng Y, He Q, Wang FS. Effect of combination treatment based on interferon and nucleos(t)ide analogues on functional cure of chronic hepatitis B: a systematic review and meta-analysis. Hepatol Int 2020;14(6):958-972 View Article PubMed/NCBI
  37. Song A, Lin X, Lu J, Ren S, Cao Z, Zheng S, et al. Pegylated Interferon Treatment for the Effective Clearance of Hepatitis B Surface Antigen in Inactive HBsAg Carriers: A Meta-Analysis. Front Immunol 2021;12:779347 View Article PubMed/NCBI
  38. Park JJ, Wong DK, Wahed AS, Lee WM, Feld JJ, Terrault N, et al. Hepatitis B Virus—Specific and Global T-Cell Dysfunction in Chronic Hepatitis B. Gastroenterology 2016;150(3):684-695.e5 View Article PubMed/NCBI
  39. Burton AR, Pallett LJ, McCoy LE, Suveizdyte K, Amin OE, Swadling L, et al. Circulating and intrahepatic antiviral B cells are defective in hepatitis B. J Clin Invest 2018;128(10):4588-4603 View Article PubMed/NCBI
  40. Wang Q, Sachse P, Semmo M, Lokhande M, Montani M, Dufour JF, et al. T- and B-cell responses and previous exposure to hepatitis B virus in ‘anti-HBc alone’ patients. J Viral Hepat 2015;22(12):1068-1078 View Article PubMed/NCBI
  41. Cannizzo ES, Tincati C, Binda F, Ronzi P, Cazzaniga FA, Antinori S, et al. Unconventional T cells in chronic hepatitis B patients on long-term suppressive therapy with tenofovir followed by a Peg-IFN add-on strategy: A randomized study. J Viral Hepat 2018;25(4):381-390 View Article PubMed/NCBI
  42. Fanning GC, Zoulim F, Hou J, Bertoletti A. Therapeutic strategies for hepatitis B virus infection: towards a cure. Nat Rev Drug Discov 2019;18(11):827-844 View Article PubMed/NCBI
  43. Boni C, Laccabue D, Lampertico P, Giuberti T, Viganò M, Schivazappa S, et al. Restored function of HBV-specific T cells after long-term effective therapy with nucleos(t)ide analogues. Gastroenterology 2012;143(4):963-73.e9 View Article PubMed/NCBI
  44. Fumagalli V, Di Lucia P, Venzin V, Bono EB, Jordan R, Frey CR, et al. Serum HBsAg clearance has minimal impact on CD8+ T cell responses in mouse models of HBV infection. J Exp Med 2020;217(11):e20200298 View Article PubMed/NCBI
  45. Xiong S, Zhu D, Liang B, Li M, Pan W, He J, et al. Longitudinal characterization of phenotypic profile of T cells in chronic hepatitis B identifies immune markers associated with HBsAg loss. EBioMedicine 2021;69:103464 View Article PubMed/NCBI
  46. Vanwolleghem T, Groothuismink ZMA, Kreefft K, Hung M, Novikov N, Boonstra A. Hepatitis B core-specific memory B cell responses associate with clinical parameters in patients with chronic HBV. J Hepatol 2020;73(1):52-61 View Article PubMed/NCBI
  47. Matsushita T, Kobayashi T, Mizumaki K, Kano M, Sawada T, Tennichi M, et al. BAFF inhibition attenuates fibrosis in scleroderma by modulating the regulatory and effector B cell balance. Sci Adv 2018;4(7):eaas9944 View Article PubMed/NCBI
  48. Mauri C, Menon M. Human regulatory B cells in health and disease: therapeutic potential. J Clin Invest 2017;127(3):772-779 View Article PubMed/NCBI
  49. Gu S, Liu Z, Lin L, Zhong S, Ma Y, Li X, et al. Identification and Mapping of HBsAg Loss-Related B-Cell Linear Epitopes in Chronic HBV Patients by Peptide Array. Front Immunol 2021;12:767000 View Article PubMed/NCBI
  50. Cao Z, Meng S, Zheng Y, Wang J, Wang R, Chen X. B cells were related to HBsAg seroconversion in inactive HBsAg carriers following peginterferon therapy. PLoS One 2020;15(12):e0242559 View Article PubMed/NCBI
  51. Yip TC, Wong VW, Tse YK, Liang LY, Hui VW, Zhang X, et al. Similarly low risk of hepatocellular carcinoma after either spontaneous or nucleos(t)ide analogue-induced hepatitis B surface antigen loss. Aliment Pharmacol Ther 2021;53(2):321-331 View Article PubMed/NCBI
  52. Park Y, Lee JH, Sinn DH, Park JY, Kim MA, Kim YJ, et al. Risk and Risk Score Performance of Hepatocellular Carcinoma Development in Patients With Hepatitis B Surface Antigen Seroclearance. Clin Transl Gastroenterol 2021;12(1):e00290 View Article PubMed/NCBI
  53. Choi J, Yoo S, Lim YS. Comparison of Long-Term Clinical Outcomes Between Spontaneous and Therapy-Induced HBsAg Seroclearance. Hepatology 2021;73(6):2155-2166 View Article PubMed/NCBI
  54. Song C, Zhu J, Ge Z, Yu C, Tian T, Wang H, et al. Spontaneous Seroclearance of Hepatitis B Surface Antigen and Risk of Hepatocellular Carcinoma. Clin Gastroenterol Hepatol 2019;17(6):1204-1206 View Article PubMed/NCBI
  55. Zhu L, Zhai X, Wang Q, Jiang J, Peng H, Song C, et al. Incidence and determinants of spontaneous hepatitis B surface antigen seroclearance and seroconversion in hepatitis B e antigen-negative chronic infection patients: A population-based prospective cohort. J Viral Hepat 2018;25(12):1588-1598 View Article PubMed/NCBI
  56. Chen YC, Jeng WJ, Chien RN, Chu CM, Liaw YF. Clinical outcomes after spontaneous and nucleos(t)ide analogue-treated HBsAg seroclearance in chronic HBV infection. Aliment Pharmacol Ther 2016;43(12):1311-1318 View Article PubMed/NCBI
  57. Lim TH, Gane E, Moyes C, Borman B, Cunningham C. HBsAg loss in a New Zealand community study with 28-year follow-up: rates, predictors and long-term outcomes. Hepatol Int 2016;10(5):829-837 View Article PubMed/NCBI
  58. Ari A, Çalik Ş, Tosun S, Özsu Yilmaz S. A persistently low HBV DNA level is a predictor of spontaneous HBsAg clearance in patients with chronic hepatitis B. Turk J Med Sci 2016;46(1):48-52 View Article PubMed/NCBI
  59. Kim MA, Kim SU, Sinn DH, Jang JW, Lim YS, Ahn SH, et al. Discontinuation of nucleos(t)ide analogues is not associated with a higher risk of HBsAg seroreversion after antiviral-induced HBsAg seroclearance: a nationwide multicentre study. Gut 2020;69(12):2214-2222 View Article PubMed/NCBI
  60. Yip TC, Wong GL, Chan HL, Tse YK, Lam KL, Lui GC, et al. HBsAg seroclearance further reduces hepatocellular carcinoma risk after complete viral suppression with nucleos(t)ide analogues. J Hepatol 2019;70(3):361-370 View Article PubMed/NCBI
  61. Suárez E, Buti M, Rodríguez M, Prieto M, Pascasio-Acevedo JM, Casanovas T, et al. Hepatitis B surface antigen loss after discontinuing nucleos(t)ide analogue for treatment of chronic hepatitis B patients is persistent in White patients. Eur J Gastroenterol Hepatol 2019;31(2):267-271 View Article PubMed/NCBI
  62. Sun Y, Zhang Y, Xu Y, Shu M, Bonroy K, Qiu H, et al. Real-world study on clinical outcomes of nucleos(t)ide analogues antiviral therapy in patients with chronic hepatitis B. Epidemiol Infect 2019;147:e193 View Article PubMed/NCBI
  63. Chi H, Wong D, Peng J, Cao J, Van Hees S, Vanwolleghem T, et al. Durability of Response After Hepatitis B Surface Antigen Seroclearance During Nucleos(t)ide Analogue Treatment in a Multiethnic Cohort of Chronic Hepatitis B Patients: Results After Treatment Cessation. Clin Infect Dis 2017;65(4):680-683 View Article PubMed/NCBI
  64. Li M, Sun F, Bi X, Lin Y, Yang L, Lu Y, et al. Consolidation treatment needed for sustained HBsAg-negative response induced by interferon-alpha in HBeAg positive chronic hepatitis B patients. Virol Sin 2022;37(3):390-397 View Article PubMed/NCBI
  65. Chen J, Qi M, Fan XG, Hu XW, Liao CJ, Long LY, et al. Efficacy of Peginterferon alfa-2b in Nucleoside Analogue Experienced Patients with Negative HBeAg and Low HBsAg: A Non-Randomized Clinical Trial. Infect Dis Ther 2021;10(4):2259-2270 View Article PubMed/NCBI
  66. Wu F, Lu R, Liu Y, Wang Y, Tian Y, Li Y, et al. Efficacy and safety of peginterferon alpha monotherapy in Chinese inactive chronic hepatitis B virus carriers. Liver Int 2021;41(9):2032-2045 View Article PubMed/NCBI
  67. Pan CQ, Li MH, Yi W, Zhang L, Lu Y, Hao HX, et al. Outcome of Chinese patients with hepatitis B at 96 weeks after functional cure with IFN versus combination regimens. Liver Int 2021;41(7):1498-1508 View Article PubMed/NCBI
  68. Wu Y, Liu Y, Lu J, Cao Z, Jin Y, Ma L, et al. Durability of Interferon-induced Hepatitis B Surface Antigen Seroclearance. Clin Gastroenterol Hepatol 2020;18(2):514-516.e2 View Article PubMed/NCBI
  69. Choi HSJ, van Campenhout MJH, van Vuuren AJ, Krassenburg LAP, Sonneveld MJ, de Knegt RJ, et al. Ultra-Long-term Follow-up of Interferon Alfa Treatment for HBeAg-Positive Chronic Hepatitis B Virus Infection. Clin Gastroenterol Hepatol 2021;19(9):1933-1940.e1 View Article PubMed/NCBI
  70. Li MH, Yi W, Zhang L, Lu Y, Lu HH, Shen G, et al. Predictors of sustained functional cure in hepatitis B envelope antigen-negative patients achieving hepatitis B surface antigen seroclearance with interferon-alpha-based therapy. J Viral Hepat 2019;26(Suppl 1):32-41 View Article PubMed/NCBI
  71. Lok AS, Zoulim F, Dusheiko G, Chan HLY, Buti M, Ghany MG, et al. Durability of Hepatitis B Surface Antigen Loss With Nucleotide Analogue and Peginterferon Therapy in Patients With Chronic Hepatitis B. Hepatol Commun 2020;4(1):8-20 View Article PubMed/NCBI
  72. Liu Y, Li H, Yan X, Wei J. Long-term efficacy and safety of peginterferon in the treatment of children with HBeAg-positive chronic hepatitis B. J Viral Hepat 2019;26(Suppl 1):69-76 View Article PubMed/NCBI
  73. Yip TC, Wong GL, Wong VW, Tse YK, Lui GC, Lam KL, et al. Durability of hepatitis B surface antigen seroclearance in untreated and nucleos(t)ide analogue-treated patients. J Hepatol 2018;68(1):63-72 View Article PubMed/NCBI
  74. Alawad AS, Auh S, Suarez D, Ghany MG. Durability of Spontaneous and Treatment-Related Loss of Hepatitis B s Antigen. Clin Gastroenterol Hepatol 2020;18(3):700-709.e3 View Article PubMed/NCBI
  75. Song A, Wang X, Lu J, Jin Y, Ma L, Hu Z, et al. Durability of hepatitis B surface antigen seroclearance and subsequent risk for hepatocellular carcinoma: A meta-analysis. J Viral Hepat 2021;28(4):601-612 View Article PubMed/NCBI
  76. Yip TC, Chan HL, Wong VW, Tse YK, Lam KL, Wong GL. Impact of age and gender on risk of hepatocellular carcinoma after hepatitis B surface antigen seroclearance. J Hepatol 2017;67(5):902-908 View Article PubMed/NCBI
  77. Anderson RT, Choi HSJ, Lenz O, Peters MG, Janssen HLA, Mishra P, et al. Association Between Seroclearance of Hepatitis B Surface Antigen and Long-term Clinical Outcomes of Patients With Chronic Hepatitis B Virus Infection: Systematic Review and Meta-analysis. Clin Gastroenterol Hepatol 2021;19(3):463-472 View Article PubMed/NCBI
  78. Vittal A, Sharma D, Hu A, Majeed NA, Terry N, Auh S, et al. Systematic review with meta-analysis: the impact of functional cure on clinical outcomes in patients with chronic hepatitis B. Aliment Pharmacol Ther 2022;55(1):8-25 View Article PubMed/NCBI
  79. Wang J, Shen T, Huang X, Kumar GR, Chen X, Zeng Z, et al. Serum hepatitis B virus RNA is encapsidated pregenome RNA that may be associated with persistence of viral infection and rebound. J Hepatol 2016;65(4):700-710 View Article PubMed/NCBI
  80. Mak LY, Cloherty G, Wong DK, Gersch J, Seto WK, Fung J, et al. HBV RNA Profiles in Patients With Chronic Hepatitis B Under Different Disease Phases and Antiviral Therapy. Hepatology 2021;73(6):2167-2179 View Article PubMed/NCBI
  81. Ghany MG, King WC, Lisker-Melman M, Lok ASF, Terrault N, Janssen HLA, et al. Comparison of HBV RNA and Hepatitis B Core Related Antigen With Conventional HBV Markers Among Untreated Adults With Chronic Hepatitis B in North America. Hepatology 2021;74(5):2395-2409 View Article PubMed/NCBI
  82. Wang X, Chi X, Wu R, Xu H, Gao X, Yu L, et al. Serum HBV RNA correlated with intrahepatic cccDNA more strongly than other HBV markers during peg-interferon treatment. Virol J 2021;18(1):4 View Article PubMed/NCBI
  83. Testoni B, Lebossé F, Scholtes C, Berby F, Miaglia C, Subic M, et al. Serum hepatitis B core-related antigen (HBcrAg) correlates with covalently closed circular DNA transcriptional activity in chronic hepatitis B patients. J Hepatol 2019;70(4):615-625 View Article PubMed/NCBI
  84. Lim SG, Phyo WW, Ling JZJ, Cloherty G, Butler EK, Kuhns MC, et al. Comparative biomarkers for HBsAg loss with antiviral therapy shows dominant influence of quantitative HBsAg (qHBsAg). Aliment Pharmacol Ther 2021;53(1):172-182 View Article PubMed/NCBI
  85. Wang G, Guan J, Khan NU, Li G, Shao J, Zhou Q, et al. Potential capacity of interferon-α to eliminate covalently closed circular DNA (cccDNA) in hepatocytes infected with hepatitis B virus. Gut Pathog 2021;13(1):22 View Article PubMed/NCBI
  86. Cheng J, Zhao Q, Zhou Y, Tang L, Sheraz M, Chang J, et al. Interferon Alpha Induces Multiple Cellular Proteins That Coordinately Suppress Hepadnaviral Covalently Closed Circular DNA Transcription. J Virol 2020;94(17):e00442-20 View Article PubMed/NCBI
  87. Yang Y, Zhao X, Wang Z, Shu W, Li L, Li Y, et al. Nuclear Sensor Interferon-Inducible Protein 16 Inhibits the Function of Hepatitis B Virus Covalently Closed Circular DNA by Integrating Innate Immune Activation and Epigenetic Suppression. Hepatology 2020;71(4):1154-1169 View Article PubMed/NCBI
  88. Chen Z, Eggerman TL, Bocharov AV, Baranova IN, Vishnyakova TG, Kurlander R, et al. Heat shock proteins stimulate APOBEC-3-mediated cytidine deamination in the hepatitis B virus. J Biol Chem 2017;292(32):13459-13479 View Article PubMed/NCBI
  89. Kuang XJ, Jia RR, Huo RR, Yu JJ, Wang JJ, Xiang BD, et al. Systematic review of risk factors of hepatocellular carcinoma after hepatitis B surface antigen seroclearance. J Viral Hepat 2018;25(9):1026-1037 View Article PubMed/NCBI
  90. Kaur SP, Talat A, Karimi-Sari H, Grees A, Chen HW, Lau DTY, et al. Hepatocellular Carcinoma in Hepatitis B Virus-Infected Patients and the Role of Hepatitis B Surface Antigen (HBsAg). J Clin Med 2022;11(4):1126 View Article PubMed/NCBI
  91. Wong DK, Cheng SCY, Mak LL, To EW, Lo RC, Cheung TT, et al. Among Patients with Undetectable Hepatitis B Surface Antigen and Hepatocellular Carcinoma, a High Proportion Has Integration of HBV DNA into Hepatocyte DNA and No Cirrhosis. Clin Gastroenterol Hepatol 2020;18(2):449-456 View Article PubMed/NCBI
  92. Yang H, Bae SH, Nam H, Lee HL, Lee SW, Yoo SH, et al. A risk prediction model for hepatocellular carcinoma after hepatitis B surface antigen seroclearance. J Hepatol 2022;77(3):632-641 View Article PubMed/NCBI
  93. Mak LY, Seto WK, Fung J, Yuen MF. Use of HBsAg quantification in the natural history and treatment of chronic hepatitis B. Hepatol Int 2020;14(1):35-46 View Article PubMed/NCBI
  94. Ozeki I, Nakajima T, Suii H, Tatsumi R, Yamaguchi M, Kimura M, et al. Analysis of hepatitis B surface antigen (HBsAg) using high-sensitivity HBsAg assays in hepatitis B virus carriers in whom HBsAg seroclearance was confirmed by conventional assays. Hepatol Res 2018;48(3):E263-E274 View Article PubMed/NCBI
  95. Wong DK, Chen C, Mak LY, Fung J, Seto WK, Yuen MF. Detection of the Hepatitis B Surface Antigen in Patients with Occult Hepatitis B by Use of an Assay with Enhanced Sensitivity. J Clin Microbiol 2022;60(2):e0220421 View Article PubMed/NCBI
  96. Shinkai N, Matsuura K, Sugauchi F, Watanabe T, Murakami S, Iio E, et al. Application of a newly developed high-sensitivity HBsAg chemiluminescent enzyme immunoassay for hepatitis B patients with HBsAg seroclearance. J Clin Microbiol 2013;51(11):3484-3491 View Article PubMed/NCBI
  97. Lou S, Taylor R, Pearce S, Kuhns M, Leary T. An ultra-sensitive Abbott ARCHITECT® assay for the detection of hepatitis B virus surface antigen (HBsAg). J Clin Virol 2018;105:18-25 View Article PubMed/NCBI
  98. Takeda K, Maruki M, Yamagaito T, Muramatsu M, Sakai Y, Tobimatsu H, et al. Highly sensitive detection of hepatitis B virus surface antigen by use of a semiautomated immune complex transfer chemiluminescence enzyme immunoassay. J Clin Microbiol 2013;51(7):2238-2244 View Article PubMed/NCBI
  99. Bazinet M, Anderson M, Pântea V, Placinta G, Moscalu I, Cebotarescu V, et al. Analysis of HBsAg Immunocomplexes and cccDNA Activity During and Persisting After NAP-Based Therapy. Hepatol Commun 2021;5(11):1873-1887 View Article PubMed/NCBI
  100. Suzuki F, Hosaka T, Imaizumi M, Kobayashi M, Ohue C, Suzuki Y, et al. 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. Hepatol Res 2021;51(4):426-435 View Article PubMed/NCBI
  101. Revill PA, Chisari FV, Block JM, Dandri M, Gehring AJ, Guo H, et al. A global scientific strategy to cure hepatitis B. Lancet Gastroenterol Hepatol 2019;4(7):545-558 View Article PubMed/NCBI
  102. Tsounis EP, Tourkochristou E, Mouzaki A, Triantos C. Toward a new era of hepatitis B virus therapeutics: The pursuit of a functional cure. World J Gastroenterol 2021;27(21):2727-2757 View Article PubMed/NCBI
  103. Hosseini SY, Sanaei N, Fattahi MR, Malek-Hosseini SA, Sarvari J. Association of HBsAg mutation patterns with hepatitis B infection outcome: Asymptomatic carriers versus HCC/cirrhotic patients. Ann Hepatol 2019;18(4):640-645 View Article PubMed/NCBI
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  • Journal of Clinical and Translational Hepatology
  • pISSN 2225-0719
  • eISSN 2310-8819

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An Ideal Hallmark Closest to Complete Cure of Chronic Hepatitis B Patients: High-sensitivity Quantitative HBsAg Loss

Zi-Long Wang, Jia-Rui Zheng, Rui-Feng Yang, Lin-Xiang Huang, Hong-Song Chen, Bo Feng
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