Spontaneous loss of surface antigen among adults living with chronic hepatitis B virus infection: a systematic review and pooled meta-analyses

Incidence, Factors, and Patient-Level Data for Spontaneous HBsAg Seroclearance: A Cohort Study of 11,264 Patients

INTRODUCTION

Spontaneous hepatitis B surface antigen (HBsAg) seroclearance, the functional cure of hepatitis B infection, occurs rarely. Prior original studies are limited by insufficient sample size and/or follow-up, and recent meta-analyses are limited by inclusion of only study-level data and lack of adjustment for confounders to investigate HBsAg seroclearance rates in most relevant subgroups. Using a cohort with detailed individual patient data, we estimated spontaneous HBsAg seroclearance rates through patient and virologic characteristics.

METHODS

We analyzed 11,264 untreated patients with chronic hepatitis B with serial HBsAg data from 4 North American and 8 Asian Pacific centers, with 1,393 patients with HBsAg seroclearance (≥2 undetectable HBsAg ≥6 months apart) during 106,192 person-years. The annual seroclearance rate with detailed categorization by infection phase, further stratified by hepatitis B e antigen (HBeAg) status, sex, age, and quantitative HBsAg (qHBsAg), was performed.

RESULTS

The annual seroclearance rate was 1.31% (95% confidence interval: 1.25-1.38) and over 7% in immune inactive patients aged ≥55 years and with qHBsAg <100 IU/mL. The 5-, 10-, 15-, and 20-year cumulative rates were 4.74%, 10.72%, 18.80%, and 24.79%, respectively. On multivariable analysis, male (adjusted hazard ratio [aHR] = 1.66), older age (41-55 years: aHR = 1.16; >55 years: aHR = 1.21), negative HBeAg (aHR = 6.34), and genotype C (aHR = 1.82) predicted higher seroclearance rates, as did lower hepatitis B virus DNA and lower qHBsAg (P < 0.05 for all), and inactive carrier state.

DISCUSSION

The spontaneous annual HBsAg seroclearance rate was 1.31%, but varied from close to zero to about 5% among most chronic hepatitis B subgroups, with older, male, HBeAg-negative, and genotype C patients with lower alanine aminotransferase and hepatitis B virus DNA, and qHBsAg independently associated with higher rates (see Visual Abstract, Supplementary Digital Content 2, http://links.lww.com/CTG/A367).

Chemiluminescent Optical Fiber Immunosensor Combining Surface Modification and Signal Amplification for Ultrasensitive Determination of Hepatitis B Antigen

Optical fiber based immunosensors are very attractive for biomarker detection. In order to improve the sensor response, we propose a promising strategy which combines porous-layer modification of the fiber surface and streptavidin-biotin-peroxidase nano-complex signal amplification in chemiluminescent detection. Two hepatitis B antigens, hepatitis B surface antigen (HBsAg) and hepatitis B e antigen (HBeAg), are used as the targets for analysis using the proposed sensor. Comparing to immunoassays using normal optical fiber sensors, the response of the present sensor is enhanced by a factor of 4.8 and 6.7 for detection of HBsAg and HBeAg, respectively. The limit-of-quantitation of the proposed method is as low as 0.3 fg/mL (0.01 fg/mL) with a wide linear response range of 3 fg/mL–150 ng/mL (0.1 fg/mL–160 ng/mL) for sensing HBsAg (HBeAg). Quantitative determination of HBsAg and HBeAg in human serum samples is performed, showing the applicability of the proposed method for biomarker detection.

Hepatitis B surface antigen seroclearance: Immune mechanisms, clinical impact, importance for drug development

HBsAg seroclearance occurs rarely in the natural history of chronic hepatitis B (CHB) infection and is associated with improved clinical outcomes. Many factors are associated with HBsAg seroconversion, including immune and viral factors. However, the immune mechanisms associated with HBsAg seroclearance are still difficult to elucidate. HBsAg seroclearance is the ideal aim of HBV treatment. Unfortunately, this goal is rarely achieved with current treatments. Understanding the mechanisms of HBsAg loss appears to be important for the development of curative HBV treatments. While studies from animal models give insights into the potential immune mechanisms and interactions occurring between the immune system and HBsAg, they do not recapitulate all features of CHB in humans and are subject to variability due to their complexity. In this article, we review recent studies on these immune factors, focusing on their influence on CHB progression and HBsAg seroconversion. These data provide new insights for the development of therapeutic approaches to partially restore the anti-HBV immune response. Targeting HBsAg will ideally relieve the immunosuppressive effects on the immune system and help to restore anti-HBV immune responses.

Hepatitis B Surface Antigen Levels Are Related to Spontaneous Hepatitis B Surface Antigen Seroconversion in Inactive Hepatitis B Carriers

BACKGROUND

The cure for hepatitis B is defined as the hepatitis B surface antigen (HBsAg) seroclearance and/or seroconversion. Predictors of spontaneous seroconversion are not well described. The objective of this study is to identify predictors of spontaneous HBsAg seroconversion from community practice.

METHODS

We performed a matched analysis of patients who HBsAg seroconverted (cases) and patients who did not HBsAg seroconvert (control) in a 1:5 ratio according to date of clinic visit between 2014 and 2019 in a large community practice situated in Los Angeles area. Baseline laboratory and clinical data were collected. Univariate analysis and 2-sided t tests were performed, χ test for proportions, and logistic regression.

RESULTS

We identified 14 cases and 70 controls. The mean (±SD) ages of the cases and controls were 53.6 (±12.2) and 49.5 (±13.1), respectively (P=0.45). Most patients were women, and all patients were of Asian descent. There were statistically significant mean (±SD) baseline differences between cases and controls in HBsAg titers (459.8±311.0 and 782.0±393.3 IU/mL, P=0.01) and alanine aminotransferase (ALT) values (17.6±4.4 and 25.1±16.7 IU/mL, P<0.01), respectively. Baseline hepatitis B virus DNA and other pertinent laboratory values did not differ between cases and controls. Eleven of 14 cases (79%) and 11 of 70 controls (16%) baseline HBsAg titers were <1000 IU/mL (P<0.01). The results of a logistic regression demonstrated that HBsAg titers and ALT values were predictor variables for HBsAg seroconversion (P=0.01 and <0.01, respectively).

CONCLUSIONS

Spontaneous HBsAg seroclearance and seroconversion is an uncommon event in patients with chronic hepatitis B. The most important predictors of seroconversion are HBsAg titers<1000 IU/mL and low baseline ALT values.

Short-term Peginterferon-Induced High Functional Cure Rate in Inactive Chronic Hepatitis B Virus Carriers With Low Surface Antigen Levels

Background

None of the current guidelines recommend antiviral therapy for inactive hepatitis B virus (HBV) carriers (IHCs).

Methods

In this real-world, multicenter, nonrandomized study, 32 participants meeting the inclusion criteria were enrolled 1:1 for treatment with peginterferon α-2b or monitoring without treatment based on participant preference. The expected treatment duration was 48 weeks. The primary end point was hepatitis B surface antigen (HBsAg) loss. The HBV vaccine could be injected after HBsAg loss.

Results

All patients had HBsAg levels of <20 IU/mL. The mean baseline HBsAg levels were 6.6 IU/mL and 5.8 IU/mL in the treated and untreated groups, respectively. Fifteen (93.8%) participants achieved HBsAg loss, 5 obtained HBsAg seroconversion after undergoing a mean of 19.7 weeks of therapy in the treated group, and no one in the follow-up group achieved HBsAg loss during a mean follow-up time of 12.6 months (P < .0001). Generally, the therapy was well tolerated. Nine of 11 individuals who exhibited HBsAg loss benefited from receiving the HBV vaccine.

Conclusions

This study provides justification for further studies of short-course peginterferon α-2b for the functional cure of IHCs with low HBsAg levels. Additionally, HBV vaccine injection is beneficial after interferon-induced HBsAg loss.

Targeting Host Innate and Adaptive Immunity to Achieve the Functional Cure of Chronic Hepatitis B

Despite the availability of an effective preventive vaccine for hepatitis B virus (HBV) for over 38 years, chronic HBV (CHB) infection remains a global health burden with around 257 million patients. The ideal treatment goal for CHB infection would be to achieve complete cure; however, current therapies such as peg-interferon and nucleos(t)ide analogs are unable to achieve the functional cure, the newly set target for HBV chronic infection. Considering the fact functional cure has been accepted as an endpoint in the treatment of chronic hepatitis B by scientific committee, the development of alternative therapeutic strategies is urgently needed to functionally cure CHB infection. A promising target for future therapeutic strategies is immune modulation to restore dysfunctional HBV-specific immunity. In this review, we provide an overview of the progress in alternative therapeutic strategies, including immune-based therapeutic approaches that enhance host innate and adaptive immunity to achieve and increase the functional cure from CHB infection.

Seroconversion of HBsAG coincides with hepatitis A super-infection: A case report

BACKGROUND

Hepatitis B virus (HBV) is a hepatotropic virus that can cause acute and chronic liver damage. According to the world health organization 257 million people are infected with chronic HBV infection worldwide. Super-infection with other hepadnaviruses, including hepatitis A virus (HAV), hepatitis C virus, hepatitis D virus, and hepatitis E virus is associated with increased risk of acute liver failure in patients with chronic HBV.

CASE SUMMARY

Here, we report a case of a 47-year old male patient with HBV-related compensated Child A cirrhosis, who presented with general fatigue, malaise and laboratory signs of acute hepatitis. Although the patient was regularly seen at a specialized university liver unit, the HAV vaccination status was unclear. Acute HAV super-infection was diagnosed by positive serological and polymerase chain reaction analysis. Following acute HAV super-infection, spontaneous HBsAg elimination and development of an anti-HBs titer were observed.

CONCLUSION

This case illustrates the importance of carefully checking the vaccination status. In our patient, unspecific immunological responses to HAV led to functional cure of HBV.

Enhancing the hepatitis B care cascade in Australia: A cost-effectiveness model

If Australia is to successfully eliminate hepatitis B as a public health threat, it will need to enhance the chronic hepatitis B (CHB) care cascade. This study used a Markov model to assess the impact, cost and cost-effectiveness of scaling up CHB diagnosis, linkage to care and treatment to reach national and international elimination targets for hepatitis B in Australia. Compared to continued current trends, the model calculated the difference in care cascade projection, disability-adjusted life years (DALYs), costs and the incremental cost-effectiveness ratio (ICER), of scaling up CHB diagnosis, linkage to care and treatment to reach: (a) Australia's 2022 national targets and (b) the WHO's 2030 global targets. Achieving the national and WHO targets had ICERs of A$13 435 (A$10 236-A$21 165) and A$14 482 (A$13 031-A$25 641) per DALY averted between 2016 and 2030 in Australia, respectively. However, this excluded implementation and demand generation costs. The ICER for the National Strategy and WHO Strategy remained under A$50 000 per DALY averted if Australia spent up to A$328 or A$538 million, respectively, per annum (for 2016-2030) on implementation and demand generation activities. Sensitivity analysis showed that cost-effectiveness was predominately driven by the cost of CHB treatment and influenced by disease progression rates. Hence for Australia to reach the National Hepatitis B Strategy 2022 targets and WHO Strategy 2030 targets, it requires an improvement in the CHB care cascade. We estimated it is cost-effective to spend up to A$328 million or A$538 million per year to reach the National and WHO Strategy targets, respectively.

Will we need novel combinations to cure HBV infection?

Chronic hepatitis B is a numerically important cause of cirrhosis and hepatocellular carcinoma. Nucleoside analogue therapy may modify the risk. However, maintenance suppressive therapy is required, as a functional cure (generally defined as loss of HBsAg off treatment) is an uncommon outcome of antiviral treatment. Chronic hepatitis B is a numerically important cause of cirrhosis and hepatocellular carcinoma. Nucleoside analogue therapy may modify the risk. However, maintenance suppressive therapy is required, as a functional cure (generally defined as loss of HBsAg off treatment) is an uncommon outcome of antiviral treatment. Currently numerous investigational agents being developed to either interfere with specific steps in HBV replication or as host cellular targeting agents, that inhibit viral replication, and deplete or inactivate cccDNA, or as immune modulators. Synergistic mechanisms will be needed to incorporate a decrease in HBV transcription, impairment of transcription from HBV genomes, loss of cccDNA or altered epigenetic regulation of cccDNA transcription, and immune modulation or immunologically stimulated hepatocyte cell turnover. Nucleoside analogue suppressed patients are being included in many current trials. Trials are progressing to combination therapy as additive or synergistic effects are sought. These trials will provide important insights into the biology of HBV and perturbations of the immune response, required to effect HBsAg loss at different stages of the disease. The prospect of cures of hepatitis B would ensure that a wide range of patients could be deemed candidates for treatment with new compounds if these were highly effective, finite and safe. Withdrawal of therapy in short-term trials is challenging because short-term therapies may risk severe hepatitis flares, and hepatic decompensation. The limited clinical trial data to date suggest that combination therapy is inevitable.

Therapeutic strategies for hepatitis B virus infection: towards a cure

Chronic hepatitis B virus (HBV) infection is a common cause of liver disease globally, with a disproportionately high burden in South-East Asia. Vaccines and nucleoside or nucleotide drugs are available and reduce both new infection rates and the development of liver disease in HBV-positive persons who adhere to long-term suppressive treatment. Although there is still considerable value in optimizing access to virus-suppressing regimens, the scientific and medical communities have embarked on a concerted journey to identify new antiviral drugs and immune interventions aimed at curing infection. The mechanisms and drug targets being explored are diverse; however, the field universally recognizes the importance of addressing the persistence of episomal covalently closed circular DNA, the existence of integrated HBV DNA in the host genome and the large antigen load, particularly of hepatitis B surface antigen. Another major challenge is to reinvigorate the exhausted immune response within the liver microenvironment. Ultimately, combinations of new drugs will be required to cure infection. Here we critically review the recent literature that describes the rationale for curative therapies and the resulting compounds that are being tested in clinical trials for hepatitis B.

Antiviral treatment for chronic hepatitis B: Safety, effectiveness, and prognosis

The goal of chronic hepatitis B (CHB) therapy is to improve the patient prognosis through the sustained inhibition of viral replication. However, due to the uncertainty and potentially unlimited duration of the treatment course, nucleus(t)ide analogue (NA) resistance and safety, financial costs and patient compliance, different endpoints of antiviral treatment have been proposed in CHB prevention and treatment guidelines. Different treatment endpoints are closely associated with the safety of drug withdrawal and improvements in prognosis. Antiviral treatment suppresses HBV DNA replication, drug withdrawal leads to relapse, and long-term treatment causes drug safety and resistance issues. Although hepatitis B e antigen seroconversion based on HBV DNA inhibition is considered as “a satisfactory endpoint”, drug withdrawal still leads to high relapse rates. Hepatitis B surface antigen (HBsAg) clearance is the “ideal endpoint” in terms of the safety of drug withdrawal and improvements in prognosis. However, the HBsAg clearance rate is low using the conventional single drug treatment and fixed course regimens. Recently, the application of an “optimized antiviral treatment strategy” has improved the HBsAg clearance rate, and make an “ideal endpoint” possible. This article reviews the different antiviral treatment endpoints in terms of the safety of drug withdrawal, improvements in prognosis and relevant advances.

Electronic Health Informatics Data To Describe Clearance Dynamics of Hepatitis B Surface Antigen (HBsAg) and e Antigen (HBeAg) in Chronic Hepatitis B Virus Infection

Advances in the diagnosis, monitoring, and treatment of hepatitis B virus (HBV) infection are urgently required if we are to meet international targets for elimination by the year 2030. Here we demonstrate how routine clinical data can be harnessed through an unbiased electronic pipeline, showcasing the significant potential for amassing large clinical data sets that can help to inform advances in patient care and provide insights that may help to inform new cure strategies. Our cohort from a large UK hospital includes adults from diverse ethnic groups that have previously been underrepresented in the literature. By tracking two protein biomarkers that are used to monitor chronic HBV infection, we provide new insights into the timelines of HBV clearance, both on and off treatment. These results contribute to improvements in individualized clinical care and may provide important clues into the immune events that underpin disease control.

HBsAg and HBeAg have gained traction as biomarkers of control and clearance during chronic hepatitis B virus infection (CHB). Improved understanding of the clearance correlates of these proteins could help inform improvements in patient-stratified care and advance insights into the underlying mechanisms of disease control, thus underpinning new cure strategies. We collected electronic clinical data via an electronic pipeline supported by the National Institute for Health Research Health Informatics Collaborative (NIHR HIC), adopting an unbiased approach to the generation of a robust longitudinal data set for adults testing HBsAg positive from a large UK teaching hospital over a 6-year period (2011 to 2016 inclusive). Of 553 individuals with CHB, longitudinal data were available for 319, representing >107,000 weeks of clinical follow-up. Among these 319 individuals, 13 (4%) cleared HBsAg completely. Among these 13, the HBsAg clearance rate in individuals on nucleos(t)ide analogue (NA) therapy (n = 4 [31%]; median clearance time,150 weeks) was similar to that in individuals not on NA therapy (n = 9 [69%]; median clearance time, 157 weeks). Those who cleared HBsAg were significantly older and less likely to be on NA therapy than nonclearers (P = 0.003 and P = 0.001, respectively). Chinese ethnicity was associated with HBeAg positivity (P = 0.025). HBeAg clearance occurred in individuals both on NA therapy (n = 24; median time, 49 weeks) and off NA therapy (n = 19; median time, 52 weeks). Improved insights into the dynamics of these biomarkers can underpin better prognostication and patient-stratified care. Our systematized approach to data collection paves the way for scaling up efforts to harness clinical data to address research questions and support improvements in clinical care.