Quantification of HBV core antibodies may help predict HBV reactivation in patients with lymphoma and resolved HBV infection

EASL Clinical Practice Guidelines on the management of hepatitis B virus infection

The updated EASL Clinical Practice Guidelines on the management of hepatitis B virus (HBV) infection provide comprehensive, evidence-based recommendations for its management. Spanning ten thematic sections, the guidelines address diagnostics, treatment goals, treatment indications, therapeutic options, hepatocellular carcinoma surveillance, management of special populations, HBV reactivation prophylaxis, post-transplant care, HBV prevention strategies, and finally address open questions and future research directions. Chronic HBV remains a global health challenge, with over 250 million individuals affected and significant mortality due to cirrhosis and hepatocellular carcinoma. These guidelines emphasise the importance of early diagnosis, risk stratification based on viral and host factors, and tailored antiviral therapy. Attention is given to simplified algorithms, vaccination, and screening to support global HBV elimination targets. The guidelines also discuss emerging biomarkers and evolving definitions of functional and partial cure. Developed through literature review, expert consensus, and a Delphi process, the guidelines aim to equip healthcare providers across disciplines with practical tools to optimise HBV care and outcomes worldwide.

Prediction of intrahepatic covalently closed circular DNA levels in patients with resolved hepatitis B virus infection: Impact of serum antibody to hepatitis B core antigen titers

AIM

The correlation between intrahepatic covalently closed circular DNA (cccDNA) levels and serum hepatitis B virus (HBV) markers in patients with resolved HBV infection (hepatitis B surface antigen [HBsAg]-negative and antibody to hepatitis B core antigen [anti-HBc]-positive) is unclear. We therefore examined the utility of anti-HBc titers as a surrogate marker of intrahepatic cccDNA levels in patients with resolved HBV infections.

METHODS

Among 1005 patients who underwent hepatectomy between 2010 and 2018, a retrospective review was performed in 114 patients (76 with resolved HBV infection and 38 HBsAg-positive) with frozen specimens of the background liver. Clinical, biochemical, and virological data, including intrahepatic cccDNA levels, were retrospectively evaluated. Intrahepatic cccDNA levels were measured using droplet digital polymerase chain reaction.

RESULTS

Intrahepatic cccDNA levels positively correlated with serum HBsAg levels (r = 0.609, p < 0.001) and anti-HBc titers (r = 0.542, p < 0.001). An intrahepatic cccDNA level of 22.2 copies/μg was the optimal cut-off for HBsAg positivity, with a sensitivity of 86.8% and specificity of 89.5%. Of the 76 cases with resolved HBV infection, 8 had high levels of intrahepatic cccDNA (≥22.2 copies/μg). Multivariate analyses showed that anti-HBc ≥ 11.0 sample/cut-off (S/CO) was an independent risk factor for high intrahepatic cccDNA levels (odds ratio, 12.6; 95% confidence interval, 2.4-66.156; P = 0.003).

CONCLUSIONS

Anti-HBc titers were positively correlated with intrahepatic cccDNA levels. Even in patients with resolved HBV infection, anti-HBc ≥ 11.0 S/CO was considered to indicate high intrahepatic cccDNA levels, comparable to those in HBsAg-positive cases. In this group, careful monitoring is required during immunosuppressive therapy to prevent HBV reactivation.

Comprehensive genome analysis of hepatitis B virus using nanopore sequencing technology in patients with previously resolved infection and spontaneous reactivation without drug exposure

A 75-year-old Japanese woman experienced persistent fatigue and progressive jaundice for 6 weeks, and was subsequently diagnosed with acute liver failure. She had not received any immunosuppressive therapies and/or antineoplastic chemotherapy. Blood tests revealed elevated levels of HBsAg, HBV-DNA, and anti-HBc IgG, while anti-HBc IgM was negative. She had undergone hepatitis virus testing 48 weeks earlier, during which HBsAg was negative, indicating that HBV reactivation occurred in a patient with a previously resolved infection, without any drug therapies as triggers, ultimately leading to acute liver failure. Despite receiving multidisciplinary intensive treatment, her condition worsened, resulting in death. Full-length genomic analysis of the HBV strain, performed using nanopore sequencing technology, identified an I126S substitution in HBsAg, known as a vaccine escape mutation, along with a quasispecies consisting primarily of two HBV clone variants: one full-length and the other with a deletion in the nt2,448-nt488 region (sp1 spliced variant). These genetic factors may have contributed to the spontaneous HBV reactivation.

Misuse of the Lower Limit of Detection in HBV DNA Testing and Anti-HBe Positive Status Will Significantly Impact the Diagnosis of Occult HBV Infection

The diagnosis of occult hepatitis B virus (HBV) infection (OBI) is influenced by factors such as the lower limit of detection (LOD) of the HBV DNA test. However, in clinical practice and scientific research, the lower limit of quantification (LOQ) is often misused as the LOD. This study aims to investigate the impact of misuse of the LOD of the HBV DNA test on the detection rate of OBI, as well as the risk factors for OBI. Four hundred twelve patients who were HBsAg-negative and had undergone high-sensitivity HBV DNA testing were included in this study. HBV DNA was detected using the Cobas 6800 System with an LOD of 2.4 IU/mL and an LOQ of 10 IU/mL. The effect of using the LOQ as the LOD on the detection rate of OBI was compared, and univariate and multivariate logistic regression analyses were used to explore the risk factors for OBI. (1) Of the 412 patients, 63.3% (n = 261) were male, with a median age of 47 (range 34-55) years. A total of 473 HBV DNA test results were obtained, with 366 individuals undergoing only one HBV DNA test and the remaining 46 patients undergoing 2 to 5 HBV DNA tests (resulting in a total of 107 test results). (2) Considering only the first HBV DNA test result, the detection rate of OBI was 4.1% (17/412). However, when the LOQ (10 IU/mL) was used as the LOD, the detection rate of OBI was only 1.5% (6/412) (p < 0.001). (3) Univariate analysis showed that there were statistically significant differences in age, anti-HBe positivity rate and anti-HBc positivity rate between OBI and non-OBI individuals (p < 0.05). Multivariate regression analysis showed that anti-HBe positivity was an independent risk factor for OBI in this study (odds ratio [OR] = 3.807, 95% confidence interval [CI]: 1.065-13.617, p = 0.040), while anti-HBs positivity was a protective factor against OBI (OR = 0.271, 95% CI: 0.093-0.787, p = 0.016). (4) Among the 46 patients who underwent repeated testing, a total of seven individuals were found to be HBV DNA-positive in the first test, and six individuals tested positive for HBV DNA one or more times in subsequent tests. When OBI was confirmed by ≥ 1 out of 1-5 tests with detectable HBV DNA, the detection rate of OBI in this study could increase from 4.1% to 5.6%. The detection rate of OBI among HBsAg-negative adult patients attending hepatology departments in this region is 4.1%. Misusing the LOQ as LOD can significantly decrease the detection rate of OBI. The presence of anti-HBe positivity and undergoing multiple HBV DNA tests can lead to a significant increase in the detection rate of OBI.

Rituximab carries high risks of hepatitis B virus reactivation in hematologic and rheumatic patients with chronic or resolved hepatitis B

BACKGROUND AND AIM

Rituximab therapy is associated with a high risk of hepatitis B virus (HBV) reactivation. We aimed to assess whether the risk of reactivation differed among various underlying diseases and between hepatitis B surface antigen (HBsAg) carriers and patients with resolved HBV infection.

METHODS

We retrospectively analyzed patients with chronic or resolved HBV infection who received rituximab without prophylactic anti-HBV therapy at a tertiary medical center. The risks of HBV reactivation, hepatitis, and hepatic decompensation were compared between the patients with hematologic and rheumatic diseases.

RESULTS

There were 78 patients with hematologic diseases and 39 patients with rheumatic diseases included. Among them, 43 (59%) HBsAg-positive patients and 24 (55%) patients with resolved HBV infection experienced HBV reactivation at a median of 14.6 months after rituximab therapy. After rituximab treatment, the 1-year HBV reactivation rate among patients with hematologic and rheumatic diseases was 29% and 45% in HBsAg-positive patients, respectively, while the rates were 38% and 17% in patients with resolved HBV infection. The reactivation risk continued to increase even 2 years after rituximab therapy and was comparable between hematologic and rheumatic patients. A higher baseline HBV DNA level (≥20 IU/mL vs <20 IU/mL) was an independent predictor for HBV reactivation (adjusted hazard ratio [aHR]: 10.9, 95% confidence interval [CI]: 1.1-107) and HBV-associated hepatitis (aHR: 14.8, 95% CI: 1.4-158).

CONCLUSIONS

Rituximab therapy is associated with a 50-64% risk of HBV reactivation regardless of underlying diseases and HBsAg status. HBV DNA levels should be assessed before initiating rituximab.

Newer Diagnostic Virological Markers for Hepatitis B Virus Infection

Chronic Hepatitis B (CHB) remains a major public health problem, leading to various complications such as liver fibrosis, cirrhosis, and hepatocellular carcinoma. The existing diagnostic markers for Hepatitis B virus (HBV) are limited in distinguishing different CHB phases and intra-hepatic viral replication activity. In the past few years, several non-invasive potential blood markers that reflect viral intra-hepatic replicative state more accurately have been in progress and are gaining importance. Despite substantial efforts, the clinical utility of these new markers in CHB management is limited and unexplored. Therefore, in this review, we will discuss some of the newer HBV markers, their potential role in the diagnosis and monitoring of CHB patients.

How to cite this article

Agarwal R, Gupta E, Samal J, et al. Newer Diagnostic Virological Markers for Hepatitis B Virus Infection. Euroasian J Hepato-Gastroenterol 2024;14(2):214-220.

Biomarkers of transfusion transmitted occult hepatitis B virus infection: Where are we and what next?

Blood transfusion is a vital procedure, where transfusion-transmitted infection of hepatitis B virus (HBV) remains an important issue, especially from blood donors with occult hepatitis B virus infection (OBI). Occult hepatitis B virus infection is a complex entity to detect using surrogate blood biomarkers for intrahepatic viral transcriptional activity, requiring a continually refined battery of tests utilised for screening. This review aims to critically evaluate the latest advances in the current blood biomarkers to guide the identification of OBI donors and discuss novel HBV markers that could be introduced in future diagnostic practice. Challenges in detecting low HBV surface antigen levels, mutants, and complexes necessitate ultrasensitive multivalent dissociation assays, whilst HBV DNA testing requires improved sensitivity but worsens inaccessibility. Anti-core antibody assays defer almost all potentially infectious donations but have low specificity, and titres of anti-surface antibodies that prevent infectivity are poorly defined with suboptimal sensitivity. The challenges associated with these traditional blood HBV markers create an urgent need for alternative biomarkers that would help us better understand the OBI. Emerging viral biomarkers, such as pre-genomic RNA and HBV core-related antigen, immunological HBV biomarkers of T-cell reactivity and cytokine levels, and host biomarkers of microRNA and human leucocyte antigen molecules, present potential advances to gauge intrahepatic activity more accurately. Further studies on these markers may uncover an optimal diagnostic algorithm for OBI using quantification of various novel and traditional blood HBV markers. Addressing critical knowledge gaps identified in this review would decrease the residual risk of transfusion-transmitted HBV infection without compromising the sustainability of blood supplies.

Prevalence and influential factors of isolated hepatitis B core antibody positivity in a Chinese adult population

Isolated anti-HBc (IAHBc) is defined by the presence of anti-HBc in the absence of HBsAg and hepatitis B surface antibody (anti-HBs). IAHBc is of great clinical significance as a specific pattern of HBV infection, but IAHBc has not been fully clarified. This study aimed to explore the prevalence and influential factors of IAHBc from routine examination results of inpatients.A total of 61,247 individuals were included in the study, with a median age of 55 years (range: 43-68), and a male-to-female ratio of 0.90:1. The prevalence of current HBV infection (HBsAg positive) was 6.82%, while the prevalence of previous HBV infection (HBsAg negative but anti-HBc positive) was 48.63%. The prevalence of IAHBc was 12.31%. Among them, the rates for males were 7.10%, 52.16%, and 13.70%, respectively, which were significantly higher than the rates for females at 6.56%, 45.45%, and 11.06% (P < 0.05). The prevalence rates mentioned above were significantly reduced after vaccination (P < 0.05). The prevalence of IAHBc increases with age, rising from 0.23% in the age group of 15-29 years to 13.57% in individuals aged 80 and above. After the age of 50, the prevalence of IAHBc closely parallels the previous infection rate but shows no significant association with the current infection rate (P > 0.05). Among IAHBc individuals, approximately 33.83% tested positive for anti-HBe, and their anti-HBc absorbance values were significantly higher compared to anti-HBe negative individuals (7.08 and 5.31, P < 0.01). The prevalence of anti-HBe positivity among IAHBc individuals does not vary with changes in the previous infection rate and age (P > 0.05).

Impact of Hepatitis B Surface and Core Antibody Levels on Hepatitis B Virus Reactivation

Hepatitis B virus reactivation (HBV-R) is a serious complication that can occur in patients with resolved HBV infection during cancer chemotherapy. We examined the levels of HBV surface antibody (HBsAb) and HBV core antibody (HBcAb) to assess the incidence of HBV-R in cancer patients including hematopoietic stem cell transplantation (HSCT) and rituximab administration. This retrospective cohort study included 590 patients with resolved HBV infection. The incidence of HBV-R was evaluated 761.5 (range, 90-3898) days after the inititiation of chemotherapy. Of the patients, 13 (2.2%) developed HBV-R after the start of chemotherapy. All 13 patients exhibited lower HBsAb (<100 mIU/mL) levels at baseline. A higher level of HBcAb (≥100 cut off index (C.O.I.)) was a possible risk factor for HBV-R as well as HSCT and rituximab administration. The simultaneous presence of HBsAb <100 mIU/mL and HBcAb ≥100 C.O.I. increased the risk of HBV-R by 18.5%. Patients treated with rituximab were at a higher risk of HBV-R (18.4%) despite having HBcAb <100 C.O.I. Our results suggest that assessment of HBsAb and HBcAb levels prior to the chemotherapy is important for identifying patients at high risk of HBV-R, especially in solid cancers without HSCT and rituximab administration.

Steady Decline of HBV DNA Load under NAs in Lymphoma Patients and a Higher Level of qAnti-HBc Predict HBV Reactivation

Background: Patients with lymphoma and chronic hepatitis B virus infection need to be treated with both chemotherapy and nucleotide analogue (NA) therapy. However, dynamic changes in HBV DNA loads with increasing chemotherapy cycles are lacking. It is unknown whether HBV replication markers, namely, the quantitative hepatitis B core antibody (qAnti-HBc), HBV RNA, and the hepatitis B virus core-related antigen (HBcrAg), are also markers for predicting HBV reactivation (HBVr). Methods: From 29 June 2010 to 6 December 2021, the data of patients with single-site diffuse large B-cell lymphoma and HBV infection (HBsAg+ and HBsAg-/anti-HBc+) were collected from a hospital medical record system, retrospectively. Serum HBV DNA loads (using real-time fluorescent quantitative PCR tests), qAnti-HBc levels (using a newly developed chemiluminescent particle immunoassay), HBV RNA levels (using the simultaneous amplification testing method based on real-time fluorescence detection), and HBcrAg levels (using a Lumipulse G HBcrAg assay) were tested, and factors related to HBVr were analyzed. Results: Under NAs, the HBV DNA loads of 69 HBsAg+ lymphoma patients declined from 3.15 (2.13-4.73) lg IU/mL to 1.00 (1.00-1.75) lg IU/mL, and further declined to 1.00 (1.00-1.04) lg IU/mL at the end of a 24-month follow-up. The qAnti-HBc levels decreased gradually during chemotherapy in HBsAg+ lymphoma patients (F = 7.090, p = 0.009). The HBV RNA and HBcrAg levels remained stable. A multivariate analysis revealed that higher qAnti-HBc levels (1.97 ± 1.20 vs. 1.12 ± 0.84 lg IU/mL, OR = 6.369, [95% CI: 1.523-26.641], p = 0.011) and higher HBV RNA levels (1.00 ± 1.13 vs. 0.37 ± 0.80 lg copies/mL, OR = 3.299, [95% CI: 1.229-8.854], p = 0.018) were related to HBVr in HBsAg-/anti-HBc+ lymphoma patients. Conclusions: HBV DNA loads declined under NAs during chemotherapy in lymphoma patients. In HBsAg-/anti-HBc+ lymphoma patients, a higher level of baseline serum qAnti-HBc and HBV RNA levels can predict the likelihood of HBVr during chemotherapy.

Interpreting Serogical Markers in Hepatitis B Virus Infection

Hepatitis B virus (HBV) is considered a global health-related problem. The World Health Organization estimates an incidence of approximately 1.5 million new cases annually despite an available effective vaccine, and approximately 296 million people worldwide are living with chronic hepatitis B. This large number of patients require continuous monitoring of the treatment efficacy, disease progression, and screening for the HBV-related liver complications. Recently, it has become more evident that we need better predictive markers to allow treatment cessation when there is a reduced risk of viral reactivation, in addition to the present need to predict disease outcome and improve the management of people living with chronic hepatitis B. Novel HBV biomarkers are focused on in this minireview. These new markers include quantification of serum HBV RNA, hepatitis B core–related antigen, quantitative hepatitis B surface antigen, quantitative anti–hepatitis B core antigen, and detection of HBV nucleic acid–related antigen. The target of finding new markers for HBV replication is to provide crucial clinical data in a noninvasive way for detecting the replicative and transcriptional activity of the virus. This may support better management of patients compared with the criterion-standard invasive marker for detecting the intrahepatic replication and transcription of HBV, which is the quantification of covalently closed circular DNA.

Expanding the donor pool: Kidney transplantation from serum HBV DNA or HBeAg-positive donors to HBsAg-negative recipients

BACKGROUND & AIMS

HBsAg-positive (HBsAg[+]) donors are rarely accepted for kidney transplantation (KT), especially when the donor is also HBV DNA-positive (HBV DNA[+]) or HBeAg-positive (HBeAg[+]) serologically. This study aimed to report kidney transplant outcomes from HBsAg(+) donors to HBsAg(-) recipients.

METHODS

Consecutive cases were retrospectively identified from 1 July 2017 to 31 December 2020. KTs from HBsAg(-)/HBcAb-positive (HBcAb[+]) donors to HBcAb(-) recipients were selected as the control group. The primary outcomes were de novo HBV infection (DNH), graft and patient survival.

RESULTS

We identified 105 HBsAg(-) recipients who received HBsAg(+) kidneys and 516 HBcAb(-) recipients who received HBcAb(+) kidneys. A higher DNH rate was observed after receiving HBsAg(+) kidneys than after receiving HBcAb(+) kidneys after a median follow-up of 23.0 months (4/105[3.8%] vs. 2/516[0.4%], p = .009). All four infected recipients receiving HBsAg(+) kidneys had HBsAg clearance after treatment. Graft and patient survival were comparable between the groups (p = .630, p = .910). The DNH rates were 0/22(0%), 3/70(4.3%) and 1/13(7.7%) after receiving HBsAg(+), HBV DNA(+) and HBeAg(+) kidneys, respectively (p = .455). The DNH rate was lower if the donor had received antiviral treatment (4/42[9.5%] vs. 0/63[0%], p = .023). HBsAb(-) recipients had a higher DNH incidence than HBsAb(+) recipients (3/25[12.0%] vs. 1/80[1.3%], p = .041).

CONCLUSIONS

The use of HBsAg(+) donors contributed to comparable graft and patient survival, but HBV DNA(+) or HBeAg(+) donors and HBsAb(-) recipients maybe associated with a higher risk of HBV infection. These findings help expand the donor pool and emphasize the role of donor antiviral treatment and recipient HBV immunity in establishing optimal prophylactic regimens.

Ultrasensitive PCR system for HBV DNA detection: Risk stratification for occult hepatitis B virus infection in English blood donors

Occult hepatitis B (HBV) infection (OBI), characterized by low viral loads, accounts for much of the risk of HBV transfusion-transmitted infection. With anticore antibodies (anti-HBc) screening introduced in England, the imperative to identify OBI donors has increased. We aimed to develop an ultra-sensitive PCR system and investigate risk factors for HBV DNA presence in blood donations. Seven extraction methods and three PCR assays were compared. The optimal system was sought to determine HBV DNA presence in anti-HBc-positive donations. Predictors of DNA positivity were subsequently investigated. Extraction from 5 mL of plasma increased sample representation and resulted in HBV DNA detection in low viral load samples (~0.5 IU/mL). Screening of 487 763 donations in 2022 identified two OBI donors and 2042 anti-HBc-positive donors, 412 of the latter with anti-HBs < 100 mIU/mL. Testing of 134 anti-HBc-positive donations utilizing the 5 mL extraction method identified two further HBV DNA-positive donations. Higher anti-HBc titer and anti-HBs negativity were significant predictors of DNA detectability in anti-HBc-positive donations. An ultrasensitive PCR assay identified potentially infectious donations increasing HBV DNA detection in anti-HBc-positive donors from 0.5% to 1.9%. Anti-HBc titers may further complement the risk stratification for DNA positivity in anti-HBc screening and minimize unnecessary donor deferral.

Establishment of a multi-parameter prediction model for the functional cure of HBeAg-negative chronic hepatitis B patients treated with pegylated interferonα and decision process based on response-guided therapy strategy

BACKGROUND & AIMS

This study aimed to establish multivariate prediction models according to a response-guided therapy (RGT) based strategy at baseline and week 12 and 24 of follow-up to predict the functional cure for HBeAg-negative patients with chronic hepatitis B (CHB) treated with pegylated interferonα (PEG-IFNα).

METHODS

A total of 242 HBeAg-negative patients with CHB were treated with PEG-IFNα for 52 weeks and followed up for 24 weeks. Responses at the end of follow-up (EOF) were defined as hepatitis B surface antigen (HBsAg) loss, and patients were defined as either responders or non-responders.

RESULTS

The three most meaningful predictors were an age ≤ 40 years, alanine aminotransferase (ALT) levels ≤ 40 U/L, and HBsAg levels ≤ 100 IU/mL at baseline; ALT levels ≥ 80 U/L, anti-HBc levels ≤ 8.42 S/CO, and HBsAg levels ≤ 50 IU/mL at week 12; and ALT levels ≥ 40 U/L, anti-HBc levels ≤ 8.46 S/CO, and HBsAg levels ≤ 0.2 IU/mL at week 24. The response rates of patients with a score of 0-1 and 4-5 at baseline, week 12, and 24 were 13.5%, 7.8%, and 11.7%; and 63.6%, 68.1%, and 98.1%, respectively. At week 12, the cumulative scores were 0-2, 3-4, 5-7, and 8-10 (response rates 5.0%, 18.9%, 41.3%, and 71.4%, respectively). At week 24, the cumulative scores were 0-3, 4-6, 7-10, and 11-15 (response rates: 1.3%, 12.3%, 37.0%, and 92.5%, respectively). At baseline, patients with scores of 0-1 were slightly recommended; at week 12, patients with 0-1 or 0-2 cumulative scores were recommended to stop treatment. At week 24, patients with a score of 0-1 or a cumulative score of 0-6 were recommended to stop treatment.

CONCLUSION

We established a multi-parameter prediction model for the functional cure of HBeAg-negative patients with CHB treated with PEG-IFNα.

Current and novel modalities for management of chronic hepatitis B infection

Over 296 million people are estimated to have chronic hepatitis B viral infection (CHB), and it poses unique challenges for elimination. CHB is the result of hepatitis B virus (HBV)-specific immune tolerance and the presence of covalently closed circular DNA as mini chromosome inside the nucleus and the integrated HBV. Serum hepatitis B core-related antigen is the best surrogate marker for intrahepatic covalently closed circular DNA. Functional HBV "cure" is the durable loss of hepatitis B surface antigen (HBsAg), with or without HBsAg seroconversion and undetectable serum HBV DNA after completing a course of treatment. The currently approved therapies are nucleos(t)ide analogues, interferon-alpha, and pegylated-interferon. With these therapies, functional cure can be achieved in < 10% of CHB patients. Any variation to HBV or the host immune system that disrupts the interaction between them can lead to reactivation of HBV. Novel therapies may allow efficient control of CHB. They include direct acting antivirals and immunomodulators. Reduction of the viral antigen load is a crucial factor for success of immune-based therapies. Immunomodulatory therapy may lead to modulation of the host immune system. It may enhance/restore innate immunity against HBV (as toll-like-receptors and cytosolic retinoic acid inducible gene I agonist). Others may induce adaptive immunity as checkpoint inhibitors, therapeutic HBV vaccines including protein (HBsAg/preS and hepatitis B core antigen), monoclonal or bispecific antibodies and genetically engineered T cells to generate chimeric antigen receptor-T or T-cell receptor-T cells and HBV-specific T cells to restore T cell function to efficiently clear HBV. Combined therapy may successfully overcome immune tolerance and lead to HBV control and cure. Immunotherapeutic approaches carry the risk of overshooting immune responses causing uncontrolled liver damage. The safety of any new curative therapies should be measured in relation to the excellent safety of currently approved nucleos(t)ide analogues. Development of novel antiviral and immune modulatory therapies should be associated with new diagnostic assays used to evaluate the effectiveness or to predict response.

Hepatitis B Core Antibody Level: A Surrogate Marker for Host Antiviral Immunity in Chronic Hepatitis B Virus Infections

The hepatitis B virus core protein (HBcAg) is a highly immunogenic particulate antigen. Nearly all patients with persistent or resolved hepatitis B virus (HBV) infection show seropositivity for hepatitis B core antibody (anti-HBc), which appears in the early stage of infection and is mostly present for life. Traditionally, the anti-HBc is regarded as an evidential serological marker of HBV infections. In the last ten years, several studies revealed the predictive value of quantitative anti-HBc (qAnti-HBc) level in the treatment response and clinical outcome of chronic HBV infections, implying new insights into this classic marker. Overall, qAnti-HBc should be regarded as an indicator of the host's immune response specific to HBV, which correlates with HBV-related hepatitis activity and liver pathology. This review summarized the latest understanding of the clinical values of qAnti-HBc for differentiating the CHB phase, predicting treatment response, and providing disease prognosis. Moreover, we also discussed the possible mechanism of qAnti-HBc regulation during different courses of HBV infection.

The Multiple Facets and Disorders of B Cell Functions in Hepatitis B Virus Infection

Chronic hepatitis B virus (HBV) infection continues to be a global public health burden. B cells play a pivotal role in mediating HBV clearance and can participate in the development of anti-HBV adaptive immune responses through multiple mechanisms, such as antibody production, antigen presentation, and immune regulation. However, B cell phenotypic and functional disorders are frequently observed during chronic HBV infection, suggesting the necessity of targeting the disordered anti-HBV B cell responses to design and test new immune therapeutic strategies for the treatment of chronic HBV infection. In this review, we provide a comprehensive summary of the multiple roles of B cells in mediating HBV clearance and pathogenesis as well as the latest developments in understanding the immune dysfunction of B cells in chronic HBV infection. Additionally, we discuss novel immune therapeutic strategies that aim to enhance anti-HBV B cell responses for curing chronic HBV infection.

HBsAg (-)/HBsAb (-)/HBeAg (-)/HBeAb (+)/HBcAb (+) predicts a high risk of hepatitis B reactivation in patients with B-cell lymphoma receiving rituximab based immunochemotherapy

Patterns of hepatitis B virus reactivation (HBV-R) in HBsAg (-)/HBcAb (+) patients with B-cell non-Hodgkin lymphoma (NHL) receiving rituximab based immunochemotherapy have not been well described. The retrospective study included 222 HBsAg (-)/HBcAb (+) NHL patients as training cohort and 127 cases as validation cohort. The incidence of HBV-R in HBsAg (-)/HBcAb (+) B-cell NHL patients was 6.3% (14/222), of which that in HBsAg (-)/HBsAb (-)/HBeAg (-)/HBeAb (+)/HBcAb (+) population was 23.7% (9/38). Multivariate analysis showed that HBsAg (-)/HBsAb (-)/HBeAg (-)/HBeAb (+)/HBcAb (+) correlated with a high risk of HBV-R in B-cell lymphoma patients (training phase hazard ratio [HR], 10.123; 95% confidence interval [CI], 3.389-30.239; p < 0.001; validation phase HR, 18.619; 95% CI, 1.684-205.906; p = 0.017; combined HR, 12.264; 95% CI, 4.529-33.207; p < 0.001). In the training cohort, the mortality rate of HBsAg (-)/HBcAb (+) B-cell NHL caused by HBV-R was 14.3% (2/14) while that for HBV reactivated HBsAg (-)/HBsAb (-)/HBeAg (-)/HBeAb (+)/HBcAb (+) population was up to 44.4% (4/9). As a high incidence of HBV-R and high mortality after HBV-R was found in HBsAg (-)/HBsAb (-)/HBcAb (+)/HBeAg (-)/HBeAb (+) patients with B-cell NHL receiving rituximab based immunochemotherapy, prophylactic antiviral therapy is recommended for these patients.

Clinical Utility of Quantitative HBV Core Antibodies for Solving Diagnostic Dilemmas

The present-day management of hepatitis B virus (HBV) infection relies on constant and appropriate monitoring of viral activity, disease progression and treatment response. Traditional HBV infection biomarkers have many limitations in predicting clinical outcomes or therapy success. Quantitation of HBV core antibodies (qAnti-HBc) is a new non-invasive biomarker that can be used in solving multiple diagnostic problems. It was shown to correlate well with infection phases, level of hepatic inflammation and fibrosis, exacerbations during chronic infection and presence of occult infection. Further, the level of qAnti-HBc was recognised as predictive of spontaneous or therapy-induced HBeAg and HBsAg seroclearance, relapse after therapy discontinuation, re-infection after liver transplantation and viral reactivation upon immunosuppression. However, qAnti-HBc cannot be relied upon as a single diagnostic test to solve all dilemmas, and its diagnostic and prognostic power can be much improved when combined with other diagnostic biomarkers (HBV DNA, HBeAg, qHBsAg and anti-HBs antibodies). The availability of commercial qAnti-HBc diagnostic kits still needs to be improved. The comparison of results from different studies and definitions of universal cut-off values continue to be hindered because many methods are only semi-quantitative. The clinical utility of qAnti-HBc and the methods used for its measurement are the focus of this review.

Low anti-HBc levels are associated with lower risk of virological relapse after nucleos(t)ide analogue cessation in HBe antigen-negative patients

BACKGROUND AND AIMS

Low anti-HBc serum levels at the time of therapy cessation were linked to a higher relapse risk in predominantly HBeAg-positive cohorts. We investigated the association of anti-HBc levels with relapse in HBeAg-negative patients.

METHODS

Serum levels of anti-HBc, HBsAg and HBcrAg were determined in 136 HBeAg-negative patients, participating in a vaccination trial (ABX-203, NCT02249988), before treatment cessation or vaccination. Importantly, vaccination showed no impact on relapse. The correlation between the biomarkers and their predictive value for relapse (HBV DNA >2000 IU/ml ± ALT >2xULN) was investigated.

RESULTS

After therapy cessation 50% (N = 68) of patients relapsed. Median anti-HBc prior to treatment stop was significantly higher among relapsers compared to off-treatment responders (520 IU/ml vs. 330 IU/mL, p = .0098). The optimal anti-HBc cut-off to predict relapse was 325 IU/ml according to the Youden-Index. About 35% of patients with anti-HBc level < 325 IU/ml versus 60% of those with values ≥325 IU/mL relapsed (p = .0103; sensitivity 50%, specificity 75%). Combining the optimal cut-offs of HBsAg (>3008 IU/mL) or HBcrAg (≥1790 U/ml) with anti-HBc increased the proportion of patients with relapse to 80% (p < .0001) and 74% (p = .0006), respectively.

CONCLUSION

In contrast to predominantly HBeAg-positive cohorts, in our cohort of HBeAg-negative patients lower anti-HBc levels are associated with a significantly lower relapse risk after nucleos(t)ide analogue cessation. The vast majority of included patients were either genotype B or C and the applicability to other genotypes has to be further evaluated. However, anti-HBc level as an indicator of the host response might be prospectively further explored for prediction models.

A roadmap for serum biomarkers for hepatitis B virus: current status and future outlook

Globally, 296 million people are infected with hepatitis B virus (HBV), and approximately one million people die annually from HBV-related causes, including liver cancer. Although there is a preventative vaccine and antiviral therapies suppressing HBV replication, there is no cure. Intensive efforts are under way to develop curative HBV therapies. Currently, only a few biomarkers are available for monitoring or predicting HBV disease progression and treatment response. As new therapies become available, new biomarkers to monitor viral and host responses are urgently needed. In October 2020, the International Coalition to Eliminate Hepatitis B Virus (ICE-HBV) held a virtual and interactive workshop on HBV biomarkers endorsed by the International HBV Meeting. Various stakeholders from academia, clinical practice and the pharmaceutical industry, with complementary expertise, presented and participated in panel discussions. The clinical utility of both classic and emerging viral and immunological serum biomarkers with respect to the course of infection, disease progression, and response to current and emerging treatments was appraised. The latest advances were discussed, and knowledge gaps in understanding and interpretation of HBV biomarkers were identified. This Roadmap summarizes the strengths, weaknesses, opportunities and challenges of HBV biomarkers.

Review article: novel biomarkers in hepatitis B infection

BACKGROUND

Chronic hepatitis B remains a global health problem with an estimated 296 million people affected worldwide. Individuals are at risk of serious complications such as cirrhosis and hepatocellular carcinoma and accurately predicting these clinical endpoints has proven difficult. However, several viral biomarkers have recently been developed, including quantitative HBV surface antigen (qHBsAg), hepatitis B RNA (HBV RNA) and core-related antigen (HBcrAg), and shown promise in a range of clinical settings.

AIMS

To critically appraise these novel biomarkers, exploring their potential uses, availability of assays and areas for future development.

METHODS

We performed a literature search of PubMed, identifying articles published in the field of hepatitis B biomarkers between 2010 and 2022.

RESULTS

Novel biomarkers such as HBcrAg, HBV RNA and qHBsAg may be useful in predicting treatment outcomes, stratifying the risk of future complications and estimating off-treatment viral reactivation. Furthermore, HBV RNA and HBcrAg titres may accurately reflect cccDNA transcriptional activity, and this is particularly informative in the context of nucleoside analogue therapy. On a cautionary note, most studies have been performed in Caucasian or Asian populations, and methods for detecting HBV RNA lack standardisation.

CONCLUSION

Novel viral biomarkers have the potential to provide additional insights into the natural history of infection and allow a more bespoke, cost-effective framework of care. However, access remains limited, and further efforts are needed to validate their use in ethnically diverse populations, confirm predictive cut-off values, and establish their role in the era of novel antiviral therapies.

Quantitative anti-HBc combined with quantitative HBsAg can predict HBsAg clearance in sequential combination therapy with PEG-IFN-α in NA-suppressed chronic hepatitis B patients

Background and aims

Precise predictors are lacking for hepatitis B surface antigen (HBsAg) clearance under the combination therapy of nucleos(t)ide analogs (NA) and pegylated interferon-alpha (PEG-IFN-α) in patients with chronic hepatitis B (CHB). This study aimed to determine the quantitative anti-hepatitis B core antibody (qAnti-HBc) and quantitative hepatitis B core-related antigen (qHBcrAg) as predictors for HBsAg clearance in NA-suppressed patients with CHB receiving PEG-IFN-α add-on therapy.

Methods

Seventy-four CHB patients who achieved HBV DNA suppression (HBV DNA &lt; 20 IU/ml) and quantitative HBsAg (qHBsAg) &lt; 1,500 IU/ml after ≥1 year of NA treatment were enrolled. Fifteen patients continued on NA monotherapy, while 59 patients received PEG-IFN-α add-on therapy. Serum qAnti-HBc and qHBcrAg levels were detected every 12 or 24 weeks for add-on and NA-alone groups, respectively.

Results

Serum qAnti-HBc but not qHBcrAg levels at baseline were negatively correlated with the duration of prior NA therapy. After 48-week treatment, both qAnti-HBc and qHBcrAg levels declined further, and 17/59 (28.81%) and 0/15 (0%) achieved HBsAg clearance in add-on and NA groups, respectively. In the add-on group, the rate of HBsAg clearance was significantly higher in patients with baseline qAnti-HBc &lt; 0.1 IU/ml (52.63%). Logistic regression analysis identified baseline qAnti-HBc but not qHBcrAg, which was an independent predictor for HBsAg loss. Receiver operating characteristic curve analysis showed that the combination of qAnti-HBc and qHBsAg had a better predictive value for HBsAg clearance.

Conclusions

A combination of qHBsAg and baseline qAnti-HBc levels may be a better prediction strategy for HBsAg clearance in NA-suppressed CHB patients receiving PEG-IFN-α add-on therapy.

Cost-effectiveness of managing HBV reactivation in patients with resolved HBV infection treated with anti-CD20 antibody for B-cell non-Hodgkin lymphoma

There is no universal recommendation for managing the reactivation of HBV in patients with resolved HBV infection treated with anti-CD20 monoclonal antibodies for B-cell non-Hodgkin lymphoma. This study compared the cost-effectiveness of two commonly used strategies: prophylactic anti-HBV nucleos(t)ide analog therapy (Pro NAT), and HBV DNA monitoring followed by on-demand antiviral therapy (HBV DNA monitoring). Using a decision tree model, the incremental cost-effectiveness ratio (ICER) expressed as cost per quality-adjusted life-year (QALY) gained was calculated. The threshold for cost-effectiveness was set at 5,000,000 JPY, equivalent to 45,662 USD. In a base–case analysis, HBV DNA monitoring was found to be more cost-effective based on the calculation of ICER as 132,048 USD per QALY, a value that far exceeds 45,662 USD. The same results were consistently obtained by a one-way deterministic sensitivity analysis, even after changing each parameter value within the predetermined range. A probabilistic sensitivity analysis with 10,000 simulations also revealed that HBV DNA monitoring is more cost-effective than Pro NAT in 96.8% of cases. Therefore, this study suggests that HBV DNA monitoring is an appropriate managing measure in Japan from a cost-effectiveness perspective.

Dose-response relationship between qAnti-HBc and liver inflammation in chronic hepatitis B with normal or mildly elevated ALT based on liver biopsy

BACKGROUND

The proportion of chronic hepatitis B(CHB) patients with normal or mildly elevated ALT(NMALT) levels who have moderate to severe inflammation was not rare. However, we lacked appropriate biomarkers to evaluate liver inflammation in these populations. We aimed to explore the relationship between quantitative hepatitis B core antibody(qAnti-HBc) and hepatic histological inflammation.

METHOD

This multi-center cohort study enrolled participants from 34 Chinese hospital including 1376 treatment-naive CHB patients with liver biopsy(934 with NMALT entered treatment-naive cohort; 423 with secondary liver biopsy entered treatment cohort). Using unadjusted and multivariate-adjusted generalized linear models, generalized additive models with smooth curve fitting, we evaluated the associations between qAnti-HBc and liver inflammation in these patients.

RESULTS

In the treatment-naive patients, qAnti-HBc was positively associated with liver inflammation(histology activity index[HAI] evaluated by Ishak scoring system)(fully-adjusted model: β=0.48, 95%CI[0.30-0.66], P<0.001). For per-SD increase in qAnti-HBc, the risk of moderate to severe inflammation(HAI≥5) increased by 56%(OR=1.56, 95%CI[1.28-1.91], P<0.001). The curve fitting indicated a significant "threshold effect" (inflection point was 4.5 log₁₀ IU/mL, P<0.001). Subgroup analyses and interactions were not significant(all P>0.05). In the treatment patients, there was no significant correlation between qAnti-HBc and liver inflammation, whether based on unadjusted, minimally-adjusted, or fully-adjusted models(all P>0.100). Paired analyses showed a significant correlation between decreasing in qAnti-HBc and alleviation of liver inflammation.

CONCLUSIONS

qAnti-HBc was positively correlated with liver inflammation in treatment-naive CHB patients with NMALT. The cutoff value of qAnti-HBc for the diagnosis of moderate to severe inflammation was 4.5 log₁₀ IU/mL. Decreasing in qAnti-HBc was positively correlated with liver inflammation relieving. This article is protected by copyright. All rights reserved.

Biomarkers for predicting nucleos(t)ide analogs discontinuation and hepatitis B virus recurrence after drug withdrawal in chronic hepatitis B patients

AIM

To summarize HBV-related biomarkers predicting nucleos(t)ide analogs (NAs) discontinuation and hepatitis B virus (HBV) recurrence after drug withdrawal in chronic hepatitis B (CHB) patients, providing references for clinical medication, so as to manage CHB patients more scientifically.

METHODS

Related pieces of literature were retrieved in PubMed and the results were sorted out. We then analyzed and summarized these articles.

RESULTS

We found that HBV related biomarkers maybe could predict NAs withdrawal safely and the possibility of relapse after treatment cessation, including hepatitis B e antigen (HBeAg), hepatitis B surface antigen (HBsAg), HBV DNA, HBV RNA, pregenomic-RNA (pgRNA), hepatitis B core-related antigen (HBcrAg), hepatitis B core antibody (anti-HBc), and models containing several indicators for predicting the effectiveness of treatment.

CONCLUSIONS

HBV DNA, HBV RNA, pgRNA, HBcrAg, anti-HBc, as well as the prediction models formed by several biomarkers could predict the safe discontinuation of NAs before HBsAg loss and recurrence.

Protective Role of Rheumatic Diseases Against Hepatitis B Virus Infection and Human Leukocyte Antigen B27 Highlighted

BACKGROUND

By determining the hepatitis B virus (HBV) surface antigen (HBsAg) positive rate postexposure and HBV-specific antigen/antibody (Ag/Ab) level in patients with rheumatic diseases, we aimed at exploring the rheumatic link to HBV control.

METHODS

Patients who underwent HBV screening in the Ruijin Hospital from 2020 to 2021 were enrolled for the exposure rate estimation. Among antibody to HBV core antigen (HBcAb)-positive patients, we adopted propensity score matching (PSM) to study the impact of rheumatism on HBsAg seroprevalence after exposure. A second PSM evaluated the Ag/Ab differences. We also had HBsAg prevalence in human leukocyte antigen B2 (HLA-B27) tested patients studied.

RESULTS

With 33,989 screened patients, exposure rates remained comparable between rheumatic and non-rheumatic patients: 48.94 vs. 49.86%. PSM first yielded 2,618 balanced pairs. We observed significantly fewer patients with rheumatic diseases in HBsAg positive cases than negative ones (p < 0.001). In the second round, PSM matched 279 pairs, HBsAg (p < 0.001) and HBeAg (p < 0.05) positivity rates were significantly lower in the rheumatic patients, whereas HBsAb positivity rate (p < 0.001) and level (p < 0.01) were significantly higher. Though the value of HBcAb was overall significantly lower (p < 0.001) within the realm of rheumatic diseases, patients with ankylosing spondylitis (AS) demonstrated a significantly higher value than other rheumatic diseases. We saw significantly fewer HBV infections in HLA-B27 positive subjects than in the negative ones (p < 0.001).

CONCLUSION

In this propensity score-matched study, rheumatic patients had an advantage in HBV control. In rheumatic patients, HBcAb levels, together with the beneficial role of HLA-B27, were highlighted.

Highly Sensitive HBsAg, Anti-HBc and Anti HBsAg Titres in Early Diagnosis of HBV Reactivation in Anti-HBc-Positive Onco-Haematological Patients

The role of novel HBV markers in predicting Hepatitis B virus reactivation (HBV-R) in HBsAg-negative/anti-HBc-positive oncohaematological patients was examined. One hundred and seven HBsAg-negative/anti-HBc-positive oncohaematological patients, receiving anti-HBV prophylaxis for >18 months, were included. At baseline, all patients had undetectable HBV DNA, and 67.3% were anti-HBs positive. HBV-R occurred in 17 (15.9%) patients: 6 during and 11 after the prophylaxis period. At HBV-R, the median (IQR) HBV-DNA was 44 (27–40509) IU/mL, and the alanine aminotransferase upper limit of normal (ULN) was 44% (median (IQR): 81 (49–541) U/L). An anti-HBc > 3 cut-off index (COI) plus anti-HBs persistently/declining to <50 mIU/mL was predictive for HBV-R (OR (95% CI): 9.1 (2.7–30.2); 63% of patients with vs. 15% without this combination experienced HBV-R (p < 0.001)). The detection of highly sensitive (HS) HBsAg and/or HBV-DNA confirmed at >2 time points, also predicts HBV-R (OR (95% CI): 13.8 (3.6–52.6); 50% of positive vs. 7% of negative patients to these markers experienced HBV-R (p = 0.001)). HS-HBs and anti-HBc titration proved to be useful early markers of HBV-R. The use of these markers demonstrated that HBV-R frequently occurs in oncohaematological patients with signs of resolved HBV infection, raising issues of proper HBV-R monitoring.

Humoral immunity in hepatitis B virus infection: Rehabilitating the B in HBV

Insights into the immunopathogenesis of chronic HBV infections are fundamental in the quest for novel treatment approaches aimed at a functional cure. While much is known about the ineffective HBV-specific T-cell responses that characterise persistent HBV replication, B cells have been left largely understudied. However, an important role for humoral immunity during the natural history of HBV infections, as well as after functional cure, has been inadvertently revealed by the occurrence of HBV flares following B cell-depleting treatments. Herein, we review our current understanding of the role of the humoral immune response in chronic HBV, both at the level of HBV-specific antibody production and at the phenotypic and broader functional level of B cells. The recent development of fluorescently labelled HBV proteins has given us unprecedented insights into the phenotype and function of HBsAg- and HBcAg-specific B cells. This should fuel novel research into the mechanisms behind dysfunctional HBsAg-specific and fluctuating, possibly pathogenic, HBcAg-specific B-cell responses in chronic HBV. Finally, novel immunomodulatory treatments that partly target B cells are currently in clinical development, but a detailed assessment of their impact on HBV-specific B-cell responses is lacking. We plead for a rehabilitation of B-cell studies related to both the natural history of HBV and treatment development programmes.

Hepatitis B Virus Reactivation Associated With Therapeutic Interventions

Hepatitis B virus (HBV) reactivation associated with various therapeutic interventions is an important cause of morbidity and mortality in patients with current or resolved HBV infection. Because no curative treatment for HBV infection is yet available, there are many individuals at risk for HBV reactivation in the general population. Populations at risk for HBV reactivation include patients who are currently infected with HBV or who have been exposed to HBV in the past. HBV reactivation and its potential consequences is a concern when these populations are exposed to anti-cancer chemotherapy, immunosuppressive or immunomodulatory therapies for the management of various malignancies, rheumatologic diseases, inflammatory bowel disease, or solid-organ or hematologic stem cell transplantation. Accordingly, it has become important to understand the basics of HBV reactivation and the mechanisms by which certain therapies are more susceptible to HBV reactivation. This review aims to raise the awareness of HBV reactivation and to understand the mechanisms and the risks of HBV reactivation in various clinical settings.

Significance of anti-HBc serological status in primary immune thrombocytopenia

The association of previous hepatitis B virus (HBV) exposure [hepatitis B surface antigen (HBsAg) negative, hepatitis B core antibody (anti-HBc/HBcAb) positive] with disease severity and decision on treatment option in primary immune thrombocytopenia (ITP) patients remains unclear. Data from 725 patients diagnosed with ITP were analyzed to elucidate the association between anti-HBc serological status and disease severity. Data from a published prospective study [high-dose dexamethasone (HD-DXM), HD-DXM plus recombinant human thrombopoietin, NCT01734044] and two retrospective studies (standard-dose and low-dose rituximab) were rearranged to evaluate the impact of anti-HBc serological status on the response and outcome to ITP-specific treatments and the risk of HBV reactivation related to these treatments. The prevalence of HBsAg^- HBcAb⁺ and HBsAg^- HBcAb^- in ITP patients was 51·03% and 48·97% respectively. Compared to the HBsAg^- HBcAb^- group, patients in the HBsAg^- HBcAb⁺ group had lower platelet count, higher bleeding score, and longer hospitalization (P = 0·002, 0·033, and 0·008 respectively). Moreover, the initial complete response rate of HBsAg^- HBcAb⁺ patients was lower than that of HBsAg^- HBcAb^- patients (45·2% vs 59·8%, P = 0·027). In conclusion, previous HBV exposure was correlated with disease severity and hospitalization in ITP patients. Anti-HBc positivity may be considered as a predictor for poor response to ITP-specific treatments.

Moving towards core antigen for the management of patients with overt and occult HBV infection

Chronic Hepatitis B virus (HBV) infection encompasses a wide virologic and clinical spectrum with heterogeneous outcomes. The natural history of chronic HBV infection ranges from an inactive carrier state (hepatitis B e antigen-negative chronic infection) to progressive chronic hepatitis that may evolve in end-stage liver disease and hepatocellular carcinoma. The issue becomes even more complicated when we consider the unique biology of the virus; the HBV covalently-closed-circular DNA, that acts as virus transcription template, is the key factor responsible of the persistence of the infection even after hepatitis B surface antigen loss. In the last decade, novel serological and immunological biomarkers associated to the core protein of HBV have been approached in different clinical conditions. Remarkable results have been obtained both in the setting of overt and occult HBV infection. Here, we reviewed the meaning and the potential clinical applications of the measurement of core antigen and antibodies.

Current laboratory tests for diagnosis of hepatitis B virus infection

BACKGROUND

Hepatitis B virus (HBV) has a long history in human infectious diseases. HBV infection can progress chronically, leading to cancer. After introduction of a vaccine, the overall incidence rate of HBV infection has decreased, although it remains a health problem in many countries.

PURPOSE

The aim of this review was to summarise current diagnostic efforts for HBV infection and future HBV diagnosis perspectives.

METHODS

We reviewed and summarised current laboratory diagnosis related with HBV infection in clinical practice.

RESULTS

There have been various serologic- and molecular-based methods to diagnose acute or chronic HBV infection. Since intrahepatic covalently closed circular DNAs (cccDNAs) function as robust HBV replication templates, cure of chronic HBV infection is limited. Recently, new biomarkers such as hepatitis B virus core-related antigen (HBcrAg) and HBV RNA have emerged that appear to reflect intrahepatic cccDNA status. These new biomarkers should be validated before clinical usage.

CONCLUSION

An effective diagnostic approach and current updated knowledge of treatment response monitoring are important for HBV infection management. Brand new ultrasensitive and accurate immunologic methods may pave the way to manage HBV infection in parallel with immunotherapy era.

Novel strategies for the early diagnosis of hepatitis B virus reactivation

Hepatitis B virus (HBV) reactivation under systemic chemotherapy or immunosuppressive therapy is a serious complication among HBV-resolved patients. Some medications, such as more than 2 weeks of corticosteroid therapy, can influence HBV reactivation; therefore, screening tests that measure hepatitis B surface antigen (HBsAg), hepatitis B core antibody, and hepatitis B surface antibody before therapy are required. Additionally, because HBV reactivation has been reported in patients positive for HBsAg treated with immune checkpoint inhibitors (ICIs), the prophylactic administration of nucleos(t)ide analogues prior to administering ICIs is recommended for HBsAg-positive patients. Under these circumstances, highly sensitive novel biomarkers are expected to be used for the early diagnosis of HBV reactivation. A fully automated high-sensitivity HBsAg assay (detection limit: 5 mIU/ml) by Lumipulse HBsAg-HQ, with 10-fold higher sensitivity than that of conventional assays, is currently used. Furthermore, ultra-sensitive HBsAg assays using a semi-automated immune complex transfer chemiluminescence enzyme immunoassay (ICT-CLEIA; detection limit: 0.5 mIU/ml) have been developed. Recently, a fully automated, novel high-sensitivity hepatitis B core-related antigen assay (iTACT-HBcrAg; cut-off value: 2.1 Log U/mL) has been developed and reported. The utility of ICT-CLEIA and iTACT-HBcrAg for the diagnosis of HBV reactivation appears comparable to the use of HBV DNA. In this review, we provide the latest information related to medications that influence HBV reactivation and recently developed novel biomarkers that predict and monitor HBV reactivation.

Role of quantitative hepatitis B surface antibodies in preventing hepatitis B virus-related hepatitis in patients treated with rituximab

Hepatitis B virus (HBV) reactivation is a well-known complication after rituximab-based chemotherapy in patients with B cell lymphoma (BCL) who have resolved HBV infection. This retrospective cohort study used electronic medical records from the Kaohsiung Chang Gung Memorial Hospital. There were 128 patients with BCL and resolved HBV infection treated with 1st-line rituximab-containing therapy from 2008 to 2013. No patient received antiviral prophylaxis. Patients with high pretreatment hepatitis B surface antibody (anti-HBs titer ≥100 mIU/mL), had significantly less HBV reactivation (2.0%, 1/49) than patients with low (10-100 mIU/mL, 10.8%, 4/37) or negative anti-HBs (<10 mIU/mL, 23.8%, 10/42) (p = 0.001). No patient in the high group vs. 1 (2.7%) low group vs. 6 (14.3%) negative group developed HBV-related hepatitis (p = 0.002). Patients with high pretreatment anti-HBs have a low risk of HBV-related complications and may not require antiviral prophylaxis. We propose an algorithm for the management of HBV reactivation risk in BCL.

Management of hepatitis B virus infection in patients with inflammatory bowel disease under immunosuppressive treatment

Hepatitis B remains a significant global clinical problem, despite the implementation of safe and effective vaccination programs. The prevalence of hepatitis B virus (HBV) in patients with inflammatory bowel disease (IBD) largely follows the regional epidemiologic status. Serological screening with hepatitis B surface antigen (HBsAg), and antibodies to hepatitis B surface (anti-HBs) and core (anti-HBc) proteins is a key element in the management of IBD patients and, ideally, should be performed at IBD diagnosis. Stratification of individual cases should be done according to the serologic profile and the IBD-specific treatment, with particular emphasis in patients receiving immunosuppressive regimens. In patients who have not contracted HBV, vaccination is indicated to accomplish protective immunity. Vaccination in immunosuppressed patients, however, is a challenging issue and several strategies for primary and revaccination have been proposed. The risk of HBV reactivation in patients with IBD should be considered in both HBsAg-positive and HBsAg-negative/anti-HBc-positive patients, when immunosuppressive therapies are administered. HBV reactivation is preventable via the administration of prophylactic nucleot(s)ide analogues and should be the standard approach in HBsAg-positive patients. HBsAg-negative/anti-HBc-positive patients represent a non-homogeneous group and bear a significantly lower risk of HBV reactivation. Biochemical, serological and molecular monitoring is currently the recommended approach for anti-HBc patients. Acute HBV infection is rarely reported in IBD patients. In the present review, we outline the problems associated with HBV infection in patients with IBD and present updated evidence for their management.

Prediction of hepatic inflammation in chronic hepatitis B patients with a random forest-backward feature elimination algorithm

BACKGROUND

Persistent liver inflammatory damage is the main risk factor for developing liver fibrosis, cirrhosis, and even hepatocellular carcinoma in chronic hepatitis B (CHB) patients. Thus, accurate prediction of the degree of liver inflammation is a high priority and a growing medical need.

AIM

To build an effective and robust non-invasive model for predicting hepatitis B-related hepatic inflammation.

METHODS

A total of 650 treatment-naïve CHB (402 HBeAg-positive and 248 HBeAg-negative) patients who underwent liver biopsy were enrolled in this study. Histological inflammation grading was assessed by the Ishak scoring system. Serum quantitative hepatitis B core antibody (qAnti-HBc) levels and 21 immune-related inflammatory factors were measured quantitatively using a chemiluminescent microparticle immunoassay. A backward feature elimination (BFE) algorithm utilizing random forest (RF) was used to select optional features and construct a combined model. The diagnostic abilities of the model or variables were evaluated based on the estimated area under the receiver operating characteristics curve (AUROC) and compared using the DeLong test.

RESULTS

Four features were selected to predict moderate-to-severe inflammation in CHB patients using the RF-BFE method. These predictive features included qAnti-HBc, ALT, AST, and CXCL11. Spearman’s correlation analysis indicated that serum qAnti-HBc, ALT, AST, and CXCL11 levels were positively correlated with the histology activity index (HAI) score. These selected features were incorporated into the model to establish a novel model named I-3A index. The AUROC [0.822; 95% confidence interval (CI): 0.790-0.851] of the I-3A index was significantly increased compared with qAnti-HBc alone (0.760, 95%CI: 0.724-0.792, P < 0.0001) in all CHB patients. The use of an I-3A index cutoff value of 0.41 produced a sensitivity of 69.17%, specificity of 81.44%, and accuracy of 73.8%. Additionally, the I-3A index showed significantly improved diagnostic performance for predicting moderate-to-severe inflammation in HBeAg-positive and HBeAg-negative CHB patients (0.829, 95%CI: 0.789-0.865 and 0.810, 95%CI: 0.755-0.857, respectively).

CONCLUSION

The selected features of the I-3A index constructed using the RF-BFE algorithm can effectively predict moderate-to-severe liver inflammation in CHB patients.

Novel Biomarkers of Hepatitis B Virus and Their Use in Chronic Hepatitis B Patient Management

Even though an approved vaccine for hepatitis B virus (HBV) is available and widely used, over 257 million individuals worldwide are living with chronic hepatitis B (CHB) who require monitoring of treatment response, viral activity, and disease progression to reduce their risk of HBV-related liver disease. There is currently a lack of predictive markers to guide clinical management and to allow treatment cessation with reduced risk of viral reactivation. Novel HBV biomarkers are in development in an effort to improve the management of people living with CHB, to predict disease outcomes of CHB, and further understand the natural history of HBV. This review focuses on novel HBV biomarkers and their use in the clinical setting, including the description of and methodology for quantification of serum HBV RNA, hepatitis B core-related antigen (HBcrAg), quantitative hepatitis B surface antigen (qHBsAg), including ultrasensitive HBsAg detection, quantitative anti-hepatitis B core antigen (qAHBc), and detection of HBV nucleic acid-related antigen (HBV-NRAg). The utility of these biomarkers in treatment-naïve and treated CHB patients in several clinical situations is further discussed. Novel HBV biomarkers have been observed to provide critical clinical information and show promise for improving patient management and our understanding of the natural history of HBV.

Risk factors for de novo hepatitis B during solid cancer treatment

BACKGROUND

Reactivation of hepatitis B virus (HBV) during anticancer treatment is a critical issue. When treating patients with solid tumors, it is unclear whether specific cancer types or treatments affect HBV reactivation in hepatitis B surface antigen (HBsAg)-negative and hepatitis B core antibody (HBcAb)-positive patients, so-called de novo hepatitis B patients. The risk of de novo hepatitis B may vary based on different background factors.

AIM

To determine the frequency and risk factors for de novo hepatitis B during solid tumor treatment.

METHODS

This retrospective cohort study comprised 1040 patients without HBsAgs and with HBcAbs and/or hepatitis B surface antibodies (HBsAbs). The patients were treated for solid cancer from 2008 to 2018 at the National Kyushu Cancer Center and underwent HBV DNA measurements. Patient characteristics and disease and treatment information were investigated. HBV DNA measurements were performed using TaqMan polymerase chain reaction (PCR). To identify the risk factors associated with HBV DNA expression, the age, sex, original disease, pathology, treatment method, presence or absence of hepatitis C virus (HCV), and HBsAb and/or HBcAb titers of all subjects were investigated. In patients with HBV DNA, the time of appearance, presence of HBsAgs and HBsAbs at the time of appearance, and course of the subsequent fluctuations in virus levels were also investigated.

RESULTS

Among the 1040 patients, 938 were HBcAb positive, and 102 were HBcAb negative and HBsAb positive. HBV DNA expression was observed before the onset of treatment in nine patients (0.9%) and after treatment in 35 patients (3.7%), all of whom were HBcAb positive. The HBV reactivation group showed significantly higher median HBcAb values [9.00 (8.12-9.89) vs 7.22 (7.02-7.43), P = 0.0001] and significantly lower HBsAb values (14 vs 46, P = 0.0342) than the group without reactivation. Notably, the reactivated group showed a significantly higher proportion of cancers in organs related to digestion and absorption (79.0% vs 58.7%, P = 0.0051). A high HBcAb titer and cancers in organs involved in digestion and absorption were identified as independent factors for HBV reactivation (multivariate analysis, P = 0.0002 and P = 0.0095). The group without HBsAbs tended to have a shorter time to reactivation (day 43 vs day 193), and the frequency of reactivation within 6 mo was significantly higher in this group (P = 0.0459) than in the other group.

CONCLUSION

A high HBcAb titer and cancers in organs involved in digestion and absorption are independent factors that contribute to HBV reactivation during solid tumor treatment.

Biomarkers for hepatitis B virus replication: an overview and a look to the future

INTRODUCTION

Hepatitis B virus (HBV) infection is a major public health issue but there are no powerful drugs to eradicate the virus. HBV markers including HBsAg, HBcrAg, HBV RNA, HBcAb, and HBV DNA are becoming promising biomarkers to reflect the natural phases of chronic HBV infection and predict the outcome of anti-HBV treatment.

AREAS COVERED

The authors summarized the biomarkers of HBV replication and presented the current advances of these biomarkers on predicting the outcome of anti-HBV treatment and identifying the progression of chronic HBV infection.

EXPERT OPINION

HBsAg, HBcrAg, HBV RNA, HBcAb, and HBV DNA are noninvasive and feasible biomarkers for monitoring the process of anti-HBV therapy and predicting the progress of HBV infection. However, there are still no strong biomarkers with high sensitivity and specificity for clinical application. Combination of two or more HBV biomarkers, new technique for measuring HBV cccDNA, and searching novel HBV biomarkers are essential for anti-HBV treatment in the future.

Hepatitis B Virus Screening and Management for Patients With Cancer Prior to Therapy: ASCO Provisional Clinical Opinion Update

PURPOSE

This Provisional Clinical Opinion update presents a clinically pragmatic approach to hepatitis B virus (HBV) screening and management.

PROVISIONAL CLINICAL OPINION

All patients anticipating systemic anticancer therapy should be tested for HBV by 3 tests-hepatitis B surface antigen (HBsAg), hepatitis B core antibody (anti-HBc) total immunoglobulin (Ig) or IgG, and antibody to hepatitis B surface antigen-but anticancer therapy should not be delayed. Findings of chronic HBV (HBsAg-positive) or past HBV (HBsAg-negative and anti-HBc-positive) infection require HBV reactivation risk assessment.Patients with chronic HBV receiving any systemic anticancer therapy should receive antiviral prophylactic therapy through and for minimum 12 months following anticancer therapy. Hormonal therapy alone should not pose a substantial risk of HBV reactivation in patients with chronic HBV receiving hormonal therapy alone; these patients may follow noncancer HBV monitoring and treatment guidance. Coordination of care with a clinician experienced in HBV management is recommended for patients with chronic HBV to determine HBV monitoring and long-term antiviral therapy after completion of anticancer therapy.Patients with past HBV infection undergoing anticancer therapies associated with a high risk of HBV reactivation, such as anti-CD20 monoclonal antibodies or stem-cell transplantation, should receive antiviral prophylaxis during and for minimum 12 months after anticancer therapy completion, with individualized management thereafter. Careful monitoring may be an alternative if patients and providers can adhere to frequent, consistent follow-up so antiviral therapy may begin at the earliest sign of reactivation. Patients with past HBV undergoing other systemic anticancer therapies not clearly associated with a high risk of HBV reactivation should be monitored with HBsAg and alanine aminotransferase during cancer treatment; antiviral therapy should commence if HBV reactivation occurs.Additional information is available at www.asco.org/supportive-care-guidelines.

Hepatitis B virus reactivation during temozolomide administration for malignant glioma

INTRODUCTION

The purpose of this study is to clarify the clinical features of temozolomide (TMZ)-related hepatitis B virus (HBV) reactivation and to identify HBV reactivation predictive factors.

METHOD

We retrospectively reviewed the clinical course of 145 patients newly diagnosed or with recurrent malignant glioma treated with TMZ. Before treatment, we screened patients for HB surface antigen (HBsAg) positivity (HBV carrier) and HBsAg negativity. Patients were also screened for antibody for HB core antigen (anti-HBc) positivity and/or for HB surface antigen positivity (resolved HBV infection). The patients were monitored by HBV DNA, alanine, and aspartate aminotransaminase during and after the completion of TMZ. HBV carriers and those with resolved HBV infections with HBV reactivation received preemptive entecavir treatment. In those with resolved HBV infections, we analyzed clinical characters for the predictive factors for HBV reactivation.

RESULTS

In one of two HBV carriers, HBV DNA turned positive 8 months after the completion of TMZ and entecavir. In four (16.7%) of 24 resolved HBV infections, HBV DNA turned detectable at completion of concomitant radiation and TMZ or during monthly TMZ. HBV DNA turned negative with entecavir in all patients without liver dysfunction. In resolved HBV infections, those with a high anti-HBc titer had significantly higher incidence of HBV reactivation than those with low anti-HBc titers (60% vs. 5.3%: p = 0.018).

CONCLUSION

Screenings, monitoring, and preemptive entecavir were important for preventing TMZ-related HBV reactivations. Anti-HBc titers could be the predictive markers for HBV reactivation in the those with resolved HBV infections.

Recent Advances in Understanding, Diagnosing, and Treating Hepatitis B Virus Infection

Chronic hepatitis B virus (HBV) infection affects 292 million people worldwide and is associated with a broad range of clinical manifestations including cirrhosis, liver failure, and hepatocellular carcinoma (HCC). Despite the availability of an effective vaccine HBV still causes nearly 900,000 deaths every year. Current treatment options keep HBV under control, but they do not offer a cure as they cannot completely clear HBV from infected hepatocytes. The recent development of reliable cell culture systems allowed for a better understanding of the host and viral mechanisms affecting HBV replication and persistence. Recent advances into the understanding of HBV biology, new potential diagnostic markers of hepatitis B infection, as well as novel antivirals targeting different steps in the HBV replication cycle are summarized in this review article.

Hepatitis B Virus Reactivation: What Is the Issue, and How Should It Be Managed?

Hepatitis B virus (HBV) reactivation, in the background of cleared and overt chronic HBV infection, can be seen in patients receiving immunosuppressive agents. Risk of reactivation is variably associated with HBV serologic status and types of immunosuppressive therapy. Prevention of HBV reactivation by antiviral prophylaxis is an effective strategy to reduce morbidity and mortality in those with immunocompromised states. This article defines HBV reactivation, discusses risk stratification and common medications that can induce HBV reactivation as well as guideline recommendations for prevention of HBV reactivation, and describes the prognosis and management of patients who experience HBV reactivation.

Hepatitis B core-specific memory B cell responses associate with clinical parameters in patients with chronic HBV

BACKGROUND & AIMS

Little is known about the frequency, phenotype and function of HBV-specific B cells during chronic infection. Here we study HBcAg and HBsAg-specific B cells in different clinical phases of a chronic HBV infection.

METHODS

We included 118 treatment naïve and 34 nucleos(t)ide analogue-treated patients with chronic HBV and 23 healthy HBsAg-vaccinated controls. Global and HBV-specific B lymphocytes were examined by FACS using fluorescently labeled HBsAg and HBcAg as baits. Functional HBV-specific B cell responses were quantified in B cell ELISPOT assays. Anti-HBs and anti-HBc antibodies were measured in serum and in ELISPOT supernatant by ELISA.

RESULTS

Higher HBcAg-directed B cell responses were found in HBV clinical phases with elevated vs. low serum alanine aminotransferase (ALT) levels, irrespective of the HBeAg-status. In contrast, HBsAg-directed responses were lower and did not significantly fluctuate. In individual patients a mean 17.8-fold more circulating B cells target HBcAg than HBsAg baits. These HBcAg-specific B cells present a classical memory B cell profile and have slightly higher CD69 expression levels compared to global memory B cells. Viral suppression and ALT normalization upon treatment led to a numeric and functional reduction of HBcAg-specific B cell responses, accompanied by progressive decreases in serum anti-HBc antibodies.

CONCLUSION

HBcAg-specific memory B cells present a classical memory B cell phenotype, vary in number and function throughout HBV's natural history and are significantly reduced during antiviral treatment.

LAY SUMMARY

In recent years, studies examining the role of B cells during chronic hepatitis B virus infection have regained interest. We show that circulating B cells more often target the hepatitis B core antigen than the hepatitis surface antigen. Moreover, these hepatitis B core-specific B cells associate with the natural history of chronic HBV, and their responses decline during effective antiviral treatment.