Anti-HBc mirrors the activation of HBV-specific CD8+ T cell immune response and exhibits a direct effect on HBV control.

BACKGROUND: Hepatitis B core antibody (anti-HBc) is commonly present in patients with chronic hepatitis B virus (HBV) infection and serves as a marker of humoral immunity. Herein, we aim to investigate the correlation between anti-HBc and antiviral immune response and its putative role in HBV control. METHODS: Quantitative anti-HBc and levels of anti-HBc subtypes were measured in chronic hepatitis B (CHB) patients. The effects of anti-HBc on immune cells and HBV replication were evaluated using the HBV mouse models and human hepatoma cell lines. RESULTS: Baseline levels of IgG1 and IgG3 anti-HBc were elevated in CHB patients with favorable treatment response, and correlated with the virological response observed at week 52. Additionally, increased levels of IgM and IgG1 anti-HBc were observed exclusively in CHB patients with liver inflammation. Notably, significant correlations were identified between quantitative levels of anti-HBc and the frequencies of HBcAg-specific CD8+ T cells. Intriguingly, HBcAg efficiently activates T cells aided by B cells in vitro experiments. Moreover, anti-HBc inhibits HBV replication either by a direct effect or through complement-mediated cytotoxicity in HBV-producing cell lines. CONCLUSIONS: Anti-HBc reflects the activation of an HBV-specific CD8+ T cell immune response and may have anti-HBV activity.

Quantitative hepatitis B core antibody and quantitative hepatitis B surface antigen: Novel viral biomarkers for chronic hepatitis B management.

The management of hepatitis B virus (HBV) infection now involves regular and appropriate monitoring of viral activity, disease progression, and treatment response. Traditional HBV infection biomarkers are limited in their ability to predict clinical outcomes or therapeutic effectiveness. Quantitation of HBV core antibodies (qAnti-HBc) is a novel non-invasive biomarker that may help with a variety of diagnostic issues. It was shown to correlate strongly with infection stages, hepatic inflammation and fibrosis, chronic infection exacerbations, and the presence of occult infection. Furthermore, qAnti-HBc levels were shown to be predictive of spontaneous or treatment-induced HBeAg and HBsAg seroclearance, relapse after medication termination, re-infection following liver transplantation, and viral reactivation in the presence of immunosuppression. qAnti-HBc, on the other hand, cannot be relied on as a single diagnostic test to address all problems, and its diagnostic and prognostic potential may be greatly increased when paired with qHBsAg. Commercial qAnti-HBc diagnostic kits are currently not widely available. Because many methodologies are only semi-quantitative, comparing data from various studies and defining universal cut-off values remains difficult. This review focuses on the clinical utility of qAnti-HBc and qHBsAg in chronic hepatitis B management.

[Clinical significance and research progress of quantitative hepatitis B virus core antibody measurement].

Hepatitis B virus core antibodies are specific antibodies produced after viral infection that appear early and last for a long time, and its levels in serum are measured by the double-antigen sandwich chemiluminescent microparticle immunoassay method, which has higher sensitivity and specificity, providing new clinical indicators for hepatitis B patients diagnosis, treatment, and drug withdrawal management. This article reviews the clinical significance and research progress of quantitative hepatitis B core antibody measurement and expounds on its research applications and prospects in clinical practice.

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

The proportion of chronic hepatitis B (CHB) patients with normal or mildly elevated alanine transaminase (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. This multicenter cohort study enrolled participants from 34 Chinese hospitals 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. 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: ß = 0.48, 95% confidence interval [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% (odds ratio [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. 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.

[Correlation of qAnti-HBc with antiviral efficacy in children with chronic hepatitis B and exploration of its possible immune mechanism].

Objective: To compare the baseline difference in the quantitative hepatitis B core antibody levels (qAnti-HBc) between non-response and response group in children with HBeAg-positive chronic hepatitis B (CHB) who received antiviral therapy, and further explore the proportion and functional activity of CD8 + memory T lymphocyte subsets with different qAnti-HBC levels in peripheral blood of children. Methods: The baseline anti-HBc quantification (qAnti-HBc) levels of 85 children with HBeAg-positive CHB who visited the Department of Infectious Diseases, Children's Hospital of Chongqing Medical University from June 2018 to December 2020 were detected retrospectively. The relationship between the baseline qAnti-HBc level and HBeAg serological response in 37 children who received antiviral therapy was analyzed. The proportion of CD8(+) memory T lymphocyte subsets and the secretion levels of interferon (IFN) γ, and tumor necrosis factor (TNF) α in peripheral blood of 59 children at baseline were detected by flow cytometry. The relationship between qAnti-HBc level and the proportion and functional activity of CD8(+) memory T lymphocyte subsets was analyzed. Pearson's Chi-square test was used to compare the count data. Mann-Whitney U test or Kruskal-Wallis test was used to compare measurement data between two or more groups, and Spearman's rank correlation analysis was used for the correlation between continuous variables. Results: Among 37 children who received entecavir (ETV, 21/37 cases) or pegylated interferon (Peg-IFN, 16/37 cases), 18 cases had developed HBeAg seroconversion (10/ 21 cases in the ETV group, 8/16 cases in the Peg-IFN group). The baseline qAnti-HBc level was significantly higher in the response group [4.71 (4.64~4.81) log(10)IU/ml] than the non-response group children [4.54 (4.45~4.64) log(10)IU/ml, Z = -3.316, P = 0.001]. The proportion of CD8(+) Tem, CD38(+)CD8(+) Tem, CD38(+)CD8(+) Temra cells and the levels of IFNγ and TNFα secreted by CD8(+) T lymphocytes were significantly higher in the high-qAnti-HBc group than the low-qAnti-HBc group (P < 0.05). The proportion of CD8(+) Tem, CD38(+)CD8(+) Tem and CD38(+)CD8(+) Temra cells was significantly higher in ALT > 1× upper limit of normal value (ULN) group than ALT≤1×ULN group (P < 0.05). However, there were no significant differences in the levels of IFNγ and TNFα secreted by CD8(+) T lymphocytes between the two groups (P > 0.05). Spearman's correlation analysis showed that qAnti-HBc was positively correlated with the proportion of CD8(+) Tem, CD38(+)CD8(+) Tem, CD38(+)CD8(+) Temra cells and the level of IFNγ secreted by CD8(+)T lymphocytes (P < 0.05). Additionally, ALT was only positively correlated with the proportion of CD38(+)CD8(+) TEM and CD38(+) CD8(+) Temra cells (P < 0.05). Conclusion: Raised baseline qAnti-HBc level is related to the HBeAg serological response to antiviral therapy in children with CHB. Peripheral blood effector CD8+ T lymphocytes of CHB children with higher qAnti-HBc show stronger phenotype and functional activation characteristics, which may shed some light on the underlying immune mechanism related to antiviral therapy efficacy in children with CHB.

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.

[Clinical significance of quantitative level of hepatitis B core antibody].

Hepatitis B core antibody (anti-HBc) targets viral core protein and is produced in patients with hepatitis B virus (HBV) infection, and seroconversion occurs in the early stage of infection and often lasts for a lifetime. Qualitative detection of anti-HBc has been used in clinical practice for many years, while the clinical significance of its quantitative level remains unclear. A novel anti-HBc immunoassay based on double-antigen sandwich ELISA has been developed in recent years and lays a foundation for illustrating the change in the quantitative level of anti-HBc (qAnti-HBc) in HBV infection and its clinical significance. Several recent studies have revealed that qAnti-HBc is associated with the degree of hepatitis activity and response to pharmacotherapy and may become an important basis for selecting antiviral drugs, optimizing therapeutic regimen, and predicting treatment outcome.

Clinical significance of quantitative level of hepatitis B core antibody / 中华肝脏病杂志

Hepatitis B core antibody (anti-HBc) targets viral core protein and is produced in patients with hepatitis B virus (HBV) infection, and seroconversion occurs in the early stage of infection and often lasts for a lifetime. Qualitative detection of anti-HBc has been used in clinical practice for many years, while the clinical significance of its quantitative level remains unclear. A novel anti-HBc immunoassay based on double-antigen sandwich ELISA has been developed in recent years and lays a foundation for illustrating the change in the quantitative level of anti-HBc (qAnti-HBc) in HBV infection and its clinical significance. Several recent studies have revealed that qAnti-HBc is associated with the degree of hepatitis activity and response to pharmacotherapy and may become an important basis for selecting antiviral drugs, optimizing therapeutic regimen, and predicting treatment outcome.