Anti-HBc IgG Levels: A Predictor of HBsAg Seroclearance in Chronic Hepatitis B Patients with Nucleos(t)ide Analogue-Induced HBeAg Seroclearance

Anti-HBc: a significant host predictor of spontaneous HBsAg seroclearance in chronic hepatitis B patients - a retrospective longitudinal study

BACKGROUND AND AIM

In chronic hepatitis B infection (CHB), seroclearance of hepatitis B surface antigen (HBsAg) is associated with favourable clinical outcomes compared to those with persistent HBsAg seropositivity, and thus considered as a desired treatment endpoint. This current study explores the possibility of serum antibody to hepatitis B core antigen (anti-HBc) as a potential predictive factor of HBsAg seroclearance.

METHODS

This is a retrospective study that analyzed the plasma samples of CHB patients using the LUMIPULSE® G1200 analyzer. The longitudinal anti-HBc level between patients who subsequently achieved HBsAg seroclearance (S-losers) and those with persistent HBsAg-positivity (controls) were compared at multiple time points before the event.

RESULTS

A total of 240 subjects (120 S-losers and 120 controls; age- and gender-matched) were included (mean age 56.42 ± 10.81, 65% male). Compared to controls, S-losers had significantly lower plasma anti-HBc levels prior to HBsAg seroclearance, with a significant trend of declining plasma anti-HBc 8-5 years prior to HBsAg seroclearance (p < 0.01), while such trend was not observed in controls. ROC curve analysis revealed that plasma anti-HBc at multiple time points before HBsAg seroclearance return AUC greater than 0.7. Plasma anti-HBc level at the cut-off value of 82.50 COI was 68.3% sensitive and 90% specific for HBsAg seroclearance within 1 year. Combining with quantitative HBsAg < 100 IU/mL, anti-HBc < 82.5 COI identified 88.2% patients who would develop HBsAg seroclearance within 1 year.

CONCLUSION

Plasma anti-HBc level began to decline 10 years prior to HBsAg seroclearance and can serve as a potential predictor for subsequent HBsAg seroclearance.

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.

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.

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.