On-therapy HBsAg kinetics can predict HBsAg loss after nucleos(t)ide analogues interruption in HBeAg-negative patients. The cup is half full and half empty

Quantitative Change of Hepatitis B Surface Antigen Leading to Final Hepatitis B Surface Antigen Loss in Patients with Chronic Hepatitis B Receiving Nucleos(t)ide Analogs in China

INTRODUCTION

Loss of hepatitis B surface antigen (HBsAg) is the pivotal component of functional cure in patients suffering from chronic hepatitis B (CHB). The predictive value of quantitative HBsAg (qHBsAg) in HBsAg loss among those undergoing nucleos(t)ide analog (NAs) therapy is an area of ongoing investigation.

METHODS

A retrospective cohort study using electronic medical records was performed. CHB patients with NAs treatment between January 1, 2012, and December 31, 2020 were enrolled and followed up until discontinuation of NAs, as indicated by a gap more than 12 months in prescription refills, past medical record, or study end. Patients were grouped into NAs treatment-naïve cohort and treatment-experienced cohort. In both cohorts, Cox regression models assessed associations between 12-month reduction in qHBsAg, baseline qHBsAg, and HBsAg loss.

RESULTS

Overall, 2,627 CHB patients with NAs treatment was identified, including 1,179 in treatment-naïve cohort and 1,448 in treatment-experienced cohort. In treatment-naïve cohort, 9 patients had HBsAg loss (0.51/100 person-years). In treatment-experienced cohort, 30 patients had HBsAg loss (1.03/100 person-years). HBsAg loss was significantly associated with a 0.5-1 log10 (treatment-naïve: adjusted hazard ratio [aHR] 8.06, 95% confidence interval [CI] 1.29-50.40; treatment-experienced: aHR 4.34, 95% CI 1.40-13.47) and >1 log10 qHBsAg decrease (treatment-naïve: aHR 9.19, 95% CI 1.47-57.65; treatment-experienced: aHR 8.02, 95% CI 1.76-36.57) compared with qHBsAg not reduced. HBsAg loss was significantly associated with lower baseline qHBsAg in treatment-experienced cohort, while such difference was not significant in treatment-naïve cohort.

DISCUSSION

A rapid decline of qHBsAg in 12 months during NAs therapy, as opposed to merely maintaining a low level of qHBsAg, was associated with HBsAg loss.

Factors associated with low hepatitis B surface antigen levels in chronic hepatitis B patients treated with nucleot(s)ide analogs

OBJECTIVES

Several studies have reported that chronic hepatitis B (CHB) patients with low hepatitis B surface antigen (HBsAg) levels (100 or 10 IU/mL) at the cessation of nucleot(s)ide analogs (NA) have a favorable prognosis. In this retrospective study, we evaluated the duration of NA treatment and the factors associated with achieving these low HBsAg levels. We also examined the relationship between HBsAg and hepatitis B core-related antigen (HBcrAg) levels at the time of NA discontinuation and subsequent clinical outcomes.

METHODS

This study included 153 CHB patients who initiated NA therapy at our hospital, received treatment, and were followed up for over 1 year.

RESULTS

The cumulative incidence rates of achieving low HBsAg levels at 5 and 10 years post-NA administration were as follows: 19.0% and 29.2% for HBsAg <100 IU/mL, 13.8% and 17.6% for HBsAg <10 IU/mL, and 9.5% and 13.5% for HBsAg <0.05 IU/mL, respectively. Hepatitis B virus genotypes other than genotype C (hazard ratio [HR] 3.47; p < 0.001) and an HBsAg level <1000 IU/mL at the start of NA therapy (HR 2.49; p = 0.008) were significantly associated with achieving HBsAg levels <100 IU/mL. Among 27 patients who discontinued NA therapy, 5 patients with HBsAg levels <100 IU/mL and HBcrAg levels <3 log U/mL at the time of discontinuation did not experience virological relapse.

CONCLUSIONS

The cumulative rates of achieving HBsAg levels <100 IU/mL were relatively high. Discontinuation of NA may be considered based on HBsAg and HBcrAg levels during the course of NA therapy.

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.

Past, present, and future of long-term treatment for hepatitis B virus

The estimated world prevalence of hepatitis B virus (HBV) infection is 316 million. HBV infection was identified in 1963 and nowadays is a major cause of cirrhosis and hepatocellular carcinoma (HCC) despite universal vaccination programs, and effective antiviral therapy. Long-term administration of nucleos(t)ide analogues (NA) has been the treatment of choice for chronic hepatitis B during the last decades. The NA has shown a good safety profile and high efficacy in controlling viral replication, improving histology, and decreasing the HCC incidence, decompensation, and mortality. However, the low probability of HBV surface antigen seroclearance made necessary an indefinite treatment. The knowledge, in recent years, about the different phases of the viral cycle, and the new insights into the role of the immune system have yielded an increase in new therapeutic approaches. Consequently, several clinical trials evaluating combinations of new drugs with different mechanisms of action are ongoing with promising results. This integrative literature review aims to assess the knowledge and major advances from the past of hepatitis B, the present of NA treatment and withdrawal, and the future perspectives with combined molecules to achieve a functional cure.

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

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