Quantification of serum hepatitis B surface antigen in predicting the response of pegylated interferon alfa-2a in HBeAg-positive chronic hepatitis B with prior lamivudine exposure

The role of quantitative HBsAg in patients with HBV DNA between 2000-20,000 IU/ml

AIMS

We aimed to determine the contribution of quantitative HBsAg in differentiating chronic infections from chronic hepatitis in HBeAg negative patients with HBV DNA 2000-20,000 IU/ml.

MATERIAL AND METHODS

A total of 79 untreated HBeAg negative patients were included. Patients were divided into 3 groups based on HBV DNA levels: group 1 (HBV DNA ≤ 2000 IU/ml), group 2 (HBV DNA: 2000-20,000 IU/ml) and group 3 (HBV DNA > 20,000 IU/ml). We collected serum from all patients for quantitative HBsAg analysis. We compared serum quantitative HBsAg levels with biochemical parameters, HBV DNA and liver biopsy results.

RESULTS

In this study 46 patients were female and the mean age was 42 years. Serum quantitative HBsAg levels were found to be significantly lower in chronic infections compared with chronic hepatitis. There was a positive correlation between quantitative HBsAg and HBV DNA, ALT (alanine aminotransferase), HAI score (histological activity index), fibrosis score and disease stage. The cut-off level of quantitative HBsAg was determined as 4425 IU/ml to differentiate chronic infection from chronic hepatitis. With the test specificity of 95%, we found quantitative HBsAg cut-off values 1026 IU/ml and 20,346 IU/ml for the diagnosis of chronic infection and chronic hepatitis, respectively.

CONCLUSION

Our study suggests that the quantitative HBsAg ≤ 1000 IU/ml limit value might be used for the diagnosis of chronic infection not only in HBV DNA ≤ 2000 IU/ml but also in patients with HBV DNA between 2000-20,000 IU/ml. In addition, antiviral treatment could be considered in patients with quantitative HBsAg > 20,000 IU/ml and HBV DNA > 2000 IU/ml without further examinations such as liver biopsy.

Early Serum HBsAg Drop Is a Strong Predictor of HBeAg Seroconversion and HBsAg Loss to Pegylated Interferon Alfa-2a in Chronic Hepatitis B Patients with Prior Nucleos(t)ide Analogue Exposure

Background

High rates of HBeAg and/or HBsAg seroconversion or clearance have been achieved in chronic hepatitis B (CHB) patients receiving pegylated interferon (pegIFN) in addition to ongoing nucleos(t)ide analogue (NUC) treatment. In the present study, we aimed to evaluate HBsAg kinetics to predict HBeAg seroconversion and HBsAg clearance in these patients.

Material/Methods

A total of 33 HBeAg-positive and 17 HBeAg-negative patients were enrolled between January 2010 and January 2018. At the end of pegIFN treatment, 9 of 50 patients achieved HBsAg clearance, and 9 of 33 HBeAg-positive patients achieved HBeAg seroconversion.

Results

The cutoff value of 0.41 log₁₀ IU/mL in HBsAg decline at week 12 had a positive predictive value (PPV) of 58.3% and a negative predictive value (NPV) of 94.6% for HBsAg clearance. The cutoff value of 1.94 log₁₀ IU/mL in HBsAg decline at week 24 had a PPV of 80.0% and an NPV of 97.5% for HBsAg clearance. The cutoff value of 0.47 log₁₀ IU/mL in HBsAg decline at week 12 had a PPV of 83.3% and an NPV of 85.2% for HBeAg seroconversion. The cutoff value of 1.29 log₁₀ IU/mL in in HBsAg decline at week 24 had a PPV of 85.7% and an NPV of 88.5% for HBeAg seroconversion.

Conclusions

Early HBsAg drop has a high predictive value for HBsAg clearance and HBeAg seroconversion in patients who were treated with combination therapy of pegIFN and NUCs.

Drugs in Development for Hepatitis B

With high morbidity and mortality worldwide, there is great interest in effective therapies for chronic hepatitis B (CHB) virus. There are currently several dozen investigational agents being developed for treatment of CHB. They can be broadly divided into two categories: (1) direct-acting antivirals (DAAs) that interfere with a specific step in viral replication; and (2) host-targeting agents that inhibit viral replication by modifying host cell function, with the latter group further divided into the subcategories of immune modulators and agents that target other host functions. Included among the DAAs being developed are RNA interference therapies, covalently closed circular DNA (cccDNA) formation and transcription inhibitors, core/capsid inhibitors, reverse transcriptase inhibitors, hepatitis B surface antigen (HBsAg) release inhibitors, antisense oligonucleotides, and helioxanthin analogues. Included among the host-targeting agents are entry inhibitors, cyclophilin inhibitors, and multiple immunomodulatory agents, including Toll-like receptor agonists, immune checkpoint inhibitors, therapeutic vaccines, engineered T cells, and several cytokine agents, including recombinant human interleukin-7 (CYT107) and SB 9200, a novel therapy that is believed to both have direct antiviral properties and to induce endogenous interferon. In this review we discuss agents that are currently in the clinical stage of development for CHB treatment as well as strategies and agents currently at the evaluation and discovery phase and potential future targets. Effective approaches to CHB may require suppression of viral replication combined with one or more host-targeting agents. Some of the recent research advances have led to the hope that with such a combined approach we may have a functional cure for CHB in the not distant future.

Baseline value of intrahepatic HBV DNA over cccDNA predicts patient's response to interferon therapy

Methodology for accurate quantification of intra-hepatic cccDNA has long been a technical challenge, yet it is highly desired in the clinic. Here, we developed a sensitive method for quantification of intrahepatic cccDNA in liver biopsies from patients, which allowed to predict patient’s response to interferon therapy at baseline. Twenty-five patients with HBeAg+ CHB were recruited and liver biopsies were obtained at baseline and 1-year after interferon treatment, respectively. Both intrahepatic cccDNA and HBV DNA were absolutely quantified by a droplet digital PCR amplification system. Patients were categorized as either responder or non-responder group based on their HBeAg status 1-year after interferon therapy. Levels of both intrahepatic HBV DNA and HBV cccDNA were significantly reduced after interferon treatment among the responders, but not the non-responders, in comparison with their levels at baseline. Baseline values of intrahepatic HBV DNA over cccDNA significantly correlated with patient’s response to PEG-IFN therapy (P = 0.000). In addition, HBeAg seroconversion also correlates with a significant reduction in intrahepatic pgRNA production among the responders after interferon therapy (P = 0.030). In conclusion, our results suggest that baseline value of intrahepatic HBV DNA over cccDNA may be a preferable indicator for selecting appropriate patients for IFN-based therapy in the clinic.

Future Therapy for Hepatitis B Virus: Role of Immunomodulators

Although currently available therapies for chronic hepatitis B virus infection can suppress viremia and provide long-term benefits for patients, they do not lead to a functional cure for most patients. Advances in our understanding of the virus-host interaction and the recent remarkable success of immunotherapy in cancer offer new and promising strategies for developing immune modulators that may become important components of a total therapeutic approach to hepatitis B, some of which are now in clinical development. Among the immunomodulatory agents currently being investigated to combat chronic HBV are toll-like receptor agonists, immune checkpoint inhibitors, therapeutic vaccines, and engineered T cells. The efficacy of some immune modulatory therapies is compromised by high viral antigen levels. Cutting edge strategies, including RNA interference and CRISPR/Cas9, are now being studied that may ultimately be shown to have the capacity to lower viral antigen levels sufficiently to substantially increase the efficacy of these agents. The current advances in therapies for chronic hepatitis B are leading us toward the possibility of a functional cure.

HBsAg and HBeAg in the prediction of a clinical response to peginterferon α-2b therapy in Chinese HBeAg-positive patients

BACKGROUND

This study aimed to evaluate the predictive values of hepatitis B e antigen (HBeAg) and hepatitis B surface antigen (HBsAg) levels in 171 Chinese patients with chronic hepatitis B who received a 48-week course of pegylated interferon alfa-2b therapy at 1.5 mcg/kg.

METHODS

HBsAg, HBeAg, and hepatitis B virus (HBV) DNA levels were measured at baseline and weeks 12, 24, 48, and 72. Clinical responses were defined as a combined response (CR, HBeAg seroconversion [sustained response, SR] combined with HBV DNA level <2,000 IU/mL at week 72). The positive predictive value and negative predictive value were calculated for HBsAg alone and/or combined with HBeAg and HBV DNA at weeks 12 and 24.

RESULTS

Of 171 patients included, 58 (33.9 %) achieved a SR. Of patients who achieved a SR, 33 (56.9 %) achieved a CR. Totally 19.3 % (33/171) patients achieved CR and 80.7 % (138/171) patients did not. Patients with HBsAg <1500 IU/mL at week 12 had a 47.4 % chance of achieving an off-treatment SR and patients with a HBsAg decrease >1.5 logIU/mL at week 12 had a 54.5 % chance. Patients with HBsAg >20,000 IU/mL at weeks 12 and 24 had a 93.8 and 100.0 % chance, respectively, of not achieving a CR. An HBsAg level or changes at weeks 12 and 24, combined with HBeAg or HBV DNA, increased the chance for a SR and CR.

CONCLUSIONS

On-treatment HBsAg quantification, alone or in combination with HBeAg or HBV DNA, predicted off-treatment SR and CR after 48 weeks of PEG-IFNα-2b therapy, and thus, may guide clinicians in making a therapeutic decision to continue or terminate the therapy.

High levels of hepatitis B surface antigen are associated with poorer survival and early recurrence of hepatocellular carcinoma in patients with low hepatitis B viral loads

PURPOSE

Recurrence is a disastrous outcome in patients with hepatitis-related hepatocellular carcinoma (HCC) who have undergone curative resection, and little is known about whether high levels of hepatitis B surface antigen (HBsAg) increase the risk of HCC recurrence.

PATIENTS AND METHODS

This retrospective study included 1,360 HBsAg-positive postoperative HCC patients with hepatitis B viral (HBV) DNA levels < 2000 IU/mL, including 298 patients in a training cohort and 1,062 patients in a validation cohort. The prognostic value of the HBsAg level was evaluated using Cox regression and Kaplan-Meier analyses.

RESULTS

We demonstrated that 1,000 IU/mL, but not 10 or 100 IU/mL, was a meaningful cutoff level for significantly discriminating these patients into an HBsAg(Low) group and an HBsAg(High) group based on correlations between the HBsAg level and liver cirrhosis (p = 0.028), tumor size (p = 0.039), and hepatitis B e antigen level (p < 0.001). The postoperative 1-, 3-, and 5-year overall survival (OS) rates of HCC patients in the HBsAg(Low) group were significantly higher than those of HCC patients in the HBsAg(High) group. Accordingly, the 5-year recurrence-free survival (RFS) rates of patients in the HBsAg(Low) group were markedly higher than those of HCC patients in the HBsAg(High) group. The HBsAg level was a prognostic indicator for OS (p = 0.014) and RFS (p = 0.01).

CONCLUSION

HBsAg level is correlated with more aggressive tumor behavior and serves as a prognostic indicator in patients with surgically resected HCC with low HBV load.

Hepatitis B surface antigen quantification in chronic hepatitis B and its clinical utility

Serum HBsAg levels have been quantified extensively in recent years with simple completely automated assays in the various phases of the natural course of chronic HBV infection, have been compared with cccDNA in the liver, with various markers of HBV replication and have been correlated with several viral, host and environmental variables. Low HBsAg levels in inactive carriers predict a spontaneous HbsAg loss. Quantification of HBsAg in serum at baseline and its decline under interferon-alfa based regimens, both in HBeAg-positive and HBeAg-negative CHB, provides important information on the prediction of sustained post-treatment outcomes and on subsequent HBsAg clearance. The value of HBsAg quantification in the monitoring of long term nucleos(t)ide analogue treatment of CHB and in the prediction of sustained response remains unclear. In this review, the most recent data regarding the overall clinical utility of HBsAg measurement in HBeAg-positive and -negative CHB and in their treatment, is critically presented.