Quantification of hepatitis B surface antigen: a new concept for the management of chronic hepatitis B

Treatment of Chronic Hepatitis D with Bulevirtide-A Fight against Two Foes-An Update

HDV infection frequently causes progression to cirrhosis and hepatocellular carcinoma (HCC). In summer 2020, the first potentially effective drug Bulevirtide (BLV) has been approved for the treatment of HDV by the EMA. BLV is a synthetic N-acylated pre-S1 lipopeptide that blocks the binding of HBsAg-enveloped particles to the sodium taurocholate co-transporting polypeptide (NTCP), which is the cell entry receptor for both HBV and HDV. In this review, we discuss the available data from the ongoing clinical trials and from "real world series". Clinical trials and real-world experiences demonstrated that BLV 2 mg administered for 24 or 48 weeks as monotherapy or combined with pegIFNα reduces HDV viremia and normalizes ALT levels in a large proportion of patients. The combination of BLV and pegIFNα shows a synergistic on-treatment effect compared with either one of the monotherapies.

Ten-year efficacy and safety of tenofovir disoproxil fumarate treatment for chronic hepatitis B virus infection

BACKGROUND & AIMS

Tenofovir disoproxil fumarate (TDF) is a first-line treatment for chronic hepatitis B (CHB). We aimed to describe the efficacy and safety profiles of TDF treatment for up to 10 years in a well-described cohort of CHB patients.

METHODS

Hepatitis B e antigen (HBeAg)-negative and HBeAg-positive patients from two randomised, double-blind trials (ClinicalTrials.gov: NCT00117676 and NCT00116805) completed 48 weeks of randomised treatment with TDF or adefovir dipivoxil. A subset of these patients was then eligible to receive open-label TDF treatment for up to 10 years. At Year 10, patients were assessed for virological suppression, alanine aminotransferase (ALT) normalisation, serological response, safety and tolerability.

RESULTS

Of 641 randomised and treated patients, 585 (91%) entered the open-label extension phase with 203 (32%) patients completing Year 10 of the study. At Year 10, 118/118 (100%) of HBeAg-negative patients and 78/80 (98%) of HBeAg-positive patients with available data achieved hepatitis B virus (HBV) DNA < 69 IU/mL, while 88/106 (83%) and 60/77 (78%) patients achieved ALT normalisation, respectively. Of the 23 patients with HBeAg status available at Year 10, 12 (52%) and six (27%) experienced HBeAg loss and seroconversion, respectively. No resistance to TDF was documented up to Year 10. In the period between Year 8 and Year 10, the safety profile of TDF was similar to previous reports, with few patients experiencing renal- or bone-related adverse events.

CONCLUSIONS

Over 10 years, TDF had a favourable safety profile, was well tolerated, and resulted in continued maintenance of virological suppression with no documented resistance.

Evaluation of the highly sensitive chemiluminescent enzyme immunoassay "Lumipulse HBsAg-HQ" for hepatitis B virus screening

BACKGROUND

Ongoing efforts in the development of HBsAg detection kits are focused on improving sensitivity and specificity. The purpose of this study was to evaluate an improved, highly sensitive quantitative assay, "Lumipulse HBsAg-HQ", a chemiluminescent enzyme immunoassay designed for a fully automated instrument, the "Lumipulse G1200".

METHODS

Serum samples for reproducibility, dilution, correlation, sensitivity, and specificity studies were obtained from patients at the Osaka University Hospital. Seroconversion and sensitivity panels were purchased from a commercial vender. Subtype, sensitivity panels, and HBsAg recombinant proteins with one or two amino acid substitutions were prepared in-house.

RESULTS

The coefficients of variation for the low, medium, and high concentration samples ranged from 1.93 to 2.55%. The HBsAg-HQ reagent for dilution testing showed good linearity in the 0.005-150 HBsAg IU/mL range and no prozone phenomenon. All 102 HBV carrier samples were positive by HBsAg-HQ, while other commercial reagents showed one or more to be negative. In the seroconversion panel, the 14-day blood sample was positive. The sensitivity against HBsAg-HQ "ad" and "ay" subtypes was 0.025 ng/mL. Comparisons among the HBsAg-HQ, HISCL, and Architect HBsAg reagents were performed using the Bland-Altman plot. Specificity for 1000 seronegative individuals was 99.7%. HBsAg-HQ detected 29 positive serum among 12 231 routinely obtained serum samples, which showed concentrations of 0.005-0.05 HBsAg IU/mL.

CONCLUSIONS

According to these results, the Lumipulse HBsAg-HQ assay, with a highly sensitive limit of detection of 0.005 IU/mL, may facilitate the development of a better management strategy for a considerable proportion of infected patients.

Serum Levels of Hepatitis B Surface Antigen and DNA Can Predict Inactive Carriers With Low Risk of Disease Progression

Serum levels of hepatitis B virus (HBV) DNA (≤2000 IU/mL) and hepatitis B surface antigen (HBsAg) (<1000 IU/mL) have been shown to distinguish inactive carriers with high accuracy. The goal of this study was to validate the predictability of one-time measurement of quantitative HBsAg and HBV DNA levels for inactive carrier status and chronic hepatitis B (CHB) progression in a community-based cohort. This study included 1529 participants chronically infected with HBV genotype B or C from the REVEAL-HBV cohort. They were ascertained as inactive or active CHB after 18 months of follow-up. Validity of the one-time measurement was assessed by sensitivity, specificity, and receiver operating characteristic curves, while associations with clinical outcomes were calculated with Cox proportional hazards regressions. The one-time baseline measurement of HBsAg <1000 IU/mL and HBV DNA <2000 IU/mL distinguished inactive carriers from active CHB with a sensitivity, specificity, positive predictive value, negative predictive value, and diagnostic accuracy of 71%, 85%, 83%, 74%, and 78%, respectively. Those identified as inactive carriers using the one-time baseline measurement had multivariate adjusted hazard ratios of 0.36 (95% confidence interval [CI], 0.20-0.63) and 0.36 (0.23-0.56) for hepatocellular carcinoma and liver cirrhosis, respectively, and an adjusted rate ratio of 6.97 (95% CI, 5.21-9.33) for HBsAg seroclearance. Areas under the receiver operating characteristic curve of predicting these outcomes using the one-time definition were similar to those obtained when using long-term follow-up defined carrier status for prediction.

CONCLUSION

This study confirms the predictability of a one-time combined HBsAg and HBV DNA measurement for future inactive carriers. This single-point strategy provides new and complementary information useful for management of patients with chronic hepatitis B infection. (Hepatology 2016;64:381-389).

Hepatitis B Surface Antigen Quantification across Different Phases of Chronic Hepatitis B Virus Infection Using an Immunoradiometric Assay

BACKGROUND/AIMS

Quantification of hepatitis B surface antigen (HBsAg) is an emerging serologic test and may be useful for identifying treatment strategies for chronic hepatitis B (CHB). This study aimed to evaluate HBsAg titers during the natural course of CHB and identify correlations between HBsAg titers and hepatitis B virus (HBV) DNA concentrations across different CHB phases measured using an immunoradiometric assay (IRMA).

METHODS

CHB phases were defined on the basis of HBV DNA concentrations, the presence of hepatitis B e antigen/antibody (HBeAg/Ab) and serum alanine aminotransferase levels. Serum HBsAg titers and paired HBV DNA concentrations in the different phases of CHB were compared using 627 serum samples.

RESULTS

Mean HBsAg titers were significantly higher in the immunotolerant (IT) phase and immunoreactive (IR) HBeAg-positive phase than in the low-replicative (LR) and HBeAg-negative CHB (ENH) states. The correlation between HBsAg titers and HBV DNA concentrations was modest in the IT (n=36, r=0.804, p<0.001) and IR (n=48, r=0.773, p<0.001) phases, and it was poor in the LR state (n=116, r=0.289, p=0.002); however, no significant correlation was observed in the ENH state (n=67, r=0.146, p=0.237) or in the oral nucleos(t)ide analogue-treated group (n=267).

CONCLUSIONS

HBsAg quantification using IRMA might be useful for discriminating different CHB phases and different stages of chronic liver disease.

Hepatitis B surface antigen in late hepatitis B infection

Hepatitis B surface antigen (HBsAg) levels are used to evaluate and monitor clinical phases of chronic hepatitis B infection but their clinical significance is unclear in the late complications, cirrhosis of the liver and hepatocellular carcinoma. This study aimed to evaluate HBsAg levels across the whole natural history of hepatitis B virus infection, including late complications. This retrospective, cross-sectional study enrolled 838 treatment-naive patients diagnosed with chronic hepatitis B infection at First Affiliated Hospital of Fujian Medical University between 2009 and 2012. Patients were classified into six groups: immunotolerance, immunoclearance, low replicative, negative hepatitis e (HBeAg) phases, liver cirrhosis, and hepatocellular carcinoma. Main outcome measures were serum HBsAg, HBeAg, HBV DNA, total bilirubin, albumin, alanine and aspartate aminotransferase, and quantitative correlation of HBsAg with HBV DNA. HBsAg levels declined significantly between clinical phases of infection (all P < 0.001) and were significantly lower in decompensated than in compensated cirrhosis (2.90 vs. 3.30, P < 0.001) but not significantly different between early versus advanced hepatocellular carcinoma. Significant positive correlations were observed between serum HBsAg and HBV DNA at immunoclearance and HBeAg negative phases, compensated and decompensated liver cirrhosis and advanced but not early hepatocellular carcinoma (all P < 0.001). HBsAg and HBV DNA were significantly higher in HBeAg positive patients with advanced hepatocellular carcinoma (P < 0.001). HBsAg levels differ significantly between chronic hepatitis B infection phases, decreasing progressively from chronic infection to cirrhosis and hepatocellular carcinoma. Significant correlations are found between serum HBsAg and HBV DNA.

Changing serum levels of quantitative hepatitis B surface antigen and hepatitis B virus DNA in hepatitis B virus surface antigen carriers: a follow-up study of an elderly cohort

This study was to elucidate longitudinally quantitative changes of hepatitis B virus (HBV) surface antigen (HBsAg) and HBV DNA in elder HBsAg carriers in a community. Among 1002 residents screened for HBsAg in 2005, 405 responded to this follow-up study in 2010. Fifty-nine (14.6%) were HBsAg carriers in 2005; HBsAg quantification and HBV DNA were measured. HBsAg quantification (cutoff 1600 IU/mL) and HBV DNA (cutoff 2000 IU/mL) were combined to stratify the participants between two screens. A total of 30 men and 29 women with a mean age of 63.9 ± 7.9 years were enrolled. Quantitative levels of HBsAg and HBV DNA were significantly correlated in 2005 (r = 0.509, p < 0.001) and 2010 (r = 0.777, p < 0.001). Concentrations of HBsAg (IU/mL) significantly decreased from 2.2 ± 1.0 log in 2005 to 1.7 ± 1.5 log in 2010 (p < 0.001). The level of HBsAg was decreased in 48 (81.4%) individuals and HBsAg was undetectable in eight (13.6%). The annual incidence of HBsAg clearance was 2.7%. These 59 HBsAg carriers in 2005 were divided into four groups: low HBsAg low HBV DNA (n = 32), high HBsAg low HBV DNA (n = 5), low HBsAg high HBV DNA (n = 12) and high HBsAg high HBV DNA (n = 10). All 32 individuals in the low HBsAg low HBV DNA group were still in that group in 2010, whereas only two of the high HBsAg high HBV DNA group became inactive. As with a younger cohort in hospital, HBsAg quantification was still well correlated with HBV DNA in elderly HBsAg carriers in the community. Lower levels of both HBsAg and HBV DNA might represent an inactive HBV infection.

Comparison of two immunoassays for quantification of hepatitis B surface antigen in Chinese patients with concomitant hepatitis B surface antigen and hepatitis B surface antibodies

Two commercial quantitative immunoassay platforms are currently available for the detection of hepatitis B surface antigen (HBsAg) within a wide range of concentrations: the Architect HBsAg assay and the Elecsys HBsAg II. However, there are limited data concerning their performance in patients who are positive for both HBsAg and anti-HBs antibodies. In the present study, 127 serum samples from Chinese patients with hepatitis B carrying both HBsAg and anti-HBs antibodies were analyzed. HBsAg levels measured in parallel using the Elecsys HBsAg II and Architect HBsAg assay were compared. There was a significant correlation between HBsAg levels measured by Elecsys HBsAg II and Architect HBsAg assay (correlation coefficient, r = 0.992, P < 0.05). Bland-Altman analysis indicated only minor discordance between the methods (mean difference between Elecsys HBsAg II and Architect HBsAg assay, -0.02 log10 IU/ml; 95 % confidence interval, -0.40-0.37 log10 IU/ml). In conclusion, the results of the quantitative Elecsys HBsAg II were highly correlated with those of the Architect HBsAg assay in patients carrying both HBsAg and anti-HBs antibodies, but differences were observed between the platforms in samples with low HBsAg levels.

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.

Clinical significance of hepatitis B virion and SVP productivity: relationships between intrahepatic and serum markers in chronic hepatitis B patients

BACKGROUND

Clinical use of hepatitis B viral (HBV) quantitative seromarker\s remains questionable since it is not precisely known whether they represent intrahepatic viral replication. Covalently closed circular DNA (cccDNA), relaxed circular DNA (rcDNA), and pregenomic RNA (pgRNA) are more likely to represent active HBV replication and their measurement can be used to derive virion productivity (VP; rcDNA/cccDNA), subviral particle (SVP) productivity (quantitative HBsAg/cccDNA), and replicative activity (RA; pgRNA/cccDNA). These can be used to compare relative HBV replication between HBeAg-negative and -positive patients.

OBJECTIVE

To study the clinical significance of intrahepatic HBV replication phenomenon between HBeAg-negative and -positive patients and its correlation with quantitative HBV seromarkers.

METHOD

This was a prospective study between January 2010 and December 2011. Study subjects were naive chronic hepatitis B patients from Cipto Mangunkusumo and Medistra Hospitals. All patient samples underwent liver biochemistry and HBV seromarkers testing (HBeAg, quantitative HBsAg and HBV DNA levels), and patients underwent liver biopsy. Stored liver specimens were analysed for intrahepatic rcDNA, cccDNA, and pgRNA with quantification performed by real-time PCR. Comparison of HBV markers between HBsAg-positive and -negative patients was carried out using the Mann-Whitney U-test. Pearson's correlation test was performed among HBV intrahepatic and seromarkers using their log-transformed values.

RESULTS

A total of 104 patients were enrolled in this study; 54 (51.9%) were male. Patients' mean age was 41.9 ± 11.63 years (range 19-70 years). Sixty-one patients (58.7%) were HBeAg-negative. All HBV markers were significantly higher in HBeAg-positive than HBeAg-negative patients, except for SVP productivity and RA. Serum HBV DNA was strongly correlated with intrahepatic total HBV DNA (r = 0.771), cccDNA (r = 0.774), and rcDNA (r = 0.780) while serum quantitative HBsAg showed only moderate correlation with intrahepatic total DNA (r = 0.671), cccDNA (r = 0.632), rcDNA (r = 0.675), and SVP productivity (r = 0.557).

CONCLUSIONS

Serum HBV DNA concentration and quantitative HBsAg might not accurately predict intrahepatic viral activity. Virion and SVP production do not occur in parallel with replicative activity.

Loss of HBsAg and antiviral treatment: from basics to clinical significance

Accurate prediction of the sustained virological response (SVR) to antiviral therapy against chronic hepatitis B (CHB) is still a crucial problem needing profound investigation. In recent years, quantification of hepatitis B surface antigen (HBsAg), a reliable predictor of SVR and an ideal endpoint of treatment, has attracted increasing attention. Serum HBsAg titer may reflect the level of intrahepatic hepatitis B virus (HBV) covalently closed circular DNA (cccDNA) in most patients, and vary with natural phases of chronic HBV infection, genotypes and variants, antiviral therapy, and other related factors. Serum HBsAg <200 IU/mL or yearly reduction ≥0.5 log10IU/mL may be the optimum cut-off values for prediction of the chance of spontaneous seroclearance of HBsAg. Serum HBsAg <1,000 IU/mL with HBV DNA <2,000 IU/mL may identify most of the inactive HBV carriers from active HBeAg(-) hepatitis. Interferon-based therapy can lead to more significant HBsAg decline than therapy based on nucleoside and/or nucleotide analogues. Different patterns or kinetics of HBsAg decline during therapy are related to different probabilities of SVR. A low HBsAg level, <3,000 IU/mL at baseline, or HBsAg level, <1,500 IU/mL at week 12, or a rapid on-treatment HBsAg decline of ≥0.5 log10IU/mL at week 12, may predict higher probability of SVR. However these cut-off values must be further validated for larger cohort of patients across genotypes worldwide. Incorporation of serum HBsAg level, HBeAg status, HBV DNA load, HBV genotypes, and other related factors might help establish new concept of more practical "response-guided treatment (RGT)" rules for antiviral therapy.

Hepatitis B virus surface antigen seroconversion in HIV-infected individual after pegylated interferon-alpha treatment: a case report

Hepatitis B virus (HBV) infects from 6 to 14% of HIV-infected individuals. Concurrent HIV/HBV infection occurs due to the overlapping routes of transmission, particularly sexual and parenteral. HIV-infected patients that have acute hepatitis B have six times greater risk of developing chronic hepatitis B, with higher viral replication, rapid progression to end-stage liver disease and shorter survival. The coinfection is also associated with poor response to hepatitis B treatment with interferon-alpha and increased liver toxicity to the antiretroviral therapy. Herein, we describe the case of a 35-year-old man who engages in sex with men and presented with newly diagnosed HIV-1, serological markers for acute hepatitis B and progression to chronic hepatitis B infection (HBsAg+ > 6 months, high alanine aminotransferase levels and moderate hepatitis as indicated by liver biopsy). Lacking indication of antiretroviral treatment (CD4 768 cells/mm³), he was treated with pegylated-interferon alpha2b (1.5 mg/kg/week) by subcutaneous injection for 48 weeks. Twelve weeks after treatment, the patient presented HBeAg seroconversion to anti-HBe. At the end of 48 weeks, he presented HBsAg seroconversion to anti-HBs. One year after treatment, the patient maintained sustained virological response (undetectable HBV-DNA). The initiation of antiretroviral therapy with nucleosides and nucleotides is recommended earlier for coinfected individuals. However, this report emphasizes that pegylated interferon remains an important therapeutic strategy to be considered for selected patients, in whom the initiation of HAART may be delayed.

Virus-specific immune response in HBeAg-negative chronic hepatitis B: relationship with clinical profile and HBsAg serum levels

BACKGROUND AIMS

The immune impairment characterizing chronic hepatitis B (cHBV) infection is thought to be the consequence of persistent exposure to viral antigens. However, the immune correlates of different clinical stages of cHBV and their relation with different levels of HBsAg have not been investigated. The aim of the present study was to evaluate the relationship between HBV-specific T cells response and the degree of in vivo HBV control and HBsAg serum levels in HBeAg-HBeAb+ cHBV.

METHODS

Peripheral blood mononuclear cells from 42 patients with different clinical profiles (treatment-suppressed, inactive carriers and active hepatitis) of cHBV, 6 patients with resolved HBV infection and 10 HBV-uninfected individuals were tested with overlapping peptides spanning the entire HBV proteome. The frequency and magnitude of HBV-specific T cell responses was assessed by IFNγ ELISPOT assay. Serum HBsAg was quantified with a chemiluminescent immunoassay.

RESULTS

The total breadth and magnitude of HBV-specific T cell responses did not differ significantly between the four groups. However, inactive carriers targeted preferentially the core region. In untreated patients, the breadth of the anti-core specific T cell response was inversely correlated with serum HBsAg concentrations as well as HBV-DNA and ALT levels and was significantly different in patients with HBsAg levels either above or below 1000 IU/mL. The same inverse association between anti-core T cell response and HBsAg levels was found in treated patients.

CONCLUSIONS

Different clinical outcomes of cHBV infection are associated with the magnitude, breadth and specificity of the HBV-specific T cell response. Especially, robust anti-core T cell responses were found in the presence of reduced HBsAg serum levels, suggesting that core-specific T cell responses can mediate a protective effect on HBV control.

Sequential therapy with entecavir and PEG-INF in patients affected by chronic hepatitis B and high levels of HBV-DNA with non-D genotypes

Complete eradication of hepatitis B virus (HBV) is rarely achieved. Treatment options include currently available nucleos(t)ide analogues and pegylated interferon. The aim of our exploratory study was to assess the effectiveness of sequential therapy for chronic hepatitis B (CHB) vs the current standard of care. We evaluated an association with entecavir and pegylated interferon alfa-2a (PEG-IFN) in 20 patients with hepatitis B, high HBV viremia and genotypes A, B, C and E. Patients received entecavir alone for 12 weeks, then entecavir and PEG-IFN for 12 weeks, lastly PEG-IFN alone for 36 weeks. The results were compared with 20 patients (control group) treated in the past with 48 weeks of PEG-IFN monotherapy. Our results show that complete sustained virological response (SVR) and partial SVR were, respectively, 60% and 80% in the study group and 10% and 30% in the control group; anti-HBe seroconversion rate were 76.9% vs 15%, and anti-HBs seroconversion were 20% vs 0%, respectively. We found a correlation among different genotypes and virological and serological outcomes - genotype C has a better virological response, while genotype A had a better serological response, and E genotype had a poor response. These results show that a sequential approach is a promising strategy of treatment in patients with CHB and high viremia in comparison with PEG-IFN monotherapy. The E genotype seems to have the worse rate of response and requires other treatment strategies.

Hepatitis B viral factors and treatment responses in chronic hepatitis B

Baseline and on-treatment hepatitis B viral factors are reported to affect treatment responses. A lower baseline hepatitis B virus (HBV) DNA level is a strong predictor of the response to antiviral therapy. HBV genotype A/B patients have better responses to interferon-based therapy than those with genotypes C/D. Regarding the association of HBV mutants with responses to antiviral therapy, current evidence is limited. On-treatment viral suppression is the most important predictor of response to nucleoside analogs. On-treatment hepatitis B surface antigen decline is significantly associated with response to pegylated interferon. In the future, individualized therapy should be based on treatment efficacy, adverse effects, baseline and on-treatment predictors of antiviral therapy.

Correlation between hepatitis B surface antigen titers and HBV DNA levels

BACKGROUND/AIM

To assess the correlation between serum HBsAg titers and hepatitis B virus (HBV) DNA levels in patients with hepatitis B envelop antigen-negative (HBeAg -ve) HBV genotype-D (HBV/D) infection.

PATIENTS AND METHODS

A total of 106 treatment- naïve, HBeAg -ve HBV/D patients were included; 78 in the inactive carrier (IC) state and 28 in the active hepatitis (AH) stage. HBV DNA load and HBsAg titers were tested using TaqMan real-time polymerase chain reaction (PCR) and automated chemiluminescent microparticle immunoassay, respectively.

RESULTS

The median (range) log10 HBsAg titer was significantly lower in the IC group compared with AH group, 3.09 (-1 to -4.4) versus 3.68 (-0.77 to 5.09) IU/mL, respectively; P < 0.001. The suggested cutoff value of HBsAg titer to differentiate between the two groups was 3.79 log10 IU/mL. In addition, there was a significant positive correlation between HBsAg and HBV DNA levels in the whole cohort, AH, and IC groups (r = 0.6, P < 0.0001; r = 0.591, P = 0.001; and r = 0.243, P = 0.032, respectively).

CONCLUSION

Serum HBsAg titers may correlate with HBV DNA in treatment-naïve HBeAg -ve HBV/D patients, and supports the use of HBsAg levels in clinical practice as a predictor of serum HBV DNA levels.

Elecsys hepatitis B surface antigen quantitative assay: performance evaluation and correlation with hepatitis B virus DNA during 96 weeks of follow-up in chronic hepatitis B patients

Background

Treatment for chronic hepatitis B aims to suppress virus replication and virus sequestration in hepatocytes. Covalently closed circular (ccc) DNA is the template for transcription of viral genes and is responsible for viral persistence. However, limited data are available for quantification of hepatitis B surface antigen (HBsAg) in Korea.

Methods

We evaluated the Elecsys HBsAg II quant assay (Roche Diagnostics, USA) for within-run, between-run, and between-day precisions, linearity, carryover, and clinical specificity. In total, 156 serum samples were evaluated for correlation between HBsAg and hepatitis B virus (HBV) DNA. Serial samples were obtained from 10 patients at 0, 12, 24, 48, 72, and 96 weeks during follow-up.

Results

The assay detected HBsAg in a linear range of 0.5-48,696 IU/mL. Within-run, between-run, and between-day CVs were 2.9-4.1%, 0-1.5%, and 1.5-4.9%, respectively. Cross-reactivity between potentially interfering substances was absent, and the carryover rate was 0.00002%. The correlation of measurements between the Elecsys assay and HBV DNA PCR was weak (r=0.438, P=0.002). For predicting virologic response, cutoff values of 10,275 IU/mL and 3,846 IU/mL at 12 and 24 weeks after treatment initiation showed positive predictive values of 77.1% and 85% and negative predictive values of 84.6% and 50%, respectively.

Conclusions

The Elecsys HBsAg II quant assay showed good performance for precision, linearity, carryover rate, and specificity. HBsAg level at baseline, 12 weeks, and 24 weeks after treatment initiation can predict virologic response, and the assay can be used for HBsAg quantification in clinical practice.

Hepatitis B virus basal core promoter mutations A1762T/G1764A are associated with genotype C and a low serum HBsAg level in chronically-infected HBeAg-positive Chinese patients

The present study was aimed to obtain baseline information of basal core promoter A1762T/G1764A and precore G1896A mutations of hepatitis B virus (HBV) in 192 HBeAg-positive chronically-infected Chinese patients, who were potential candidates for antiviral treatment. The detection of these mutations (including minor mutant subpopulations) was achieved by direct sequencing, whose sensitivity for minor mutant subpopulations identification was confirmed by clone sequencing. Patients enrolled were infected with either genotype B (46.35%) or C (53.65%) HBV identified by routine tests in our laboratory. The A1762T/G1764A or G1896A mutations were detected in 125specimens (125/192, 65.10%), in which 77 (77/125, 61.60%) existed as subpopulations. The A1762T/G1764A mutations were found to be more prevalent in genotype C than that in genotype B HBV [62.14% (64/103) vs. 20.22% (18/89), P<0.0001]. There is no statistically significant link between G1896A and genotypes. The emergence of A1762T/G1764A mutations was also found to be associated with an older age, an elevated ALT/AST level, and a lower HBsAg level in serum [wild-type vs. mutant: 4.57 (3.46-5.42) vs. 3.93 (2.51-5.36), P<0.0001]. In conclusion, HBV basal core promoter mutations A1762T/G1764A are associated with genotype C and a low serum HBsAg level in chronically-infected HBeAg-positive Chinese patients.

New advances in chronic hepatitis B

PURPOSE OF REVIEW

This article reviews recent developments in the evaluation and treatment of chronic hepatitis B (CHB) based on articles published between December 2010 and January 2012.

RECENT FINDINGS

The majority of patients infected with CHB have not been diagnosed and most at-risk individuals have not been immunized. Progression to cirrhosis depends on hepatitis B virus (HBV) genotype, hepatitis B e antigen (HBeAg) presence, persistently high levels of HBV DNA, and elevated alanine aminotransferase, although hepatitis B surface antigen (HBsAg) kinetics may help predict natural history and antiviral response. Antiviral resistance limits the success of nucleos(t)ide analogs and agents such as entecavir and tenofovir with high potency and high genetic barrier to resistance are considered first-line therapy. Specialized treatment of CHB in pregnancy, coinfection, decompensated cirrhosis, and posttransplant is safe and effective.

SUMMARY

The complications of CHB can now be avoided and reversed with potent antiviral suppression of HBV DNA. For now, treatment is long-term and further studies are needed to discern whether sequential or combination therapy may be superior to current monotherapy for certain patients. Increased awareness should improve screening resulting in more frequent treatment and immunization of at-risk individuals toward eventual CHB eradication.

HBsAg Quantification in Clinical Practice

Several standardized commercial assays for quantification of hepatitis B surface antigen (qHBsAg) are now available. Studies on HBsAg kinetics from Asia and Europe have demonstrated that HBsAg levels are highest during the immune-tolerant phase, become lower during immune-clearance phase and are the lowest in hepatitis B 'e' antigen (HBeAg)-negative inactive low-replicative phase with a rise during HBeAg-negative chronic hepatitis B (CHB). Combined use of hepatitis B virus-deoxyribonucleic acid (HBV-DNA) and HBsAg levels may help in differentiating true inactive carrier state from HBeAg-negative CHB. Several retrospective studies have demonstrated a role for decline in HBsAg level for predicting response and nonresponse to therapy. In HBeAg-positive patients treated with pegylated-interferon (PEG-IFN), a lack of decline of qHBsAg at week 12 predicts nonresponders while a decline of qHBsAg at week 24 predicts responders to PEG-IFN. In HBeAg-negative patients, if at week 12, there is no decline in qHBsAg and the HBV-DNA decline is < 2 log, the patient is unlikely to respond, then stopping of PEG-IFN should be considered. With nucleos(t)ide analogs, the decline in HBsAg is lower than that with PEG-IFN and more marked in patients with HBeAg-positive chronic hepatitis, with elevated alanine aminotransaminase (ALT), thus suggesting that active immune response against HBV is required to lower HBsAg. In patients with HBeAg-negative chronic hepatitis, fall in HBsAg may help in developing stopping rules to reduce the need for lifelong therapy. Information provided by HBsAg is complementary to HBV-DNA and cannot replace the same. Prospective studies on HBsAg kinetics from all regions of the world are required to define optimum time of testing and cutoff levels before stopping rules can be recommended.

Hepatitis B: modern end points of treatment and the specter of viral resistance

The goal of antiviral treatment of chronic hepatitis B is to prevent the complications of cirrhosis, hepatic decompensation, HCC, and death. Because these clinical outcomes may take a long period of time to develop, it is important to use intermediate or surrogate end points to evaluate the efficacy and response to antiviral treatment, and to determine whether treatment can be safely stopped, especially given concern for the development of antiviral resistance with NUC therapy. Although normalization of ALT and suppression of HBV DNA viral replication are associated with favorable outcomes, the durability of their response is low, and these end points are insufficient markers for stopping treatment. HBeAg seroconversion is currently used to discontinue NUC treatment in patients with HBeAg-positive chronic hepatitis B, whereas the stopping rule for HBeAg-negative disease relies on HBsAg loss. However, HBsAg loss occurs very infrequently and is not a practical end point for clinical use, although quantitative HBsAg levels may be useful in identifying patients who could achieve a sustained virologic response to treatment.

Recent advances in the treatment of chronic hepatitis B

INTRODUCTION

At present, two strategies exist for the treatment of chronic hepatitis B (CHB): i) standard or pegylated interferon alpha (IFN) with mainly immune modulatory effects; and ii) nucleos(t)ide analogues (NA) with direct antiviral effects. The optimal treatment for an individual patient remains controversial.

AREAS COVERED

The treatment efficacy and prediction of response to antiviral agents for chronic hepatitis B are reviewed and discussed.

EXPERT OPINION

The rates of hepatitis B e antigen (HBeAg) and hepatitis B surface antigen (HBsAg) loss or seroconversion are continuously increasing in CHB patients after stopping a finite course of IFN, whereas long-term NA therapy is usually required to improve the adverse outcomes of CHB. Lower baseline HBV DNA level is a strong predictor for both sustained viral suppression and HBeAg seroconversion in patients receiving IFN-based as well as NAs therapy. In addition, HBeAg-positive patients with genotype A or B infection have better responses to IFN-based therapy than those with genotypes C or D infection. Furthermore, on-treatment predictors such as declines of serum HBV DNA, HBsAg and HBeAg levels may be helpful in making decisions of subsequent therapy. Regarding the association of host genetic factors with responses to antiviral therapy, current evidence is limited.