Serum HBV RNA predicts HBeAg clearance and seroconversion in patients with chronic hepatitis B treated with nucleos(t)ide analogues

This study evaluated the predictive value of serum HBV DNA, HBV RNA, HBcrAg, HBsAg, intrahepatic HBV DNA and cccDNA for HBeAg clearance and seroconversion during long-term treatment with nucleos(t)ide analogues (NAs) in patients with chronic hepatitis B (CHB). A single centre, prospective cohort of CHB patients was used for this study. Serum HBV RNA levels were retrospectively measured at baseline, 6, 12, 24, 36, 48, 60, 72 and 84 months post-NAs treatment. Serum HBsAg and HBcrAg levels were quantified at baseline, month 6, 60 and 72. Histological samples from liver biopsy at baseline and month 60 were analysed for intrahepatic HBV DNA and cccDNA. Eighty-three HBeAg-positive patients were enrolled with a median follow-up time of 108 months (range 18-138 months). Of them, 53 (63.86%) patients achieved HBeAg clearance, and 37 (44.58%) achieved HBeAg seroconversion. Cox multivariate analysis showed that only baseline HBV RNA was independently associated with HBeAg clearance and seroconversion (<5.45 log₁₀ copies/mL, HR = 5.06, 95% CI: 1.87-13.71, p = .001; HR = 3.38, 95% CI: 1.28-8.91, p = .01). The independent association with HBeAg clearance and seroconversion remained for HBV RNA levels at month 6 (<4.72 log₁₀ copies/mL, HR = 4.16, 95% CI: 1.61-10.72, p = .003; HR = 6.52, 95% CI: 1.85-22.94, p = .003) and month 12 (<4.08 log₁₀ copies/mL, HR = 3.68, 95% CI: 1.96-6.90, p < .001; HR = 2.79, 95% CI: 1.31-5.94, p = .008). The AUCs of baseline HBV RNA for predicting the HBeAg clearance (0.83, 95% CI: 0.70-0.96, 0.83, 95% CI: 0.70-0.96 and 0.82, 95% CI: 0.69-0.95 respectively) and seroconversion (0.89, 95% CI: 0.77-1.00; 0.81, 95% CI: 0.66-0.95 and 0.84, 95% CI: 0.71-0.98 respectively) at month 36, 60 and 84 were higher than those of HBV DNA, HBsAg and HBcrAg. In conclusion, lower serum HBV RNA at baseline, month 6 and 12 post-NAs treatment could predict HBeAg clearance and seroconversion during long-term NAs treatment.

HBsAg Loss as a Treatment Endpoint for Chronic HBV Infection: HBV Cure

Despite the availability of effective vaccines and antiviral therapy over the past two to three decades, chronic hepatitis B virus (HBV) infection remains a major global health threat as a leading cause of cirrhosis and liver cancer. Functional HBV cure defined as hepatitis B surface antigen (HBsAg) loss and undetectable serum HBV DNA is associated with improved clinical outcomes in patients with chronic HBV infection. However, spontaneous loss of HBsAg is rare and occurs in only 1% of all HBsAg-positive individuals annually. Furthermore, the rate of functional cure with currently available antiviral therapy is even lower, <1% patients on treatment per year. Nonetheless, HBsAg loss has become the new target or therapeutic endpoint for antiviral treatment. Recently, there has been much excitement surrounding the development of novel antiviral agents such as small interfering RNA (siRNA), core assembly modulators (CAMs), nucleic acid polymers (NAPs) among others, which may be used in combination with nucleos(t)ide analogs and possibly immunomodulatory therapies to achieve functional cure in a significant proportion of patients with chronic hepatitis B. Novel assays with improved sensitivity for detection of very low levels of HBsAg and to determine the source of HBsAg production will also be required to measure efficacy of newer antiviral treatments for HBV cure. In this narrative review, we will define HBV cure, discuss various sources of HBsAg production, evaluate rates of HBsAg loss with current and future antiviral agents, review clinical factors associated with spontaneous HBsAg loss, and explore clinical implications of functional cure.

Usefulness of a Hepatitis B Surface Antigen-Based Model for the Prediction of Functional Cure in Patients with Chronic Hepatitis B Virus Infection Treated with Nucleos(t)ide Analogues: A Real-World Study

In patients with chronic hepatitis B (CHB) under long-term treatment with nucleso(t)ide analogues (NAs), the loss of hepatitis B surface antigen (HBsAg) is a rare event. A growing body of evidence supports the use of quantitative HBsAg for the prediction of functional cure, although these results are mainly derived from studies performed on Asian patients with hepatitis B e antigen (HBeAg)-positive CHB. Here, we investigated the clinical role of quantitative HBsAg in a real-life cohort of CHB patients under treatment with NAs in a tertiary care center from North-West Italy. A total of 101 CHB patients (HBeAg-negative, n = 86) undergoing NAs treatment were retrospectively enrolled. HBsAg was measured at baseline (T0), 6 months (T1), 12 months (T2) and at the last follow-up (FU). Median FU was 5.5 (3.2–8.3) years; at the end of FU, 11 patients lost the HBsAg (annual incidence rate = 1.8%). Baseline HBsAg levels were significantly different between patients with no HBsAg loss and those achieving a functional cure (3.46, 2.91–3.97 vs. 1.11, 0.45–1.98 Log IU/mL, p < 0.001). Similarly, the HBsAg decline (Δ) from T0 to T2 was significantly different between the two groups of patients (0.05, −0.04–0.13, vs. 0.38, 0.11–0.80 Log IU/mL, p = 0.002). By stratified cross-validation analysis, the combination of baseline HBsAg and ΔHBsAg T0–T2 showed an excellent accuracy for the prediction of HBsAg loss (C statistic = 0.966). These results corroborate the usefulness of quantitative HBsAg in Caucasian CHB patients treated with antivirals for the prediction of HBsAg seroclearance.

Changes in the Hepatitis B Surface Antigen Level According to the HBeAg Status and Drug Used in Long-term Nucleos(t)ide Analog-treated Chronic Hepatitis B Patients

Backgrounds/Aims

The HBsAg levels have been used to monitor the chronic hepatitis B (CHB) treatment response to antiviral therapy. On the other hand, it is unclear if the HBsAg quantification levels at each treatment point differ according to the HBeAg status and drug in CHB patients. This study compared the changes in HBsAg in CHB patients according to the HBeAg status and treatment drugs.

Methods

CHB patients with at least 1 year of follow-up treatment with one drug, either entecavir (ETV) or tenofovir (TDF), were enrolled in this study. The mean HBsAg levels were measured annually for up to 6 years. A linear mixed model was used to compare the HBsAg quantification levels during the follow-up period. An independent samples t-test was used to analyze the differences in the HBsAg quantification levels at each treatment time point.

Results

Ninety-seven patients were enrolled in this study; 59 among them were HBeAg-positive. Two patients in the TDF group achieved HBsAg seroconversion. The HBsAg level decreased during the follow-up in the ETV and TDF groups. The HBsAg level was lower in the TDF group than the ETV group during the follow-up. On the other hand, subgroup analysis showed that this trend was the same only in the HBeAg-negative patients, not in the HBeAg-positive patients. In the HBeAg-negative patients, HBsAg level in the TDF group was significantly lower than that in the ETV group at 36, 48, and 72 months. The change in HBsAg level from the baseline increased at a decreasing rate during the follow-up in both groups. Furthermore, the change in the HBsAg level in the TDF group was significantly larger than that of the ETV group at 36 months in the HBeAg-negative patients.

Conclusions

Although TDF might be more efficient than ETV in reducing the HBsAg level in HBeAg-negative patients in a few years, HBsAg seroconversion occurred very rarely. A further large-scale, long-term study will be needed to confirm the antiviral effects on the HBsAg level.

Quantative HBsAg level correlates dendritic cells maturation in chronic hepatitis B patients

BACKGROUND

In order to better understand the role of Dendritic cells (DCs) in Chronic Hepatitis B (CHB), we investigated the frequencies and maturation markers on DCs in CHB patients and its change during entecavir treatment.

METHODS

Twenty-six CHB patients on anti-virus treatment for 48 weeks were included in this study. Patients' blood samples were collected on every 3 months since starting treatment. Samples on baseline and after 48 weeks treatment were examined using flow-cytometry to investigate frequencies and maturation markers of DCs.

RESULTS

The frequencies of myeloid DCs (mDCs) and plasmacytoid DCs (pDCs) were lower in CHB patients than healthy controls on baseline. pDCs frequencies and mDCs maturation markers expression were increased after entecavir (ETV) treatment. Patients with higher baseline HBsAg levels showed a poorer maturation status than those with low baseline HBsAg levels, regardless of changes in HBsAg levels after treatment.

CONCLUSIONS

Entecavir treatment could restore the decreased DCs frequencies in CHB patients and improve DCs maturation levels. Baseline HBsAg level is an important factor that affecting DCs.

Development and validation of a model for hepatitis B e antigen seroconversion in entecavir-treated patients with chronic hepatitis B

Achieving hepatitis B e antigen (HBeAg) seroconversion is a satisfactory endpoint during antiviral treatment for chronic hepatitis B (CHB). This study aimed to develop and validate a novel scoring system to predict HBeAg seroconversion during entecavir (ETV) treatment. A total of 526 patients with HBeAg-positive CHB treated with ETV for at least 1 year were randomly assigned to the training and validation cohorts. Baseline parameters including hepatitis B virus DNA, hepatitis B surface antigen (HBsAg), hepatitis B core antibody (HBcAb), and alanine aminotransferase level were quantified. Patients who achieved HBeAg seroconversion were compared with those without HBeAg seroconversion. A prediction model was established to predict HBeAg seroconversion during ETV treatment. After a median follow up of 2.67 years, 93 (36.0%) and 87 (32.5%) patients in the training and validation cohorts developed HBeAg seroconversion. A prediction score composed of age, HBsAg and HBcAb quantification was derived. Areas under receiver operating characteristic curve at 5 years of this prediction score were 0.70 and 0.72 in the training and validation cohorts. By using the dual cutoff values of 0.28 and 0.58, the model was endowed with high sensitivity and specificity to exclude or identify patients developing HBeAg seroconversion (90.3% sensitivity and 90.2% specificity in the training cohort as well as 92.8% sensitivity and 84.4% specificity in the validation cohort, respectively). A novel prediction score that uses baseline clinical variables was developed and validated. The score accurately estimates the probabilities of developing HBeAg seroconversion at 5-years ETV therapy in patients with CHB.

Baseline HBsAg levels associated with HBsAg loss in HBeAg-negative chronic hepatitis B infection with persistently normal alanine aminotransferase

BACKGROUND

We aimed to assess the long-term outcomes of e antigen-negative chronic hepatitis B (CHB) infection with low hepatitis B virus (HBV) DNA level (< 200 IU/mL) and persistently normal alanine aminotransferase (PNALT) and to explore the factors associated with the results.

METHODS

This retrospective cohort study enrolled consecutive baseline CHB patients with PNALT from January 2005 to June 2008. In total, 252 e antigen-negative CHB patients with PNALT and low HBV DNA level (< 200 IU/mL) were enrolled, of whom 188 were eligible for this analysis. Among the 188 patients, 131 were followed up more than twice per year and 57 were followed up at least once per year, with a median follow-up period of 102 (73-123) months.

RESULTS

Of 188 patients, 16 had HBV DNA level of > 200 IU/mL and PNALT, 164 had HBV DNA level of < 200 IU/mL and PNALT and 8 had HBV DNA level of > 200 IU/mL and elevated ALT level, of which 3 used an antiviral drug during follow-up. Twelve of 164 experienced HBsAg loss. Cox regression analysis suggested that baseline HBsAg levels were associated with HBsAg loss in patients after follow-up, especially the baseline HBsAg levels of < 200 IU⁄mL, which is a risk factor for HBsAg loss. The AUC of baseline HbsAg level in the e antigen-negative CHB group was 0.772 (cutoff value 426, P < 0.001). The cumulative probability of HBsAg loss in the HBsAg < 400 IU/L group was 20% (7/35), which ws higher than that in the HBsAg ≥ 400 IU/L group (3.88%; 5/129; X2 = 11.75, P = 0.0006).

CONCLUSION

The e antigen-negative CHB infection with low HBV DNA level (< 200 IU/mL) and PNALT will progress to chronic hepatitis, although the probability of its occurrence is low. Spontaneous HBsAg loss may not occur frequently because the manifested cumulative probability of HBsAg loss was higher in the HBsAg < 400 IU/L group than in the HBsAg ≥ 400 IU/L group.

Clinical utility of hepatitis B surface antigen kinetics in treatment-naïve chronic hepatitis B patients during long-term entecavir therapy

AIM

To investigate the utility of hepatitis B surface antigen (HBsAg) kinetics in chronic hepatitis B patients during long-term entecavir treatment.

METHODS

This retrospective study included treatment-naïve chronic hepatitis B patients who received at least 2 years of consecutive entecavir treatment. Patients were followed up at three to six month intervals with liver biochemistry, hepatitis B virus DNA, and abdominal sonography. In hepatitis B e antigen (HBeAg)-positive patients, HBeAg levels were assessed every three to six month until results became negative. Serum HBsAg levels were determined at the baseline, one-year and five-year time points. Liver cirrhosis was diagnosed through liver biopsy, imaging examinations, or clinical findings of portal hypertension. Hepatocellular carcinoma was diagnosed by histological examination or dynamic image studies.

RESULTS

A total of 211 patients were enrolled. The median treatment time was 5.24 (2.00-9.62) years. Multivariate analysis showed that lower baseline HBsAg levels were associated with an earlier virological response, earlier hepatitis B e antigen (HBeAg) seroconversion, and earlier biochemical response in HBeAg-positive patients (cut-off value: 4 log IU/mL) and an earlier virological response in HBeAg-negative non-cirrhotic patients (cut-off value: 2.4 log IU/mL). Although HBsAg levels decreased slowly during long-term entecavir treatment, higher HBsAg decrease rates were found in the first year for HBeAg-positive non-cirrhotic patients, and patients with higher baseline HBsAg levels. More favorable clinical outcomes were not observed by a rapid HBsAg decline per se, but depended on lower baseline HBsAg levels.

CONCLUSION

Baseline HBsAg can be used to predict treatment responses. HBsAg levels and decrease rates should be considered together according to disease status while interpreting HBsAg changes.

The role of interleukin-27 in predicting spontaneous HBeAg seroconversion in chronic hepatitis B infection

BACKGROUND AND AIMS

Hepatitis B e seroconversion, associated with preceding hepatic inflammation, marks the transition from immune active to residual phase in the natural disease history of chronic hepatitis B. Recently, interleukin-27 has been reported to be associated with hepatic inflammation in hepatitis B infection. We aimed to evaluate the role of interleukin-27 in predicting spontaneous e seroconversion in chronic hepatitis B.

METHODS

A total of 142 treatment-naive hepatitis B patients with positive e antigen were recruited. Interleukin-27, hepatitis B viral DNA levels and liver function parameters, were measured on presentation. Patients who had spontaneous e seroconversion within 3 years of follow-up were compared with those without e seroconversion within the same period of time. Factors predictive of spontaneous e seroconversion were identified.

RESULTS

Of the 142 patients (M:F=80:62, median age: 31), 44 (31%) had spontaneous e seroconversion within 3 years of follow-up. Multivariate analyses revealed that younger age, lower viral DNA and lower interleukin-27 levels on presentation independently predicted spontaneous e seroconversion: the rate was significantly higher in patients aged <31 (OR: 11.022, 95% CI: 3.658-33.205; P<.001), viral DNA <5 log IU/mL (OR: 2.311, 95% CI: 1.049-5.091; P=.038) and interleukin-27 <67.3 pg/mL (OR: 3.276, 95% CI: 1.257-8.536; P=.015). Among patients with all these three favourable factors on presentation, 77% of them underwent spontaneous e seroconversion within 3 years.

CONCLUSIONS

Low interleukin-27 levels were associated with early e seroconversion. The combination of baseline interleukin-27 <67.3 pg/mL and viral DNA <5 log IU/mL in young patients was useful for predicting early spontaneous e seroconversion in treatment-naïve chronic hepatitis B patients.

Long-term real-world entecavir therapy in treatment-naïve hepatitis B patients: base-line hepatitis B virus DNA and hepatitis B surface antigen levels predict virologic response

BACKGROUND/AIMS

Entecavir is a potent nucleoside analogue with high efficacy and barrier for resistance. We aimed to investigate the long-term efficacy and viral resistance rate of entecavir and explore the factors associated with virologic response, including quantitative hepatitis B surface antigen (qHBsAg) levels.

METHODS

One thousand and nine treatment-naïve chronic hepatitis B (CHB) patients were evaluated for cumulative rates of virologic response, biochemical response, and entecavir mutations. The role of baseline qHBsAg for virologic response was assessed in 271 patients with qHBsAg prior to entecavir treatment.

RESULTS

The median duration of entecavir treatment was 26.5 months. The cumulative rate of virologic response at years 1, 3, and 5 were 79.0%, 95.6%, and 99.4%, respectively. The cumulative rate of entecavir resistance was 1.0% and 2.1% in years 3 and 5. Multivariate analysis identified baseline hepatitis B e antigen (HBeAg) negative status (p < 0.001) and lower hepatitis B virus (HBV) DNA (p < 0.001) as predictors of virologic response. Lower qHBsAg was an independent predictor of virologic response in patients with baseline qHBsAg. There were no serious adverse events during treatment.

CONCLUSIONS

Long-term entecavir treatment of nucleos(t)ide-naïve CHB patients was associated with an excellent virologic response and a low rate of entecavir-resistant mutations at 5 years. Baseline HBV DNA load, qHBsAg levels, and HBeAg status were predictors of virologic response during entecavir treatment.

A scoring model predicts hepatitis B e antigen seroconversion in chronic hepatitis B patients treated with nucleos(t)ide analogs: real-world clinical practice

AIM

This study developed and validated a non-invasive scoring model to predict 1-year hepatitis B e antigen (HBeAg) seroconversion in response to nucleos(t)ide analog (NA) treatment in NA-naïve patients with HBeAg-positive chronic hepatitis B (CHB).

METHODS

Baseline data from 1014 patients visiting the outpatient and inpatient clinics of Beijing Ditan Hospital, Capital Medical University, China between October 2008 and April 2015 were included. These patients received NAs for HBeAg-positive CHB. The patients were assigned randomly to the derivation (n=710) and validation (n=304) cohorts in a 7:3 ratio. A prediction scoring model was established based on univariate and multivariate Cox proportional hazards regression analyses to identify independent prediction factors. In the derivation cohort, the odds ratio of the predictors were converted to integer risk scores by rounding the quotient from dividing the odds ratio, and the final score was the sum of these values. The predictive accuracy of the scoring model was further assessed using Harrell's concordance index (C-index).

RESULTS

The 1-year cumulative HBeAg seroconversion rates were 11.83% and 8.55% in the derivation and validation cohorts, respectively. In the derivation cohort, baseline pretreatment alanine aminotransferase (ALT), gamma-glutamyl transpeptidase (GGT), globulin (GLO), and quantitative HBeAg (qHBeAg) levels were independently associated with HBeAg seroconversion and were included in the scoring system. The model had good discrimination in the derivation and validation cohorts (C-index=0.750, 95% confidence interval 0.694-0.806 and C-index=0.776, 95% confidence interval 0.698-0.855, respectively). The prediction scores ranged from 0 to 4; scores of 0-1 and 2-4 identified patients with lower and higher levels of HBeAg seroconversion, respectively. Kaplan-Meier analysis was used to determine the 1-year cumulative HBeAg seroconversion rates in the two groups (scores of 0-1 and 2-4) of the primary cohort, and log-rank tests revealed a significant difference (4.87% vs. 20.9%, p<0.0001).

CONCLUSIONS

The 1-year prediction scoring model based on baseline levels of ALT, GGT, GLO, and qHBeAg offered a reliable predictive value for the response to NA therapy in a Chinese cohort.

The role of quantitative hepatitis B surface antigen revisited

In the past 10years, there has been a lot of enthusiasm surrounding the use of serum hepatitis B surface antigen (HBsAg) quantification to predict disease activity and monitor treatment response in chronic hepatitis B. The measurement of HBsAg levels have been standardized in IU/ml, and nowadays it is almost a mandatory measurement due to the development of new antiviral treatments aiming at HBsAg seroclearance, i.e., functional cure of hepatitis B. Recently, there has been an improved understanding of the molecular virology of HBsAg, and particularly the relative roles of covalently closed circular DNA and integrated hepatitis B virus (HBV) DNA. This has shed new light on the interpretation of HBsAg levels in different phases of chronic hepatitis B. HBsAg level can assist the differentiation of immune tolerance and immune clearance in hepatitis B e antigen (HBeAg)-positive patients, and it can predict inactive disease and spontaneous HBsAg seroclearance in HBeAg-negative patients. The determination of HBsAg level is pivotal to individualize pegylated interferon (PegIFN) treatment; it is the key investigation to decide early termination of PegIFN among non-responders. Among patients treated by nucleos(t)ide analogues, responders tend to have dramatic reduction of HBsAg to low levels, which may be followed by HBsAg seroclearance. With newer data on combination treatment of PegIFN and nucleos(t)ide analogues as well as emerging new antiviral agents, HBsAg quantification is expected to become increasingly important to monitor and guide antiviral therapy for chronic hepatitis B.

Randomized phase II study of GS-4774 as a therapeutic vaccine in virally suppressed patients with chronic hepatitis B

BACKGROUND & AIMS

GS-4774 is a heat-inactivated, yeast-based, T-cell vaccine designed to elicit hepatitis B virus (HBV)-specific T-cell responses. We evaluated the safety, tolerability and efficacy of GS-4774 in patients with chronic HBV infection.

METHODS

In this phase II study, 178 patients with chronic HBV infection and no cirrhosis who were virally suppressed on an oral antiviral (OAV) for ⩾1year were randomized (1:2:2:2) to continue OAV alone or receive OAV plus GS-4774 2, 10, or 40 yeast units (YU) subcutaneously every 4weeks until week 20. OAV was continued for the remainder of the study. Efficacy was measured by decline in serum hepatitis B surface antigen (HBsAg) from baseline to week 24.

RESULTS

Baseline characteristics were similar across groups (mean age, 45-50years; male, 62-74%; Asian, 68-80%; hepatitis B e antigen (HBeAg)-positive, 24-26%; mean HBsAg, 2.5-3.1log10IU/ml). There were no significant differences between groups in mean HBsAg declines from baseline to week 24 or 48. Five HBeAg-positive patients receiving GS-4774 experienced HBeAg loss vs. none in the control group. Three GS-4774 40 YU-treated patients had HBsAg declines ⩾0.5log10IU/ml, but no patient experienced loss of serum HBsAg. No virologic breakthrough occurred. Injection site reactions were the most frequent adverse event (AE), and there were no treatment discontinuations.

CONCLUSIONS

GS-4774 was well tolerated, but did not provide significant reductions in serum HBsAg in virally suppressed patients with chronic hepatitis B. Efficacy of GS-4774 in treatment-naïve patients remains to be determined.

LAY SUMMARY

GS-4774 is a therapeutic vaccine designed to improve the immune response against hepatitis B virus (HBV) in patients who already have chronic infection with HBV. In this study, GS-4774 was safe and well tolerated in patients with chronic HBV infection receiving oral antiviral therapy, but did not result in a clinical benefit. Combination approaches with other agents, and evaluation in other populations of patients with HBV are ongoing to determine if GS-4774 might have a therapeutic benefit.

CLINICAL TRIAL REGISTRATION NUMBER

NCT01943799.

Virological and serological tools to optimize the management of patients with chronic hepatitis B

Molecular biology techniques are routinely used to diagnose and monitor treatment in patients with chronic hepatitis B (CHB). These tools can detect and quantify viral genomes and analyse their sequences to determine genotype. The increasing use of these tools to monitor patients has greatly improved the management of CHB infection by maximizing the potential for individualized treatment. HBV genotyping has become increasingly important and provides additional information to predict a response to therapy. More sensitive methods to determine HBV DNA levels are now available and the units of measurements have been standardized. HBsAg levels in serum have been shown to reflect active intrahepatic covalently closed circular DNA (cccDNA) and to have additional value in treatment decisions, especially as an on-treatment marker.

The predictive value of early indicators for HBeAg seroconversion in HBeAg-positive chronic hepatitis B patients with Telbivudine treatment for 104 weeks

PURPOSE

Through an observation on HBeAg-positive chronic hepatits B (CHB) patients in Telbivudine (LDT) treatment for 104 weeks, we tried to explore valuable early predictors for HBeAg seroconversion during the treatment.

MATERIALS AND METHODS

A prospective study lasting for 104 weeks was conducted, and the patients enrolled were administered with LDT 600 mg daily. The medical evaluation went every 12 weeks, then the age distribution, baseline ALT level, early HBVDNA, HBsAg and HBeAg levels at baseline, week 12 and 24 as well as the decrease of the three indicators at week 12 and 24 were analyzed for their predictive values for HBeAg seroconversion at week 104.

RESULT

Thirty-three patients finished the observation. All patients got ALT normalisation and 28 patients (84.84%) got complete virological response (HBV DNA<291 copies/ml) at week 104. Poor virological response and virologic breakthrough was observed in two (6.06%) and three patients (9.09%), respectively. Nine patients (27.27%) got HBeAg seroconversion. HBeAg levels and its decrease levels at week 12 and 24 showed significant differences between patients with and without HBeAg seroconversion. And the HBsAg levels at week 12 and 24 showed tendencies of significant differences in two groups. HBeAg level at week 24 was confirmed related to its longer term seroconversion in regression analysis. The patients with HBeAg level<2.1 S/CO at week 24 would be more possible to get HBeAg seroconversion at week 104, with sensitivity, specificity, positive and negative predictive value of 95.83%, 88.89%, 95.8% and 88.9%, respectively.

CONCLUSION

Good efficacy of long-term LDT treatment in biological and virological response and its advantage in serological response was confirmed again in our study. The HBeAg level at week 24 showed significant value in prediction for HBeAg seroconversion at week 104 compared to other serological markers in the early period.

Quantification of HBsAg in nucleos(t)ide-naïve patients treated for chronic hepatitis B with entecavir with or without tenofovir in the BE-LOW study

BACKGROUND & AIMS

Serum hepatitis B surface antigen (HBsAg) levels may predict treatment response in chronic hepatitis B (CHB). We examined the association between changes in HBsAg levels and response to treatment in the BE-LOW study.

METHODS

In this open-label, multicentre study, 379 nucleos(t)ide-naïve patients with hepatitis B e antigen (HBeAg)-positive or -negative CHB were randomized and treated with daily entecavir 0.5mg alone (n = 182) or combined with tenofovir 300 mg (n = 197) for 100 weeks. HBsAg levels were quantified (Abbott Architect assay) at baseline and at Weeks 12, 48, and 96.

RESULTS

Mean baseline HBsAg levels were comparable across subgroups by baseline alanine aminotransferase (ALT), genotype, age, and treatment type, but were higher in HBeAg-positive than in HBeAg-negative patients. Mean HBsAg changes from baseline at Weeks 12, 48, and 96 were more pronounced in HBeAg-positive than in HBeAg-negative patients, in patients with genotype A than in those with genotypes C or D, and in patients with elevated baseline ALT, but were similar between treatment groups and between patients of different age categories. Mean HBsAg changes over 96 weeks were also comparable in patients with or without HBV DNA <50 IU/ml at Week 96, but among patients that were HBeAg-positive at baseline, changes were greater for those with Week 96 HBeAg loss than for those without.

CONCLUSIONS

In this population of HBeAg-positive and HBeAg-negative, nucleos(t)ide-naïve patients, a greater HBsAg decline through 96 treatment weeks was observed in HBeAg-positive patients, especially in those who achieved subsequent HBeAg loss.

HBsAg quantification to optimize treatment monitoring in chronic hepatitis B patients

Hepatitis B surface antigen (HBsAg) levels in serum have been shown to reflect active intrahepatic covalently closed circular DNA (cccDNA) and to have additional value as a marker of on-treatment efficacy. In the past few years, immunoassays to quantify HBsAg have been developed to monitor HBsAg kinetics during treatment. Although HBsAg quantification cannot replace HBV DNA measurement in clinical practice, the combined use of HBsAg quantification and HBV DNA measurements could help predict treatment outcome. One of the most important results of the studies in this new marker is that a decline in HBsAg titres during pegylated-interferon (PEG-IFN) treatment is a strong predictor of response so that a 'week 12 stopping rule' could be established for both Hepatitis B e antigen (HBeAg)-positive and HBeAg-negative patients. However, the positive predictive value (PPV) for a sustained viral response (SVR) remains low. The role of HBsAg measurements during nucloes(t)ides analogue (NAs) treatment is unclear. It may be a useful marker for stopping NAs by limiting the chance of relapse or for add-on strategies. Monitoring serum HBsAg levels in chronic hepatitis B (CHB) patients during treatment may provide significant complementary information to HBV DNA measurements.

Serum hepatitis B surface antigen levels predict treatment response to nucleos(t)ide analogues

Quantification of hepatitis B surface antigen (HBsAg) has been suggested to be helpful in the management of chronic hepatitis B (CHB) patients. Nucleos(t)ide analogs (NAs) are the therapy of choice for CHB and are used in the majority of CHB patients. NAs are able to induce hepatitis B virus (HBV) viral suppression, normalization of alanine aminotransferase (ALT) levels, and improvement in liver histology. Automated quantitative assays for serum HBsAg have recently become available, facilitating standardized quantification of serum HBsAg. This has led to increased interest in the clinical application of quantitative serum HBsAg for predicting therapeutic response to NAs. Recent studies have shown that a decline in serum HBsAg levels in patients receiving peginterferon may signal successful induction of immune control over HBV, and can therefore be used to predict therapeutic response. NA treatment typically induces a less rapid decline in HBsAg than interferon treatment; it has been estimated that full HBsAg clearance can require decades of NA treatment. However, a rapid HBsAg decline during NA therapy may identify patients who will show clearance of HBsAg. Currently, there is no consensus on the clinical utility of serum HBsAg monitoring for evaluating patient responses to NA therapy. This review focuses on recent findings regarding the potential application of HBsAg quantification in the management of CHB patients receiving NA therapy.

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.

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.

Is HBsAg quantification ready, for prime time?

Despite the availability of an efficient hepatitis B vaccine, approximately 240 million individuals are chronically infected with hepatitis B virus worldwide. One-fourth of hepatitis B surface antigen (HBsAg)-positive patients will develop complications, such as cirrhosis or hepatocellular carcinoma, both major causes of liver-related deaths. Antiviral therapies, such as pegylated interferon alpha or nucleoside/nucleotide analogues, are effective in suppressing HBV DNA and reducing the subsequent risk of fibrosis progression, cirrhosis and hepatocellular carcinoma. HBsAg has proven to be a steady, reliable marker of chronic HBV carriage that can also be used to predict clinical outcomes. Three commercial enzyme immunoassays are now available for HBsAg quantification. A number of recent studies have shown clinical utility of HBsAg quantification in combination with HBV DNA levels to identify inactive carriers who need antiviral therapy and in interferon treated-patients in order to predict the virological response to pegylated interferon alpha.

HBsAg quantification to predict natural history and treatment outcome in chronic hepatitis B patients

There is a growing interest in serum HBsAg quantification (qHbsAg). HBsAg titers are negatively correlated with liver fibrosis in HBeAg(+) patients. In HBeAg(-) HBsAg level <1000 IU/ml and HBV-DNA titer <2000 IU/ml accurately identify inactive carriers. During PEG-IFN treatment qHBsAg identifies patients with no benefit from therapy at week 12, allowing stopping or switched- "week 12 stopping rule". During nucleos(t)ide analogues the role of qHBsAg need to be clarified. In clinical practice qHBsAg is a simple and reproducible tool that may be used in association with HBV-DNA to classify patients during the natural history of HBV and to monitor therapy.

Long-term hepatitis B surface antigen (HBsAg) kinetics during nucleoside/nucleotide analogue therapy: finite treatment duration unlikely

BACKGROUND & AIMS

Information regarding long-term HBsAg kinetics during treatment with nucleoside/nucleotide analogues is limited. The aim of the present study was to assess whether finite nucleoside/nucleotide analogue treatment duration could be envisaged during the patient's lifetime.

METHODS

Patients with chronic hepatitis B receiving different schedules of nucleoside/nucleotide analogues were followed for a median duration of 102 months, i.e., 8.5 years (interquartile range: 88-119 months). Long-term HBV DNA and HBsAg level kinetics were modeled in order to estimate time to clear HBsAg during therapy in patients with undetectable HBV DNA.

RESULTS

Antiviral therapy was associated with a slow but consistent reduction in the level of HBsAg in most of the patients. Three patterns of HBsAg level declines were identified: decline during both the detectable and undetectable HBV DNA phases; decline during the HBV DNA detectable period only; decline during the HBV DNA undetectable period only. The mean HBsAg titer at the time when HBV DNA became undetectable was 3.29 ± 0.49 Log₁₀ international units (IU)/ml, and the mean slope was -0.007 ± 0.007 Log₁₀ IU/month, i.e., an average decline of 0.084 Log₁₀ IU/year. The corresponding calculated median number of years needed to clear HBsAg was 52.2 years (interquartile range: 30.8-142.7).

CONCLUSIONS

This study, based on the very long-term follow-up of patients with chronic hepatitis B treated with potent nucleoside/nucleotide analogues, shows that HBsAg clearance is unlikely to occur during the patient's lifetime, even if HBV replication is well controlled. Thus, lifetime therapy is required in the vast majority of HBV-infected patients.

Kinetics and prediction of HBsAg loss during therapy with analogues in patients affected by chronic hepatitis B HBeAg negative and genotype D

BACKGROUND & AIMS

In patients affected by chronic hepatitis because of HBV infection, long-term suppressive therapy with nucleos(t)ides analogues in the HBeAg- patients has shown low effects on HBsAg titre (qHBsAg) decrease, and HBsAg loss is difficult to achieve. Thus, in this type of patients the main goals of antiviral therapy is the suppression of HBV-DNA and ALT normalization.

METHODS

We retrospectively evaluated different qHBsAg kinetics in 134 treatment-naïve patients having the same characteristics: HBeAg-, infection sustained by HBV genotype D and persistently undetectable HBV-DNA. Patients were treated with NAs therapy (lamivudine, adefovir, telbivudine, entecavir and tenofovir) for at least 2 years. qHBsAg was performed every 6 months.

RESULTS

Our results showed a significantly greater qHBsAg decline after 2 years in patients treated with tenofovir (0.45 logIU/ml) than in patients treated with telbivudine (0.12 logIU/ml; P < 0.001). The calculated expected time to HBsAg loss was shorter in the tenofovir group than in the telbivudine group (nearly 17 vs 63 years, P < 0.001).

CONCLUSIONS

HBeAg negative patients infected by HBV genotype D should be treated with more potent NAs such as entecavir or tenofovir to obtain a significant qHBsAg decrease, but the achievement of HBsAg loss seems to require almost two decades of therapy.

Quantitative hepatitis B surface antigen analysis in hepatitis B e antigen-positive nucleoside-naive patients treated with entecavir

BACKGROUND

Entecavir is a potent nucleoside analogue for treating chronic hepatitis B (CHB). Quantitative hepatitis B surface antigen (qHBsAg) levels are predictive of response to interferon-α in CHB treatment; however, the clinical utility of qHBsAg in nucleoside/nucleotide analogue-based CHB therapy is not fully characterized. This study assessed changes in qHBsAg in patients treated with entecavir in the Phase III study ETV-022.

METHODS

This retrospective post hoc analysis included nucleoside/nucleotide-naive, hepatitis B e antigen (HBeAg)-positive patients receiving entecavir (0.5 mg daily) in ETV-022 who had samples available for qHBsAg analysis through week 48. qHBsAg, HBV DNA and alanine aminotransferase levels were assessed for the overall patient cohort, for cohorts with or without HBeAg loss or HBsAg loss by week 48, and by HBV genotype.

RESULTS

Overall, 95 patients from ETV-022 had available samples for qHBsAg analysis through week 48. In all cohorts, 48 weeks of entecavir therapy resulted in effective HBV DNA suppression. In the overall cohort, qHBsAg declined by -0.92 log10 IU/ml through week 48. The decline in qHBsAg was more pronounced in patients with subsequent HBeAg loss or HBsAg loss, and in patients infected with HBV genotype D or A. On-treatment qHBsAg changes did not correlate with changes in HBV DNA; no on-treatment or baseline factor was found to be predictive of HBeAg loss or HBsAg loss.

CONCLUSIONS

Through 48 weeks of entecavir therapy, qHBsAg declined predominantly in those patients who achieved seroclearance of HBeAg or HBsAg. However, unlike with interferon-α-based therapy, early qHBsAg decline was not predictive of serological response at year 1 of entecavir treatment.

Association of on-treatment serum hepatitis B surface antigen level with sustained virological response to nucleos(t)ide analog in patients with hepatitis B e-antigen positive chronic hepatitis B

AIM

  This study evaluated the on-treatment serum hepatitis B surface antigen (HBsAg) level during nucleos(t)ide analog (NUC) therapy and the correlation with off-treatment sustained virological response (SVR).

METHODS

  Fifty-one consecutive patients with hepatitis B e-antigen (HBeAg) positive chronic hepatitis B who achieved HBeAg loss/seroconversion after NUC therapy and completed 12 months or more of additional therapy were included. Serum HBsAg and hepatitis B virus (HBV) DNA levels were determined at baseline, 3, 6, 9 and 12 months, and at the end of treatment. SVR was defined as HBV DNA levels of less than 10 000 copies/mL until 6 or 12 months off-treatment without reappearance of HBeAg.

RESULTS

  Twenty-two (43.1%) and 13 (25.5%) patients maintained SVR at 6 and 12 months off-treatment, respectively. In univariate analyses, a decline of HBsAg of 0.5 log(10)  IU/mL or less at 6 months (P = 0.006) and 12 months (P = 0.013), the mean change in HBsAg level at 6 months (P = 0.024), and lamivudine or entecavir treatment (P = 0.019) were significant predictive factors for SVR at 6 months off-treatment. A decline of HBsAg of 0.5 log(10)  IU/mL or less at 6 months and lamivudine or entecavir treatment were independent factors on multivariate analyses (odds ratio [OR], 16.67; 95% confidence interval [CI], 1.86-142.86 [P = 0.012]; and OR, 14.83; 95% CI, 1.18-185.73 [P = 0.036]; respectively).

CONCLUSION

  On-treatment serum HBsAg level predicted early off-treatment SVR to NUC therapy in patients infected with genotype C.

The role of HBsAg quantification for monitoring natural history and treatment outcome

Since its discovery by Blumberg in 1965, the hepatitis B virus antigen (HBsAg) is used as the fingerprint of hepatitis B infection. The HBsAg level is a reflection of the transcriptional activity of cccDNA. It is an important marker that not only indicates active hepatitis B infection but can also predict clinical and treatment outcomes. Assays for HBsAg quantification are fully automated and have high output. HBsAg titres are higher in HBe antigen (HBeAg)(+) than in HBeAg(-) patients and are negatively correlated with liver fibrosis in HBeAg(+) patients. In HBeAg(-) chronic hepatitis B, an HBsAg level <1000 IU/ml and an HBV DNA titre <2000 IU/ml accurately identify inactive carriers. During PEG-IFN treatment, HBsAg quantification is used to identify patients who will not benefit from therapy as early as week 12 on therapy, so that treatment may be stopped or switched- 'week 12 stopping rule'. With nucleos(t)ide analogues (NA), the role of HBsAg quantification must be clarified. Several studies show that baseline and on-treatment HBsAg levels might identify patients that can be treated with no subsequent risk of reactivation. In clinical practice, HBsAg quantification is a simple and reproducible tool that can be used in association with HBV DNA to classify patients during the natural history of HBV and to monitor therapy.

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.

Comparison between Elecsys HBsAg II and architect HBsAg QT assays for quantification of hepatitis B surface antigen among patients coinfected with HIV and hepatitis B virus

Hepatitis B surface antigen (HBsAg) quantification has been steadily gaining interest as a clinical marker of therapeutic efficacy, for which two commercial assays are currently available: Architect HBsAg QT (Architect) and Elecsys HBsAg II (Elecsys). HBsAg quantification was evaluated using both assays in 126 human immunodeficiency virus (HIV) and hepatitis B virus (HBV)-coinfected patients initiating treatment with tenofovir dipivoxil fumarate. Linear regression and correlation were used to establish the relationship between the two methods. Bland-Altman analysis was performed to determine mean between-assay difference and limits of agreement (LOA) (±2 standard deviations [SD]) both overall and stratified on HBV (hepatitis B envelope antigen [HBeAg] status, replication, genotype, HBV mutants) or HIV (CD4(+) cell count) cofactors. There was a significant correlation between Elecsys and Architect assays (correlation coefficient, r = 0.959; P < 0.001). HBsAg quantification using the Elecsys assay was on average 0.200 log(10) IU/ml (LOA, -0.500, 0.800) higher than that using Architect, which was consistent across levels of CD4(+) cell count, presence of precore and YMDD mutations, and HBeAg status. A slightly larger mean between-assay difference was observed with genotypes A and G (0.196 and 0.201, respectively) versus HBV genotypes D and E (0.036 and 0.030, respectively). Mutations on the S region at position s120/s145 were the only determinant in which the mean between-assay difference in HBsAg quantification was lower than the null value (-0.078). In conclusion, the Elecsys assay, with automatic on-board dilution, is capable of quantifying serum HBsAg levels in HIV-HBV-coinfected patients, with very high correlation with the Architect assay.