Serum hepatitis B surface antigen monitoring in long-term lamivudine-treated hepatitis B virus patients

ARB-1740, a RNA Interference Therapeutic for Chronic Hepatitis B Infection

Current approved nucleoside analogue treatments for chronic hepatitis B virus (HBV) infection are effective at controlling viral titer but are not curative and have minimal impact on the production of viral proteins such as surface antigen (HBsAg), the HBV envelope protein believed to play a role in maintaining the immune tolerant state required for viral persistence. Novel agents are needed to effect HBV cure, and reduction of HBV antigenemia may potentiate activation of effective and long-lasting host immune control. ARB-1740 is a clinical stage RNA interference agent composed of three siRNAs delivered using lipid nanoparticle technology. In a number of cell and animal models of HBV, ARB-1740 caused HBV RNA reduction, leading to inhibition of multiple elements of the viral life cycle including HBsAg, HBeAg, and HBcAg viral proteins as well as replication marker HBV DNA. ARB-1740 demonstrated pan-genotypic activity in vitro and in vivo, targeting three distinct highly conserved regions of the HBV genome, and effectively inhibited replication of nucleoside analogue-resistant HBV variants. Combination of ARB-1740 with a capsid inhibitor and pegylated interferon-alpha led to greater liver HBsAg reduction which correlated with more robust induction of innate immune responses in a human chimeric mouse model of HBV. The preclinical profile of ARB-1740 demonstrates the promise of RNA interference and HBV antigen reduction in treatment strategies driving toward a cure for HBV.

Long-Term Follow-up and Quantitative Hepatitis B Surface Antigen Monitoring in North American Chronic HBV Carriers

INTRODUCTION

Quantitative hepatitis B surface antigen (qHBsAg) combined with HBV DNA may be useful for predicting chronic hepatitis B (CHB) activity and nucleoside analogue (NA) response.

MATERIAL AND METHODS

In this retrospective cohort study we evaluated qHBsAg levels according to CHB disease phase and among patients on treatment. Random effect logistic regression analysis was used to analyze qHBsAg change with time in the NA-treated cohort.

RESULTS

545 CHB carriers [56% M, median age 48 y (IQR 38-59), 73% Asian] had qHBsAg testing. In the untreated group (44%), 8% were classified as immune tolerant, 10% immune clearance, 40% inactive, and 43% had HBeAg- CHB and the median HBsAg levels were 4.6 (IQR 3.4-4.9), 4.0 (IQR 3.4-4.5), 2.9 (IQR 1.4-3.8), and 3.2 log IU/mL (IQR 2.6-4.0), respectively; p < 0.001. In the NA-treated group (28% entecavir, 68% tenofovir, 4% lamivudine), no significant change in qHBsAg levels occured with time. However, 19% of patients on long-term NA had sustained qHBsAg < 2 log10 IU/mL.

CONCLUSION

qHBsAg titers were associated with CHB phase and remained stable in those on long-term NA. A significant number of treated patients had low-level qHBsAg, of which some may be eligible for treatment discontinuation without risk of flare.

Hepatitis B s antigen kinetics during treatment with nucleos(t)ides analogues in patients with hepatitis B e antigen-negative chronic hepatitis B

BACKGROUND/AIMS

Serum hepatitis B s antigen (HBsAg) levels might be used as a predictor of virological breakthrough or of sustained off-treatment virological response in hepatitis B e antigen (HBeAg)-negative chronic hepatitis B (CHB) patients. We evaluated the changes of HBsAg in those patients under nucleos(t)ide analogue(s) [NA(s)] therapy for ≥12 months.

METHODS

We included 99 HBeAg-negative CHB patients treated with low-genetic barrier NA(s) for a mean of 66 months (lamivudine: 66, adefovir: 6, lamivudine plus adefovir: 11 and telbivudine: 16) and 86 HBeAg-negative CHB patients treated under entecavir or tenofovir for a mean of 30 months as the comparison group.

RESULTS

Compared to baseline, HBsAg levels decreased by a median of 162, 1525, 943, 1545, 2163 and 3859 IU/mL at 6, 12, 24, 36, 48 and 60 months of therapy with low-genetic barrier NA(s) respectively. The 6-, 12-, 24-, 36-, 48- and 60-month cumulative rates of HBsAg<100 IU/mL were 2%, 3%, 3%, 5%, 5% and 5%, and <1000 IU/mL 6%, 9%, 15%, 19%, 24% and 61% respectively. Baseline HBsAg levels were the only significant variable associated with the time to HBsAg drop <1000 IU/mL. HBsAg loss occurred in 3.0% of patients. The high-genetic barrier NAs were not found to offer a greater or faster HBsAg decline.

CONCLUSIONS

In HBeAg-negative CHB patients, long-term therapy with low-genetic barrier NA(s) decreases serum HBsAg levels, but the rate of decline is slow. Lower baseline HBsAg levels are significantly associated with on-therapy HBsAg drop <1000 IU/mL. Serum HBsAg decline is similar during therapy with low- or high-genetic barrier NAs.

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.

High treatment modification rates with lamivudine therapy in HBV-infected patients with low baseline viremia and early virological response: A multicenter study

OBJECTIVE

Low baseline viremia and an early treatment response predict the best outcomes in hepatitis B virus (HBV)-infected patients treated with nucleoside analogues with low barriers to resistance. The aim of this study was to assess the long-term results and effectiveness of lamivudine in patients with low baseline viremia and early virological treatment response.

METHODS

In this multicenter, real-life setting study, 111 antiviral-naive patients with low baseline viremia (HBV DNA <10(7) copies/mL) plus an early virological response (HBV DNA <300 copies/mL at week 24) treated with lamivudine were enrolled. The primary end-point was treatment failure, defined as the re-emergence of detectable viremia or at least a 1 log increase in HBV DNA, resulting in a titer of ≥ 300 copies/mL with lamivudine treatment after week 24, which required treatment modification.

RESULTS

Altogether 111 patients, including 78 non-cirrhotic and 33 cirrhotic patients, were included in the study. Treatment failure occurred in 30.8% of the non-cirrhotic patients over a median follow-up period of 32.5 months, and the 1-, 2-, 3-, 4- and 5-year treatment failure rates were 6.5%, 14.0%, 31.4%, 39.6% and 43.1%, respectively. Treatment failure occurred in 28.8% of the whole group. There were no differences between the cirrhotic and non-cirrhotic patients.

CONCLUSIONS

Lamivudine treatment had a high treatment modification rate in patients with low baseline viremia and early virological response over a long-term follow-up in a real-life setting. The pretreatment and on-treatment favorable characteristics found in the studies with telbivudine appeared to be inapplicable to lamivudine.

Potential mechanisms of hepatitis B virus induced liver injury

Chronic active hepatitis (CAH) is acknowledged as an imperative risk factor for the development of liver injury and hepatocellular carcinoma. The histological end points of CAH are chronic inflammation, fibrosis and cirrhosis which are coupled with increased DNA synthesis in cirrhotic vs healthy normal livers. The potential mechanism involved in CAH includes a combination of processes leading to liver cell necrosis, inflammation and cytokine production and liver scaring (fibrosis). The severity of liver damage is regulated by Hepatitis B virus genotypes and viral components. The viral and cellular factors that contribute to liver injury are discussed in this article. Liver injury caused by the viral infection affects many cellular processes such as cell signaling, apoptosis, transcription, DNA repair which in turn induce radical effects on cell survival, growth, transformation and maintenance. The consequence of such perturbations is resulted in the alteration of bile secretion, gluconeogenesis, glycolysis, detoxification and metabolism of carbohydrates, proteins, fat and balance of nutrients. The identification and elucidation of the molecular pathways perturbed by the viral proteins are important in order to design effective strategy to minimize and/or restore the hepatocytes injury.

Clinical utility of hepatitis B surface antigen levels during the natural history and treatment of chronic hepatitis B infection

Introduction

Hepatitis B surface antigen (HBsAg) level quantitation may be helpful for understanding the natural history of the disease and its response to treatment.

Aim

To determine the serum HBsAg levels during the different phases of chronic hepatitis B (CHB) infection and HBsAg levels of patients who are on treatment with oral antiviral drugs.

Material and methods

Patients were categorized in four groups: 9 patients in the immune clearance (IC) phase, 46 patients in the inactive carrier (INC) phase, 25 patients in the reactivated HBeAg negative disease (END) phase and 60 HBeAg negative patients who were on treatment with oral antiviral drugs. HBsAg levels were compared between all groups. HBsAg and HBV DNA levels were compared in three phases of HBV infection. Patients on treatment were divided into two groups, taking lamivudine (L) and taking tenofovir (T). HBsAg levels were compared between END, L and T groups.

Results

The HBsAg levels were different between each phase of CHB (p < 0.0001). HBsAg levels were highest in the IC phase and lowest in the INC phase. The HBsAg/HBV DNA ratio was significantly higher in the INC phase than the END and IC phases (p < 0.0001). HBsAg levels were higher in the END phase than the INC phase (p < 0.0001) and higher than the treatment group (p = 0.007). The HBsAg levels had a good correlation with HBV DNA in the natural course of CHB (r = 0.72, p < 0.0001). HBsAg levels were higher in the END group than the L and T groups (p < 0.05). HBsAg levels were higher in the L than the T group (p < 0.05).

Conclusions

This study demonstrates that HBsAg levels vary during the natural history of chronic hepatitis B infection. Also, the monitoring of HBsAg levels may help us to determine the best management strategy and to decide future treatment algorithms.

Pretreatment HBsAg level and an early decrease in MELD score predict prognosis to lamivudine treatment for HBeAg-negative acute-on-chronic liver failure

BACKGROUND AND OBJECTIVE

Few data are available about the predictability of HBsAg quantification to nucleos(t)ide analogues treatment in acute-on-chronic liver failure (ACLF). The aim of this study was to investigate HBsAg level combined with the model for end-stage liver disease (MELD) score for predicting prognosis to lamivudine monotherapy in HBeAg-negative ACLF.

METHODS

Fifty-seven nucleoside-naïve patients with HBeAg-negative ACLF were treated with 100mg of lamivudine daily. Serum levels of HBsAg, HBV DNA and biochemical items were detected at baseline, before death (patients died within 3months) or month 3 meanwhile MELD score was calculated. Dynamic of these items and 3-month mortality were analyzed.

RESULTS

HBV DNA level significantly decreased while HBsAg level did not after treatment. Twenty-six patients died within 3months and the others survived. Regardless pre- or post-treatment, HBsAg level of survival group was significantly higher than that of dead group meanwhile MELD scores of the former were significantly lower than those of the latter (all P<0.05). Post-treatment MELD scores of 32 patients with pretreatment HBsAg levels above 4000 COI were significantly lower than those of 25 patients below to it (t=-2.116, P=0.044) and the 3-month mortality of the formers was significantly lower than that of the latter (34.3% [11/32] vs 64.0% [16/25], χ(2)=4.941, P=0.026).

CONCLUSIONS

In HBeAg-negative ACLF, patient with higher pretreatment HBsAg levels and early decrease in MELD score has lower 3-month mortality than one without it during lamivudine monotherapy.

HBsAg quantification: useful for monitoring natural history and treatment outcome

The template of hepatitis B virus transcription, the covalently closed circular DNA (cccDNA), plays a key role in the life cycle of the virus and permits the persistence of infection. It has been suggested that hepatitis B surface antigen (HBsAg) quantification reflects the concentration of cccDNA in the liver. In hepatitis B e antigen (HBeAg) positive chronic hepatitis B, HBsAg levels are higherduring the immune tolerance phase than during the immune clearance phase. During the natural history of chronic hepatitis B, serum HBsAg declines progressively from the immune-tolerant to the low replicative phase. In HBeAg negative patients, the combination of low hepatitis B virus (HBV) DNA (<2000 IU/ml) and low HBsAg levels (<1000 IU/ml) can predict inactive carrier status, low risk of hepatocellular carcinoma, and the probability of HBsAg loss. HBsAg in combination with HBV DNA predicts the outcome of Peg-Interferon therapy: An absence of decline at week 12 is a good predictor of non-response and to stop therapy. Any decline at week 24, suggests that therapy should be continued to 48 weeks. Although the decrease in HBsAg decline slow with nucleos(t)ide analogue therapy, a rapid decline can predict future HBsAg seroclearance. A level <100 IU/ml during six consecutive months could be a marker of a sustained response after treatment cessation.

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.

Serum hepatitis B surface antigen quantification as a useful assessment for significant fibrosis in hepatitis B e antigen-positive hepatitis B virus carriers

BACKGROUND AND AIMS

The role of serum quantitative hepatitis B surface antigen (qHBsAg) in identifying hepatitis B virus (HBV) carriers with significant fibrosis is unknown. This study aims to evaluate the diagnostic value of qHBsAg for hepatic fibrosis in hepatitis B e antigen (HBeAg)-positive HBV carriers.

METHODS

Consecutive biopsy-proven HBeAg-positive HBV carriers were prospectively recruited in our center from 2009 to 2011 and were randomly divided into training and validation set. Area under receiver-operator curve (AUC) was used to determine the diagnostic accuracy of simple tests for significant fibrosis (Scheuer stage, F ≥ 2).

RESULTS

Overall, a total of 197 eligible patients (median age 31 years; 149 males) were enrolled. The median qHBsAg was 4.20 (log10 IU/mL). Significant fibrosis was confirmed in 112 (56.9%) patients. By logistical regression analysis, qHBsAg and γ-glutamyl transpeptidase were identified as predictors for significant fibrosis in training set (n = 124). Thus, qHBsAg index and γ-glutamyl transpeptidase to qHBsAg ratio (GqHBsR) were selected for the subsequent analysis. In the training set, an AUC of 0.762, 0.826, 0.749, and 0.771 was observed for qHBsAg index, GqHBsR, FIB-4, and aspartate aminotransferase to platelet ratio index, respectively (all P < 0.05). GqHBsR yielded a higher AUC than aspartate aminotransferase to platelet ratio index and FIB-4 (both P < 0.05). Using the optimal cut-off of 7.78, GqHBsR showed a sensitivity of 78.9% and a specificity of 73.6%. About 80% of liver biopsy could be avoided in the entire cohort.

CONCLUSIONS

Serum qHBsAg-based simple tests, especially GqHBsR, can accurately and specifically identify significant fibrosis in treatment-naïve HBeAg-positive HBV carriers.

Reduction of hepatitis B surface antigen levels and hepatitis B surface antigen seroclearance in chronic hepatitis B patients receiving 10 years of nucleoside analogue therapy

The profile and clinical significance of serum hepatitis B surface antigen (HBsAg) levels during long-term nucleoside analogue (NA) therapy in chronic hepatitis B (CHB) is undetermined. From 1994 to 2002, 322 Chinese CHB patients were started on lamivudine in our center. Patients were recruited if they were continuously treated with lamivudine for at least 10 years and maintained favorable virologic responses throughout therapy (HBV DNA <2,000 IU/mL). HBsAg and HBV DNA levels were measured serially, and the predictability of HBsAg kinetics in determining NA-related HBsAg seroclearance was determined. Seventy patients were recruited, of which 43 (61.4%) were hepatitis B e antigen (HBeAg)-positive. Fifty-two (74.3%) patients had undetectable viremia (HBV DNA <20 IU/mL) during therapy. Fifteen (21.4%) patients were followed up for 15 years. The median rate of HBsAg reduction was 0.104 log IU/mL/year, with no significant difference found when comparing patients who were HBeAg-positive versus HBeAg-negative, were genotype B versus C, and had detectable versus undetectable viremia during therapy (all P > 0.05). Seven (10%) patients achieved HBsAg seroclearance, and when compared with the remaining 63 patients, had significantly lower median baseline HBsAg levels (P = 0.012) and a greater median rate of HBsAg reduction (P < 0.001). Baseline HBsAg levels and the rate of HBsAg reduction achieved an area under the receiver operating characteristic curve of 0.860 (P = 0.004; 95% confidence interval [CI], 0.742-0.978) and 0.794 (P = 0.018; 95% CI, 0.608-0.979), respectively. Baseline HBsAg <1,000 IU/mL and on-treatment reduction of HBsAg >0.166 log IU/mL/year were optimal cutoff levels in predicting subsequent HBsAg seroclearance (negative predictive values, 98.1% and 97.8%, respectively).

CONCLUSION

Low baseline HBsAg levels and greater rate of HBsAg reduction achieved high predictive values for predicting HBsAg seroclearance, strengthening the prognostic role of HBsAg measurements during NA therapy.

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.

Efficacy and Safety of Telbivudine Compared to Entecavir Among HBeAg+ Chronic Hepatitis B Patients: a Meta-Analysis Study

BACKGROUND

Hepatitis B virus (HBV) infection is a serious global health problem that is associated with huge social and economic costs. Early antiviral drugs, such as interferon-α2b, peginterferon-α2a, lamivudine, and adefovir, all have their limitations (such as low responses or safety concerns) in clinical application. Telbivudine and entecavir are two of the latest nucleotide drugs and both have been shown to have potent viral suppression. However, in patients with hepatitis B e antigen (HBeAg)-positive chronic hepatitis B (CHB), inconsistent results have been generated for efficacy between telbivudine and entecavir. Therefore, evidence-based medical data are required to compare the efficacies, in terms of virological and biochemical responses, and safety between telbivudine and entecavir.

OBJECTIVES

We aimed to compare the early antiviral efficacy and safety of telbivudine and entecavir in the treatment of patients with hepatitis B e antigen (HBeAg)-positive chronic hepatitis B (CHB).

PATIENTS AND METHODS

A search for relevant randomized controlled trials (RCTs) on HBeAg-positive CHB patients treated with telbivudine and entecavir for 24 or 52 weeks, published before December 2011, was performed. Primary efficacy endpoint was the cumulative rate of undetectable HBV DNA, and secondary efficacy endpoints included rates of alanine aminotransferase (ALT) normalization, HBeAg disappearance, HBeAg seroconversion and adverse events. Meta-analysis was performed using the Review Manager v5.1.4 software package. We assessed the pooled risk ratios (RRs) and 95% confidence intervals (CIs) using the fixed-or random-effects model.

RESULTS

Six randomized controlled trials (RCTs) involving 555 patients were included. Telbivudine was associated with significantly higher rates of HBeAg disappearance (RR = 1.46, 95% CI: 1.11 - 1.91) and HBeAg seroconversion (RR = 1.76, 95%CI: 1.25-2.48) than entecavir, but had higher adverse events (RR = 2.11, 95%CI: 1.23 - 3.60), compared with entecavir. There was no difference between telbivudine and entecavir in the rate of cumulative undetectable HBV DNA (RR = 0.99, 95% CI: 0.90 - 1.10) and ALT normalization (RR = 0.93, 95% CI: 0.85 - 1.00).

CONCLUSIONS

Telbivudine is associated with significantly higher rates of HBeAg disappearance and HBeAg seroconversion than entecavir, whereas entecavir is superior to telbivudine in safety. Both drugs have similar efficacy on rates of cumulative undetectable HBV DNA and ALT normalization.

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.

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.

Hepatitis B surface antigen could contribute to the immunopathogenesis of hepatitis B virus infection

Various findings concerning the clinical significance of quantitative changes in hepatitis B surface antigen (HBsAg) during the acute and chronic phase of hepatitis B virus (HBV) infection have been reported. In addition to being a biomarker of HBV-replication activity, it has been reported that HBsAg could contribute to the immunopathogenesis of HBV persistent infection. Moreover, HBsAg could become an attractive target for immune therapy, since the cellular and humeral immune response against HBsAg might be able to control the HBV replication and life cycle. However, several reports have described the immune suppressive function of HBsAg. HBsAg might suppress monocytes, dendritic cells (DCs), natural killer (NK), and natural killer T (NK-T) cells by direct interaction. On the other hand, cytotoxic T lymphocytes (CTLs) and helper T (Th) cells were exhausted by high amounts of HBsAg. In this paper, we focused on the immunological aspects of HBsAg, since better understanding of the interaction between HBsAg and immune cells could contribute to the development of an immune therapy as well as a biomarker of the state of HBV persistent infection.

HBV DNA suppression and HBsAg clearance in HBeAg negative chronic hepatitis B patients on lamivudine therapy for over 5 years

BACKGROUND & AIMS

In long-term responder patients, it is unclear whether lamivudine (LAM) monotherapy should be continued or switched to a high-genetic-barrier analogue. This study aims at assessing LAM efficacy over a 5-year period and the residual risk of drug resistance. The rate of HBsAg clearance and LAM long-term safety profile were also evaluated.

METHODS

One hundred and ninety-one patients with chronic HBeAg-negative hepatitis B successfully treated with LAM monotherapy for at least 5 years were included. Biochemical and virological tests were assessed every 3 months in all patients and HBsAg quantification was performed in 45/191. Reverse-transcriptase (RT) region was directly sequenced in virological breakthrough patients.

RESULTS

One hundred and ninety-one patients (148 males, median age 53 years, 72 with compensated cirrhosis) responding to 60-month LAM monotherapy continued to receive LAM monotherapy beyond the initial 5 years and were followed for an additional 36-month median period (range 1-108). Virological response was maintained in 128/191 patients (67%) and HBsAg clearance was observed in 15/128 (11.7%) after a 32-month median period (range 1-65). The 63 remaining patients (33%) showed virological breakthrough after a 15-month median treatment (range 1-78). RT region analysis was performed in 38/63 breakthrough patients and LAM resistant mutations were found in 37/38. No significant side effects were observed.

CONCLUSIONS

In long-term responder patients, continuation of LAM monotherapy resulted in persistent viral suppression in most cases with undetectable HBV DNA by real-time PCR; moreover, 11.7% of these patients cleared HBsAg. Selection of LAM resistance, however, can still occur even after successful long-term therapy, thus emphasising the importance of a careful virological monitoring.