Sustained HBeAg and HBsAg loss after long-term follow-up of HBeAg-positive patients treated with peginterferon alpha-2b

Management of hepatitis B: Consensus of the Japan Society of Hepatology 2009

Recently, much progress has been made in the field of hepatitis B, such as natural history of the disease in relation to the amount of hepatitis B virus (HBV) DNA, genotypes of HBV influencing the natural course and treatment effects, mutations of HBV influencing the severity of the disease and development of hepatocellular carcinoma, and antiviral treatment such as nucleos(t)ide analogues and pegylated interferon. To make the consensus for the diagnosis, management and treatment of hepatitis B, a meeting was held during 45th annual meeting of Japan Society of Hepatology (JSH) in June 2009. In the meeting, recommendations and informative statements were discussed on the following subjects: (i) natural history of HBV infection; (ii) clinical implication of HBV genotypes; (iii) HBV mutations and their potential impact on pathogenesis of HBV infection; (iv) indications for antiviral treatment of chronic hepatitis B; (v) nucleos(t)ide analogues for chronic hepatitis B; and (vi) interferon therapy for chronic hepatitis B. The presenters reviewed the data on these subjects and proposed the consensus statements and recommendations. These statements were discussed among the organizers and presenters, and were approved by the participants of the meeting. In the current report, the relevant data were reviewed and the 12 consensus statements and nine recommendations on chronic hepatitis B were described.

Treatment of HBeAg-negative chronic hepatitis B patients with nucleos(t)ide analogues

Current agents used in the treatment of chronic hepatitis B (CHB) can be classified into interferons-α (IFN-α: standard or pegylated) and nucleos(t)ide analogues (NUCs). NUCs are now used in most CHB patients for several reasons. They can be given to all CHB patients, even those with contraindications to IFN-α. NUCs are more convenient to use (one oral tablet daily) than IFN-α (subcutaneous injections) and are well tolerated with a good safety profile, while IFN-α has frequent and potentially severe side effects and worsens the patient's quality of life. All NUCs are potent anti-hepatitis B virus agents (all but adefovir are more potent than IFN-α) with entecavir(ETV) and tenofovir offering the highest potency and most importantly minimal to negligible risk of resistance during long-term monotherapy [corrected]. Prolongation of entecavir or tenofovir monotherapy maintains and slightly increases the initially high virological remission rates (67-76% of HBeAg-positive and 90-93% of HBeAg-negative patients) and this is expected to result in improved long-term outcomes. The need for long-term, perhaps indefinite, treatment is the main limitation of NUCs and the finite duration (48 weeks) the main advantage of IFN-α. However, only a minority of IFN-α-treated patients achieve durable sustained off-treatment responses (HBeAg-positive: 30-35%, HBeAg-negative: 20-25%), while NUCs may be safely discontinued in HBeAg-positive patients with stable HBeAg seroconversion. Because there will always be concerns for safety and family planning issues with long-term therapy, NUCs should be used judiciously and should not be prescribed in young CHB patients with mild liver disease.

Chronic hepatitis B: peginterferon or nucleos(t)ide analogues?

Pegylated interferon-α (PEG-IFN) is still an important treatment option for both HBeAg-positive and HBeAg-negative chronic hepatitis B (CHB) patients even with the availability of potent nucleos(t)ide analogues (NUCs) with a low risk of resistance. The major advantages of PEG-IFN-based treatment include the limited duration of treatment and the good probability of achieving a sustained off-treatment response. Responders to PEG-IFN have an increased probability of HBsAg loss and survival. However, the limited number of patients who achieve a response and the high costs and side-effects associated with PEG-IFN limit its clinical use. The potent NUCs entecavir and tenofovir are therefore often used as a first-line treatment option. Unfortunately, the off-treatment durability of response to NUCs is generally low, requiring long-term continuous therapy. Recent progress making it possible to select patients with a high probability of achieving a response to PEG-IFN, and to adapt therapy early on in probable non-responders, should help further optimize the utilization of PEG-IFN in CHB.

Three-year efficacy and safety of tenofovir disoproxil fumarate treatment for chronic hepatitis B

BACKGROUND & AIMS

Tenofovir disoproxil fumarate (TDF), a nucleotide analogue and potent inhibitor of hepatitis B virus (HBV) polymerase, showed superior efficacy to adefovir dipivoxil in treatment of chronic hepatitis B through 48 weeks. We evaluated long-term efficacy and safety of TDF monotherapy in patients with chronic hepatitis B who were positive or negative for hepatitis B e antigen (HBeAg(+) or HBeAg(-)).

METHODS

After 48 weeks of double-blind comparison of TDF to adefovir dipivoxil, patients who underwent liver biopsy were eligible to continue the study on open-label TDF for 7 additional years; data presented were collected up to 3 years (week 144) from 85% of participants. Primary efficacy end points at week 144 included levels of HBV DNA and alanine aminotransferase, development of resistance mutations, and presence of HBeAg or hepatitis B surface antigen (HBsAg).

RESULTS

At week 144, 87% of HBeAg(-) and 72% of HBeAg(+) patients treated with TDF had levels of HBV DNA <400 copies/mL. Among patients who had previously received adefovir dipivoxil and then received TDF, 88% of the HBeAg(-) and 71% of the HBeAg(+) patients had levels of HBV DNA <400 copies/mL; overall, 81% and 74%, respectively, maintained normalized levels of alanine aminotransferase and 34% had lost HBeAg. Amino acid substitutions in HBV DNA polymerase that are associated with resistance to tenofovir were not detected in any patient. Cumulatively, 8% of HBeAg(+) patients lost HBsAg. TDF maintained a favorable safety profile for up to 3 years.

CONCLUSIONS

TDF was safe and effective in the long-term management of HBeAg(+) and HBeAg(-) patients with chronic hepatitis B.

The clinical implications of hepatitis B virus genotype: Recent advances

Outcomes of chronic hepatitis B virus (HBV) infection are heterogeneous. Estimates of annual incidence of cirrhosis and hepatocellular carcinoma (HCC) are 2-10% and 1-3%, respectively. Several viral factors, including HBV genotype, viral load and specific viral mutations, have been associated with disease progression. Among these, HBV genotype is not only predictive of clinical outcomes but has also been associated with response to interferon treatment. Currently, at least 10 HBV genotypes and several subtypes have been identified; they have distinct geographic distribution. Acute infection with genotypes A and D results in higher rates of chronicity than genotypes B and C. Compared to genotype A and B cases, patients with genotypes C and D have lower rates of spontaneous hepatitis B e antigen (HBeAg) seroconversion; when this occurs, it tends to be delayed. HBV genotype C has a higher frequency of basal core promoter (BCP) A1762T/G1764A mutation, pre-S deletion and is associated with higher viral load than genotype B. Similarly, genotype D has a higher prevalence of BCP A1762T/G1764A mutation than genotype A. These observations suggest important pathogenic differences between HBV genotypes. These may contribute to more severe liver disease, including cirrhosis and HCC with genotypes C and D HBV infection. In addition, genotype A and B patients have better responses to interferon-based therapy than genotypes C and D, but there are few consistent differences for direct HBV antivirals. In conclusion, genotyping of chronic HBV infections can help practicing physicians identify those at risk of disease progression and determine optimal anti-viral therapy.

Serum HBsAg quantification to predict response to peginterferon therapy of e antigen positive chronic hepatitis B

BACKGROUND

On-treatment predictors of response to peginterferon can guide individualization of therapy in chronic hepatitis B virus infection.

AIM

To investigate the use of serum hepatitis B surface antigen quantification to predict sustained response.

METHODS

Hepatitis B e antigen-positive chronic hepatitis B patients who received peginterferon for 32-48 weeks with or without lamivudine combination were studied. Sustained response was defined as hepatitis B e antigen seroconversion and chronic hepatitis B virus DNA <10 000 copies/mL until 12 months post-treatment.

RESULTS

Twenty-one of 92 (23%) patients achieved sustained response. At month 6, the area under receiver operating characteristics curve for hepatitis B surface antigen to predict sustained response was 0.77 (95% confidence interval 0.65-0.89, P < 0.001). An hepatitis B surface antigen cutoff at 300 IU/mL at month 6 could give the maximum combination of sensitivity (62%) and specificity (89%) to predict sustained response. Nine of 21 (43%) sustained responders vs. 9 of 71 (13%) nonsustained responders had >1 log hepatitis B surface antigen reduction at month 6 (P < 0.001). Combined hepatitis B surface antigen ≤ 300 IU/mL and >1 log reduction at month 6 had sensitivity, specificity, positive and negative predictive values of 43%, 96%, 75% and 85% to predict sustained response, respectively.

CONCLUSION

On-treatment serum hepatitis B surface antigen can predict response to peginterferon therapy in chronic hepatitis B.

The Role of Interferon in Hepatitis B Therapy

Despite the introduction of new nucleos(t)ide analogues in recent years, peginterferon is still recommended as a potential first-line treatment option by current practice guidelines for the management of chronic hepatitis B. Peginterferon offers the advantage of higher sustained off-treatment response rates compared to nucleos(t)ide analogues because of its immunomodulatory effects. Sustained transition to the inactive hepatitis B surface antigen (HBsAg) carrier state can be achieved in about 30% of hepatitis B e antigen (HBeAg)-positive patients and 20% of HBeAg-negative patients. Recent studies have focused on identification of pretreatment and on-treatment factors that allow the selection of patients who are likely to achieve a sustained response to peginterferon therapy in order to avoid the side-effects and costs associated with unnecessary treatment. Future studies need to address whether specific virologic benchmarks can guide individualized decisions concerning therapy continuation and whether peginterferon combined with new potent nucleos(t)ide analogues improves treatment outcomes.

Prediction of sustained response to peginterferon alfa-2b for hepatitis B e antigen-positive chronic hepatitis B using on-treatment hepatitis B surface antigen decline

Serum hepatitis B surface antigen (HBsAg) levels may reflect the immunomodulatory efficacy of pegylated interferon (PEG-IFN). We investigated within a large randomized trial whether quantitative HBsAg levels predict response to PEG-IFN in patients with hepatitis B e antigen (HBeAg)-positive chronic hepatitis B. Serum HBsAg was measured in samples taken at baseline and weeks 4, 8, 12, 24, 52, and 78 of 221 patients treated with PEG-IFN alfa-2b with or without lamivudine for 52 weeks. HBsAg decline was compared between treatment arms and between responders and nonresponders. Response was defined as HBeAg loss with HBV DNA < 10,000 copies/mL at 26 weeks after treatment (week 78); 43 of 221 (19%) patients achieved a response. One year of PEG-IFN with or without lamivudine resulted in a significant decline in serum HBsAg, which was sustained after treatment (decline 0.9 log IU/mL at week 78, P < 0.001). Patients treated with combination therapy experienced a more pronounced on-treatment decline, but relapsed subsequently. Responders experienced a significantly more pronounced decline in serum HBsAg compared to nonresponders (decline at week 52: 3.3 versus 0.7 log IU/mL, P < 0.001). Patients who achieved no decline at week 12 had a 97% probability of nonresponse through posttreatment follow-up and no chance of HBsAg loss. In a representative subset of 149 patients similar results were found for prediction through long-term (mean 3.0 years) follow-up.

CONCLUSION

PEG-IFN induces a significant decline in serum HBsAg in HBeAg-positive patients. Patients who experience no decline from baseline at week 12 have little chance of achieving a sustained response and no chance of HBsAg loss and should be advised to discontinue therapy with PEG-IFN.

Change in serum hepatitis B surface antigen level and its clinical significance in treatment-naïve, hepatitis B e antigen-positive patients receiving entecavir

BACKGROUND/AIM

We investigated changes in hepatitis B surface antigen (HBsAg) level and its correlation with clinical outcomes in treatment-naive chronic hepatitis B (CHB) patients undergoing entecavir therapy.

PATIENTS AND METHODS

Among 51 hepatitis B e antigen (HBeAg)-positive treatment-naive CHB patients receiving entecavir for more than 1 year, 28 were enrolled. HBsAg levels were measured at baseline, 6 months, and 12 months after treatment using the Architect HBsAg QT assay (Abbott, dynamic; range: 0.05 to 125,000 IU/mL). Serum alanine aminotransferase, HBeAg, anti-HBe, and hepatitis B virus (HBV) DNA (Cobas Taqman: low detection limit 1.84 log10 copies/mL) were measured at baseline and every 3 months. The HBsAg response was defined as an HBsAg level that decreased more than 1 log10 IU/mL from baseline level at 12 months after entecavir treatment.

RESULTS

Twenty-eight patients were treated for a median period of 21 months (range: 18 to 24 mo). Serum HBsAg level showed a mean of 4.0, 3.7, and 3.6 log10 IU/mL at pretreatment, 6, and 12 months, respectively, and declined significantly (P<0.001). Serum HBV DNA level showed a mean of 8.1, 3.1, and 2.4 log10 copies/mL at pretreatment, 6, and 12 months, respectively, and declined significantly (P<0.001). The decline in HBsAg level was significantly correlated with that of the HBV DNA level at 12 months from baseline (γ=0.391, P=0.044). Five patients showed an HBsAg response, and cumulative incidence of HBeAg loss at 1 year after entecavir treatment was 80% versus 30% in patients with an HBsAg response and those without, respectively (P=0.034).

CONCLUSIONS

Monitoring changes in quantitative HBsAg level could be a useful parameter for assessing the response to entecavir therapy in HBeAg-positive treatment-naive CHB patients.

Tenofovir and entecavir are the most effective antiviral agents for chronic hepatitis B: a systematic review and Bayesian meta-analyses

BACKGROUND & AIMS

The relative efficacies of licensed antiviral therapies for treatment-naive chronic hepatitis B (CHB) infection in randomized controlled trials have not been determined. We evaluated the relative efficacies of the first 12 months of CHB treatments.

METHODS

Drugs evaluated were lamivudine, pegylated interferon, adefovir, entecavir, telbivudine, and tenofovir, as monotherapies and combination therapies, in treatment-naive individuals. Databases were searched for randomized controlled trials of the first 12 months of therapy in hepatitis B e antigen (HBeAg)-positive and/or HBeAg-negative patients with CHB published in English before October 31, 2009. Bayesian mixed treatment comparisons were used to calculate the odds ratios, including 95% credible intervals and predicted probabilities of surrogate outcomes to determine the relative effects of each treatment.

RESULTS

In HBeAg-positive patients, tenofovir was most effective in inducing undetectable levels of HBV DNA (predicted probability, 88%), normalization of alanine aminotransferase (ALT) levels (66%), HBeAg seroconversion (20%), and hepatitis B surface antigen loss (5%); it ranked third in histologic improvement of the liver (53%). Entecavir was most effective in improving liver histology (56%), second for inducing undetectable levels of HBV DNA (61%) and normalization of ALT levels (70%), and third in loss of hepatitis B surface antigen (1%). In HBeAg-negative patients, tenofovir was the most effective in inducing undetectable levels of HBV DNA (94%) and improving liver histology (65%); it ranked second for normalization of ALT levels (73%).

CONCLUSIONS

In the first year of treatment for CHB, tenofovir and entecavir are the most potent oral antiviral agents for HBeAg-positive patients; tenofovir is most effective for HBeAg-negative patients.

Endpoints of hepatitis B treatment

The goal of hepatitis B treatment is to prevent the development of cirrhosis, liver failure, and hepatocellular carcinoma. Ideally, clinical studies should demonstrate that hepatitis B therapies can prevent liver-related complications; however, these clinical endpoints evolve over years or decades. Therefore, clinical trials have relied on intermediate endpoints to evaluate the efficacy of treatment and to determine when treatment can be stopped. Intermediate endpoints that have been used include biochemical, histological, virological, and serological endpoints. This review will discuss the validity of these intermediate endpoints as surrogates of clinical endpoints, and the rates at which these intermediate endpoints can be achieved with currently available therapies.

Prediction of the response to peg-interferon-alfa in patients with HBeAg positive chronic hepatitis B using decline of HBV DNA during treatment

Peginterferon (PEG-IFN) results in HBeAg loss combined with virologic response in only a minority of patients with HBeAg positive chronic hepatitis B. Baseline predictors of response to PEG-IFN include HBV-genotype, pre-treatment HBV DNA levels, and ALT. The aims of this study were to develop a model, which improves the baseline prediction of response to PEG-IFN for individual patients by including early HBV DNA measurements during treatment and to establish an early indication for cessation of treatment. One hundred thirty-six patients treated with PEG-IFN were included in the study. Response was defined as loss of HBeAg and HBV DNA <10,000 copies/ml at 26 weeks post-treatment. Logistic regression analysis techniques were used to develop a dynamic prediction model with HBV DNA during the first 32 weeks of therapy. An early clinically useful rule for dis(continuation) of treatment was identified with a grid of cut-off values of HBV DNA decline during treatment. Adding HBV DNA decline to baseline prediction increased c-statistics from 0.846 to 0.857, 0.855 to 0.866 at weeks 4, 12, and 24. A HBV DNA decline of at least 2 log(10) within 24 weeks was strongly associated with response when added to the baseline prediction model: OR 5.7 (95% CI: 1.70-20.0; P = 0.004). A dynamic model including HBV DNA decline during treatment provides more accurate predictions of response to PEG-IFN. The model strongly supports individual decision making on treatment (dis)continuation in patients with HBeAg positive chronic hepatitis B. It is recommended that PEG-IFN treatment is stopped by 24 weeks if HBV DNA declined <2 log(10).

Hepatitis B virus DNA and hepatitis B surface antigen levels in chronic hepatitis B

Despite universal vaccination, chronic hepatitis B (CHB) continues to be a major health burden worldwide, with an estimated 350-400 million people infected with the virus. Over the past decade, rapid progress has been made with regards to antiviral therapy for CHB, from conventional interferon to pegylated interferon, and with the earliest oral agent lamivudine to the current, more potent drugs such as entecavir and tenofovir. There have also been new developments in the diagnostic and monitoring tools for CHB. Qualitative hepatitis B surface antigen (HBsAg) testing has been used to diagnose patients infected with CHB. More recently, quantitative HBsAg titers have been used to predict treatment outcome when measured at baseline or early into treatment. The progress on the use of hepatitis B virus (HBV) DNA levels has been more rapid. Serum HBV DNA levels have been shown to be important in the natural history of CHB infection, with higher levels being significantly associated with the development of cirrhosis and hepatocellular carcinoma. For patients receiving antiviral therapy, the baseline and early on-treatment HBV DNA levels are important in determining treatment outcomes. Monitoring of HBV DNA levels during therapy will allow for early detection of drug resistance. The end-of-treatment and post-treatment HBV DNA levels have been demonstrated to be important indicators of treatment success and relapse, respectively. With newer and more powerful antiviral agents, and with the development of quantitative assays that are highly sensitive, further studies are needed to optimize the use of these tools and agents in the modern management of CHB.

Quantitative serum HBsAg and HBeAg are strong predictors of sustained HBeAg seroconversion to pegylated interferon alfa-2b in HBeAg-positive patients

BACKGROUND AND AIM

To evaluate the usefulness of quantitative hepatitis B surface antigen (HBsAg) and hepatitis B e antigen (HBeAg) for predicting HBeAg seroconversion in chronic hepatitis B patients treated with conventional interferon (IFN) alfa-2b or PegIFN alfa-2b.

METHODS

Fifty-eight patients were enrolled; 29 for the training group and 29 for the validating group. Quantification of HBsAg and HBeAg was carried out at baseline, week 12, week 24, and then again at 12 and 24 weeks follow up, respectively, for two groups. Sixteen patients in the training group were followed up for 5 years.

RESULTS

The cutoff of 1500 IU/mL in serum HBsAg at week 12 had a positive predictive value (PPV) of 33% and a negative predictive value (NPV) of 91%, and 2890 IU/mL at week 24 had a PPV of 43% and an NPV of 95% for HBeAg seroconversion at week 48. The cutoff of 17.55 Paul Ehrlich Institute units/mL (PEI-U/mL) in serum HBeAg at week 12 had a PPV of 38% and an NPV of 95%, and 8.52 PEI-U/mL at week 24 had a PPV of 44% and a NPV of 100% for HBeAg seroconversion at week 48. Moreover the HBsAg and HBeAg levels of PegIFN alfa-2b group were lower than those of the conventional IFN alfa-2b group. During follow up, patients with HBeAg seroconversion remained HBeAg negative and none of them progressed to cirrhosis, but among the patients with non-HBeAg seroconversion, two progressed to cirrhosis. Two additional patients with negative HBeAg were observed.

CONCLUSIONS

On-treatment serum HBsAg and HBeAg had high predictive values to predict sustained HBeAg seroconversion by PegIFN alfa-2b. Patients who cleared HBeAg had better survival free of hepatic complications during long-term follow-up study.

New pharmacologic therapies in chronic hepatitis B

Approximately 350 million persons worldwide are chronically infected with hepatitis B, which can result in cirrhosis, liver failure, and hepatocellular carcinoma. Currently, 2 interferons and 5 nucleos(t)ide analogues have been approved for the treatment of chronic hepatitis B (CHB). This article discusses the mechanisms of action, pharmacokinetics, optimal dose, clinical efficacy, and side effects of medications used for the treatment of CHB.

Nucleos(t)ide analogues only induce temporary hepatitis B e antigen seroconversion in most patients with chronic hepatitis B

BACKGROUND & AIMS

Inconsistencies in results and guideline recommendations regarding the durability of nucleos(t)ide analogue-induced hepatitis B e antigen (HBeAg) seroconversion require clarification. We studied the long-term durability of nucleos(t)ide analogue-induced HBeAg seroconversion in patients with chronic hepatitis B virus (HBV) infection.

METHODS

We performed a single-center cohort study of 132 HBeAg-positive patients who had received nucleos(t)ide analogue therapy.

RESULTS

During a median treatment duration of 26 months (range, 16-43 mo), HBeAg seroconversion occurred in 46 of 132 subjects (35%). Forty-two subjects (91%) had follow-up evaluation after HBeAg seroconversion. During a median follow-up period of 59 months (range, 28-103 mo) after HBeAg seroconversion, 13 of 42 patients (31%) showed a durable remission (defined as HBeAg negative and HBV-DNA level<10,000 copies/mL). Overall, 33 of 42 subjects (79%) continued therapy after HBeAg seroconversion; of these, 22 (67%) showed serologic and/or virologic recurrence. Nine of 42 subjects (21%) discontinued therapy after HBeAg seroconversion and at least 6 months of consolidation therapy. Only 2 patients showed a durable response in the absence of therapy. Disease recurrence in patients who continued therapy after HBeAg seroconversion was preceded by the development of resistance (80% of these patients); resistance only occurred in subjects given lamivudine monotherapy. In contrast, recurrence after treatment discontinuation or noncompliance was observed in all patients given nucleos(t)ide analogues.

CONCLUSIONS

Induction of HBeAg seroconversion by nucleos(t)ide analogues is temporary in most patients with chronic HBV infection. Long-term continuation of nucleos(t)ide analogue treatment, irrespective of the occurrence of HBeAg seroconversion, appears to be necessary.

Cost-effectiveness analysis of roadmap models in chronic hepatitis B using tenofovir as the rescue therapy

BACKGROUND

The roadmap approach is recommended to guide chronic hepatitis B treatment. We evaluated the cost-effectiveness of various treatment strategies in the global market.

METHODS

Lamivudine and telbivudine were tested in roadmap models with switch-to tenofovir if HBV was detectable at week 24 or add-on tenofovir if resistance developed at year 1. Tenofovir and entecavir were tested as continuous monotherapy. In the reference arm, lamivudine was used with add-on tenofovir if resistance developed at year 1. The primary measure of effectiveness was undetectable HBV DNA at year 2. Cost-effectiveness was measured by incremental cost-effectiveness ratio (ICER) in US dollars against the reference arm.

RESULTS

In the US and Germany, costs of the reference arms were US $14,486 and US $9,998 for hepatitis B e antigen (HBeAg)-positive and US $11,398 and US $7,531 for HBeAg-negative patients, respectively. In HBeAg-positive patients, the lamivudine roadmap was most cost-effective (ICER US $15,260 in the US and US $29,113 in Germany) with comparable effectiveness (75.1%) to other strategies. In HBeAg-negative patients, tenofovir and entecavir monotherapies were most effective (91-96%) and cost-effective (ICER US $31,297-43,387 in the US and US $53,976-59,822 in Germany). In Asia, where telbivudine cost was lower, both telbivudine and lamivudine roadmaps were cost-effective in HBeAg-positive patients. Tenofovir would be most cost-effective in HBeAg-negative patients if its cost equaled that of telbivudine in Asia.

CONCLUSIONS

In HBeAg-positive patients, lamivudine roadmap was most cost-effective; in Asia, telbivudine roadmap had comparable cost-effectiveness to lamivudine roadmap because of the relatively low price of telbivudine. In HBeAg-negative patients, entecavir and tenofovir monotherapies were more cost-effective than the roadmap models.

Hepatitis B surface antigen seroclearance during chronic HBV infection

Hepatitis B surface antigen (HBsAg) seroclearance in chronic HBV infection occurs at an annual incidence of 1-2%. The long-term outcome after HBsAg seroclearance is excellent if there is no pre-existing cirrhosis or viral superinfection. For this reason, HBsAg seroclearance has attracted recent interest in both long-term studies of the natural history of HBV infection and in patients receiving antiviral therapy. Here, we review a diverse range of studies investigating spontaneous HBsAg seroclearance in varied groups of patients and consider the many predictive factors - of both viral and host origin - for seroclearance. Studies to assess the effects of antiviral therapy, and in particular interferon treatment, are also discussed together with virological, biochemical and histological profiles following HBsAg seroclearance and the long-term outcomes.

Durability of peginterferon alfa-2b treatment at 5 years in patients with hepatitis B e antigen-positive chronic hepatitis B

Approximately 30%-40% of patients with hepatitis B e antigen (HBeAg)-positive chronic hepatitis B treated with peginterferon and/or lamivudine achieve HBeAg seroconversion 6 months after the end of treatment. The durability and long-term effect of treatment are unknown. In this study, 85 HBeAg-positive patients who received peginterferon alfa-2b 1.5 microg/kg/week for 32 weeks and lamivudine 100 mg/day for 52 or 104 weeks were prospectively followed for 6.1 +/- 1.7 years posttreatment. Twenty-five (29%) patients had virologic response (HBeAg seroconversion and HBV DNA <10,000 copies/mL) at 5 years. The rate of HBeAg seroconversion rose progressively from 37% at the end of treatment to 60% at 5 years. Twenty-seven (32%) and 11 (13%) patients had undetectable HBV DNA (<100 copies/mL) at the end of peginterferon treatment and at 5 years, respectively. Two (2.4%) patients achieved hepatitis B surface antigen (HBsAg) seroclearance at 2.6 and 84 months posttreatment. Among virologic responders at the end of treatment, 82% and 57% and sustained HBeAg seroconversion and virologic response at 5 years. End-of-treatment serum quantitative HBsAg was significantly lower in patients with sustained virologic response at 5 years (median 1,431 IU/mL versus 2,689 IU/mL [P = 0.041]). At the last follow-up, the liver stiffness measurement by transient elastography was 5.8 +/- 2.7 kPa. Only two patients had liver stiffness suggestive of advanced fibrosis. Week 16 HBV DNA, end-of-treatment HBeAg seroconversion, and undetectable HBV DNA were independent factors associated with virologic response at 5 years. The duration of concomitant lamivudine treatment had no impact on any long-term response.

CONCLUSION

Peginterferon has high durability in HBeAg-positive chronic hepatitis B patients with end-of-treatment virologic response.

Pros and Cons of Peginterferon Versus Nucleos(t)ide Analogues for Treatment of Chronic Hepatitis B

The emergence of new and more potent treatment options has markedly changed the treatment landscape of chronic hepatitis B. Both peginterferon and nucleos(t)ide analogues have considerable advantages and limitations, and current treatment guidelines refrain from clearly suggesting a first-line treatment option. Peginterferon offers the advantage of higher sustained response rates in both hepatitis B early antigen (HBeAg)-positive and HBeAg-negative patients, at the price of considerable side effects and high costs. Nucleos(t)ide analogues offer easy daily oral dosing, and newly registered agents can maintain viral suppression for prolonged treatment duration. However, relapse is common after therapy discontinuation and extended therapy therefore often necessary. Prolonged treatment with nucleos(t)ide analogues may enhance chances of virologic and serologic response at the potential cost of the emergence of viral resistance and side effects. Baseline and on-treatment prediction of response may help select patients for peginterferon therapy and can aid individualized treatment decisions concerning therapy continuation or discontinuation.

Avoiding and managing lamivudine resistance in chronic hepatitis B: current approaches and potential strategies including pegylated interferon

Since its approval for the treatment of chronic hepatitis B in 1998, lamivudine (LAM) has been used extensively throughout the world, because of its relatively low costs and favourable tolerability. However, clinical trials and cohort studies have demonstrated that a high rate of resistance to this drug develops and, as a result, it is no longer included as a first-line therapy in most current treatment guidelines. Nevertheless, because of its low cost, this drug continues to be used in many countries and the pool of patients who have developed resistance to LAM continues to increase. Thus, there is a clear need to develop coherent management strategies to treat such patients as well as limit the emergence of resistance in the first instance. The purpose of this review is to highlight the need to aim for long-term treatment success while limiting the emergence of drug resistance and its consequences for the future. In addition to add-on/switch strategies with other nucleos(t)ide analogs, currently available data suggest that interferon-based therapies, with their potential to induce a sustained response, are worthy of consideration not only for reducing de novo resistance but as an option for the management of those patients in whom drug resistance has already developed.

On-treatment serum HBsAg level is predictive of sustained off-treatment virologic response to telbivudine in HBeAg-positive chronic hepatitis B patients

BACKGROUND

Effective management of chronic hepatitis B infection is still very challenging, despite decades of clinical research. Telbivudine is one of the most frequently used antiviral drug at the current stage, but its long-term effectiveness, particularly at off-treatment, is still unclear.

OBJECTIVES

To assess on-treatment HBsAg kinetics in patients treated with telbivudine for 2 years, and predicting sustained virologic response (SR) at 2 years off-treatment.

STUDY DESIGN

Serum HBV DNA/HBsAg levels were assessed from 17 HBeAg+ patients treated with telbivudine 600 mg/day for 104 weeks, at baseline, weeks 24, 52 and 104, as well as during off-treatment follow-up.

RESULTS

HBsAg levels <2 log(10)IU/ml at treatment week 104 were highly predictive of SR (i.e., HBV DNA <300 copies/ml, HBeAg seroconversion, ALT normalization) at 2 years off-treatment (positive predictive value [PPV], 93%; negative predictive value [NPV], 100%). HBsAg levels consistently declined from baseline only in patients achieving SR during 2 years off-treatment. At weeks 24 and 52, HBsAg decline rate was a better predictor of off-treatment response than HBV DNA decline rate. HBsAg decline rates of >0.8 and >1 log(10)IU/ml at treatment weeks 24 and 52 were predictive of SR (PPV, 75%; NPV, 86% at week 24; PPV, 75%; NPV, 86% at week 52).

CONCLUSIONS

Serum HBsAg levels <2 log(10)IU/ml at treatment week 104 are highly predictive of SR to telbivudine at 2 years off-treatment. HBsAg decline rate at on-treatment weeks 24 and 52 from baseline were also more predictive of SR than HBV DNA decline rate.

Is response to antiviral treatment influenced by hepatitis B virus genotype?

Recently released clinical practice guidelines and consensus conference statements point to the importance of hepatitis B virus (HBV) genotyping in therapeutic algorithms for the treatment of chronic hepatitis B. This information usually comes from post hoc analyses of clinical trials which were not designed to study associations with the HBV genotype. We have performed a literature search through to April 2009 and have selected randomized clinical trials of currently approved anti-HBV drugs providing information on HBV genotypes and (i) baseline characteristics of study subjects, (ii) any response to antiviral therapy, (iii) interaction between HBV genotypes and the type of therapy. There were several intrinsic features and weaknesses in the majority of clinical trials conducted so far which make it difficult to reach firm conclusions about the role of HBV genotypes in response to antiviral therapy. Indeed, most trials were necessarily multicenter in order to reach a sufficient statistical power, but pooling together patients of different ethnicities may have revealed false-positive associations between response to antiviral therapy and HBV genotype. Moreover, endpoint definitions, especially for the composite ones, varied substantially among studies, leading to lack of homogeneity. Finally, possible interactions between the type of therapy and the HBV genotype were only seldom analysed. The present review highlights several caveats regarding current indications proposed by the major clinical practice guidelines and consensus conference statements published thus far and emphasise the need for further long term studies in the field.

Predictors of treatment response in chronic hepatitis B

The ultimate goal of treatment for chronic hepatitis B is to reduce liver-related complications and mortality. Sustained hepatitis B e antigen (HBeAg) seroconversion and hepatitis B surface antigen (HBsAg) clearance 6-12 months after stopping treatment are the short-term surrogate outcomes for interferon or peginterferon therapy. As most patients require long-term nucleos(t)ide analogue treatment, which also has the risk of drug resistance in the case of incomplete viral suppression, maintained hepatitis B virus (HBV) DNA suppression to an undetectable level is the appropriate surrogate outcome. Because no antiviral treatment is perfect, it is desirable for treatment response to be predicted and the treatment regimen modified accordingly. At baseline, high ALT and low HBV DNA levels can predict response to both (peg)interferon and nucleos(t)ide analogues. Genotype A HBV responds best to peginterferon but HBV genotype has no predictive value for nucleos(t)ide analogue treatment. HBV DNA is a good on-treatment predictor of response for nucleos(t)ide analogues but not for (peg)interferon. The data supporting the use of quantitative HBsAg and HBeAg to predict response to peginterferon is stronger than that for nucleos(t)ide analogues. In conclusion, predictors of response are useful to provide the most appropriate antiviral therapy to the most suitable patients, in order to achieve the best response and improve the clinical outcome of chronic hepatitis B patients.

Factors that predict response of patients with hepatitis B e antigen-positive chronic hepatitis B to peginterferon-alfa

BACKGROUND & AIMS

Therapy with pegylated interferon (PEG-IFN)-alfa results in sustained response in a minority of patients with chronic hepatitis B virus (HBV) infection and has considerable side effects. We analyzed data from the 2 largest global trials of hepatitis B e antigen (HBeAg)-positive patients with chronic hepatitis B to determine which are most likely to respond to PEG-IFN-alfa therapy.

METHODS

The study included 542 patients treated with PEG-IFN-alfa-2a (180 microg/wk, 48 wk) and 266 patients treated with PEG-IFN-alfa-2b (100 microg/wk, 52 wk). Eighty-seven patients were excluded, leaving 721 patients for analysis. A sustained response was defined as HBeAg loss and HBV-DNA level less than 2.0 x 10(3) IU/mL 6 months after treatment. Logistic regression analysis was used to identify predictors of sustained response and a multivariable model was constructed.

RESULTS

HBV genotype, high levels of alanine aminotransferase (ALT; >or=2 x upper limit of normal), low levels of HBV DNA (<2.0 x 10(8) IU/mL), female sex, older age, and absence of previous IFN therapy predicted a sustained response. Genotype A patients with high ALT and/or low HBV-DNA levels had a high predicted probability (>30%) of a sustained response. The strongest predictors of response were a high level of ALT in genotype B patients and a low level of HBV DNA in genotype C patients. Genotype D patients had a low chance of sustained response, irrespective of ALT or HBV-DNA levels.

CONCLUSIONS

The best candidates for a sustained response to PEG-IFN-alfa are genotype A patients with high levels of ALT or low levels of HBV DNA, and genotypes B and C patients who have both high levels of ALT and low HBV DNA. Genotype D patients have a low chance of sustained response.

HBV and HCV therapy

One year of interferon therapy inhibits HBV replication in one third of the patients whereas long-term administration of oral nucleos(t)ide analogues is efficient in most of them, as long as early treatment adaptation in patients with partial virological response and resistance is provided. Following the demonstration of a more potent antiviral effect in terms of sustained virological response (SVR) rates, Pegylated-IFN coupled with Ribavirin has become the standard treatment for chronic hepatitis C, with nearly 65% of all treated patients achieving a SVR. Long-term suppression of HBV and eradication of HCV would halt the progression of chronic hepatitis to cirrhosis, hepatocellular carcinoma and liver decompensation.

New developments in antiviral therapy for chronic hepatitis B

Chronic hepatitis B affects approximately 400 million people in the world with a substantial disease burden like liver cirrhosis and hepatocellular carcinoma (HCC). Treatment for chronic hepatitis B has improved dramatically in the last decade, resulting in more patients achieving a state of inactive disease. Currently two treatment strategies are available; treatment with peginterferon (peg-IFN) or nucleos(t)ide analogues with the aim to suppress hepatitis B virus (HBV) DNA to subsequently avoid the development of cirrhosis and HCC. Unfortunately, treatment with peg-IFN can be suboptimal with important adverse effects and nucleos(t)ide analogues provoke resistance. At present, no new promising compounds attacking the HBV life cycle are in development. However, for prediction of sustained response or treatment failure, data from the long-term large peg-IFN trials provide important response markers. For the future the focus is to achieve HBsAg loss and anti-HBs conversion which is the closest the treatment can get to a cure. This review summarizes the current treatment options with their response rates and discusses future strategies for chronic hepatitis B treatment.

[Comparison of lamivudine-induced HBsAg loss rate according to age in children with chronic hepatitis B]

BACKGROUND/AIMS

The aim of this study was to establish the characteristics of children with hepatitis B e antigens (HBeAg) positive chronic hepatitis B who were cleared of hepatitis B surface antigens (HBsAg) as a result of lamivudine treatment.

METHODS

Seventy-six children with chronic hepatitis B who were seropositive for HBeAg were treated with lamivudine for at least 6 months. HBeAg seroconversion occurred during treatment in 49 of these children, who were then followed up to assess their clearance of serum HBsAg. Various clinical variables were compared between those patients who were cleared of HBsAg and those who were not, including age, pretreatment serum levels of alanine aminotransferase (ALT) and hepatitis B virus (HBV) DNA, treatment duration, the time elapsed between initiation of treatment and ALT normalization, HBV DNA negativization, HBeAg seroconversion, and HBsAg clearance.

RESULTS

HBsAg disappeared in 13 of the 49 (26.5%) patients who experienced lamivudine-induced HBeAg seroconversion; HBsAg did not reappear during follow-up period (1-86 months). The time that elapsed between initiation of lamivudine treatment and total HBsAg clearance was 25.9+/-27.1 months (mean+/-SD; range: 5-104 months). The age at which treatment was initiated was the only factor associated with HBsAg clearance. Children who were cleared of HBsAg were significantly younger than those who were not (5.1+/-4.3 years vs. 7.9+/-4.9 years, respectively; P=0.006). All 13 of these patients eventually produced antibodies to HBsAg.

CONCLUSIONS

Younger children (age <7 years old) have a higher chance of HBsAg clearance than older children after the treatment of HBeAg-positive chronic hepatitis B with lamivudine.

Early HBeAg loss during peginterferon alpha-2b therapy predicts HBsAg loss: results of a long-term follow-up study in chronic hepatitis B patients

OBJECTIVES

Treatment with pegylated interferon (PEG-IFN) alpha-2b results in hepatitis B e antigen (HBeAg) loss in 36% of patients at 6 months post treatment. The aim of this study was to determine whether a long-term response to PEG-IFN is dependent on the timing of HBeAg loss.

METHODS

A total of 91 patients treated with PEG-IFN alpha-2b alone (100 microg per week) and 81 patients treated with PEG-IFN alpha-2b and lamivudine (100 mg/day) for 52 weeks were enrolled in this study. Patients were initially followed up at 4-week intervals and had one additional long-term follow-up (LTFU) visit (mean: 3.03+/-0.77 years 26 weeks post treatment).

RESULTS

Of the 172 patients included, 78 patients (46%) did not have loss of HBeAg, 47 (27%) lost HBeAg within 32 weeks, and 47 patients (27%) had loss of HBeAg after week 32. At LTFU, patients with HBeAg loss< or =32 weeks had hepatitis B virus DNA of <400 copies/ml significantly more often than did those who lost HBeAg after week 32 (47 vs. 21%, respectively; P=0.009). Hepatitis B surface antigen (HBsAg) negativity was also observed significantly more often in patients with early HBeAg loss (36 vs. 4%, respectively, P<0.001). Early HBeAg loss tended to occur more often in patients treated with PEG-IFN and lamivudine combination therapy than in those treated with PEG-IFN alone (35 vs. 21%; P=0.10), as did HBsAg loss (15 vs. 8%; P=0.14).

CONCLUSIONS

Early PEG-IFN-induced HBeAg loss results in a high likelihood of HBsAg loss and may be associated with more profound viral suppression during the first 32 weeks of therapy in patients treated with lamivudine combinations.

The role of quantitative hepatitis B serology in the natural history and management of chronic hepatitis B

Chronic hepatitis B (CHB) remains a serious clinical problem worldwide. Advances in molecular technology have enabled the development of sensitive assays for the detection and quantification of hepatitis B virus (HBV) nucleic acid and demonstrated a positive correlation between serum HBV DNA levels and disease progression. Assessment of specific serologic and virologic factors also plays a pivotal role in the diagnosis and effective management of individuals with CHB. Recent development of quantitative assays for intrahepatic HBV replicative intermediates, as well as hepatitis B e antigen and hepatitis B surface antigen, has spurred investigation into the relationship between these factors and response to antiviral therapy and disease progression. Recent findings from preclinical and clinical investigations indicate that these factors may have promise in identifying patients likely to respond to treatment. Additional work is needed to standardize and validate these assays before they can be considered to be of true diagnostic value. Further evaluation is needed to decide which will have the greatest clinical applicability.

Sustained response of hepatitis B e antigen-negative patients 3 years after treatment with peginterferon alpha-2a

BACKGROUND & AIMS

Patients with hepatitis B e antigen (HBeAg)-negative chronic hepatitis B treated with peginterferon alpha-2a with or without lamivudine achieve significantly higher 6-month posttreatment rates of response compared with those treated with lamivudine alone. The durability of <or=3-year posttreatment response was investigated in this study.

METHODS

Patients received peginterferon alpha-2a only (180 microg once weekly; n = 177), in combination with lamivudine (100 mg daily; n = 179) or lamivudine alone (n = 181) for 48 weeks. A total of 315 patients (116, 114, and 85, respectively) participated in this posttreatment observational study.

RESULTS

Three years after treatment, the percentage of patients with normal alanine aminotransferase (ATL) was higher for patients treated with peginterferon alpha-2a (31%) than with lamivudine (18%; P = 0.032). Similarly, 28% of patients treated with peginterferon had hepatitis B virus (HBV) DNA levels <or= 10,000 copies/mL versus 15% of patients treated with lamivudine (P = .039). Peginterferon alpha-2a treatment and high baseline ALT level were independent baseline predictors of long-term virologic response (P = .040 and P = .01, respectively). Of the patients who had been treated with a peginterferon alpha-2a-containing regimen, 8.7% cleared hepatitis B surface antigen (HBsAg; 44% of those with undetectable HBV at 3-year posttreatment follow-up) compared with none treated with lamivudine alone.

CONCLUSIONS

Biochemical and virologic responses were sustained for <or=3 years in approximately 25% of patients given a 48-week course of peginterferon alpha-2a, with or without lamivudine. The increased rate of HBsAg clearance in patients with HBeAg-negative chronic hepatitis B supports the use of peginterferon alpha-2a as a first-line treatment.

High rates of HBsAg seroconversion in HBeAg-positive chronic hepatitis B patients responding to interferon: a long-term follow-up study

BACKGROUND/AIMS

To assess the HBsAg seroconversion rate and its impact on the long-term outcome in chronic hepatitis B patients treated with conventional interferon, and to analyze the serum HBsAg concentration prior to seroconversion.

METHODS

Ninety-seven HBeAg-positive patients were retrospectively evaluated. Sustained virological response (SVR) was defined as HBeAg seroconversion and undetectable serum HBV-DNA 48 weeks after treatment discontinuation. HBsAg level was assessed at yearly intervals until seroconversion in SVRs.

RESULTS

Twenty-five patients (26%) achieved SVR. By multivariate analysis, SVR was associated with low serum HBV DNA level and severe liver fibrosis. During a median follow-up of 14 years (range, 5-20 years), 28 patients (29%) developed HBsAg seroconversion including 16 SVRs (64%) and 12 non-SVRs (16%), p < 0.001. HBsAg quantification showed a major decrease (median = 46%, range = 19-100%) in the first year after interferon starting in SVR patients. Six patients developed hepatocellular carcinoma, none of them had undergone HBsAg seroconversion. Liver fibrosis improved in 70% of patients with HBsAg seroconversion compared to 30% of those without HBsAg seroconversion (p < 0.01).

CONCLUSIONS

HBsAg seroconversion is achieved with a high steady rate in patients responding to interferon, and associated with excellent outcome. Prospective studies are needed to clarify the utility of on-treatment quantitative serum HBsAg in interferon-based therapy.

Current prophylactic strategies against hepatitis B virus recurrence after liver transplantation

Prophylactic strategies against hepatitis B virus (HBV) recurrence after liver transplantation (LT) are essential for patients with HBV-related disease. Before LT, lamivudine (LAM) was proposed to be down-graded from first- to second-line therapy. In contrast, adefovir dipivoxil (ADV) has been approved not only as first-line therapy but also as rescue therapy for patients with LAM resistance. Furthermore, combination of ADV and LAM may result in lower risk of ADV resistance than ADV monotherapy. Other new drugs such as entecavir, telbivudine and tenofovir, are probably candidates for the treatment of hepatitis-B-surface-antigen-positive patients awaiting LT. After LT, low-dose intramuscular hepatitis B immunoglobulin (HBIG), in combination with LAM, has been regarded as the most cost-effective regimen for the prevention of post-transplant HBV recurrence in recipients without pretransplant LAM resistance and rapidly accepted in many transplant centers. With the introduction of new antiviral drugs, new hepatitis B vaccine and its new adjuvants, post-transplant HBIG-free therapeutic regimens with new oral antiviral drug combinations or active HBV vaccination combined with adjuvants will be promising, particularly in those patients with low risk of HBV recurrence.

Benefits and risks of interferon therapy for hepatitis B

Alpha interferon is the only licensed drug for hepatitis B with immunomodulatory as well as viral inhibitory properties. Potential advantages of interferon compared to nucleoside analogs include a lack of drug resistance, a finite and defined treatment course, and a higher likelihood for hepatitis B surface antigen (HBsAg) clearance. Approximately 30% of hepatitis B e antigen (HBeAg)-positive and 40% of HBeAg-negative cases have a sustained virological response (when defined as HBeAg seroconversion and/or hepatitis B virus (HBV) DNA levels below 20,000 copies/mL, respectively) 6 months after completion of a 48-week course of peginterferon alfa-2a These responses remain durable in 80% and 50% of cases, respectively, when evaluated several years later. Recent studies have shown that changes in HBsAg and HBeAg concentration during treatment predict sustained virological response and serial monitoring of HBsAg is helpful in predicting HBsAg clearance. HBeAg-positive patients with genotype A have higher rates of HBeAg and HBsAg clearance, whereas HBeAg-negative patients with genotype D have the lowest rate of response to interferon therapy. Long-term follow-up of virological responders to either standard alpha interferon or peginterferon has demonstrated a progressive increase in the rate of HBsAg clearance, particularly in patients who were initially HBeAg-positive. Future studies need to address if specific virological benchmarks during therapy can be used to tailor treatment duration.

CONCLUSION

Peginterferon alfa has a place as first-line therapy of hepatitis B in patients who are carefully selected on the basis of pretreatment serum HBV DNA and aminotransferase levels, safety considerations, and viral genotype.

Benefits and risks of combination therapy for hepatitis B

In successful antiviral therapy of hepatitis B, drug combinations, particularly combinations without cross-resistance, can delay or prevent the emergence of drug-resistant mutants. Because drug-resistant mutants are archived and may limit future therapeutic options, prevention is important for long-term therapeutic efficacy. Additionally, combining drugs may achieve synergistic or additive antiviral effects compared with single drug therapy. Undesirable aspects of combination therapy include higher treatment costs and possibly lower adherence rates (due to pill number or complexity of regimen). Potentially harmful effects of combination therapy include higher rates of side effects, reduced efficacy due to drug competition, and the risk of multidrug-resistant hepatitis B virus (HBV) if combination therapy is insufficient to prevent resistance. Combination therapy has been shown to reduce the rate of drug resistance in chronic hepatitis B, but only when drugs with a low barrier to resistance are used (lamivudine, adefovir). Combination therapies may achieve greater degrees of HBV DNA suppression, but this has not been associated with higher rates of seroconversion (hepatitis B e antigen or hepatitis B surface antigen) compared to single drug therapy. The benefit of combination therapy has yet to be demonstrated with agents that are associated with a high barrier to resistance (tenofovir, entecavir). The use of combination therapy is recommended in specific patient groups: those with decompensated cirrhosis, those coinfected with human immunodeficiency virus and HBV who are on antiretroviral therapy, those who have undergone liver transplantation, and those with drug-resistant HBV infection. There is insufficient evidence to recommend combination therapy as first-line therapy for all patients with chronic hepatitis B.

Monitoring during and after antiviral therapy for hepatitis B

Recent studies suggest that long-term suppression of viral replication is critical to reducing the complications of chronic hepatitis B virus (HBV) infection. Monitoring for continued virological response during and after treatment is essential because current treatment options have limited success in achieving durable endpoints, and antiviral resistance may emerge during long-term therapy. Methods of monitoring treatment response include tests for serum aminotransferase levels, HBV DNA level, hepatitis B e antigen (HBeAg) and antibody (anti-HBe), hepatitis B surface antigen (HBsAg) or antibody (anti-HBs), and liver histology. Virological suppression and loss of HBeAg or HBsAg with or without seroconversion play a prominent role in decision-making regarding the success and duration of antiviral therapy. Guidelines recommend that testing for serum markers be repeated every 12-24 weeks during antiviral therapy and every 6-12 months afterward. Recent data also suggest that serum HBV DNA levels should be assessed at weeks 12 and 24 of therapy, because early viral response may predict the likelihood of sustained response and antiviral resistance. The use of serum HBV DNA levels for this purpose requires an assay with a wide range of quantification, such as real-time polymerase chain reaction assays, which have a 7-8 log(10) dynamic range. Newer, investigational methods for monitoring treatment response include quantitative measurement of HBsAg, HBeAg, and intrahepatic covalently closed circular DNA.

CONCLUSIONS

Better methods for defining durable treatment endpoints are needed. Other areas requiring further research include the optimal treatment duration and the establishment of the optimal use of early viral kinetics for decision-making during antiviral therapy.

Update on viral hepatitis: 2008

PURPOSE OF REVIEW

The present review is a concise review of recent developments in the field of viral hepatitis, based on publications between December 2007 and November 2008.

RECENT FINDINGS

The incidence of acute hepatitis A and B infection has declined significantly, especially among children less than 15 years of age. Five oral antiviral agents have been approved for the treatment of chronic hepatitis B. Telbivudine is more potent than lamivudine but is associated with a high rate of antiviral resistance compared with entecavir or tenofovir. De-novo combination of lamivudine and adefovir reduces the rate of antiviral resistance compared with lamivudine monotherapy. Individualizing dose and duration of pegylated interferon and ribavirin according to on-treatment virologic response may improve sustained virologic response rates. Several specifically targeted antiviral therapies notably protease and polymerase inhibitors are promising but must be used in combination with pegylated interferon and ribavirin. Hepatitis E virus has been reported to result in chronic hepatitis in transplant patients.

SUMMARY

Multiple treatment options are available for hepatitis B but long-term treatment is required. Several specifically targeted antiviral therapies have shown promise. In the meantime, individualizing dose and duration of pegylated interferon and ribavirin might improve sustained virologic response rates in patients with hepatitis C.

Hepatitis B therapy in children

Chronic hepatitis B virus (HBV) infection is a major cause of liver disease throughout the world, leading to cirrhosis and hepatocellular carcinoma in many individuals. Children are more likely to develop chronic HBV infection as they demonstrate greater immunotolerance to the virus, and response to therapy in children remains disappointing. Three therapeutic agents for chronic HBV infection in children have been approved in the USA, including standard IFN-alpha, lamivudine and adefovir. IFN-alpha has been the most effective ( approximately 30% hepatitis B e antigen [HBeAg] seroconversion; 10% hepatitis B surface antigen [HBsAg] seroconversion), although benefits are primarily observed in children with alanine aminotransferase levels over two-times the upper limit of normal and must be weighed against significant side effects. Studies comparing the long-term outcome of chronic hepatitis B in children treated with IFN-alpha and in untreated controls show that the rate of anti-HBeAb seroconversion tends to overlap in treated and untreated patients within a few years of follow-up, suggesting that IFN-alpha simply accelerates a spontaneous event. Lamivudine's virologic response rates mirror those of IFN-alpha (23-31% HBeAg seroconversion) with easier administration and a better safety profile but lower HBsAg seroconversion (2-3%) and high rates of drug resistance. Adefovir data show low rates of resistance and a good safety profile, but virologic response was limited to adolescent patients and was lower than that of lamivudine (16% HBeAg seroconversion; <1% HBsAg seroconversion). Entecavir and tenofovir, both approved therapies for adults with chronic HBV infection, are in trials for use in children. Future therapies will probably include these agents as well as combined therapies. Finally, watchful waiting of children is an option since current therapies are only 30% effective at best, although the long-term impact of therapy in childhood on rates of cirrhosis and hepatocellular carcinoma remains unknown.

Peginterferon for the treatment of chronic hepatitis B in the era of nucleos(t)ide analogues

The practising clinician is currently faced with a number of effective treatment options for chronic hepatitis B, including two formulations of interferon (standard IFN and pegylated IFN) and five nucleos(t)ide analogues (lamivudine, adefovir, entecavir, telbivudine and tenofovir). Treatment strategies can be divided into those aiming for sustained response after discontinuation of therapy and those that need to be maintained by prolonged antiviral therapy. Sustained response is particularly achieved with interferon-based therapy, while treatment-maintained response can be achieved with long-term nucleos(t)ide analogue therapy in the majority of patients. Of currently available drugs for the treatment of chronic hepatitis B, PEG-IFN seems to result in the highest rate of off-treatment sustained response after a 1-year course of therapy. Sustained transition to the immune-control phase (inactive HBsAg carrier state) can be achieved in 30-35% of HBeAg-positive patients and 20-25% of HBeAg-negative patients. Loss of HBsAg has been observed in 11% of both HBeAg-positive and HBeAg-negative patients after 3-4 years. Since hepatitis B virus (HBV) genotype is an important predictor of response to PEG-IFN, determination of HBV genotype is essential in patients in whom sustained off-treatment response is pursued. Aiming for sustained response is of particular interest because many HBV-infected patients are in need of antiviral therapy at a young age and may otherwise require indefinite antiviral therapy.

Natural history: the importance of viral load, liver damage and HCC

Chronic hepatitis B and hepatitis C virus infections are the major causes of liver disease, hepatocellular carcinoma (HCC) and liver-related mortality worldwide. Among factors known to influence the natural history of viral hepatitis are age at the time of infection, duration of infection, serum alanine aminotransferase (ALT) levels, male sex, alcohol consumption, and coinfections. In hepatitis B, serum HBV DNA concentration emerges as the key factor for predicting the development of liver disease. Even patients with low viraemia seem at increased risk for liver cirrhosis and HCC. Coinfections with hepatitis C, hepatitis D and/or HIV are common and are associated with a more severe liver disease. The course of chronic hepatitis C is variable, but usually fibrosis advances slowly. In addition to the better-known factors- including coinfections with HBV and HIV- progression of liver disease is adversely affected by smoking, hepatic steatosis and insulin resistance.