Therapy of hepatitis B -- viral suppression or eradication?

Interferon and Hepatitis B: Current and Future Perspectives

Chronic hepatitis B virus (HBV) infection remains a major health burden worldwide for which there is still no effective curative treatment. Interferon (IFN) consists of a group of cytokines with antiviral activity and immunoregulatory and antitumor effects, that play crucial roles in both innate and adaptive immune responses. IFN-α and its pegylated form have been used for over thirty years to treat chronic hepatitis B (CHB) with advantages of finite treatment duration and sustained virologic response, however, the efficacy is limited and side effects are common. Here, we summarize the status and unique advantages of IFN therapy against CHB, review the mechanisms of IFN-α action and factors affecting IFN response, and discuss the possible improvement of IFN-based therapy and the rationale of combinations with other antiviral agents in seeking an HBV cure.

Quantitative HBsAg levels do not identify hepatic fibrosis in HBeAg-negative chronic hepatitis B patients

BACKGROUND/AIMS

Quantitative serum hepatitis B surface antigen (qHBsAg) has been evaluated in limited patient groups as a marker of histological fibrosis. The accurate identification of inactive chronic hepatitis B virus (HBV) carriers from those with active carriers is difficult because of wide and frequent HBV DNA fluctuations. We aimed to assess the utility of qHBsAg in distinguishing histologically significant fibrosis in untreated HBeAg-negative chronic HBV patients.

PATIENTS AND METHODS

qHBsAg levels were measured at baseline as single-point quantification and correlated with virologic and biochemical profiles of consecutive carriers (median, 29; range, 12-110 months). HBeAg-negative patients (n = 75) with HBV DNA <2000 (n = 5), 2000-20,000 (n = 16) and >20,000 IU/mL (n = 54) were included and all had liver biopsy. A qHBsAg cutoff point of 1000 IU/mL was assessed to demonstrate whether it better delineated patients with non-significant histology (F0-1, inflammatory grade A0-1).

RESULTS

Mean age of the patients was 39.4 ± 11.4 years and 58 (77.3%) were male. Patients with qHBsAg levels >1000 IU/mL were more likely to be males (84.5%, P = 0.006) or with elevated AST (68.4%, P = 0.0002) and ALT levels (72.4%, P < 0.0001), higher HBV DNA (log₁₀ 6.4 ± 1.4, P < 0.0001) and those with F2-4 fibrosis (48.3%, P = 0.028). Serum log₁₀ qHBsAg were significantly lower in patients with HBV DNA <2000 (2.80 ± 1.47) and HBV DNA 2000-20,000 (2.71 ± 0.83) vs. >20,000 IU/mL (3.89 ± 0.61, P < 0.0001). Overall, qHBsAg were not different in patients with F0-1 (3.44 ± 0.91) and F2-4 fibrosis (3.74 ± 0.85, P = 0.161). Serum qHBsAg were higher in patients with significant (A2-3) inflammation (3.85 ± 0.72) compared to A0-1 (3.38 ± 0.95; P = 0.018). Serum qHBsAg demonstrated poor accuracy (AUROC, 0.61, P = 0.111) in identification of F2-4 fibrosis.

CONCLUSION

Serum qHBsAg levels do not help differentiate between those with HBV DNA <2000 or 2000 - 20,000 IU/mL or distinguish patients with significant fibrosis. Moreover, more than half of the patients with non-significant fibrosis have a qHBsAg level greater than 1000 IU/mL.

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

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

Relationship between adhesion molecules and virological response to pegylated interferon-alpha-2a treatment in patients with chronic hepatitis B: A pilot study

AIM

We performed a clinical study to investigate potential association between serum levels of soluble adhesion molecules and virological response to pegylated interferon-alpha-2a (PEG IFN-α-2a) treatment in patients with chronic hepatitis B (CHB).

METHODS

Thirty-two patients with chronic hepatitis B virus genotype B were recruited in this study, who were treated with PEG IFN-α-2a 180 μg every week and then followed up for 24 weeks. Thirty healthy control subjects were recruited from volunteer blood donors. Serum concentrations of soluble intercellular adhesion molecule-1 (sICAM-1), soluble vascular cell adhesion molecule-1 (sVCAM-1), soluble E-selectin (sE-selectin), soluble L-selectin (sL-selectin) in patients were investigated by enzyme-linked immunoassay before and after treatment.

RESULTS

Serum concentrations of sICAM-1, sVCAM-1, sE-selectin and sL-selectin in CHB patients were significantly higher compared to the control group before treatment (P < 0.00001, respectively). In CHB patients responding to the PEG IFN-α-2a treatment, serum levels of sICAM-1, sVCAM-1, sE-selectin and sL-selectin were higher than those in non-responders before treatment (PI  = 0.001, PV  = 0.002, PE  = 0.02, PL  = 0.004). The levels of sICAM-1, sVCAM-1, sE-selectin and sL-selectin decreased in virological responders of treatment at 12 and 24 weeks (PI  = 0.0001, PV  = 0.00004, PE  = 0.002, PL  = 0.0004; PI  = 0.00007, PV  = 0.00001, PE  = 0.0003, PL  = 0.00003), while no obvious changes were observed in non-responders (P > 0.05, respectively).

CONCLUSION

Results obtained indicated increased levels of sICAM-1, sVCAM-1, sE-selectin and sL-selectin could be related to virological response to PEG IFN-α-2a treatment in CHB patients, and have a prognostic effect on virological response.

Safety and efficacy of two-step peginterferon α-2a treatment in patients of chronic hepatitis B with acute exacerbation

The focus of this study was to evaluate the safety and efficacy of sequential peginterferon α-2a (Pegasys) therapy for chronic hepatitis B with acute exacerbation [ALT > 10 × upper limit of normal (ULN), bilirubin <2.0 mg/dL]. Four groups of patients categorized by HBeAg status and treatment regimens were studied since May 2007. Nineteen HBeAg-positive patients (Group 1) had received entecavir  pretreatment  (when ALT > 10 × ULN) plus Pegasys (180 μg/kg/week, when ALT was 5-10 × ULN) for 24 weeks. Thirteen HBeAg-negative patients (Group 2) had the same protocol for 48 weeks. In both groups, entecavir was then discontinued 14 days after the initiation of Pegasys. The results were compared, respectively, to 35 HBeAg-positive patients (Group 3) and 24 HBeAg-negative patients (Group 4), all with ALT > 5 × ULN, under continual entecavir monotherapy. The ALT levels of patients in Group 1 and 2 who had received entecavir pretreatment for a duration of 19.63 ± 3.34 days were below four times of ULN following 4 weeks of Pegasys treatment. At week 96, the rates of sustained virological response were 69.2% (9/13) and 80% (8/10), and the relapse rates were 23.1% (3/13) and 11.2% (1/9) for HBeAg-positive and HBeAg-negative patients with two-step Pegasys treatment, respectively. The HBeAg seroconversion rates were 46.2% in Group 1, and 42.1% in Group 3; HBsAg loss rates were 15.4% (2/13) in Group 1, and 30% (3/10) in Group 2, whereas none achieved HBsAg loss with entecavir monotherapy (Group 3 and 4). The two-step Pegasys treatment offers an alternative, other than the nucleos(t)ides, for treating chronic hepatitis B with acute exacerbation and provides a safe, efficacious, short-term and finite strategy.

Impact of liver steatosis on response to pegylated interferon therapy in patients with chronic hepatitis B

AIM

To evaluate the impact of liver steatosis upon response to given therapy in chronic hepatitis B (CHB) patients.

METHODS

84 consecutive CHB patients treated with 48-wk PEGylated interferon (PEG-IFN) therapy were enrolled. Baseline characteristics and sustained viral response (SVR) to PEG-IFN therapy were evaluated.

RESULTS

Mean body mass index (BMI) was 27.36 ± 4.4 kg/m². Six (7.1%) had hypertension and three (3.5%) had diabetes mellitus. Steatosis was present in 22.6% (19/84) of liver biopsy samples. Age, BMI, and triglyceride levels of the patients with hepatic steatosis were significantly higher than those without hepatic steatosis (P < 0.05). SVR to PEG-IFN therapy was 21.4% (18/84). Sixteen of these 18 CHB patients with SVR (88.9%) did not have any histopathologically determined steatosis. On the other hand, only two of the 19 CHB patients with hepatic steatosis had SVR (10.5%). Although the SVR rate observed in patients without steatosis (16/65, 24.6%) was higher compared to those with steatosis (2/19, 10.5%), the difference was not statistically significant (P > 0.05).

CONCLUSION

Occurrence of hepatic steatosis is significantly high in CHB patients and this association leads to a trend of decreased, but statistically insignificant, SVR rates to PEG-IFN treatment.

Sequential therapy with adefovir dipivoxil and pegylated interferon alfa-2a for HBeAg-negative patients

To assess the impact of sequential therapy with adefovir dipivoxil (ADV) and pegylated interferon alfa-2a (PEG-IFN) on virological (serum HBV-DNA) and serological (serum HBsAg) response in 20 consecutive HBeAg-negative patients. Patients received ADV for 20 weeks, then ADV and PEG-IFN for 4 weeks and lastly PEG-IFN for 44 weeks. Serum HBV-DNA and HBsAg were assessed at baseline, during therapy (weeks 20, 44 and 68) and follow-up (weeks 92 and 116). Sustained virological response (SVR) was defined as serum HBV-DNA <10 000 copies/mL (partial) or <70 copies/mL (complete) 24 weeks after stopping treatment. A serological response was defined as a serum HBsAg decrease ≥1 log(10) IU/mL at the end of treatment. Baseline median serum HBV-DNA and HBsAg levels were 7.6 log(10) copies/mL and 3.8 log(10) IU/mL, respectively. Ten patients (50%) achieved SVR, six of them had partial response and four complete response. Four patients (20%) achieved serological response. Complete SVRs showed a major and steep decline in HBsAg level with a median decrease of 0.5, 1.6 and 2.0 log(10) IU/mL at treatment week 20, 44 and 68, respectively. Partial SVRs showed a slight and slow decline in serum HBsAg level (0.1, 0.4, and 0.6 log IU/mL at weeks 20, 44 and 68, respectively). On-treatment serum HBsAg decrease had a high accuracy to predict SVR (AUROC = 0.88). Our results suggest that sequential therapy might be an interesting strategy for HBeAg-negative patients. Serum HBsAg kinetics seem to be an accurate tool to predict SVR. Large clinical trials are needed to explore this strategy with more potent analogues.

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.

Serum HBeAg sero-conversion correlated with decrease of HBsAg and HBV DNA in chronic hepatitis B patients treated with a therapeutic vaccine

Currently, there are various approaches for developing therapeutic vaccines for chronic hepatitis B patients. Previously, an antigen-antibody-based therapeutic vaccine (YIC) has been conducted in a double-blind placebo controlled phase IIb clinical trial in 242 chronic hepatitis B patients. At the end of follow-up for 24 weeks, HBeAg sero-conversion rate was 21.6% in the 60 μg immunized group, compared to 9% in the alum immunized control group (p=0.03). To analyze the correlation between HBeAg-seroconversion, and decrease of serum HBsAg and HBV DNA, serum samples were back quantified for serum HBsAg and HBV DNA collected at baseline, end of treatment, and end of follow-up from patients who were treated either with 60 μg of YIC, or with placebo. Patients were dichotomized to HBeAg sero-converted and non-converted groups in comparison with patients in the placebo group. The correlations between HBeAg seroconversion and the decrease of HBsAg, HBV DNA and ALT levels during study period were analyzed using a logistic regression model. Results showed marked and sustained reduction of HBsAg, HBV DNA and ALT level in HBeAg sero-converted patients compared to those in patients of HBeAg non-converted and placebo groups. Reduction of HBV DNA and elevation of ALT was markedly associated with HBeAg seroconversion with an adjusted OR of 0.09 (95%CI: 0.01-0.62) and 0.08 (95%CI: 0.02-0.37) respectively after adjusted by age and sex, while reduction of HBsAg level was close to of significance (p=0.054). Analysis indicated that HBeAg sero-conversion was a reasonable endpoint for therapeutic vaccination.

Combination therapy of lamivudine and interferon-alpha in pediatric patients with chronic hepatitis B in Bangladesh: a safe and effective therapeutic approach for pediatric CHB patients in developing countries

Hepatitis B virus (HBV) is mainly transmitted during birth or perinatal period, however, treatment is not usually recommended for pediatric patients with chronic hepatitis B (CHB). Twelve pediatric patients with CHB in Bangladesh were treated with both lamivudine and interferon. Lamivudine was given at a dose of 3 mg/kg, daily for 12 months. Two months after commencement of lamivudine therapy, all patents were given interferon-alpha (3 million IU/square meter of body surface area) three times weekly, subcutaneously for 10 months. Combination therapy was safe for all pediatric CHB patients. The levels of serum HBV DNA became undetectable (less than 500 copies/ml) in 8 patients and reduced in 4 patients after the end of therapy. Anti-HBe was detected in 10 of 12 patients at this time point. The levels of serum alanine aminotransferase (ALT) were significantly reduced in these patients (p less than 0.05) due to therapy. Neither flare of HBV DNA nor elevation of serum ALT were detected during follow-up. In conclusion, combination therapy with lamivudine and interferon-alpha represents a new and novel therapeutic option for treatment of pediatric CHB patients.

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.

Entecavir for the long-term treatment of chronic hepatitis B

Hepatitis B virus is a major cause of chronic liver disease worldwide and is associated with an increased risk of hepatocellular carcinoma, progressive hepatic fibrosis and end-stage liver disease. Suppression of HBV replication is recognized as the primary on-treatment goal of antiviral therapy, as reduction of serum HBV DNA to low or undetectable levels is highly likely to have a positive impact on long-term clinical outcomes in HBV-associated chronic liver disease. Entecavir is an oral nucleoside analogue that effectively inhibits HBV polymerase, resulting in rapid viral suppression. Long-term data on patients receiving entecavir for chronic hepatitis B have demonstrated high potency, a low incidence of antiviral drug resistance and good tolerability, making entecavir an ideal first-line agent for the treatment of chronic hepatitis B.

Loss of HBsAg antigen during treatment with entecavir or lamivudine in nucleoside-naïve HBeAg-positive patients with chronic hepatitis B

This retrospective analysis was conducted to describe the characteristics of nucleoside-naïve hepatitis B e antigen (HBeAg)-positive patients with chronic hepatitis B, who achieved hepatitis B surface antigen (HBsAg) loss during entecavir or lamivudine therapy. HBeAg-positive adults with chronic hepatitis B, elevated serum alanine aminotransferase, and compensated liver disease were randomized to double-blind treatment for up to 96 weeks with entecavir 0.5 mg/day or lamivudine 100 mg/day. HBsAg and hepatitis B virus (HBV) DNA were measured at regular intervals during and off-treatment follow-up. Through a maximum duration of 96 weeks on-treatment and 24 weeks off-treatment, HBsAg loss was confirmed in 18/354 (5.1%) patients treated with entecavir and 10/355 (2.8%) patients treated with lamivudine. Among the 28 patients with confirmed HBsAg loss, 27 (96%) achieved HBV DNA <300 copies/mL, and 27 (96%) achieved confirmed HBeAg loss. All entecavir recipients with HBsAg loss had HBV DNA <300 copies/mL. Caucasian patients, and those infected with HBV genotype A or D, were significantly more likely to lose HBsAg. This retrospective analysis of data from a randomized, global phase three trial shows that confirmed loss of HBsAg occurred in 5% of nucleoside-naïve HBeAg-positive patients treated with entecavir, and that HBsAg loss is associated with sustained off-treatment suppression of HBV DNA.

Treatment of hepatitis B virus-infected patients: utility of therapeutic recommendations in developing countries

BACKGROUND

The treatment of individuals infected with hepatitis B virus (HBV) is a complex issue in practical settings, despite the explosion of new and effective antiviral agents.

OBJECTIVE

To assess the scope and limitations of ongoing treatment guidelines against HBV from a global perspective.

METHODS

Present therapeutic guidelines against HBV have been discussed with emphasis on their value in developing countries that harbor about 90% of the total number of global patients who are infected with HBV.

RESULTS/CONCLUSION

Treatment of HBV-infected patients should be appropriately followed up and healthcare delivery systems should be able to combat treatment-induced adverse side effects. Current therapeutic guidelines should be optimized based on the socio-economic conditions of developing countries.

Chronic hepatitis B and C: update on therapy

Chronic infections with HBV and HCV are a major cause of liver-associated morbidity and mortality worldwide. An increased knowledge of HBV and HCV virology, natural history and predictors of virological response has led to the development of new strategies to improve treatment outcomes. The use of new antiviral agents with greater potency and a high genetic barrier to resistance, as well as on-treatment monitoring of virological response, may result in improved outcomes in HBV therapy. A greater understanding of predictors of virological response has led to the ability to individualize therapy in chronic HCV infection. Several new antiviral agents specifically targeting HCV are in development and should have a major impact on treatment response rates over the next few years.

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.

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.

Early serum HBsAg drop: a strong predictor of sustained virological response to pegylated interferon alfa-2a in HBeAg-negative patients

Pegylated interferon alfa-2a (PEG-IFN) may induce sustained virological response (SVR) in 20% of hepatitis B e antigen (HBeAg)-negative chronic hepatitis B (CHB) patients. In addition, loss of hepatitis B surface antigen (HBsAg) is achieved with a 10% yearly rate after treatment cessation in sustained responders. The aim of this study was to assess on-treatment serum HBsAg kinetics to predict SVR in HBeAg-negative patients treated with PEG-IFN. Forty-eight consecutive patients were treated with PEG-IFN (180 microg/week) for 48 weeks. Serum hepatitis B virus (HBV) DNA (COBAS TaqMan) and HBsAg (Abbott Architect HBsAg QT assay) were assessed at baseline, during treatment (weeks 12, 24, and 48), and during follow-up (weeks 72 and 96). SVR was defined as undetectable serum HBV DNA (<70 copies/mL) 24 weeks after treatment cessation. Twenty-five percent of patients achieved SVR. They were not different from those who failed treatment regarding age, sex, ethnicity, HBV genotype, baseline serum HBV DNA and HBsAg levels, or liver histology. During treatment, serum HBsAg levels decreased only in patients who developed SVR, with mean decreases of 0.8 +/- 0.5, 1.5 +/- 0.6, and 2.1 +/- 1.2 log(10) IU/mL at weeks 12, 24, and 48, respectively. A decrease of 0.5 and 1 log(10) IU/mL in serum HBsAg levels at weeks 12 and 24 of therapy, respectively, had high predictive values of SVR (negative predictive value [NPV] 90%, positive predictive value [PPV] 89% for week 12; NPV 97%, PPV 92% for week 24). HBsAg loss was observed in three patients, all with SVR.

CONCLUSION

Early serum HBsAg drop has high predictive values of SVR to PEG-IFN in HBeAg-negative CHB patients. Serum quantitative HBsAg may be a useful tool to optimize the management of PEG-IFN therapy in these patients.

A treatment algorithm for the management of chronic hepatitis B virus infection in the United States: 2008 update

Chronic HBV infection is an important public health problem worldwide and in the United States. A treatment algorithm for the management of this disease, published previously by a panel of U.S. hepatologists, has been revised on the basis of new developments in the understanding of the disorder, the availability of more sensitive molecular diagnostic tests, and the licensure of new therapies. In addition, a better understanding of the advantages and disadvantages of new treatments has led to the development of strategies for reducing the rate of resistance associated with oral agents and optimizing treatment outcomes. This updated algorithm was based primarily on available evidence by using a systematic review of the literature. Where data were lacking, the panel relied on clinical experience and consensus expert opinion. The primary aim of antiviral therapy is durable suppression of serum HBV DNA to low or undetectable levels. Assays can now detect serum HBV DNA at levels as low as 10 IU/mL and should be used to establish a baseline level, monitor response to antiviral therapy, and survey for the development of drug resistance. Interferon alfa-2b, lamivudine, adefovir, entecavir, peginterferon alfa-2a, telbivudine, and tenofovir are approved as initial therapy for chronic hepatitis B and have certain advantages and disadvantages. Although all of these agents can be used in selected patients, the preferred first-line treatment choices are entecavir, peginterferon alfa-2a, and tenofovir. Issues for consideration for therapy include efficacy, safety, rate of resistance, method of administration, and cost.

Advances in the diagnosis and treatment of hepatitis B

PURPOSE OF REVIEW

Hepatitis B virus is responsible for much morbidity and mortality worldwide. Although the armament of drugs licensed for its treatment grows, it is increasingly apparent that the efficacy of these drugs is dependent upon much more that their pharmacology.

RECENT FINDINGS

A better understanding of the natural history of chronic hepatitis B infection together with recent advances in the molecular biology of antiviral resistance have given added dimensions to physicians' decision-making thought processes.

SUMMARY

The present review outlines the recent advances in diagnostic testing that enable a better understanding of an individual patient's phase of illness and also how such information can update treatment choices better. In the second part of this review, the licensed therapies and their relative merits are discussed, as is their role in managing resistance to antiviral therapy.

Tailored regimen of interferon alpha for HBeAg-positive chronic hepatitis B: a prospective controlled study

The response to interferon-alpha treatment of patients with chronic hepatitis B under the current protocol is not satisfactory. The aim of this study was to try an alternative approach to improve treatment outcome. Of 374 HBeAg-positive patients, 127 of them received 5 million units of interferon-alpha thrice weekly for 6 months and constituted the control group, while 247 in the study group received the same dosage but the duration of treatment was tailored. The study protocol provided for continuation of treatment if HBV DNA levels were continuously decreasing. The treatment ended when viral, antigenic and biochemical endpoints were reached or when HBV DNA levels were no longer decreasing. The median length of tailored treatment was 10 (range 6-24) months. The end-of-treatment response rates were 39.3% and 23.6% (P = 0.002), and after 12-month, follow-up, the sustained response rates were 40.5% and 28.3% (P = 0.013) in the study and control groups, respectively. Excluding the patients who dropped out, 228 and 115 completed a median of 40- and 44-month-long follow-up; the long-term response was thus 45.3% and 33.1% (P = 0.014) in the respective groups. Interferon-alpha treatment tailored in length demonstrated significantly increased efficacy in patients with chronic hepatitis B.

Diagnosis of hepatitis B virus infection through serological and virological markers

Hepatitis B virus (HBV) infection is an important health problem and the major cause of chronic hepatitis, cirrhosis and hepatocellular carcinoma (HCC) worldwide. The natural history of chronic HBV infection can be divided into four dynamic phases in HBV carriers who acquire the virus early in life. Diagnosis of HBV infection is usually through serological and virological markers. Hepatitis B surface antigen (HBsAg) is the hallmark of HBV infection and is the first serological marker to appear in acute hepatitis B, and persistence of HBsAg for more than 6 months suggests chronic HBV infection. Hepatitis B e antigen (HBeAg) usually indicates active HBV replication and risk of transmission of infection. Recently, occult HBV infection is recognized as the absence of circulating HBsAg in individuals positive for serum or tissue HBV DNA, irrespective of other HBV serological markers. Meanwhile, monitoring the serum HBV DNA level is valuable for assessing liver disease activity, differentiating other etiologies of hepatitis activity in HBV carriers, predicting risk of HCC development or liver-related mortality, deciding to administer antiviral therapy, determination of the response to antiviral treatment, predicting the risk of developing drug resistance, and detecting the emergence of drug-resistant mutants. On the other hand, HBV genotype C, basal core promoter mutant and pre-S deletion mutant are reported to be associated with increased risk of HCC development. The roles of quantitative HBV serology and intrahepatic HBV covalently closed circular (ccc)DNA deserve further studies. In conclusion, it is particularly important for physicians to screen for HBV infection in HBV-endemic areas and to monitor liver disease progression in HBV carriers by using both serological and virological markers, so that effective treatment can be initiated early before the development of advanced liver disease.

Review article: current antiviral therapy of chronic hepatitis B

BACKGROUND

The long-term goals of therapy for chronic hepatitis B are to reduce serum HBV DNA to low or undetectable levels and ultimately reduce or prevent the development of cirrhosis and hepatocellular carcinoma.

AIM

To review the current treatment of chronic hepatitis B, with a focus on diagnosis and management of resistance and active management of suboptimal responses.

METHODS

A systematic review of the literature, with a focus on recent guidelines, was undertaken.

RESULTS

Among the six drugs licensed for the treatment of chronic hepatitis B in the US, the preferred agents in 2008 will include entecavir, peginterferon alfa-2a, possibly telbivudine, and tenofovir following licensure. When using an oral agent, a major focus of management is on the selection of a drug with high potency and low rate of resistance, and active on-treatment management to optimize therapy. Preventing the sequelae of antiviral drug resistance and appropriate management when resistance is initially detected are also the major focus of current management. The addition of an antiviral agent that is not cross-resistant is critical to restore suppression of viral replication.

CONCLUSIONS

Newer agents and modified treatment strategies, especially using combination therapy, hold promise to optimize the management of patients with chronic hepatitis B by achieving the high potency and the lowest rate of resistance.

Hepatitis B: reflections on the current approach to antiviral therapy

This article summarizes the current state of antiviral therapy of hepatitis B with special attention given to areas that remain controversial or poorly defined. Strict adherence to liver association practice guidelines may result in missed opportunities to treat patients with significant underlying liver disease. In particular, recommended ALT thresholds may not appropriately reflect disease activity or degree of fibrosis. There is growing evidence that an alternative treatment paradigm for preventing late-stage disease complications may be indicated in highly viremic patients with early life exposure to hepatitis B. Pegylated interferon therapy is often a better choice for young to middle-aged patients with genotype A and B because of the higher rate of HBeAg seroconversion and a greater chance for HBsAg seroconversion in both HBeAg-positive and -negative patients as compared to nucleoside analogs. Nucleoside analog monotherapy is the current standard of care for many patients. However, long-term monotherapy results in resistance to a variable degree and sequential monotherapy may result in multi-drug resistant virus. Which patients would specifically benefit from early combination therapy also remains poorly defined. The rapidity and robustness of the suppression of HBV DNA while on a nucleoside analog should be monitored relatively early during treatment because it affects treatment outcome and the rate of resistance. While great progress has been made in treating hepatitis B, many important issues require further study.

Lamivudine-resistant chronic hepatitis B: an observational study on adefovir in monotherapy or in combination with lamivudine

BACKGROUND/AIMS

In lamivudine-resistant patients with chronic hepatitis B (CHB), we compared efficacy, predictive response factors and changes in viral mutants in two antiviral approaches with adefovir.

METHODS

A prospective cohort study on therapy with adefovir alone (29 patients) or combined with ongoing lamivudine (23 patients) was performed.

RESULTS

A virological response was achieved in 55% of patients treated with adefovir and in 83% of those treated with the combination (p>0.05). This response was directly related to the basal viral load (p<0.0001) and obtained in 10 patients with basal HBV-DNA<17,200 IU/ml using both strategies. In patients with a higher basal viral load, the virological response was more frequent when treated with the combination (p<0.05). Mutation at locus rt181 predicted HBV-DNA persistence during therapy. A virological rebound was observed in 18% of non-responders while on adefovir monotherapy.

CONCLUSIONS

To achieve a complete virological response and reduce the risk of adefovir-resistant mutants in lamivudine-resistant patients, rescue therapy is preferable at early evidence of genotypic resistance. However, in subjects with a significant viral load, combination therapy is more effective. The presence of the rt181 mutation is associated with incomplete response.

Cellular chromosome DNA interferes with fluorescence quantitative real-time PCR detection of HBV DNA in culture medium

Fluorescence quantitative real-time PCR (FQ-PCR) is a recently developed technique increasingly used for clinical diagnosis by detection of hepatitis B virus (HBV) DNA in serum. FQ-PCR is also used in scientific research for detection of HBV DNA in cell culture. Understanding potential FQ-PCR interference factors can improve the accuracy of HBV DNA quantification in cell culture medium. HBV positive serum was diluted with culture medium to produce three test groups with HBV DNA levels of 5 x 10(7) copies/ml (high), 5 x 10(5) copies/ml (medium), and 5 x 10(3) copies/ml (low). Chromosome DNA was extracted from HepG2 cells and then added to high, medium, and low group samples at final concentrations of 0, 12.5, 25, 50, and 100 microg/ml. The samples were quantified by FQ-PCR and data were evaluated using statistical software. No marked changes were seen in the quantitative curves for high level HBV DNA samples when the samples were supplemented with 0-100 microg/ml of chromosome DNA. Interference was observed in medium level samples when 50 and 100 microg/ml of chromosome DNA was added. Interference was also observed in low level HBV DNA samples when the concentration of added chromosome DNA was greater than 25 microg/ml. The interference was eliminated when samples were digested by DNase I prior to PCR detection. In Conclusions, the presence of cellular chromosome DNA can interfere with the detection of HBV DNA by FQ-PCR. Removal of cellular chromosome DNA from culture media prior to FQ-PCR is necessary for reliable HBV DNA quantitative detection.

Cost-effectiveness analysis of entecavir versus lamivudine in the first-line treatment of Australian patients with chronic hepatitis B

BACKGROUND

Chronic hepatitis B (CHB) virus infection is a major global healthcare problem. The recent introduction of entecavir in Australia for the treatment of CHB patients in the naive treatment setting has triggered significant optimism with regards to improved clinical outcomes for CHB patients.

OBJECTIVE

To estimate, from an Australian healthcare perspective, the cost effectiveness of entecavir 0.5 mg/day versus lamivudine 100 mg/day in the treatment of CHB patients naive to nucleos(t)ide therapy.

METHODS

A cost-utility analysis to project the clinical and economic outcomes associated with CHB disease and treatment was conducted by developing two decision-tree models specific to hepatitis B e antigen-positive (HBeAg+ve) and HBeAg-ve CHB patient subsets. This analysis was constructed using the Australian payer perspective of direct costs and outcomes, with indirect medical costs and lost productivity not being included. The study population comprised a hypothetical cohort of 1000 antiviral treatment-naive CHB patients who received either entecavir 0.5 mg/day or lamivudine 100 mg/day at model entry. The population of patients used in this analysis was representative of those patients likely to receive initial antiviral therapy in clinical practice in Australia. The long-term cost effectiveness of entecavir compared with lamivudine in the first-line treatment of CHB patients was expressed as an incremental cost per life-year gained (LYG) or QALY gained.

RESULTS

Results revealed that the availability of entecavir 0.5 mg/day as part of the Australian hepatologist's treatment armamentarium should result in significantly lower future rates of compensated cirrhosis (CC), decompensated cirrhosis (DC), and hepatocellular carcinoma (HCC) events (i.e. 54 fewer cases of CC, seven fewer cases of DC, and 20 fewer cases of HCC over the model's timeframe for HBeAg+ve CHB patients, and 69 fewer cases of CC, eight fewer cases of DC and 25 fewer cases of HCC over the model's timeframe for HBeAg-ve CHB patients). Compared with lamivudine 100 mg/day, entecavir 0.5 mg/day generated an estimated incremental cost per LYG of Australian dollars ($A, year 2006 values) 5046 and an estimated incremental cost per QALY of $A5952 in the HBeAg+ve CHB patient population, an estimated incremental cost per LYG of $A7063 and an estimated incremental cost per QALY of $A8003 in the HBeAg-ve CHB patient population, and an overall estimated incremental cost per LYG of $A5853 and an estimated incremental cost per QALY of $A6772 in the general CHB population.

CONCLUSION

The availability of entecavir in Australian clinical practice should make long-term suppression of hepatitis B virus replication increasingly attainable, resulting in fewer CHB sequelae, at an acceptable financial cost.

Role of viral factors in the natural course and therapy of chronic hepatitis B

Hepatitis B virus (HBV) infection is a global health problem that causes a wide spectrum of liver disease, including acute or fulminant hepatitis, inactive carrier state, chronic hepatitis, cirrhosis, and hepatocellular carcinoma (HCC). The pathogenesis of hepatocyte damage associated with HBV is mainly through immune-mediated mechanisms. On the basis of the virus and host interactions, the natural history of HBV carriers who are infected in early life can be divided into four dynamic phases. The frequency, extent, and severity of hepatitis flares or acute exacerbation in the second immune clearance and/or fourth reactivation phase predict liver disease progression in HBV carriers. In the past decade, hepatitis B viral factors including serum HBV DNA level, genotype, and naturally occurring mutants predictive of clinical outcomes have been identified. The higher the serum HBV DNA level after the immune clearance phase, the higher the incidence of adverse outcomes over time. In addition, high viral load, genotype C, basal core promoter mutation, and pre-S deletion correlate with increased risk of cirrhosis and HCC development. As to the treatment of chronic hepatitis B, patients with high HBV DNA level and genotype C or D infection are shown to have a worse response to interferon therapy. In conclusion, serum HBV DNA level, genotype, and naturally occurring mutants are identified to influence liver disease progression and therapy of chronic hepatitis B. More investigations are needed to clarify the molecular mechanisms of the viral factors involved in the pathogenesis of each stage of liver disease and the response to antiviral treatments.

Defining Optimal Therapeutic Outcomes in Chronic Hepatitis

The definition of optimal therapeutic response has been evolving concurrent with the advancement of diagnostic tests. What once was considered "therapeutic success" is considered now disease persistence or relapse. As the laboratory tools become increasingly sensitive, it follows that the criteria of successful therapeutic response are becoming more stringent. The main objectives of chronic hepatitis B and C treatment are to achieve eradication of the virus and, with this, reduction or prevention of hepatic injury and disease progression. However, in the case of hepatitis B, viral suppression is for the moment a more realistic therapeutic objective, although eradication still remains the ultimate goal. In chronic hepatitis C, sustained virologic response, defined as the absence of HCV RNA 6 months post-antiviral treatment completion, is within reach. Better test sensitivity allows for additional levels of confidence in the achievements of virus eradication in patients with hepatitis C. Challenges persist despite great advances in the treatment of chronic viral hepatitis. Now that clearer therapeutic outcomes have been refined, more efficacious, and better-tolerated drugs may change the current therapeutic landscape of chronic viral hepatitis B and C.

Experiences on antiviral treatment for chronic viral B and C hepatitis patients in Hungary. 1998–2004

Az utolsó évtizedben számos multicentrikus, randomizált vizsgálat bizonyította az előrehaladást a krónikus vírushepatitisek kezelésében. Ugyanakkor csak korlátozott számú és ellentmondásos adatokat közöltek az antivirális terápia reális értékéről a mindennapos rutin klinikai gyakorlatában. Cél: Retrospektív felmérést végeztünk a terápia hatékonyságának megállapítására krónikus B- és C-hepatitisben, egy 7 éves periódus alatt kezelt országos populációban. Emellett bemutatjuk még egy hazai prospektív vizsgálat néhány adatát is. Módszerek: 220 krónikus B-hepatitises beteget kezeltünk, közülük 112 standard interferon-, 23 pegilált interferon-, 85 lamivudin-terápiában részesült, akikben a HbeAg-szerokonverzió és/vagy HBV-DNS-negatívvá válás arányát vizsgáltuk. A retrospektív elemzésben szereplő 2442 krónikus C-hepatitises közül 333 standard interferon-monoterápiát, 1122 standard interferon + ribavirin kombinációt és 987 pegilált interferon + ribavirin-kezelést kapott. A prospektív vizsgálatban 69 HCV1-beteg pegilált interferon α-2a + ribavirin terápiában részesült 6–12 hónapon át. A tartós virológiai válasz mellett vizsgáltuk a kedvező kimenetel prediktorait és a mellékhatások előfordulását. Eredmények: Krónikus B-hepatitisben a standard interferon 31%-os, a pegilált interferon 30%-os, a lamivudin 31–33%-os tartós vírusnegativitáshoz vezetett. Krónikus C-hepatitisben a tartós virológiai válasz aránya az interferon-monoterápiával észlelt 13%-ról a pegilált interferon + ribavirin mellett 31%-ra nőtt, a prospektív vizsgálatban ez 48% volt. A jó prognózis prediktora a rapid (4 hetes) és a korai (12 hetes) virológiai válasz, a női nem, az életkor, BMI és az adherencia volt. A betegek 9%-ában fordult elő mellékhatás, leggyakrabban cytopenia, haemolysis és depresszió. Következtetés: A krónikus B-hepatitisszel ellentétben, a hepatitis C-vírusinfekció kezelésének effektivitása hazánkban is fokozatosan javult. A mindennapi gyakorlat országos adatai azonban elmaradnak a prospektív vizsgálat sikerességétől. A jövőben hatékonyabb terápiás stratégiák szükségesek, beleértve az individualizált dozírozást és az új antivirális szerek alkalmazását.

[Treatment of viral hepatitis (I). Treatment of chronic hepatitis B]

In the past 25 years remarkable progress has been made in our understanding of the natural history of chronic HBV. The infection is now perceived as having three consecutive phases: immune tolerance, immune clearance, and inactive carrier status, with possible reactivation episodes. Accumulating evidence indicates that antiviral therapy can prevent progression of HBV-related liver disease, particularly among patients with sustained response. Five agents are now approved for therapy of chronic hepatitis B: interferon-alpha (standard and pegylated), lamivudine, adefovir and entecavir. All five drugs are effective in suppressing HBV DNA levels and improving serum alanineaminotransferase levels and hepatic histology, but it is still unclear who should be treated, with which agent (or combination of agents), for how long, and what endpoints measure the success or failure of treatment. Until a drug therapy results in lasting virological remission in most patients after a reasonably short period of treatment, individualized treatment decisions will remain key to maximizing efficacy, and chronic HBV infection will continue to be treated as a liver disease rather than as an infectious disease.