Peg-interferon improves liver histology in patients with HBeAg-positive chronic hepatitis B: no additional benefit of combination with lamivudine

Efficacy and safety of anti-hepatic fibrosis drugs

Recent progress in our understanding of the pathways linked to progression from hepatic insult to cirrhosis has led to numerous novel therapies being investigated as potential cures and inhibitors of hepatic fibrogenesis. Liver cirrhosis is the final result of prolonged fibrosis, which is an intimate balance between fibrogenesis and fibrinolysis. A number of these complex mechanisms are shared across the various etiologies of liver disease. Thankfully, investigation has yielded some promising results in regard to reversal of fibrosis, particularly the indirect benefits associated with antiviral therapy for the treatment of hepatitis B and C and the farnesoid receptor agonist for the treatment of primary biliary cholangitis and metabolic associated fatty liver disease. A majority of current clinical research is focused on targeting metabolic associated fatty liver disease and its progression to metabolic steatohepatitis and ultimately cirrhosis, with some hope of potential standardized therapeutics in the near future. With our ever-evolving understanding of the underlying pathophysiology, these therapeutics focus on either controlling the primary disease (the initial trigger of fibrogenesis), interrupting receptor ligand interactions and other intracellular communications, inhibiting fibrogenesis, or even promoting resolution of fibrosis. It is imperative to thoroughly test these potential therapies with the rigorous standards of clinical therapeutic trials in order to ensure the highest standards of patient safety. In this article we will briefly review the key pathophysiological pathways that lead to liver fibrosis and present current clinical and experimental evidence that has shown reversibility of liver fibrosis and cirrhosis, while commenting on therapeutic safety.

"Let my liver rather heat with wine" - a review of hepatic fibrosis pathophysiology and emerging therapeutics

Cirrhosis is characterized by extensive hepatic fibrosis, and it is the 14th leading cause of death worldwide. Numerous contributing conditions have been implicated in its development, including infectious etiologies, medication overdose or adverse effects, ingestible toxins, autoimmunity, hemochromatosis, Wilson’s disease and primary biliary cholangitis to list a few. It is associated with portal hypertension and its stigmata (varices, ascites, hepatic encephalopathy, combined coagulopathy and thrombophilia), and it is a major risk factor for hepatocellular carcinoma. Currently, orthotopic liver transplantation has been the only curative modality to treat cirrhosis, and the scarcity of donors results in many people waiting years for a transplant. Identification of novel targets for pharmacologic therapy through elucidation of key mechanistic components to induce fibrosis reversal is the subject of intense research. Development of robust models of hepatic fibrosis to faithfully characterize the interplay between activated hepatic stellate cells (the principal fibrogenic contributor to fibrosis initiation and perpetuation), hepatocytes and extracellular matrix components has the potential to identify critical components and mechanisms that can be exploited for targeted treatment. In this review, we will highlight key cellular pathways involved in the pathophysiology of fibrosis from extracellular ligands, effectors and receptors, to nuclear receptors, epigenetic mechanisms, energy homeostasis and cytokines. Further, molecular pathways of hepatic stellate cell deactivation are discussed, including apoptosis, senescence and reversal or transdifferentiation to an inactivated state resembling quiescence. Lastly, clinical evidence of fibrosis reversal induced by biologics and small molecules is summarized, current compounds under clinical trials are described and efforts for treatment of hepatic fibrosis with mesenchymal stem cells are highlighted. An enhanced understanding of the rich tapestry of cellular processes identified in the initiation, perpetuation and resolution of hepatic fibrosis, driven principally through phenotypic switching of hepatic stellate cells, should lead to a breakthrough in potential therapeutic modalities.

Progression and Regression of Hepatic Lesions in a Mouse Model of NASH Induced by Dietary Intervention and Its Implications in Pharmacotherapy

Understanding of the temporal changes of hepatic lesions in the progression and regression of non-alcoholic steatohepatitis (NASH) is vital to elucidation of the pathogenesis of NASH, and critical to the development of a strategy for NASH pharmacotherapy. There are challenges in studying hepatic lesion progression and regression in NASH patients due to the slow development of NASH in humans, one being the requirement for multiple biopsies during the longitudinal follow-up. Here we studied lesion progression and regression in the diet-induced animal model of NASH by application or removal of the pathogenic diet for multiple time periods. Male C57BL/6 mice fed Western diet developed progressive hepatic steatosis/macrovesicular vacuolation, inflammation, and hepatocyte degeneration, as well as perisinusoidal fibrosis and occasionally portal fibrosis as early as 2 months after initiation of the Western diet. In the same period, the mice exhibited elevated ALT (alanine aminotransferase) and AST (aspartate aminotransferase) enzyme activities, CK18 (cytokeratin−18), PIIINP (N-terminal propeptide of type III collagen), and TIMP-1 (tissue inhibitor of metalloproteinase−1). Hepatic steatosis diminished rapidly when the Western diet was replaced by normal rodent chow diet and hepatic inflammation and hepatocyte degeneration were also reduced. Interestingly, perisinusoidal fibrosis and portal fibrosis regressed 8 months after chow diet replacement. To understand pharmacotherapy for NASH, mice with established NASH hepatic lesions were treated with either FXR agonist obeticholic acid (Ocaliva), or CCR2/5 antagonist Cenicriviroc. Similar to the diet replacement, metabolic modulator Ocaliva markedly reduced steatosis/macrovesicular vacuolation, hepatic inflammation, and hepatocyte degeneration effectively, but exhibited no significant effect on liver fibrosis. Anti-inflammation drug Cenicriviroc, on the other hand, markedly decreased inflammation and hepatocyte degeneration, and mildly decreased liver fibrosis, but exhibited no effect on hepatic steatosis/macrovesicular vacuolation. In conclusion, we found the progression of NASH hepatic steatosis/macrovesicular vacuolation, and inflammation eventually lead to hepatocyte death and fibrosis. Life style change and current pharmacotherapies in development may be effective in treating NASH, but their effects on NASH–induced fibrosis may be mild. Since fibrosis is known to be an independent risk for decompensated cirrhosis, cardiovascular events, and mortality, our study suggests that effective anti-fibrosis therapy should be an essential component of the combined pharmacotherapy for advanced NASH.

Reversal of liver cirrhosis: current evidence and expectations

In the past, liver cirrhosis was considered an irreversible phenomenon. However, many experimental data have provided evidence of the reversibility of liver fibrosis. Moreover, multiple clinical studies have also shown regression of fibrosis and reversal of cirrhosis on repeated biopsy samples. As various etiologies are associated with liver fibrosis via integrated signaling pathways, a comprehensive understanding of the pathobiology of hepatic fibrogenesis is critical for improving clinical outcomes. Hepatic stellate cells play a central role in hepatic fibrogenesis upon their activation from a quiescent state. Collagen and other extracellular material components from activated hepatic stellate cells are deposited on, and damage, the liver parenchyma and vascular structures. Hence, inactivation of hepatic stellate cells can lead to enhancement of fibrolytic activity and could be a potential target of antifibrotic therapy. In this regard, continued efforts have been made to develop better treatments for underlying liver diseases and antifibrotic agents in multiple clinical and therapeutic trials; the best results may be expected with the integration of such evidence. In this article, we present the underlying mechanisms of fibrosis, current experimental and clinical evidence of the reversibility of liver fibrosis/cirrhosis, and new agents with therapeutic potential for liver fibrosis.

Current and future antiviral drug therapies of hepatitis B chronic infection

Despite significant improvement in the management of chronic hepatitis B virus (HBV) it remains a public health problem, affecting more than 350 million people worldwide. The natural course of the infection is dynamic and involves a complex interplay between the virus and the host’s immune system. Currently the approved therapeutic regimens include pegylated-interferon (IFN)-α and monotherapy with five nucleos(t)ide analogues (NAs). Both antiviral treatments are not capable to eliminate the virus and do not establish long-term control of infection after treatment withdrawal. IFN therapy is of finite duration and associates with low response rates, liver decompensating and numerous side effects. NAs are well-tolerated therapies but have a high risk of drug resistance development that limits their prolonged use. The imperative for the development of new approaches for the treatment of chronic HBV infection is a challenging issue that cannot be over-sided. Research efforts are focusing on the identification and evaluation of various viral replication inhibitors that target viral replication and a number of immunomodulators that aim to restore the HBV specific immune hyporesponsiveness without inducing liver damage. This review brings together our current knowledge on the available treatment and discusses potential therapeutic approaches in the battle against chronic HBV infection.

Improving clinical outcomes of chronic hepatitis B virus infection

Chronic hepatitis B virus (HBV) infection is a global health problem, leading to cirrhosis, hepatocellular carcinoma (HCC) and liver-related deaths. Universal hepatitis B vaccination is the most cost-effective way to eradicate HBV infection with the remarkable reduction of chronic carriage, neonatal fulminant hepatitis and childhood HCC. The introduction of highly effective antiviral agents, including lamivudine, adefovir dipivoxil, entecavir, telbivudine, tenofovir disoproxil fumarate and pegylated interferons further improve short-, medium- and long-term outcomes of chronic HBV infection, such as ALT normalization, HBV DNA suppression, HBeAg seroconversion, HBsAg seroclearance, fibrosis regression, reduction of cirrhosis, HCC, liver-related deaths and the need for liver transplantation. Above all, sustained and profound viral suppression is the key to improve the clinical outcomes of chronic hepatitis B.

Combination therapy of interferon and nucleotide/nucleoside analogues for chronic hepatitis B

Chronic hepatitis B is one of the leading causes of cirrhosis and hepatocellular carcinoma globally. At present, seven drugs, including two interferons and five oral nucleos(t)ide analogues (NAs), have been approved for the treatment of chronic hepatitis B. Interferon works by immunomodulation, but is successful in less than a third of treated patients and is a relatively weak antiviral. NAs directly suppress the hepatitis B virus but have limited durability. Based on current data, combination of NA and interferon results in greater viral suppression but does not translate to off-treatment sustained response. Concomitant or sequential treatment also does not make a difference. Combining telbivudine and interferon also runs the risk of severe peripheral neuropathy. On the other hand, interferon switch or additional therapy in patients well controlled with NAs appears to improve the durability of off-treatment response. This article reviews current data on interferon and NA combination and discusses potential future developments.

Loss of intrahepatic HBsAg expression predicts sustained response to peginterferon and is reflected by pronounced serum HBsAg decline

There is a lack of knowledge regarding the effect of peginterferon (PEG-IFN) on the expression of intrahepatic hepatitis B core and surface antigen (HBcAg and HBsAg) in chronic hepatitis B (CHB) and its relation with response to therapy. Fifty-two HBeAg-positive and 67 HBeAg-negative CHB patients with paired liver biopsies taken at baseline and after 1 year of PEG-IFN therapy were studied. After PEG-IFN therapy, HBeAg-negative patients showed a significant reduction in both intrahepatic HBcAg (P = 0.04) and HBsAg expression (P < 0.001). In contrast, a reduction in intrahepatic HBcAg expression was not observed in HBeAg-positive patients, while a trend in reduction of intrahepatic HBsAg staining was found (P = 0.09). Post-treatment, 7 (13%) HBeAg-positive and 9 (14%) HBeAg-negative patients had no expression of intrahepatic HBsAg. Patients without any intrahepatic HBsAg expression post-treatment were more likely to achieve a combined response (HBeAg loss with hepatitis B virus (HBV) DNA <2000 IU/mL for HBeAg -positive and HBV DNA <2000 IU/mL and normal alanine aminotransferase for HBeAg-negative CHB): 71% vs 5% for HBeAg-positive (P < 0.001) and 60% vs 16% for HBeAg-negative patients (P = 0.004), respectively. Moreover, a more profound decline of serum HBsAg was observed in patients with absence of intrahepatic HBsAg staining (3.1 vs 0.4 log IU/mL, P < 0.001 and 1.7 vs 0.4 log IU/mL, P = 0.005 for HBeAg-positive and HBeAg-negative CHB, respectively). In conclusion, PEG-IFN reduces expression of intrahepatic HBsAg. Loss of HBsAg as assessed by immunohistochemistry from the liver predicts a sustained response and is reflected in a pronounced serum HBsAg decline.

Antiviral therapy for chronic hepatitis B virus infection and development of hepatocellular carcinoma in a US population

BACKGROUND & AIMS

Antiviral therapy could reduce the risk of hepatocellular carcinoma (HCC) among persons with chronic hepatitis B virus (HBV) infection. We evaluated the relationship between therapy for chronic HBV infection and HCC incidence using data from a longitudinal study of patients at 4 US healthcare centers.

METHODS

We analyzed electronic health records of 2671 adult participants in the Chronic Hepatitis Cohort Study who were diagnosed with chronic HBV infection from 1992 through 2011 (49% Asian). Data analyzed were collected for a median of 5.2 years. Propensity-score adjustment was used to reduce bias, and Cox regression was used to estimate the relationship between antiviral treatment and HCC. The primary outcome was time to event of HCC incidence.

RESULTS

Of study subjects, 3% developed HCC during follow-up period: 20 cases among the 820 patients with a history of antiviral HBV therapy and 47 cases among the 1851 untreated patients. In propensity-adjusted Cox regression, patients who received antiviral therapy had a lower risk of HCC than those who did not receive antiviral therapy (adjusted hazard ratio, 0.39; 95% confidence interval, 0.27-0.56; P < .001), after adjusting for abnormal level of alanine aminotransferase. In a subgroup analysis, antiviral treatment was associated with a lower risk of HCC after adjusting for serum markers of cirrhosis (adjusted hazard ratio, 0.24; 95% confidence interval, 0.15-0.39; P < .001). In a separate subgroup analysis of patients with available data on HBV DNA viral load, treated patients with viral loads >20,000 IU/mL had a significantly lower risk of HCC than untreated patients with viral loads >20,000 IU/mL.

CONCLUSIONS

In a large geographically, clinically, and racially diverse US cohort, antiviral therapy for chronic HBV infection was associated with a reduced risk for HCC.

Immunotherapeutic interventions in chronic hepatitis B virus infection: a review

Chronic hepatitis B virus (HBV) infection is a public health challenge worldwide. Antiviral agents (nucleos(t)ide analogues, NAs) and immune-based therapies (IFN-α or Pegylated-IFN-α) are two therapeutic approaches available currently against chronic hepatitis B (CHB). However, these approaches are associated with the development of acquired drug resistance or poor response rates and are accompanied by numerous side effects. Furthermore, due to defective innate and adaptive immune responses, HBV cannot be effectively controlled or completely eliminated, which may ultimately result in liver decompensation and hepatocelluar carcinoma. The imperative for development of new approaches targeting CHB cannot be overstated. Various immunotherapeutic interventions have been tried as adjuvants to inhibit HBV replication. In this paper, we will review immunotherapeutic interventions in the treatment of CHB.

Combination therapy with a nucleos(t)ide analogue and interferon for chronic hepatitis B: simultaneous or sequential

Currently available antiviral treatment for chronic hepatitis B virus infection can be divided into two classes of therapeutic agents: nucleos(t)ide analogues (NAs) and interferon (IFN). The major advantages of NAs are good tolerance and potent antiviral activity associated with high rates of on-treatment response to therapy; the advantages of IFN include a finite course of treatment, absence of drug resistance, and an opportunity to obtain a post-treatment durable response to therapy. The use of these two antiviral agents with different mechanisms of action in combination is theoretically an attractive approach for treatment. Here, we have reviewed previous reports of either simultaneous or sequential combination therapy with NA and IFN for chronic hepatitis B patients. In previous studies comparing the lamivudine/IFN combination and lamivudine monotherapy in a finite course, combination therapy was associated with higher rates of sustained post-treatment response and lower rates of drug resistance than lamivudine monotherapy. However, NAs such as lamivudine are generally administered indefinitely because of high rates of post-treatment relapse. In addition, concern for drug resistance has decreased significantly with newer, high-potency NAs even when administered alone. In previous studies comparing the lamivudine/IFN combination and IFN monotherapy, the combination therapy showed greater on-treatment viral suppression, but no difference was observed in the post-treatment sustained response. Thus, whether combination therapy confers an additional benefit compared to monotherapy for treating chronic hepatitis B remains unclear. The efficacy of IFN in combination with a more potent NA, such as entecavir or tenofovir, remains to be comprehensively evaluated.

Effect of response to interferon-α therapy on the occurrence of hepatocellular carcinoma in patients with chronic hepatitis B

OBJECTIVES

The aim of this study was to examine whether interferon-α (IFN-α) therapy may reduce the occurrence of hepatocellular carcinoma (HCC) in chronic hepatitis B (CHB) and to determine its effect based on responsiveness to IFN-α therapy.

METHODS

A total of 641 biopsy-proven CHB patients were treated with IFN-α2b. They were followed by biochemistry and/or imaging studies at 3- to 6-month intervals for a median period of 113 months (range 6-222).

RESULTS

HCC was detected in 22 patients and 5- and 10-year cumulative occurrence rates were 0.4 and 3.2%, respectively. In univariate analysis, age (p < 0.001), serum AFP levels (p < 0.001), and serum HBV-DNA levels (p = 0.002) at baseline were associated with HCC development. HCC occurred less frequently in biochemical responders at the end of treatment than in non-responders (p = 0.001). However, virologic response was not associated with HCC development. Multivariate analysis showed that poor biochemical response (p = 0.007) as well as older age (p = 0.018) and a higher serum AFP level (p < 0.001) remained independent predisposing factors of HCC development in CHB patients treated with IFN-α.

CONCLUSION

The results suggest that the biochemical but not virologic response to IFN-α therapy reduces independently the occurrence of HCC in patients with CHB.

Systematic review of the literature on comparative effectiveness of antiviral treatments for chronic hepatitis B infection

OBJECTIVES

To evaluate the comparative effectiveness of antiviral drugs in adults with chronic hepatitis B monoinfection for evidence-based decision-making.

METHODS

A systematic review of randomized controlled clinical trials (RCTs) published in English. Results after interferon and nucleos(t)ides analog therapies were synthesized with random-effects meta-analyses and number needed to treat (NNT).

RESULTS

Despite sustained improvements in selected biomarkers, no one drug regimen improved all intermediate outcomes. In 16 underpowered RCTs, drug treatments did not reduce mortality, liver cancer, or cirrhosis. Sustained HBV DNA clearance was achieved in one patient when two were treated with adefovir (NNT from 1 RCT=2 95%CI 1;2) or interferon alpha-2b (NNT from 2 RCTs=2 95%CI 2;4), 13 with lamivudine (NNT from 1 RCT=13 95%CI 7;1000), and 11 with peginterferon alpha-2a vs. lamivudine (NNT from 1 RCT=11 95%CI 7;25). Sustained HBeAg seroconversion was achieved in one patient when eight were treated with interferon alpha-2b (NNT from 2 RCTs=8 95%CI 5;33) or 10--with peginterferon alpha-2b vs. interferon alpha-2b (NNT from 1 RCT=10 95%CI 5;1000). Greater benefits and safety after entecavir vs. lamivudine or pegylated interferon alpha-2b vs. interferon alpha-2b require future investigation of clinical outcomes. Adverse events were common and more frequent after interferon. Treatment utilization for adverse effects is unknown.

CONCLUSIONS

Individual clinical decisions should rely on comparative effectiveness and absolute rates of intermediate outcomes and adverse events. Future research should clarify the relationship of intermediate and clinical outcomes and cost-effectiveness of drugs for evidence-based policy and clinical decisions.

Meta-analysis: reduction in hepatic events following interferon-alfa therapy of chronic hepatitis B

BACKGROUND

The long-term benefit of interferon-alfa (IFN-α) treatment in preventing various hepatic complications is not certain.

AIM

To study the effects of IFN-α on reducing the risk of developing overall hepatic events (hepatocellular carcinoma, cirrhotic complications and liver-related mortality) in chronic hepatitis B patients.

METHODS

Randomized controlled trials, case-control studies and cohort studies were retrieved from electronic databases and conference abstracts. Relative risks (RRs) of different hepatic complications among patients treated by IFN-α vs. no treatment or placebo were studied.

RESULTS

Eleven studies were identified totalling 975 patients treated by IFN-α vs. 1147 untreated controls for analysis. Patients were treated by IFN-α for 1-24 months with a post-treatment follow-up of 1-13 years. Treatment by IFN-α reduced the risk of overall hepatic events (RR 0.55, 95% confident interval or CI 0.43-0.70, P < 0.001) and cirrhotic complications (RR 0.46, 95% CI 0.32-0.67, P < 0.001) by 45% and 54% respectively. Patients who responded to IFN-α had more profound reduction in overall hepatic events (RR 0.20, 95% CI 0.05-0.87, P = 0.03) and cirrhotic complications (RR 0.19, 95% CI 0.09-0.38, P < 0.001) vs. the untreated controls.

CONCLUSION

Interferon-alfa treatment reduces the risk of hepatic events particularly among responders to treatment.

Treatment of chronic hepatitis B in Asia-Pacific countries: is the Asia-Pacific consensus statement being followed?

BACKGROUND

The Asia-Pacific consensus guidelines for the management of chronic hepatitis B state that the principal indicators for starting therapy are increased HBV DNA levels (> or =20,000 IU/ml for hepatitis B e antigen [HBeAg]-positive status and >2,000 IU/ml for HBeAg-negative status) and alanine aminotransferase (ALT) levels >2x the upper limit of normal. We aimed to determine whether clinicians in the Asia-Pacific region are treating patients with chronic hepatitis B according to the Asia-Pacific consensus statement on the management of chronic hepatitis B.

METHODS

An online survey of chronic hepatitis B treatment practices was prepared, consisting of 14 questions grouped into seven categories: patient statistics, treatment statistics, treatment decision, first-choice treatment, treatment duration, future directions and patient preference.

RESULTS

In total, 124 respondents from 12 countries completed the survey. Most respondents indicated that detectable HBV DNA was either the first or second most important factor when deciding whether to initiate therapy. Many physicians were unsure about initiation of treatment in patients >40 years of age when ALT levels were within the normal range. Oral antiviral drugs were the most frequently used medication because of their effectiveness, safety and ability to provide sustained viral suppression. Conversely, the most important reasons for selecting interferon therapy were effectiveness, fixed duration of treatment and lack of drug resistance. Criteria for stopping treatment generally followed the recommendations included in the guidelines.

CONCLUSIONS

These data suggest that clinicians from the Asia-Pacific region use criteria beyond those advocated in treatment guidelines when deciding whether to initiate treatment in HBV-infected patients.

[Reversibility of hepatitis B virus-induced liver cirrhosis after prolonged antiviral therapy]

Reversibility of liver fibrosis or cirrhosis involves complete restoration of normal liver architecture. This phenomenon has been well documented in chronic liver diseases such as autoimmune hepatitis, biliary obstruction, hemochromatosis, nonalcoholic steatohepatitis, and viral hepatitis. There are very few reports of reversal of cirrhosis after antiviral therapy in patients with chronic hepatitis B virus (HBV) infection. We report a case of disappearance of HBV-induced liver cirrhosis after years of treatment with distinct antiviral drugs, documented by successive biopsy results. This disappearance was accompanied by normalization of platelet count, gammaglobulin titers, and radiologic findings.

Current treatments for patients with HBeAg-positive chronic hepatitis B virus infection: a comparison focusing on HBeAg seroconversion

HBeAg seroconversion, in association with undetectable levels of hepatitis B virus DNA as determined by polymerase chain reaction, is an important goal in the treatment of patients with HBeAg-positive chronic hepatitis B (CHB). Achievement of sustained HBeAg seroconversion at an early age (<40 years) is associated with a reduced incidence of hepatic complications, increased rates of HBsAg loss and seroconversion and improved survival rates, whether the seroconversion is spontaneous or treatment induced. Patients with HBeAg-positive CHB who achieve sustained HBeAg seroconversion and complete 6-12 months of consolidation therapy are eligible for stopping therapy. In randomized clinical studies involving patients with HBeAg-positive CHB, treatment with pegylated interferon (PegIFN)-alpha is associated with higher and more durable HBeAg seroconversion rates than are lamivudine and adefovir. More recently, newer generation oral nucleos(t)ide analogs (NAs) have become available. These include entecavir, telbivudine and tenofovir, and they demonstrate superior antiviral potency and efficacy. This review examines the importance of HBeAg seroconversion as an end point for therapy in the treatment of patients with HBeAg-positive CHB, and examines the rates and durability of HBeAg seroconversion with PegIFN and oral NA therapy. The mechanisms for enhanced HBeAg seroconversion rates with new-generation NAs are also discussed.

Advances in hepatic barrier function and injury

Hepatic barrier is a very important structure to protect hepar, and also considerable to protect liver's function. It can prevent endotoxin and virus from entering hepar to damage hepatocyte. The primary aim of this review is to introduce the research status of hepatic barrier and analyze its function and structure. We also introduce several kinds of factors that can induce the failure of the barrier's structure and function and some countermeasures that can resist this factors.

Interferons and their use in persistent viral infections

In 2007, the world celebrated the 50th anniversary of the discovery of interferon (IFN) by Isaacs and Lindenmann. Subsequently, the IFN-alpha gene was cloned, fully sequenced and IFN-alpha was produced in recombinant form. Recombinant IFN-alpha is now used as the basis for treatment of chronic hepatitis C virus infection and can also be used to treat certain forms of chronic hepatitis B virus infections. IFNs have also been used in other viral infections, although with less success. The antiviral mechanisms of IFNs are reviewed in this chapter as well as the utility of IFNs in the treatment of persistent viral infections.

Meta-analysis: Treatment of hepatitis B infection reduces risk of hepatocellular carcinoma

BACKGROUND

Chronic hepatitis B (CHB) infection leads to development of hepatocellular carcinoma (HCC), but the effects of treatment in preventing HCC are not clear.

AIM

To study the effects of interferon (IFN) or nucleoside/tide analogue (NA) on the risk of developing HCC in CHB patients.

METHODS

Randomized trials, case-control and cohort studies were retrieved from five electronic databases and international conferences over the past 10 years. Relative risks (RRs) of HCC with or without treatment were studied.

RESULTS

Twelve studies (n = 2742) enrolling patients treated by IFN vs. control showed that the risk of HCC after treatment was reduced by 34% (RR: 0.66, 95% CI: 0.48-0.89). Benefit is more significant among patients with early cirrhosis than among those without cirrhosis. Five studies (n = 2289) compared patients treated by NA with control. The risk of HCC after treatment was reduced by 78% (RR: 0.22, 95% CI: 0.10-0.50). HBeAg-positive patients showed more significantly reduced HCC risk with treatment. Patients without cirrhosis benefited more from NA than those with cirrhosis. Resistance to NA has obviated the benefit of the treatment.

CONCLUSIONS

IFN or NA treatment significantly reduces risk of HCC. While IFN benefited patients with cirrhosis, NA benefited patients with no cirrhosis and HBeAg-positive CHB infection.

New paradigms for the treatment of chronic hepatitis B

The main goals of chronic hepatitis B treatment should be the long-term suppression of viral replication to minimize disease progression and the risk for the development of hepatocellular carcinoma. Treatment end-points, depending on surrogate markers alone, in particular hepatitis B e-antigen seroconversion, may not be ideal for patients who acquire the disease early in life. Currently-available drugs include interferons and oral nucleoside/nucleotide analogs. Although interferon therapy provides a finite treatment period, a significant proportion of patients may not respond, and long-term outcome is inconclusive. Long-term efficacy has been demonstrated for both lamivudine and adefovir. However, prolonged nucleoside/nucleotide analog therapy is associated with the emergence of drug-resistant mutations. Therefore, nucleoside/nucleotide analogs with a high genetic barrier and potent antiviral activity, such as entecavir, should be used to reduce the chance of developing drug-resistant mutations. Drugs with a low genetic barrier, including lamivudine and telbivudine, should be used in conjunction with early testing for antiviral response. This can predict favorable outcomes in the long term. The early detection of drug-resistant mutations should prompt clinicians to either add or switch to another agent with a different drug-resistance profile. There are currently no treatment models in the use of combination or sequential therapy in treatment-naïve patients. To date, long-term treatment appears to be the most effective option. Despite recent advances made with better understanding on the natural history of chronic hepatitis B infection and with newer antiviral drugs available, challenges remain with respect to treatment criteria, treatment end-points, and duration of treatment.

Pharmacology, clinical efficacy and safety of lamivudine in hepatitis B virus infection

Lamivudine was the first nucleoside analog for the treatment of chronic hepatitis B (CHB). It is well-tolerated and induces a decrease in serum HBV DNA levels associated with normalization of serum alanine aminotransferase levels. However, a sustained response with hepatitis B 'e' antigen to anti-hepatitis B e seroconversion is obtained in a smaller proportion of patients and hepatitis B surface antigen loss is exceptional. The response is maintained during therapy, and needs to be continued indefinitely in the majority of patients since withdrawal of treatment is generally followed by a rapid reappearance of the virus. However, mutations can be induced in long-term treatment.

Systematic review: combination therapies for treatment-naïve chronic hepatitis B

BACKGROUND

There is a renewed interest in use of combination therapies in treatment-naïve chronic hepatitis B (CHB) because of limitations of monotherapies.

AIM

To discuss the current status of combination therapies in treatment-naïve CHB.

METHODS

PubMed search was done using 'combination', 'sequential' and 'chronic hepatitis B' as the search terms.

RESULTS

The two most popular combination therapies include 'combination of nucleos(t)ide analogues' and 'combination of interferons and nucleos(t)ide analogues'. Combination therapies using two nucleos(t)ide analogues do not lead to higher long-term efficacy. However, addition of a nucleos(t)ide analogue with a good resistance profile to a nucleos(t)ide analogue with a lower genetic barrier to resistance decreases the risk of emergent resistance to the latter. Greater sustained virological, biochemical and seroconversion rates are observed with addition of lamivudine to conventional interferon, but pegylated-interferon monotherapy is equally effective as combination with lamivudine. Again, resistance to lamivudine is lower with its combination with interferons.

CONCLUSIONS

The answer to the question whether hepatitis B can be treated better with combination or monotherapy remains largely unknown. Additional trials are warranted of combination therapies of peginterferon and potent nucleos(t)ide analogues or therapies with the combined use of nucleos(t)ide analogues or immunomodulators.

Positive serum hepatitis B e antigen is associated with higher risk of early recurrence and poorer survival in patients after curative resection of hepatitis B-related hepatocellular carcinoma

BACKGROUND/AIMS

To study the impact of hepatitis B e antigen on tumor recurrence and patients' survival after curative resection of hepatocellular carcinoma.

METHODS

Two hundred and three patients with small hepatocellular carcinomas (3cm) who had undergone curative resection were divided into HBeAg-positive group and HBeAg-negative group. Clinicopathological factors and postoperative outcomes were compared between groups, and risk factors for survival and recurrence were studied.

RESULTS

The median follow-up time was 32.9months. Patients with negative HBeAg had higher 5-year overall survival rates (76% vs 53.9%, hazards ratio (HR): 2.363, 95% CI: 1.335-4.181, p=0.002) and 5-year disease-free survival rates (52.9% vs 37.4%, HR: 1.603, 95% CI: 1.00-2.561, p=0.046). There was no significant difference in operative morbidity and tumor factors between the two groups, but younger age, higher serum alanine aminotransferase levels, and more macronodular cirrhosis were found in the HBeAg-positive group. Multivariate analysis revealed that age >50years, HBeAg positivity and macronodular cirrhosis were independent factors for overall survival, and HBeAg positivity and multiple tumor nodules were independent factors for disease-free survival. Positive serum HBeAg was associated with a higher risk of early recurrence (within 1year).

CONCLUSIONS

HBeAg is associated with a higher risk of early recurrence and poorer survival in patients after curative resection of small HCC.

Interferon and lamivudine vs. interferon for hepatitis B e antigen-positive hepatitis B treatment: meta-analysis of randomized controlled trials

AIMS

To compare interferon monotherapy with its combination with lamivudine for hepatitis B e antigen (HBeAg)-positive hepatitis B treatment.

METHODS

Two independent researchers identified pertinent randomized controlled trials. The trials were evaluated for methodological quality and heterogeneity. Rates of sustained virological and biochemical responses, and HBeAg clearance and seroconversion were used as primary efficacy measures. Quantitative meta-analyses were conducted to assess differences between groups for conventional and pegylated interferon, and overall.

RESULTS

Greater sustained virological, biochemical and seroconversion rates were observed with addition of lamivudine to conventional [odds ratio (OR)=3.1, 95% confidence intervals (CI) (1.7-5.5), P<0.0001, OR=1.8, 95% CI (1.2-2.7), P=0.007 and OR=1.8, 95% CI (1.1-2.8), P=0.01 respectively], although not pegylated [OR=1.1, 95% CI (0.5-2.3), P=0.8, OR=1.0, 95% CI (0.7-1.3), P=0.94, and OR=0.9, 95% CI (0.6-1.2), P=0.34 respectively] interferon-alpha, with no significant affect on HBeAg clearance rates [OR=1.6, 95% CI (0.9-2.7), P=0.09, and OR=0.8, 95% CI (0.6-1.1), P=0.26 respectively]. Excluding virological response (P<0.001), pegylated interferon monotherapy and conventional interferon and lamivudine combination therapy were similarly efficacious (P>0.05), with the former studied in harder to treat patients, as evidenced by the superior virological response observed with conventional as compared with pegylated interferon monotherapy (P<0.0001).

CONCLUSION

In comparable populations, pegylated interferon monotherapy is likely to be equally or more efficacious than conventional interferon and lamivudine combination therapy, thus constituting the treatment of choice, with no added benefit with lamivudine addition. However, when conventional interferon is used, its combination with lamivudine should be considered.

Treatment of Viral Hepatitis in Children

Hepatitis B and hepatitis C are important causes of chronic liver disease in children and adolescents, and later on for potential cirrhosis and primary hepatocellular carcinoma. The risk of developing chronic hepatitis B (HB) infection ranges from 90% in neonates to <5% in adults. Hepatitis C induces chronic infection in at least 85% of affected persons. HBV and HCV associated liver damage appears to be less severe in children than in adults. At the present time, lamivudine and a combination of interferon and lamivudine seem to be the best options for HB infection treatment in the pediatric population, even though they induce the presence of drug-resistant mutations, and new therapies have to be developed to improve reduction and cessation of viral replication and decrease the emergence of mutations. Therapy with interferon and ribavirin seems to offer the best results for children and adolescents. Results from a study on pegylated interferon in a pediatric population might lead to better therapeutic responses. Cost of treatment for chronic viral hepatitis is very high and efforts have to continue to extend hepatitis B vaccination to the general population worldwide to reduce vertical and horizontal transmission of hepatitis C.