Clinical outcomes of chronic hepatitis B patients with persistently detectable serum hepatitis B virus DNA during lamivudine therapy

Evidence of susceptibility to lamivudine-based HAART and genetic stability of hepatitis B virus (HBV) in HIV co-infected patients: A South African longitudinal HBV whole genome study

BACKGROUND

Reports on the concomitant impact of HIV co-infection and long term highly active anti-retroviral therapy (HAART) on the genetic stability and molecular evolution of HBV are limited in sub-Saharan Africa.

MATERIALS AND METHODS

This retrospective study investigated the molecular evolution of chronic HBV in HIV co-infected patients on lamivudine (3TC)-based HAART over a 5year period. Four HIV co-infected patients, consecutively recruited and followed-up, were screened for hepatitis B serological markers, and their viral loads determined. The HBV genome was amplified from longitudinal samples and characterized by Bayesian inference, mutational analysis, and identification of immune selection pressure.

RESULTS

All patients exhibited persistent chronic HBV infection at baseline, as well as over the course of follow-up despite exposure to 3TC-based HAART. The polymerase gene in all isolates was relatively variable prior to HAART initiation at baseline and during the course of follow-up, although primary drug resistance mutations were not detected. All but one patient were infected with HBV subgenotype A1. The divergence rates between baseline and the last follow-up sequences ranged from 0 to 2.0×10(-3) substitutions per site per year (s/s/y). Positive selection pressure was evident within the surface and core genes.

CONCLUSION

Despite persistent HBV infection in the HIV co-infected patients exposed to long term 3TC-based HAART, the molecular evolution of HBV over a 5year period was unremarkable. In addition, HBV exhibited minimal genetic variability overtime.

Recent advances in micro/nanotechnologies for global control of hepatitis B infection

The control of hepatitis B virus (HBV) infection is a challenging task, specifically in developing countries there is limited access to diagnostics and antiviral treatment mainly due to high costs and insufficient healthcare infrastructure. Although the current diagnostic technologies can reliably detect HBV, they are relatively laborious, impractical and require expensive resources that are not suitable for resource-limited settings. Advances in micro/nanotechnology are pioneering the development of new generation methodologies in diagnosis and screening of HBV. Owing to combination of nanomaterials (metal/inorganic nanoparticles, carbon nanotubes, etc.) with microfabrication technologies, utilization of miniaturized sensors detecting HBV and other viruses from ultra-low volume of blood, serum and plasma is realized. The state-of-the-art microfluidic devices with integrated nanotechnologies potentially allow for inexpensive HBV screening at low cost. This review aims to highlight recent advances in nanotechnology and microfabrication processes that are employed for developing point-of-care (POC) HBV assays.

High dose of Lamivudine and resistance in patients with chronic hepatitis B

Background. Lamivudine is the most affordable drug used for chronic hepatitis B and has a high safety profile. With the daily dose of 100 mg there is progressive appearance of resistance to lamivudine therapy. In our study we used 150 mg of lamivudine daily as a standard dose which warrants further exploration for the efficacy of the drug. Aims of the Study. To assess the efficacy of lamivudine 150 mg daily on resistance in patients with chronic hepatitis B. Methods. This retrospective study consists of 53 patients with chronic hepatitis B treated with 150 mg of lamivudine daily. The biochemical and virological response to the treatment were recorded at a 1-year and 2-, 3-, 4-, and 5-year period and time of emergence of resistance to the treatment was noted. Results. The mean age of the patients was 54 years with 80% being males. The resistance to lamivudine 150 mg daily at 1 year and 2, 3, and 5 years was 12.5%, 22.5%, 37.5%, and 60%, respectively, which is much less compared to the standard dose of 100 mg of lamivudine. Conclusions. Lamivudine is safe and a higher dose of 150 mg daily delays the resistance in patients with chronic hepatitis B.

Current status of antiviral therapy for hepatitis B

Chronic hepatitis B (CHB) is a major public health problem affecting up to 400 million people globally. Complications of CHB including liver failure and hepatocellular carcinoma result in 1.2 million deaths per year, making CHB the 10th leading cause of mortality worldwide. The natural history of CHB is variable and complex. The past decade witnessed important developments for the therapy of hepatitis B and marked the new era of oral therapy. The ultimate goal of CHB therapy is to arrest the progression of liver injury and to prevent the development of liver failure and hepatocellular carcinoma. Currently, six agents are approved for the treatment of CHB. Each of these agents, given as monotherapy, has been shown to produce virological, biochemical, and histological benefits for both HBeAg positive and negative CHB. There are, however, limitations in spite of their efficacy. The significant side-effect profile of interferon, for example, limits its long-term use. The approved oral agents are tolerable with prolonged use but drug resistance could limit long-term monotherapy. To date, combination therapy with nucleoside analogue and pegylated interferon or two nucleos(t)ide analogues given for one year does not show superiority in durability of response compared to monotherapy. Ongoing research effort is critical to identify the ideal hepatitis B therapy that is safe, effective, and produces durable response with a finite course of therapy. It is equally important to conduct a well designed, prospective natural history study to identify predictors of disease progression. This will accurately guide treatment strategy for this important disease.

Chronic Hepatitis B Infection: Principles of Therapy

Chronic hepatitis B is a global health concern in many resource-limited settings due to perinatal or pediatric hepatitis B virus transmission. In the United States, pediatric infection has been virtually eliminated due to maternal screening during pregnancy and the availability of an effective vaccine. However, young adults remain an at-risk group for hepatitis B virus infection due to sexual transmission and injection drug use. The frequency of progression from acute hepatitis B virus infection to chronic hepatitis B infection depends on multiple factors, including host immune function and age at time of hepatitis B virus infection. Fortunately, there are 7 currently approved therapies for chronic hepatitis B infection, and several emerging therapies that show promise. Despite the availability of these agents, many clinical questions still surround chronic hepatitis B therapy including when to start therapy, which agent is ideal for first and second line therapy, the appropriate duration of therapy, and the role of combination antiviral therapy. This review focuses on agents available for chronic hepatitis B management, including pharmacology, safety and efficacy data, monitoring parameters, and the role for each in chronic hepatitis B therapy in adult patients.

[Change of HBV DNA level as a predictor of HBeAg loss after lamivudine treatment]

BACKGROUND AND AIMS

Lamivudine is an effective, safe therapeutic agent for the treatment of chronic hepatitis B. The aim of this study was to investigate whether early suppression of the viral load predicts HBeAg loss within 1 year during lamivudine therapy.

METHODS

This prospective study encompassed 74 patients (mean age: 37.1 years, male/female: 51/23) who were positive HBeAg, their AST or ALT levels were > or =2 times the upper limit of normal and their HBV DNA was > or =10(5) copies/mL. The patients received lamivudine 100 mg for 12 months with monitoring their HBV DNA, AST, ALT, HBeAg and anti-HBe, and all these tests were performed at pretreatment and 1, 3, 6, 9 and 12 months after treatment. The serum HBV DNA was measured by HBV branched DNA assay.

RESULTS

HBeAg loss was observed in 12 patients (16.2%), and 9 patients achieved anti-HBe seroconversion during up to 1 year of lamivudine therapy. The mean time to HBeAg loss was 5.6 months (range: 1-12 months). The posttreatment HBV DNA (<2,000 copies/mL) after 3 month (P=0.008) and 6 month (P=0.012)) were significant predictors of HBeAg loss after 1 year of lamivudine treatment on univariate analysis. Pretreatment HBV DNA, AST/ALT, gender, age and liver cirrhosis had no impact on HBeAg loss. The six-month posttreatment HBV DNA level <2,000 copies/mL was a significant predictor of HBeAg loss on multivariate analysis (P=0.008, odds ratio=0.108).

CONCLUSION

We suggest that an HBV DNA level <2,000 copies/mL at 6 month after lamivudine therapy is the most important predictor of HBeAg loss during up to 1 year of lamivudine therapy.