Old and New Diagnostic Tools in the Management of Chronic HBV
Hepatitis B virus (HBV) is a very complex and intricate DNA structure associated with a particular genomic organization and replication cycle. However, many years of investigations allowed clarification of the real HBV natural history, through a deeper knowledge of the behavior of HBV antigens and viral structures. Several of the old diagnostic tools, such as HBV surface antigen (HBsAg) and HBV e antigen (HBeAg) determinations, gained prominence now, since the variation of both HBsAg and HBeAg plasma levels was shown to predict treatment response. In addition, the availability of more sensitive methods, such as HBV DNA detection by real-time PCR, has improved the current knowledge of the relationships between HBV replication levels and the natural history of the disease. It is now well established that some HBV genotypes are associated with a better response to treatment with pegylated interferon. Despite the widely accepted value of liver biopsy as a staging tool, transient elastography is being increasingly acknowledged as a non-invasive method to assess liver stiffness, chiefly for detection of advanced fibrosis. Current international guidelines for the management of chronic hepatitis B have provided several accurate biochemical and serological criteria for selecting patients for treatment, allowing a higher number of cases to be enrolled into antiviral therapy. This review describes the different serological markers used for the study of HBV and their clinical significance. It also deals with methods used for detection of genotypes and HBV DNA, emphasizing the effectiveness of such determinations for both patient selection and chronic hepatitis B therapy/monitoring.
Since the discovery of hepatitis B virus (HBV) by Blumberg in 1965, a wide variety of antigens and components of the virus has been detected. The increasing knowledge of these biological structures has improved our understanding of the viral cycle and provided a fruitful field for developing some useful tools for the clinical management of the disease.
The complexity observed in both replication cycle and genomic organization of HBV affects directly its complex antigen expression and the related antibody responses.
On the other hand, molecular biology assays allowed characterization of the different phases involved in the natural history of HBV infection, as well as the two major forms of chronic hepatitis B, namely HBeAg-positive and HBeAg-negative/anti-HBe-positive or precore mutant.
Nowadays, more sensitive and sophisticated molecular biology techniques are available for differentiation of HBV genotypes, as well as new tools which are sensitive enough to detect viral particles in hepatocyte in absence of serological markers.
This review describes the different serological markers used for the study of hepatitis B and their clinical significance, focusing mainly on their predictive value of treatment response. In addition, this article will deal with some methods used for detection of genotypes and HBV DNA, emphasizing the effectiveness of such determinations for both patient selection and chronic hepatitis B therapy or monitoring.
Abstract and Introduction
Abstract
Hepatitis B virus (HBV) is a very complex and intricate DNA structure associated with a particular genomic organization and replication cycle. However, many years of investigations allowed clarification of the real HBV natural history, through a deeper knowledge of the behavior of HBV antigens and viral structures. Several of the old diagnostic tools, such as HBV surface antigen (HBsAg) and HBV e antigen (HBeAg) determinations, gained prominence now, since the variation of both HBsAg and HBeAg plasma levels was shown to predict treatment response. In addition, the availability of more sensitive methods, such as HBV DNA detection by real-time PCR, has improved the current knowledge of the relationships between HBV replication levels and the natural history of the disease. It is now well established that some HBV genotypes are associated with a better response to treatment with pegylated interferon. Despite the widely accepted value of liver biopsy as a staging tool, transient elastography is being increasingly acknowledged as a non-invasive method to assess liver stiffness, chiefly for detection of advanced fibrosis. Current international guidelines for the management of chronic hepatitis B have provided several accurate biochemical and serological criteria for selecting patients for treatment, allowing a higher number of cases to be enrolled into antiviral therapy. This review describes the different serological markers used for the study of HBV and their clinical significance. It also deals with methods used for detection of genotypes and HBV DNA, emphasizing the effectiveness of such determinations for both patient selection and chronic hepatitis B therapy/monitoring.
Introduction
Since the discovery of hepatitis B virus (HBV) by Blumberg in 1965, a wide variety of antigens and components of the virus has been detected. The increasing knowledge of these biological structures has improved our understanding of the viral cycle and provided a fruitful field for developing some useful tools for the clinical management of the disease.
The complexity observed in both replication cycle and genomic organization of HBV affects directly its complex antigen expression and the related antibody responses.
On the other hand, molecular biology assays allowed characterization of the different phases involved in the natural history of HBV infection, as well as the two major forms of chronic hepatitis B, namely HBeAg-positive and HBeAg-negative/anti-HBe-positive or precore mutant.
Nowadays, more sensitive and sophisticated molecular biology techniques are available for differentiation of HBV genotypes, as well as new tools which are sensitive enough to detect viral particles in hepatocyte in absence of serological markers.
This review describes the different serological markers used for the study of hepatitis B and their clinical significance, focusing mainly on their predictive value of treatment response. In addition, this article will deal with some methods used for detection of genotypes and HBV DNA, emphasizing the effectiveness of such determinations for both patient selection and chronic hepatitis B therapy or monitoring.
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