Natural History and Clinical Consequences of Hepatitis B Virus Infection

Abstract

Despite the existence of Hepatitis B vaccination, hepatitis B virus (HBV) infection is still prevalent worldwide and accounts for significant morbidity and mortality. It is encouraging that majority of patients do recover from the acute infection, however, those that progress to chronic disease state is at great risk of developing complications such as hepatocellular carcinoma, cirrhosis and liver failure. Hepatitis B virus infection can be influenced by many factors such as host immune status, age at infection, and level of viral replication. The discovery about the existence of various genotypes and its association with different geographic distribution as well as the knowledge regarding mutant species has aid us in better understanding the nature of HBV infection and in delivering better care for patients. It is especially important to recognize those individuals with HBeAg-negative chronic HBV as they have a poorer prognosis compare with their counterparts, HBeAg-positive. Tremendous progress has been made over the years in understanding the behavior and clinical course of the disease; however, the natural history of HBV is complex and we still have much to explore and learn.

Figure 1

Stages of HBV infection based on virus-host interaction. In persistent infected patients, the stages of immune tolerance and immune clearance clinically present as HBeAg positive chronic hapatitis B. The stage of inactive phase clinically presents as HBsAg carrier. * During the stage of reactivation, majority of patients remain HBeAg negative with positive HBeAb and their clinical presentation can be HBeAg negative chornic hepatitis B, but some patients may have seroreversion of HBeAg and present as HBeAg positive chornic hepatitis B.