Immunopathogenesis of Hepatitis B Virus Infection

The immune response plays conflicting roles in the outcome of Hepatitis B virus (HBV) infection. It simultaneously controls HBV in the liver and drives liver damage responsible for progression of disease. During acute HBV infection, the balance leans toward effective viral control with robust T and B cell immunity, limiting the duration of liver damage inflicted by the immune system and providing long-term immunity to the virus. During chronic infection, dysregulated innate and adaptive immunity fails to effectively clear the virus, resulting in life-long infection and persistent liver damage that can lead to fibrosis and cirrhosis. This chapter will cover the current state of knowledge of HBV immunity and what we know about the immune-pathogenic mechanisms causing liver damage. We have incorporated new knowledge, made possible by technological advancements, that provide the most detailed picture of the immune response in chronically infected patients to date. These advances continue to open opportunities for immune targeting immunotherapeutic strategies to achieve cure in chronic hepatitis B.