Abstract
The prognosis of hepatitis B virus (HBV) infection is determined by innate immunity, adaptive immunity, and a variety of regulatory factors in the host. Controversy still exists over the role of innate immunity in the progression of HBV infection. Adaptive immunity, especially the immune response mediated by CD8+ T cells, plays an important role in HBV clearance. However, in patients with chronic infection, such CD8+ T cells are often exhausted and associated with various regulatory factors including programmed cell death 1 and T-cell immunoglobulin mucin-3. This article elaborates on the association of chronicity of HBV infection with host immune system and various regulating factors.