The influences of antiviral therapy on T-cell function in adult patients with chronic hepatitis B

T cells play an important role in the clearance of acute infection and control of hepatitis B virus (HBV) infection during the chronic phase. Chronic HBV is characterized by a weak and limited T-cell response. Several hypotheses, such as presence of Tregs or occurrence of T-cell exhaustion have been proposed to explain these observations. The two registered classes of anti-HBV drugs: pegylated-IFN-alpha (PEG-IFN-alpha) and nucleos(t)ide analogs (NUCs) have, next to their antiviral effect, also an immunomodulatory effect. Although NUCs have no direct immunomodulatory effects, they may indirectly positively affect the T-cell response through their viral suppressive action. In this review, effects of both PEG-IFN-a and NUC therapy will be discussed with regard to the cellular immune response against HBV.