Perspective of antiviral therapeutics for hepatitis C after liver transplantation

Table 1 Category, mode of action and major side-effects of anti-hepatitis C virus therapy

Category	Specific target	Mechanism of action	Major side-effect
Interferon α	Host hepatocytes and immune cells	Enhance host immune response	Flu-like symptoms
Ribavirin (nucleoside inhibitor)	Nucleoside guanosine analogue	Stop viral RNA synthesis and viral mRNA capping Enhance interferon response	Cytopenia
DAA
Protease inhibitor (NS3 inhibitor or NS3/4A inhibitor)	NS 3 serine protease ± NS4A cofactor	Inhibit cleavage of the HCV proteins from the polyprecursor	Transfusion-dependent anemia; drug interaction with calcineurin inhibitors
HCV polymerase inhibitor (NS 5B inhibitor)	NS 5B protein (RNA-dependent RNA polymerase)	Inhibit HCV replication	Minimal
NS 5A replication complex inhibitor	NS 5A protein (protein for viral RNA replication and inteferon-resistance)	Stop viral RNA replication	Minimal

DAA: Direct acting antiviral agent; NS: Non-structural; HCV: Hepatitis C virus.