Pegylated interferon therapy in chronic hepatitis C: lights and shadows of an innovative treatment.

Pegylated interferon (PEG-IFN) in combination with ribavirin is the standard of treatment for chronic hepatitis C. Several viral and host factors influence the outcome of treatment, such as hepatitis C virus (HCV) genotype, baseline viral load, viral kinetics, race, body weight, advanced liver disease, HIV co-infection, and adherence to therapy. Monitoring the response of HCV to treatment during the early time points (4 weeks or 12 weeks) after initiation of therapy has emerged as a critical tool to predict sustained virologic response (SVR), defined as undetectable serum HCV RNA 24 weeks after the end of therapy. To counterbalance the influence of host and viral factors, treatment duration can be individualised to achieve an optimal treatment outcome, potentially reduce costs, and minimize side effects.