Pegylated IFN-α and ribavirin: emerging data in the treatment of special populations.

Hepatitis C virus (HCV) is one of the most common causes of chronic liver disease and is currently the leading indication for liver transplantation in the USA. Pegylated IFN-α (PEG-IFN-α) and ribavirin comprise the standard of care for the treatment of chronic HCV. The expansion of antiviral therapy to include special populations that were not well represented or excluded from registration trials has occurred in recent years. Data have emerged that demonstrate that these groups have variable responses to therapy and, in some cases, different side-effect profiles. The etiologies for the varied response rates remain under investigation. This review will address the clinical efficacy and safety profiles of PEG-IFN-α and ribavirin in populations of patients coinfected with HIV, obese patients, liver transplant recipients, children and African-Americans.