Challenges in Special Populations: HIV/HCV Coinfection, Liver Transplantation and Patients with End-Stage Renal Disease.

Until recently, the combination of PEG-interferon and ribavirin (RBV) was the main treatment for all genotypes of chronic hepatitis C virus (HCV) infection. Sustained virological response (SVR) rates varied signixFB01;cantly across patient subgroups and the concept of 'special populations' emerged. Now, in the era of direct acting antivirals, with a better safety profile and higher efficacy rates, those patients with comorbidities or conditions that limited IFN-based antiviral treatment but with unmet medical needs have been considered for therapy again. With the currently approved all-oral antivirals, patients coinfected with human immunodeficiency virus and HCV have SVR rates similar to patients with HCV monoinfection. However, drug-drug interactions (DDIs) with antiretroviral drugs are still challenging. In the setting of liver transplantation, with an accelerated course of hepatitis C, previous IFN-RBV treatments were poorly tolerated and attained low SVR rates. Today, all-oral therapies have proven to be efficacious and safe in this population. Nevertheless, questions such as the optimal treatment duration or the need for RBV still remain opened. In this population as well, DDIs are an issue, as some regimens require adjustments and monitoring of immunosuppressive drugs during therapy. Finally, preliminary data show promising results in terms of efficacy and safety in patients with end-stage renal disease. However, there is clear need for more clinical studies since treatment options are still very limited.