Abstract
Host genetic factors have long been suspected to play a role in predicting outcome and treatment response in hepatitis C virus (HCV) infection. This was confirmed recently by three landmark genome-wide association studies (GWAS) published in 2009, which identified single nucleotide polymorphisms near the interleukin (IL) 28B region that were more common in responders to treatment. There has subsequently been rapidly increasing data regarding the significance of the IL28B polymorphism not only in response to therapy but also in spontaneous clearance of acute HCV infection. This clinical association of Il28B genotype with HCV may lead to personalized HCV therapy, where the clinician may tailor the duration and type of therapy for an individual patient. This review summarizes the available data on the impact of IL28B polymorphisms on HCV infection and discusses the possible approach to translate this association into clinical decision making for the treatment of HCV infection.