Meta-analysis: IL28B polymorphisms predict sustained viral response in HCV patients treated with pegylated interferon-α and ribavirin

Does IL28B genotyping still have a role in the era of direct-acting antiviral therapy for chronic hepatitis C infection?

IL28B genotype has been shown to be the strongest pretreatment predictor of sustained virological response (SVR) in patients with genotype 1 chronic hepatitis C infection (CHC) treated with pegylated interferon (peg-IFN) and ribavirin (RBV). Patients carrying the good response genotype have a two- to threefold higher chance of SVR than those with a poor response genotype, manifest as dramatically improved early viral kinetics. However, the treatment paradigm for CHC is changing with the introduction of potent direct-acting antivirals (DAAs). IL28B genotype remains relevant to both telaprevir and boceprevir treatment regimens, although the strength of association with virological response is attenuated. The association between IL28B genotype and outcomes of treatment regimens that involve peg-IFN plus combination DAA therapy, or IFN-free regimens, is currently being evaluated. IL28B genotype may remain relevant to individualizing the choice of treatment regimen in the future.

The impact of interferon lambda 3 gene polymorphism on natural course and treatment of hepatitis C

Host genetic factors may predict the outcome and treatment response in hepatitis C virus (HCV) infection. Very recently, three landmark genome-wide association studies identified single nucleotide polymorphisms near the interleukin 28B (IL28B) region which were more frequent in responders to treatment. IL28B encodes interferon (IFN)λ3, a type III IFN involved in host antiviral immunity. Favourable variants of the two most widely studied IL28B polymorphisms, rs12979860 and rs8099917, are strong pretreatment predictors of early viral clearance and sustained viral response in patients with genotype 1 HCV infection. Further investigations have implicated IL28B in the development of chronic HCV infection versus spontaneous resolution of acute infection and suggest that IL28B may be a key factor involved in host immunity against HCV. This paper presents an overview about the biological activity and clinical applications of IL28B, summarizing the available data on its impact on HCV infection. Moreover, the potential usefulness of IFNλ in the treatment and natural history of this disease is also discussed.