Source Dr. Gonzalez is an Attending Physician in the Division of General and Transplant Hepatology at the Baylor Regional Transplant Institute at Baylor All Saints Medical Center in Fort Worth, Texas and Baylor University Medical Center in Dallas, Texas.
Genome-wide association studies have recently identified single nucleotide polymorphisms in proximity to the interleukin-28B (IL-28B) gene that can predict sustained virologic response (SVR) in patients with chronic hepatitis C virus (HCV) infection who are undergoing therapy with pegylated interferon (IFN) a and ribavirin. IL-28B encodes IFN-λ3, a type III IFN involved in host antiviral immunity. Favorable variants of the 2 most widely studied IL-28B polymorphisms, rs1 2979860 and rs8099917, are strong pretreatment predictors of early viral clearance and SVR in patients with genotype 1 HCV infection. Variations in the distribution of IL-28B alleles may partly explain differences in SVR rates among ethnic groups. Further investigations have implicated IL-28B in the development of chronic HCV infection versus spontaneous resolution of acute infection and suggest that IL-28B may be a key factor involved in host immunity against HCV. Clinical trials of IFN-λ as a therapeutic agent for chronic HCV infection are currently underway. The use of IL-28B polymorphisms as a predictive tool will have a major impact on treatment strategies for chronic HCV infection, particularly in the context of emerging therapies and direct-acting antiviral agents.