Association of IL-10, IL-4, and IL-28B gene polymorphisms with spontaneous clearance of hepatitis C virus in a population from Rio de Janeiro

Cytokines play an important role in the regulation of the immune response. In hepatitis C virus (HCV) infection, cytokine levels may influence the outcome of acute HCV infection. Polymorphisms in cytokine genes have been associated to different expression levels in response to infection. This study was carried out to investigate the association of several cytokine gene polymorphisms with disease outcome in HCV-infected patients. Patients with chronic or spontaneously resolved HCV infection were included in a cross-sectional study. A comparative analysis was performed between the groups regarding frequency distribution of the following cytokines' gene polymorphisms: IL-10 (-1082 A/G; -819 T/C; -592 A/C), IL-4 (+33C/T), IFN-γ (+874 T/A), TNF-α (-238 G/A and -308 G/A) and IL-28B (rs12979860 C/T and rs8099917 T/G). Eighteen patients with spontaneous viral clearance and 161 with chronic HCV infection were included. In the comparative analysis, the GG genotype of the IL-10 polymorphism -1082A/G was more frequent in patients with spontaneous viral clearance when compared to patients with chronic HCV (41.2% vs 6.2%; p = 0.001). This association was also found for the CC genotype of the IL-4 polymorphism +33C/T (72.2% vs 36.7%; p = 0.017) and the CC and TT genotypes of the IL-28B polymorphisms rs 12979860 and rs 8099917 (88.9% vs 30.3%; p