Relationship between IL28B gene rs8099917 polymorphism and SVR in Turkish patients with hepatitis C virus genotype 1

Background and objective: The hepatitis C virus (HCV) which infects 3% of the world's population is a global challenge. Recently, genome-wide association studies (GWAS) have identified that the IL28B gene rs8099917 polymorphism was associated with the response to the pegylated-interferon alpha/ribavirin (PegIFNα/RBV) combination therapy in patients infected with HCV genotype 1. IL28B gene rs8099917 polymorphism should be determined before beginning treatment of HCV-infected patients to predict an individual's response. The aims of this study were to analyze the correlation between IL28B gene rs8099917 (T/G) polymorphism and PegIFNα/RBV therapy outcome in the Turkish population.

Methods: Genotypes of the IL28B gene rs8099917 (T/G) single nucleotide polymorphism (SNP) were determined in 308 patients with HCV infection by using a polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) assay. One group consisted of 148 patients with a sustained virological response (SVR), whereas the second group consisted of 160 nonresponders (non-SVR).

Results: Allele and genotype associations of IL28B gene rs8099917 polymorphism with a sustained virological response were observed in comparisons between the SVR and non-SVR groups (P<0.001). In addition, the characteristics of the subjects did not differ between these two groups except for age and fibrosis stage (P<0.05). Additionally, neither SVR nor rs80999917 genotypes were associated by HCV RNA levels.

Conclusions: In conclusion, the rs8099917 polymorphism was thus found strongly associated with a sustained virological response to therapy in Turkish patients infected with HCV genotype 1. Consequently, we suggest determining IL28B gene rs8099917 polymorphism of patients with HCV genotype 1 before onset of treatment.