Background and aim: IL28B gene polymorphisms have been associated with treatment-response (sustained virological response, SVR) in genotype 1 hepatitis C virus (HCV)-infected patients, but only with early phase of viral decline (rapid virological response, RVR) with genotype 3 HCV-infected patients. Association between IL28B variants and SVR in genotype 3 HCV- infected patients is unclear. Our study aimed to replicate the association of IL28Bsingle nucleotide polymorphism (SNP) rs8099917 with SVR and to validate its association with RVR in genotype 3 HCV-infected patients.
Methods: 72 patients receiving combination therapy (interferon-alpha and ribavirin) at different Indian centers were retrospectively recruited and their genotype atrs8099917 was determined. The association with RVR and SVR was tested taking in to account the variation in relevant covariates such as age, gender, baseline HCV RNA copy number and liver enzymes.
Results: The minor allele frequency (MAF) in the pooled samples was 0.17 at rs8099917 (G allele). 68% had TT, 29% had GT and 3% had the GG genotype. SVR was achieved in 71% of patients. A significant association ofrs8099917 with both RVR (p = 0.026) and SVR (p = 0.016) was observed with none of the covariates showing any significant association. The relapse rate was high (20%) but no association of rs8099917 was observed with relapse (p = 0.420).
Conclusion: An IL28B SNP associates with both early phase of viral decline and sustained response in a cohort of genotype 3 HCV-infected patients from India.