The response of the hepatitis C virus (HCV) to pegylated interferon α treatment in association with ribavirin is variable and depends on virological and host characteristics. Genetic ancestry has been shown to be a factor in therapeutic progress. Patients of African-American and Amerindian descent typically show reduced sustained virological response (SVR) rates with pegylated interferon α and ribavirin compared with Caucasian patients. 1, 2 In contrast, Asian populations appear to have higher rates of SVR, 3 which suggests an association between genetics and the development of SVR.

Recently, genome-wide association studies described several common and highly correlated single nucleotide polymorphisms (SNPs) in the vicinity of three interferon-λ genes, including IL28B, as being highly predictive of the response of HCV patients to treatment with pegylated interferon α and ribavirin, irrespective of the genotype involved. 4, 5 The same set of SNPs was subsequently associated with the natural elimination of HCV during the acute phase. 6 This association was also demonstrated in HCV/HIV-coinfected patients. 7 The Brazilian population conceivably consists of a mixture of people with Caucasian, African and Amerindian ancestries. 8 Therefore, the present study assessed the association between IL28B gene polymorphisms and SVR in a cohort of HCV/HIV-coinfected Brazilian patients who were treated with pegylated interferon α and ribavirin.