Modeling the Probability of Sustained Virological Response to Therapy with Pegylated Interferon plus Ribavirin in Patients Coinfected with Hepatitis C Virus and HIV

Background. A single-nucleotide polymorphism (SNP) near the IL28B gene (rs12979860) strongly predicts sustained virological response to pegylated interferon plus ribavirin (pegIFN-RBV) treatment for chronic hepatitis C virus (HCV) infection. Given that therapy is poorly tolerated and rates of response are lower in patients coinfected with HCV and human immunodeficiency virus (HIV), the recognition of predictors of response is a high priority in this population. Methods. A baseline noninvasive index was derived on the basis of the probability of achieving sustained virological response in a group of 159 HIV-HCV-coinfected patients treated at one clinic in Spain. The index was then validated using data from a separate cohort of 86 coinfected individuals. Only individuals who had completed a course of pegIFN-RBV therapy and had validated outcomes were considered. Results. The final score included 4 variables: 2 host-related variables (IL28B SNP rs12979860 and liver stiffness) and 2 HCV-related variables (genotype and viral load). The area under the receiver operating characteristic curve was 0.89 in the derivation group and 0.85 in the validation group. Conclusions. The probability of achieving sustained virological response with pegIFN-RBV therapy in HIV-HCV-coinfected patients can be reliably estimated prior to initiation of therapy using an index that includes 4 noninvasive parameters.