Impact of ribavirin exposure on early virological response to hepatitis C therapy in HIV-infected patients with chronic hepatitis C

Background: The use of pegylated interferon (PEG-IFN) plus ribavirin (RBV) is currently the recommended treatment for chronic hepatitis C virus (HCV) infection. Coinfection with HIV is a negative predictor of response, for reasons not well understood. Methods: We examined the virological response at weeks 4 and 12 in 198 HCV/HIV-coinfected patients enrolled in a prospective trial in which PEG-IFN alpha 2a (180 μg per week) and RBV (1000-1200 mg daily) were provided. Results: In an on-treatment analysis, 52.8% of patients achieved undetectable HCV-RNA (<600 IU/ml) at week 4, while 63% and 77.2% of patients had a decline of at least 2 and 1 log₁₀, respectively. At week 12, 73.1% of patients reached undetectable HCV-RNA, and 83.5% and 89% achieved at least a 2- and 1-log₁₀ drop, respectively. More than 85% of HCV genotypes 2/3 cleared HCV-RNA at week 4, a proportion significantly higher when compared with genotypes 1 (33.8%) and 4 (28.6%). Multivariate logistic regression analysis identified genotype 3 and RBV exposure (mg/kg of body weight) as independent predictors of virological response at week 12 of therapy. Conclusion: Early virological response rates to PEG-IFN plus RBV in HCV/HIV-coinfected patients seem to be similar to those reported for HCV-monoinfected subjects. The use of suboptimal doses of RBV in most earlier trials might account for the low response rates seen in coinfected patients. To our knowledge, this is the first report demonstrating that RBV exerts a significant independent effect on early virological response. Therefore, strategies aimed at optimizing doses and adherence to RBV might help to improve responses to HCV therapy in coinfected patients.