Kinetics of hepatitis C virus RNA load during pegylated interferon alpha-2a and ribavirin treatment in na？ve genotype 1 patients

Twenty patients treated with Peg-IFN alpha-2a and ribavirin for 48 weeks were studied. Six months after the end of treatment, a SVR (negative HCV RNA measured by PCR six months after the end of therapy) was obtained in 9 patients. Samples were obtained before and at week 2, 4, 8, and 12. At the end of week 2, viral load decreased more than 1.39 log in 8 out of the 9 patients with SVR and in 1 out of the 11 other patients. When we considered the viral load reduction from baseline to each week of treatment, week 2 appeared to be the best point time for predicting SVR, with a sensitivity of 91% (95%CI: 59;99), a specificity of 89% (52;98), a positive predictive value of 91% (59;99) and a negative predictive value of 89% (57;98).During treatment with Peg-IFN alpha-2a plus ribavirin in genotype 1 patients, when the main objective of the treatment is viral eradication, viral kinetics showed that week 2 appeared to be the best time point for predicting SVR. Our results must be further confirmed on a larger cohort.Interferon alpha plus ribavirin and more recently pegylated interferon (Peg-IFN) given for 24 or 48 weeks constitutes the most effective initial therapy for the treatment of chronic hepatitis C [1-4]. In relapsers, we have previously shown that viral load decline at week 2 appears the best time for predicting the response to treatment [5].Understanding the kinetics and dynamics of human immunodeficiency virus (HIV) and of hepatitis B virus (HBV) has greatly improved the understanding of the life cycle of these viruses and their response to therapy [6]. Studies of the kinetics of hepatitis C virus (HCV) after initiation of IFN monotherapy have revealed that IFN alpha-2b causes a rapid dose-dependent reduction in HCV RNA levels within 24 to 48 hours. Mathematical calculations revealed that HCV has a serum half-life of 3 hours and a viral production rate of 1.0 × 1012 virions/day [2,7]. This rapid decline appears to be a strong predictor of response to treatment [8,9