Twelve week post-treatment follow-up predicts sustained virological response to pegylated interferon and ribavirin therapy in HIV/hepatitis C virus co-infected patients.

Objectives: The aim of this study was to evaluate whether the assessment of hepatitis C virus (HCV) RNA serum at 12 weeks after the end of treatment (W12) was as informative as after 24 weeks (W24) for determining sustained virological response (SVR) in HIV/HCV co-infected patients who received a combination of pegylated interferon (PEG-INF) plus ribavirin (PEG-INF/RBV) and had a virological response at the end of treatment.

Methods: Treatment-naive HIV/HCV patients were included in this prospective study if they had completed a full course of therapy with PEG-INF/RBV, had an undetectable serum HCV RNA at the end of treatment and complied with the W12 and W24 schedule for determining HCV RNA. HCV RNA levels were measured using a quantitative PCR assay (detection limit = 15 IU/mL). Positive predictive value (PPV) was defined as the probability of an undetectable serum HCV RNA at W12 and W24 after the end of treatment.

Results: Of 186 patients treated during the study period, 104 (55.9%) were included in the study. At W24, 83 (79.8%) patients had an SVR and 21 (20.2%) had a virological relapse. At W12, HCV RNA was undetectable in 83 (79.8%) patients and all of these had SVR. Undetectable HCV RNA at W12 had a 100% PPV [95% confidence interval (CI) 96.5%-100%] for SVR.

Conclusions: Our results show that undetectable HCV RNA at W12 post-treatment has a high PPV for SVR. Testing for HCV RNA at this moment may therefore be considered an appropriate point in time for identifying SVR and relapse in HIV/HCV co-infected patients receiving treatment with PEG-INF/RBV.