Objective: To investigate the utility of a week-4 virological response for sustained response prediction in hepatitis C virus (HCV) genotype 3/HIV-co-infected patients treated with interferon and ribavirin for 24 weeks.
Methods: Using a real-time polymerase chain reaction-based quantitative assay (COBAS AmpliPrep-COBAS-TaqMan 48; Roche Diagnostics) we retrospectively analysed samples obtained at baseline and weeks 4 and 12 from a subset of 35 HCV genotype 3-HIV co-infected patients enrolled in a randomized comparative trial of peginterferon alpha-2b versus interferon alpha-2b both in combination with ribavirin.
Results: In an intention-to-treat analysis, 78% of patients treated with peginterferon and 53% of those receiving standard interferon achieved a sustained virological response (SVR) Overall, at 4 weeks, 49% of patients had HCV RNA < 50 IU/ml and 63% had < 600 IU/ml. Of these rapid responders 88 and 86% achieved a SVR, respectively, with only one patient relapsing among end-of-treatment responders. In contrast, only 44 and 31% of patients with a week-4 HCV RNA >or= 50 or >or= 600 IU/ml achieved an SVR, respectively, with relapse rates of 33 and 50%, respectively. In multivariate logistic regression analysis a serum HCV RNA level below 600 IU/ml at week 4 was the strongest independent predictor of SVR (odds ratio, 11.3; 95% confidence interval, 1.7 to 75.0; P = 0.012).
Conclusion: Monitoring early viral response may be useful to tailor the duration of treatment among patients with HCV genotype 3/HIV-co-infection. Patients whose HCV RNA falls below 600 IU/ml at 4 weeks are at low risk of relapse after 24 weeks of combination therapy.