Background: A rapid decrease of hepatitis C virus (HCV) RNA is interferon (IFN) dose-dependent, and a 3-log decline of HCV-RNA is a strong predictor of sustained virological response. In this study, viral kinetics of HCV RNA in patients treated with 18 MU interferon alpha (IFN-alpha) daily for 2 weeks are presented.
Methods: Thirteen treatment-naive patients with chronic hepatitis C received 6 MU of IFN-alpha2a every 8 h for 2 weeks. Samples were obtained daily during the treatment period. HCV-RNA levels were determined using the quantitative VERSANT 3.0 bDNA assay (detection limit 520 IU/ml). When results were below the detection limit, HCV-RNA was measured by qualitative polymerase chain reaction (PCR) using the COBAS AMPLICOR HCV test, version 2.0 (detection limit of 50 IU/ml).
Results: In patients infected with genotype non-1, a 3-log decline of viral load was found 2.4 days after the start of induction therapy. Only one of three patients infected with genotype 1 had a 3-log decline in viral load within 14 days of the start of therapy. In four patients, a third phase of viral decline was observed. At the end of treatment, 10/13 (77%) and 7/13 (54%) patients were HCV-RNA-negative in quantitative assay and qualitative PCR, respectively. Only one of 13 patients achieved a sustained virological response (SVR).
Conclusion: Daily administration of 18 MU IFN-alpha to patients infected with genotype non-1 induces a 3-log decline of viral load within 2.4 days of the start of treatment. In patients infected with genotype 1, only one-third of patients have a 3-log decline at 11 days.