Background: The real-time PCR, such as Abbott RealTime assay, have replaced end-point PCR, such as Amplicor assays, for the measurement of HCV RNA. However, 'response-guided therapy' to use on-treatment response for tailoring the duration of treatment with peginterferon-alpha and ribavirin has not been fully evaluated for real-time PCR.
Methods: 43 patients with HCV genotype 1 (24 who had complete early virological responses (cEVR) on Amplicor assay and received 48-week therapy, and 19 who had late virological responses (LVR) and received 72-week therapy) were recruited. Using a RealTime assay, we retrospectively measured HCV RNA in stored sera.
Results: In 10 samples obtained during therapy, HCV RNA was undetectable on the Amplicor assay, but detectable on the RealTime assay. Among patients with cEVR on the Amplicor assay, those with detectable HCV RNA on the RealTime assay at week 12 were less likely to have a sustained virological response (SVR) than those without (2/4 vs 17/20, p = 0.116). Among patients with LVR on the Amplicor assay, those with HCV RNA detectable on the RealTime assay at week 24 were significantly less likely to have SVR than those without (1/4 vs 12/15, p = 0.041).
Conclusions: The RealTime assay may be useful for tailoring duration of treatment for the patient with HCV genotype 1.