Clinical Significance of Two Real-Time PCR Assays for Chronic Hepatitis C Patients Receiving Protease Inhibitor-Based Therapy

The aim of this study was to determine the efficacy of two hepatitis C virus (HCV) real-time PCR assays, the COBAS AmpliPrep/COBAS TaqMan HCV test (CAP/CTM) and the Abbott RealTime HCV test (ART), for predicting the clinical outcomes of patients infected with HCV who received telaprevir (TVR)-based triple therapy or daclatasvir/asunaprevir (DCV/ASV) dual therapy. The rapid virological response rates in patients receiving TVR-based triple therapy were 92% (23/25) and 40% (10/25) for CAP/CTM and ART, respectively. The false omission rate (FOR) of ART was 93.3% (14/15), indicating that CAP/CTM could accurately predict clinical outcome in the early phase. In an independent examination of 20 patients receiving TVR-based triple therapy who developed viral breakthrough or relapse, the times to HCV disappearance by ART were longer than by CAP/CTM, whereas the times to HCV reappearance were similar. In an independent experiment of WHO standard HCV RNA serially diluted in serum containing TVR, the analytical sensitivities of CAP/CTM and ART were similar. However, cell cultures transfected with HCV and grown in medium containing TVR demonstrated that ART detected HCV RNA for a longer time than CAP/CTM. Similar results were found for 42 patients receiving DCV/ASV dual therapy. The FOR of ART was 73.3% (11/15) at week 8 after initiation of therapy, indicating that ART at week 8 could not accurately predict the clinical outcome. In conclusion, although CAP/CTM and ART detected HCV RNA with comparable analytical sensitivity, CAP/CTM might be preferable for predicting the clinical outcomes of patients receiving protease inhibitor-based therapy.