Abstract
The lower limits of virus detection of hepatitis C virus (HCV) RNA detection assays are continuously improving. We aimed to assess the utility of more precise definition of 4(th) week viral load [rapid virological response (RVR)] in predicting sustained virological response (SVR) in HCV genotype 1 patients treated with pegylated-interferon (PEG-IFN) and ribavirin. Clinical data of treatment-naïve HCV genotype 1 patients were retrospectively collected from 2009 to 2014. Patients were grouped according to 4(th) week viral load as follows: undetectable (n = 90) and detectable but not quantifiable (< 12 IU/mL, n = 27). All patients received PEG-IFNα-2a or -2b and ribavirin for 24 weeks. Serum HCV RNA levels were measured by Abbott RealTime (ART; Abbott Molecular, Abbott Park, IL, USA) HCV assay. SVR was 95.5% and 63% in the undetectable group and < 12 IU/mL group of 4(th) week viral load, respectively. The between-group difference in SVR was significant (p < 0.001). We determined 4(th) week viral load was independently associated with SVR (odds ratio = 19.28; p = 0.002) and a good predictor of SVR [area under the curve (AUC) = 0.775; p = 0.001]. ART HCV assays had a stronger SVR predictive value in HCV genotype 1 patients, indicating that only the undetectable group of 4(th) week viral load patients measured by ART HCV assay should be considered for shorter treatment time (24 weeks) with PEG-IFN and ribavirin.