Evaluation of quantitative measurements of hepatitis C virus RNA to predict sustained response to interferon by genotype

Hepatitis C virus (HCV) virus load is one of the most important predictive factors for the outcome of interferon (IFN) therapy. Recent technological advances have allowed a more precise measurement of HCV load. However, the exact cutoff values that could be used to predict the outcome of IFN have not been established for each assay. Five recent quantitative assays were evaluated for the measurement of HCV (Amplicor monitor ver 1.0. Amplicor monitor ver 2.0 (GT), Amplicor monitor ver 2.0 (Cobas), Quantiplex branched DNA amplification (bDNA) ver 2.0 and HCV core protein level by enzyme immunosorbent assay) in 209 consecutive patients with chronic hepatitis C, who received IFN therapy. The results of the two second generation Amplicor monitor tests (GT and Cobas) showed the best correlation (r = 0.930), but the other tests also showed relatively good correlations (r = 0.646-0.925). Each method predicted the effect of IFN with comparable predictive efficacy, ranging from 77.0 to 80.8%. Receiver operating characteristic (ROC) curve analysis showed that Amplicor monitor ver 2.0 and bDNA ver 2.0 are superior in predicting the response in genotype 2a. The best cutoff value for predicting the response to IFN was different by genotype, which should be considered in selecting candidates for IFN treatment. (C) 2001 Elsevier Science B.V. All rights reserved.