CORRELATION OF QUANTITATIVE HCV-RNA LEVELS USING A BRANCHED DNA ENHANCED LEVEL AMPLIFICATION ASSAY WITH THERAPEUTIC EFFECTS OF INTERFERON-BETA IN PATIENTS WITH CHRONIC HEPATITIS-C

We analyzed serum HCV-RNA levels using a newly developed quantitative nucleic acid hybridization (branched DNA probe) assay in 32 Japanese patients with chronic hepatitis C treated with beta-interferon (beta-IFN). The branched DNA probe assay was less sensitive than the polymerase chain reaction (PCR) method but it provided easy and accurate quantitative analysis of HCV-RNA levels in several samples. Eleven of 32 (34%) patients had a complete response (CR) to IFN treatment, defined as normalization of ALT levels. Six patients (19%) had a partial response (PR) and 15 (47%) had no response (NR). In only one of 11 (9%) patients with CR, the pre-treatment HCV-RNA level was marginally more than the detectable limit of 350 k-equivalents/ml (keq/ml). However, serum HCV-RNA levels were detectable in four of six patients (67%) with PR and 13 of 15 (87%) patients with NR. There was a significant difference in HCV-RNA levels between CR and NR groups (9% vs. 87%, P < 0.01) using this method. We could not find a significant difference in the proportion of different genotypes of HCV-RNA between CR and NR groups. We conclude that determination of serum HCV-RNA levels prior to IFN treatment using a branched DNA probe assay is very useful in predicting the effect of IFN treatment.