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 p atients with chronic hepatitis C treated with beta-interferon (beta-IF N). The branched DNA probe assay was less sensitive than the polymeras e chain reaction (PCR) method but it provided easy and accurate quanti tative 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%) patien ts with CR, the pre-treatment HCV-RNA level was marginally more than t he detectable limit of 350 k-equivalents/ml (keq/ml). However, serum H CV-RNA levels were detectable in four of six patients (67%) with PR an d 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) usin g this method. We could not find a significant difference in the propo rtion of different genotypes of HCV-RNA between CR and NR groups. We c onclude that determination of serum HCV-RNA levels prior to IFN treatm ent using a branched DNA probe assay is very useful in predicting the effect of IFN treatment.