QUANTITATIVE MEASUREMENT OF SERUM HCV RNA IN PATIENTS WITH CHRONIC HEPATITIS-C - COMPARISON BETWEEN AMPLICOR HCV MONITOR SYSTEM AND BRANCHED DNA SIGNAL AMPLIFICATION ASSAY

Quantitative measurement of serum hepatitis C virus (HCV) RNA is impor tant in predicting and monitoring the therapeutic effects of interfero n in treating patients with chronic hepatitis C. We compared two comme rcial available assays, Roche Amplicor HCV Monitor test kits and Chiro n branched DNA signal amplification (bDNA) assay, in quantitative meas urement of serum HCV RNA in 74 patients with chronic hepatitis C. The serum HCV RNA of each of these patients was qualitatively positive by conventional reverse transcription-nested polymerase chain reaction. S erum HCV RNA was detected positive by the Amplicor test kits in 63 (85 %) patients and by the bDNA assay in 58 (78%) patients (P>0.05). The q uantitative results of HCV RNA detected by both assays showed a good l inear correlation (r=0.56, P<0.001). Amplicor test kits detected 5 pat ients with low viremia which were below the detection limit of the bDN A assay (2.0 x 10(5) genome equivalents/ml). However, the mean HCV RNA values detected by the Amplicor test kits was 1.26 log lower than tha t of the bDNA assay. The Amplicor test kits detected only 5 samples (8 %) with ii HCV RNA value greater than 5 x 10(6) copies/ml, while the b DNA assay detected 23 samples (40%) with a HCV RNA value greater than 5 x 10(6) genome equivalents/ml (P<0.01). HCV genotype did not affect the positive rate of HCV RNA measurement detected by both assays. Howe ver, a significantly higher mean serum HCV RNA value was noted in HCV genotype 1b as compared with the other genotypes. We concluded that th e Roche Amplicor HCV Monitor test kits and the Chiron branched DF IA s ignal amplification assay are equally sensitive in the quantitative me asurement of serum HCV RNA in patients with chronic hepatitis C and ca n be reliably used in measuring HCV viremia clinically. (C) 1998 Wiley -Liss, Inc.