SERUM HEPATITIS-C VIRUS-RNA LEVEL AS A PREDICTOR OF SUBSEQUENT RESPONSE TO INTERFERON-ALPHA THERAPY IN JAPANESE PATIENTS WITH CHRONIC HEPATITIS-C

Serum hepatitis C virus (HCV) RNA level has been shown to be a good pr edictor of subsequent response to interferon-alpha (IFN) therapy in US patients in whom genotype 1a/1b are both predominant. To determine wh ether serum HCV RNA level is a predictor of subsequent response to IFN in Japanese patients or not, appropriately collected pre-IFN therapy serum samples from 35 Japanese patients with chronic HCV infection wer e studied. Serum HCV RNA level and HCV genotype were determined and co rrelated with the subsequent response to IFN. Response to IFN was defi ned by serum alanine transaminase level: complete and sustained respon se (n = 15), complete response followed by relapse (n = 10), and no re sponse (n = 10). Patients with complete and sustained response had low er pre-IFN serum HCV RNA level (median: RT-PCR+, bDNA-) compared to th e complete response to relapse group (median: 5.25 x 10(6) genome equi valent/ml [eq/ml], P < 0.001) and the no response group (median: 10.63 x 10(6) eq/ml, P < 0.001). Seven (46.7%) of the complete and sustaine d response patients had HCV genotype 2a and three patients had a mixtu re of genotypes 1b and 2a. In contrast, all 10 patients in the complet e response to relapse group had genotype 1b whereas 8 of 10 patients i n the non-response group had genotype 1b and 2 had genotype 2b. The pa tients with HCV genotype 2a had lower serum HCV RNA level than those w ith 1b (P = 0.002). When the HCV viremia were controlled by stratifyin g them into < and > 10(6) eq/ml, patients with genotype 1 had a simila r complete and sustained response rate compared to genotype 2. These d ata indicated that pre-IFN serum HCV RNA is also a good predictor of s ubsequent complete and sustained response in Japanese patients with ch ronic HCV infection. (C) 1994 Wiley-Liss, Inc.