Changes in serum levels of hepatitis C virus genotype 1b monitored by real-time quantitative polymerase chain reaction as a predictor of long term response to interferon-alpha treatment.

Abstract

The aim of this study was to find whether there is a relationship between the changes in the amounts of hepatitis C virus (HCV) at the start of interferon treatment and the long term response to therapy. In 20 patients with HCV genotype 1b each given 880 MU of interferon-alpha, the changes in serum HCV RNA during the first 2 wk of therapy were monitored by real-time quantitative polymerase chain reaction (PCR). Real-time quantitative PCR detected HCV RNA at 10(1)-10(8) copies/ml. Serum HCV RNA decreased rapidly between 8 and 24 h after the first administration (first phase) and more slowly thereafter (second phase), with median exponential decays of 2.14 and 0.11 log10/day, respectively. Four patients had sustained virological responses, nine patients had transient responses, and seven patients had no responses. The differences in the rate of first-phase viral decline among the three groups were not significant (p = 0.34), but the differences in the rate of second-phase viral decline were significant (p = 0.0004); the median viral decline (interquartile range) in the second phase was 0.48 (0.42-0.50) log10/day in patients with sustained responses, 0.16 (0.10-0.19) log10/day in patients with transient responses, and 0.026 (0.017-0.040) log10/day in patients with no responses. Changes in serum levels of HCV genotype 1b in the first 2 wk of interferon-alpha treatment, monitored by real-time quantitative PCR, can be used for prediction of the long term therapeutic response.