Predictive value of rapid virological response and early virological response on sustained virological response in HCV patients treated with pegylated interferon alpha-2a and ribavirin.

BACKGROUND AND AIM: The therapeutic effect of pegylated interferon (peg-IFN)-alpha-2a combination with ribavirin on patients with chronic hepatitis C virus (HCV) infection is dependent on the rapidity of the virological response. The aim of this study was to investigate the predictive value of rapid virological response (RVR) and early virological response (EVR) on sustained virological response (SVR) in HCV patients treated with peg-IFN-alpha-2a and ribavirin.
METHODS: The HCV genotypes of 105 patients with chronic hepatitis C were detected by enzyme-immunoassay. Patients received subcutaneous 180 microg peg-IFN-alpha-2a once weekly plus daily ribavirin. Patients with genotype 1 were treated for 48 weeks and patients with genotype 2 or 3 were treated for 24 weeks. HCV RNA was assessed by qualitative PCR at pretreatment, at weeks 4 and 12 during treatment, and at week 24 of follow-up. Virological response rates at different weeks were investigated, with RVR defined as serum HCV RNA undetectable after 4 weeks and EVR defined as HCV RNA either undetectable or decrease by >or=2 log(10) after 12 weeks. The effects of virological response rates at different weeks on SVR were analyzed.
RESULTS: Of the 105 patients, 44 (41.9%) were genotype 1, 46 (43.8%) were genotype 2, and 15 (14.3%) were genotype 3. RVR rates (19.5%) of patients with genotype 1 were significantly lower than those (60.7%) of genotype 2 or 3 (chi(2) = 16.836, P = 0.000); and EVR rates (73.2%) of patients with genotype 1 were significantly lower than those (96.7%) of genotype 2 or 3 (chi(2) = 12.220, P = 0.000). The SVR rates (86.7%) of patients who had achieved RVR were significantly higher than those (43.9%) of patients who had not achieved RVR (chi(2) = 19.713, P = 0.000). The positive predictive value of RVR in all patients was higher than that of EVR, but there was no significant difference between RVR and EVR. The negative predictive value of RVR in all patients or with genotype 1 was significantly lower than that of EVR. In univariate analysis, HCV RNA level (P = 0.014), genotype (P = 0.001), RVR (P = 0.000) and EVR (P = 0.000) were associated with effect of treatment. However, in stepwise regression analysis, the independent factors associated with effect of antiviral therapy were RVR (OR = 6.501, P = 0.001), EVR (OR = 2.776, P = 0.003) and genotype (OR = 3.061, P = 0.024).
CONCLUSIONS: The RVR and EVR rates of patients with genotype 1 were significantly lower than those of patients with genotype 2 or 3. RVR had a similar predictive value as EVR on SVR. Genotype, HCV RNA level, RVR and EVR were associated with SVR. Genotype, RVR and EVR were independent factors for predicting the effect of antiviral therapy.