PREDICTIVE FACTORS IN ERADICATING HEPATITIS-C VIRUS USING A RELATIVELY SMALL DOSE OF INTERFERON

Interferon (IFN) can reduce hepatitis C virus load and even eliminate the virus in 30-40% of patients. Several predictive factors for eradic ation of the virus have been reported and a higher dose of IFN tends t o result in elimination of the virus. However, a small dose of IFN som etimes is as effective as a large dose in eradicating the virus. The p redictive factors for such a response are not well established. We ret rospectively analysed 50 patients with chronic hepatitis C who were tr eated with relatively small amounts of IFN (equal or less than 252 mil lion units). Eleven patients were responders (elimination of hepatitis C virus (HCV) and normalization of alanine amino transferase (ALT) fo r at least 6 months), but the remaining 39 were non-responders. Multiv ariate analysis showed that the pretreatment viral load and total dose of IFN per kilogram of bodyweight were significant predictive factors of response to therapy. We also assessed the amino acid substitutions in the IFN sensitivity determining region (ISDR), NS5A codon 2209-224 8, of HCV in serum samples obtained from 31 patients with HCV genotype 1b. The presence of more than one amino acid substitution in the ISDR tended to correlate with HCV genotype 1b elimination. As IFN is expen sive and has a number of serious side effects, our study suggests that the optimal dose of IFN may vary from one patient to another and that more stringent criteria should be used to select the optimal dose for therapy.