FACTORS USEFUL IN PREDICTING THE RESPONSE TO INTERFERON THERAPY IN CHRONIC HEPATITIS-C

To determine how various factors influence the response to interferon (IFN) therapy, we retrospectively studied 157 consecutive Japanese pat ients with chronic hepatitis C who received various treatment schedule s of IFN. They were divided into two groups on the bases of outcome. O ne group was comprised of 65 patients who achieved a sustained normali zation of serum alanine aminotransferase (ALT) levels for at least 6 m onths after treatment, while the other group was comprised of 84 patie nts with persistent elevation of serum ALT levels, despite treatment. Genotyping of hepatitis C virus (HCV) was done by polymerase chain rea ction (PCR) with genotype specific primers, analysing the variations i n nucleotide sequence within the NS 5 region of the HCV genome, namely genotypes PT, K1, K2a and K2b. We then used a multivariate analysis t o determine the factors related to mode of treatment, patient characte ristics and HCV genotype in relation to the response to IFN therapy. O f the 16 factors analysed, the HCV genotype (genotype K2a or K2b, P < 0.0008), treatment schedule (intermittent administration following a d aily schedule, designated as combined schedule, P > 0.0014) and liver histology just before treatment (chronic persistent hepatitis or mild chronic aggressive hepatitis, P < 0.0324) were the most strongly corre lated with a normalizing response to IFN therapy. These results sugges t that not only are the IFN treatment schedule and patient profile sig nificant, but the properties of the virus also influences the response . However, as the IFN treatment schedule is the only changeable factor , it should be designed to maximize the benefit of IFN therapy.