LONGITUDINAL GENOTYPE ANALYSIS AND QUANTIFICATION OF HEPATITIS-C VIRUS IN HEMOPHILIC PATIENTS RECEIVING INTERFERON-ALPHA THERAPY

Haemophilic patients have a high prevalence of hepatitis C virus (HCV) infection because of the use of unsterilized clotting factor concentr ates. Six major genotypes of HCV have been distinguished so far, with epidemiological evidence suggesting that genotypes 1-3 are common in t he indigenous UK and US populations. The aim of this study was to anal yse the changes in viral load and composition of the HCV quasispecies in haemophilic patients receiving therapy with interferon-alpha (IFN-a lpha) using the four major methods currently available for HCV genotyp ing. The most consistent genotype results were obtained using restrict ion fragment-length polymorphism (RFLP) analysis when compared with th e DNA sequence analysis, and showed that the dominant genotype can cha nge in patients with mixed genotype infections treated with IFN-alpha. This study indicates the difficulties in studying this group of patie nts with mixed HCV genotype infections, and that frequent sampling is necessary, together with viral load measurement to monitor response to IFN-alpha therapy.