DYNAMIC BEHAVIOR OF HEPATITIS-C VIRUS QUASI-SPECIES IN PATIENTS UNDERGOING ORTHOTOPIC LIVER-TRANSPLANTATION

We have studied the distribution of viral sequences from the 5' noncod ing region and from a fragment of the E2/NS2 region of the hepatitis C virus (HCV) genome in samples obtained before and after liver transpl antation in two patients with HCV cirrhosis. The population of viral s equences in both regions were established by sequencing cloned PCR pro ducts. In both cases, the complexity of the viral quasispecies decreas ed after transplantation, although the consensus nucleotide and amino acid sequences remained unchanged. It is suggested that both positive and negative selection and random sampling events contribute substanti ally in shaping the genetic composition of HCV quasispecies and that r ecurrence of HCV infection may occur under equilibrium conditions.