Research

Correlation between pre-treatment quasispecies complexity and treatment outcome in chronic HCV genotype 3a

Isabelle Moreau¹ , John Levis¹ , Orla Crosbie² , Elizabeth Kenny-Walsh² and Liam J Fanning¹

¹  Molecular Virology Diagnostic & Research Laboratory, Department of Medicine, Clinical Sciences Building, Cork University Hospital, Cork, Ireland

²  Department of Gastroenterology, Cork University Hospital, Cork, Ireland

author email corresponding author email

Virology Journal 2008, 5:78doi:10.1186/1743-422X-5-78

Published:	9 July 2008

Abstract

Pre-treatment HCV quasispecies complexity and diversity may predict response to interferon based anti-viral therapy. The objective of this study was to retrospectively (1) examine temporal changes in quasispecies prior to the start of therapy and (2) investigate extensively quasispecies evolution in a group of 10 chronically infected patients with genotype 3a, treated with pegylated α2a-Interferon and ribavirin.

The degree of sequence heterogeneity within the hypervariable region 1 was assessed by analyzing 20–30 individual clones in serial serum samples. Genetic parameters, including amino acid Shannon entropy, Hamming distance and genetic distance were calculated for each sample. Treatment outcome was divided into (1) sustained virological responders (SVR) and (2) treatment failure (TF).

Our results indicate, (1) quasispecies complexity and diversity are lower in the SVR group, (2) quasispecies vary temporally and (3) genetic heterogeneity at baseline can be use to predict treatment outcome.

We discuss the results from the perspective of replicative homeostasis.