Hepatitis cRNA quasispecies complexity in patients with alcoholic liver disease

Alcohol abuse is described as a major cofactor in the development of hepati tis C (HCV) associated liver disease and may play a role in the outcome of interferon-based treatment interventions. The association between HCV viral heterogeneity and alcohol has not been previously described. This study wa s designed to evaluate the quasispecies nature of the HCV population in pat ients with compensated and decompensated alcoholic liver disease, to test t he hypothesis that alcoholics have greater complexity than matched nonalcoh olic controls. A nonisotopic heteroduplex complexity assay (HCA) was first validated by comparison with results of quasispecies complexity determined by subcloning and sequencing of amplicon products from the E2/NS1 hypervari able coding region (HVR), Subsequently, this methodology was applied to com parison of 20 compensated (Child's-Pugh A) and decompensated (Child's-Pugh B/C) alcoholic and 20 nonalcoholic controls. The complexity of the HVR, as well as the S' Untranslated (5'UT) and the NS5b coding domains were evaluat ed. The HCA methodology provided a reasonable semiquantitative measure of H CV RNA quasispecies variability compared with subclone sequence homology co mparison. Overall, alcoholic patients had greater quasispecies complexity ( 2.65 bands) than nonalcoholic controls (1.6 bands; P = .01), Subset analysi s revealed that compensated alcoholic patients had a mean of 3.1 homo/heter oduplex bands per sample whereas Child's-Pugh B/C alcoholics showed interme diate complexity. A similar quasispecies complexity difference was seen in the 5'UTR, but not in the NS5b coding domain, Quasispecies complexity was n ot associated with viral titer, complementary DNA concentration, or genotyp e, The differences in quasispecies complexity may help explain reports of p oor interferon responsiveness in alcoholic patients.