Chronic hepatitis C virus (HCX) infection in humans is associated with an impairment of dendritic cells (DC). It has been hypothesized that impairment of DC function may be a central mechanism facilitating the establishment of a chronic carrier state. However, the majority of patients studied with DC impairment to date have been identified and, thus, inadvertently selected because of clinical manifestations leading to their diagnosis, which may have been many years following actual infection. We set out to determine whether impaired DC function occurred in the earlier asymptomatic phase of infection and turned to a well-defined cohort of HCV-infected chimpanzees in which the specific date of infection and the nature of the inoculum were well characterized. Results revealed that, in contrast to the observations in human subjects with advanced clinical hepatitis, there was neither impairment of the allostimulatory capacity of monocyte-derived DC from HCV chronic carriers nor impairment of the maturation process. Decreased allostimulatory capacity was only detected in 2 animals and, interestingly, in those that possessed the highest viral loads.
Nevertheless, HCV sequences were undetectable in any of the DC derived from HCVinfected chimpanzees. In conclusion, these findings suggest that the mechanisms of establishing persistent HCV infection are separate and independent from those responsible for impaired DC function. Indeed, the maturation and allostimulatory impairment, as described in patient studies, are not necessary prerequisites but rather possible consequences of persistent and active HCV infection associated with disease progression. (HEPATOLOGY 2003; 38851-858.) H epatitis C virus (HCV) is the leading cause of chronic liver infections and is strongly correlated with the risk of developing cirrhosis and hepatocellular carcinoma. HCV is capable of causing persistent infection in up to 80% of infected individuals, and there are more than 180 million HCV chronic carriers worldwide.2 For a large number of these patients, there