ABSTRACT
Mathematical models have been used to study the dynamics of HIV. Using these same
principles, the dynamics of hepatitis C virus (HCV) are reviewed during interferon
(IFN) therapy. After initiating IFN treatment, there is an IFN dose-dependent exponential
decline in viral RNA levels within the first 48 hours. This rapid 1.0 to 2.0 log decline
was best explained by an effect of IFN in inhibiting viral production with a varying
degree of effectiveness. By applying mathematical principles, viral serum half-life
was estimated to be 3.0 hours and viral production rate was calculated to be 1.0 ×
1012 virions per day. After this rapid first-phase decline there was a slower second phase
decline in viral levels that was highly variable between subjects. This phase was
dependent on the rate of elimination of HCV-infected liver cells. The rapidity of
the second phase proved to be the best predictor of early viral clearance. The use
of these models to understand the life cycle of viruses and their response to therapy
is reviewed.
KEYWORD
hepatitis C virus - interferon - ribavirin