Dynamics of hepatitis C viremia after plasma exchange

Background/Aims: The dynamics of hepatitis C viremia after perturbation by plasma exchange was addressed in two infected patients with symptomatic cry oglobulinemia, This approach may offer an alternative to studying patients treated with antivirals in order to understand the dynamics of hepatitis C virion exchange among different compartments in vivo. Methods: Plasma exchange sessions were conducted every 24 h for 3 consecuti ve days; hepatitis C virus RNA copy numbers were evaluated in sequential pl asma samples collected before (-24, -12, -8, and 0 h) and at short interval s (at 1, 3, 6, and 12 h) after each session, Results: After each plasma exchange session viremia dropped by 45.3-93.3% i n patient 1, and by 60.5-72.7% in patient 2, paralleling (or, in some cases , exceeding) the amount of fluid exchanged. No mobilization of cell-free he patitis C virus from extra-vascular sites was documented during the 2-h pla sma exchange. The dynamics of hepatitis C viremia after each procedure was also evaluated, Pre-plasma exchange levels mere restored within 3-6 h in bo th patients, and the mean doubling times of residual viremia were 4.6 h and 4.5 h for patients 1 and 2, respectively, Conclusions: The results, in agreement with recent evidence indicating that the turnover of hepatitis C virions is a highly dynamic process, extend pr evious evaluations by documenting that large amounts of newly-produced viri ons are introduced into the vascular compartment within a few hours of the drop in hepatitis C viremia caused by plasma exchange.