RESUMEN
We studied viral dynamic parameters in 44 chronic hepatitis B/hepatitis B e antigen (HBeAg)(-) patients treated with pegylated interferon alfa-2b (PEG-IFN) 100 or 200 microg weekly or lamivudine 100 mg daily or the combination of PEG-IFN 100 or 200 microg with lamivudine. Patients receiving PEG-IFN monotherapy exhibited viral load oscillations between weekly injections, which were resolved by the addition of lamivudine. The median pharmacological delay was estimated at 4.1, 5.8, and 1.8 hours in PEG-IFN monotherapy, PEG-IFN 100/200 microg + lamivudine, and lamivudine monotherapy, respectively (P = .44). The median half-life of free virus was 12.7 hours (range, 2.4-69.2 hours). The mean antiviral effectiveness of PEG-IFN 100/200 microg monotherapy was lower than that of lamivudine (82.6% vs. 96.4%; P = .005). The mean effectiveness of PEG-IFN 100 microg + lamivudine and PEG-IFN 200 microg + lamivudine was 92.8% and 94.4%, respectively. The half-life of infected cells ranged from 2.7 to 75 days. The median half-life of infected cells in patients receiving the combination regimens of PEG-IFN and lamivudine was similar to that of lamivudine patients (5.0 days vs. 6.0 days, P = .77). In conclusion, the addition of pegylated interferon alfa-2b in lamivudine treatment was found to neither enhance the potency of blocking HBV production nor the decay rates of infected cells. Supplementary material for this article can be found on the HEPATOLOGY website (http://www.interscience.wiley.com/jpages/0270-9139/suppmat/index.html).