A Comparison of the Exponential Decay Slope between PEG-IFN alfa-2b/Ribavirin and IFN alfa-2b/Ribavirin Combination Therapy in Patients with Chronic Hepatitis C Genotype 1b Infection and a High Viral Load

Abstract

Objectives: A high virological response rate can often be shown to be obtained with PEG-IFN α-2b and ribavirin combination therapy in chronic hepatitis C patients. Viral dynamics have been utilized for the evaluation of antiviral effects, especially the exponential second decay slope, which represents the elimination of infected cells. Methods: Forty-nine patients were randomly assigned to the IFN α-2b group (n = 26) or the PEG-IFN α-2b group (n = 23). Ribavirin was administered equally to both groups. Measuring the serum concentration of HCVRNA, the exponential viral decay during phase 1 and 2 was calculated. Results: The exponential decay slope in phase 2 during the first 2 weeks was greater in the IFN α-2b group than in the PEG-IFN α-2b group; however, from weeks 3 to 4, it was greater in the PEG-IFN α-2b group than in the IFN α-2b group. Interestingly, in the PEG-IFN α-2b group, the exponential decay slope was greater from weeks 3 to 4 after initiating combination therapy than during the weeks 1–2 (p < 0.01), despite administration of the same PEG-IFN α-2b dose (1.5 µg/kg once weekly). Conclusions: In PEG-IFN α-2b and ribavirin combination therapy, elimination of infected cells may be pronounced following an increase in serum ribavirin concentration in chronic hepatitis C patients with genotype 1b infection and a high viral load.

Effective prediction of outcome of combination therapy with pegylated interferon alpha 2b plus ribavirin in Japanese patients with genotype-1 chronic hepatitis C using early viral kinetics and new indices

“…The serum concentration of peginterferon alpha 2b peaks after 24 h, followed by a gradual decline [17,18]. The viral load is therefore reduced by 24 h but increases in week 1 [19,20]. A large dose of peginterferon at each administration results in a marked reduction in the viral load at 24 h but the viral load increases in week 1 regardless of the dose.…”

Twenty four-week peginterferon plus ribavirin after interferon-β induction for genotype 1b chronic hepatitis C

“…Studies have reported that the administration of 3 million units each of IFN-β in the morning and evening for 2 wk reduces HCV-RNA levels by 3 Log IU/mL in many cases, whereas the coadministration of Peg-IFN and RBV decreases them by 1-2 Log IU/mL [16,17] , clearly indicating that the former regimen results in a higher rate of HCV-RNA decrease in the early phase of treatment.…”

Outcome and Early Viral Dynamics with Viral Mutation in PEG-IFN/RBV Therapy for Chronic Hepatitis in Patients with High Viral Loads of Serum HCV RNA Genotype 1b

“…The concentration of PEG-IFN ␣ -2b in serum peaks after 24 h, then declines gradually [14,15] . The viral load is thus reduced by 24 h but increases in week 1 [16,17] ; with a large dose of PEG-IFN at each administration, it decreases markedly at 24 h but then increases in week 1 regardless of the dose. In the responder group, however, the viral load continues to decline each week thereafter [17] .…”