Plasma HCV-RNA decline in the first 48 h identifies hepatitis C virus mono-infected but not HCV/HIV-coinfected patients with an undetectable HCV viral load at week 4 of peginterferon-alfa-2a/ribavirin therapy.
ABSTRACT During peginterferon-alfa-2a/ribavirin therapy, plasma hepatitis C virus (HCV)-RNA decreases with a rapid first phase and a slower second phase. We compared the viral load decrease and slope in the first 48 h in patients with a rapid viral response (RVR, i.e. HCV-RNA < 50 IU/mL at week 4) with patients not achieving an RVR. From 23 HCV-infected (14 mono-infected and nine HCV/HIV-coinfected) genotype 1 or 4 positive peginterferon-alfa-2a/ribavirin-treated patients, plasma HCV-RNA was determined at baseline, 48 h, weeks 1, 2, 4, 8, 12, 48 and 72. The HCV viral load decrease (Delta0-48), the slope (lambda(1)) and the efficiency factor (epsilon) were determined in the first 48 h after the start of therapy. Five (36%) HCV mono-infected patients and three (33%) HIV/HCV-coinfected patients achieved an RVR whereas six (43%) HCV mono-infected patients and five (56%) HIV/HCV-coinfected patients reached a sustained viral response (SVR). In contrast to HIV/HCV-coinfected patients, five HCV mono-infected patients with an RVR showed both a larger Delta0-48 and steeper lambda(1) (-1.77log(10) IU/mL +/- 0.66 and -2.04/day +/- 0.76) compared to nine non-RVR patients (-0.66log(10) IU/mL +/- 0.39; P = 0.019 and -0.76/day +/- 0.41; P = 0.019). When divided by SVR, a greater Delta0-48 and steeper lambda(1) were also seen in both HCV mono-infected and HIV/HCV-coinfected patients. Thus, in the first 48 h after the start of therapy, HCV mono-infected patients with an RVR have a larger viral load decrease, steeper viral slope and a higher efficiency factor as compared with non-RVR patients.
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ABSTRACT: To evaluate the effect of the interleukin 28B (IL-28B) genotype on hepatitis C virus (HCV) viral kinetics in the first 4 weeks from start of treatment with pegylated interferon plus ribavirin (PEG-IFN/RBV) in HIV/HCV co-infected patients. HIV/HCV co-infected patients naive to PEG-IFN/RBV treatment were enrolled in a prospective study. HCV RNA plasma viral loads were measured at baseline and at weeks 1, 2 and 4 after commencement of treatment. Patients were grouped by HCV genotype (genotype 1/4 versus 3) and by IL-28B genotype (CC versus non-CC). Differences in viral load reduction were evaluated by IL-28B genotype between baseline, week 1, week 2 and week 4. One hundred and nineteen HIV/HCV patients were included in the study. HCV patients with genotype 1/4 and bearing the IL-28 CC genotype showed the greatest reductions in HCV RNA plasma levels between baseline and weeks 1 (B-1), 2 (B-2) and 4 (B-4) than did those with non-CC genotypes (B-1: 1.06 ± 0.89 versus 0.48 ± 0.48 log IU/mL, P = 0.009; B-2: 1.36 ± 0.72 versus 0.77 ± 0.66 log IU/mL, P = 0.01; and B-4: 1.91 ± 0.64 versus 1.38 ± 0.96 log IU/mL, P = 0.03). However, differences between weeks 1 and 2 (W1-2) and between weeks 2 and 4 (W2-4) were not associated with the IL-28B genotype (W1-2: CC 0.48 ± 0.42 versus non-CC 0.38 ± 0.38 log IU/mL, P = 0.62; W2-4: CC 0.32 ± 0.23 versus non-CC 0.39 ± 0.31 log IU/mL, P = 0.67). No differences in decline of HCV RNA viral load were found in HCV genotype 3 patients. The IL-28B genotype impacts on viral kinetics during the first week of treatment with PEG-IFN/RBV in patients with HCV genotype 1/4.Journal of Antimicrobial Chemotherapy 01/2012; 67(1):202-5. DOI:10.1093/jac/dkr439 · 5.44 Impact Factor
European Neuropsychopharmacology 08/2010; 20. DOI:10.1016/S0924-977X(10)70479-X · 5.40 Impact Factor
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ABSTRACT: Hepatitis C viral kinetic analysis based on nonlinear mixed effect models can be used to individualize treatment. For that purpose, it is necessary to obtain precise estimation of individual parameters. Here, we evaluated by simulation the influence on Bayesian individual parameter estimation and outcome prediction of a priori information on population parameters, viral load sampling designs, and methods for handling data below detection limit (BDL). We found that a precise estimation of both individual parameters and treatment outcome could be obtained using as few as six measurements in the first month of therapy. This result remained valid even when incorrect a priori information on population parameters was set as long as the parameters were identifiable and BDL data were properly handled. However, setting wrong values for a priori population parameters could lead to severe estimation/prediction errors if BDL data were ignored and not properly accounted in the likelihood function.CPT: Pharmacometrics & Systems Pharmacology (2013) 2, e56; doi:10.1038/psp.2013.31; published online 17 July 2013.07/2013; 2(7):e56. DOI:10.1038/psp.2013.31