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Lombardo SD, Lombardo S. Some stability results for a model of Hepatitis C including alanine aminotransferase and immune system. INT J BIOMATH 2020. [DOI: 10.1142/s1793524520500801] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
In clinical practice, many cirrhosis scores based on alanine aminotransferase (ALT) levels exist. Although the most recent direct acting antivirals (DAAs) reduce fibrosis and ALT levels, the Hepatitis C virus (HCV) is not always removed. In this paper, we study a mathematical model of the HCV virus, which takes into account the role of the immune system, to investigate the ALT behavior during therapy. We find five equilibrium points and analyze their stability. A sufficient condition for global asymptotical stability of the infection-free equilibrium is obtained and local asymptotical stability conditions are given for the immune-free infection and cytotoxic T lymphocytes (CTL) response equilibria. The stability of the infection equilibrium with the full immune response is numerically performed.
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Affiliation(s)
- Salvo Danilo Lombardo
- CeMM Research Center for Molecular Medicine of the Austrian, Academy of Sciences, Lazarettgasse 14, AKH BT 25.3, A-1090 Vienna, Austria
| | - Sebastiano Lombardo
- Department of Mathematics and Computer Science, University of Catania (Ret.), 95125, Catania, Italy
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Iwami S, Koizumi Y, Ikeda H, Kakizoe Y. Quantification of viral infection dynamics in animal experiments. Front Microbiol 2013; 4:264. [PMID: 24058361 PMCID: PMC3767920 DOI: 10.3389/fmicb.2013.00264] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2013] [Accepted: 08/16/2013] [Indexed: 12/18/2022] Open
Abstract
Analyzing the time-course of several viral infections using mathematical models based on experimental data can provide important quantitative insights regarding infection dynamics. Over the past decade, the importance and significance of mathematical modeling has been gaining recognition among virologists. In the near future, many animal models of human-specific infections and experimental data from high-throughput techniques will become available. This will provide us with the opportunity to develop new quantitative approaches, combining experimental and mathematical analyses. In this paper, we review the various quantitative analyses of viral infections and discuss their possible applications.
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Affiliation(s)
- Shingo Iwami
- Department of Biology, Faculty of Sciences, Kyushu University Fukuoka, Japan
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Watanabe T, Sugauchi F, Tanaka Y, Matsuura K, Yatsuhashi H, Murakami S, Iijima S, Iio E, Sugiyama M, Shimada T, Kakuni M, Kohara M, Mizokami M. Hepatitis C virus kinetics by administration of pegylated interferon-α in human and chimeric mice carrying human hepatocytes with variants of the IL28B gene. Gut 2013; 62:1340-6. [PMID: 23135762 PMCID: PMC3756516 DOI: 10.1136/gutjnl-2012-302553] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Revised: 10/04/2012] [Accepted: 10/09/2012] [Indexed: 01/29/2023]
Abstract
OBJECTIVE Recent studies have demonstrated that genetic polymorphisms near the IL28B gene are associated with the clinical outcome of pegylated interferon α (peg-IFN-α) plus ribavirin therapy for patients with chronic hepatitis C virus (HCV). However, it is unclear whether genetic variations near the IL28B gene influence hepatic interferon (IFN)-stimulated gene (ISG) induction or cellular immune responses, lead to the viral reduction during IFN treatment. DESIGN Changes in HCV-RNA levels before therapy, at day 1 and weeks 1, 2, 4, 8 and 12 after administering peg-IFN-α plus ribavirin were measured in 54 patients infected with HCV genotype 1. Furthermore, we prepared four lines of chimeric mice having four different lots of human hepatocytes containing various single nucleotide polymorphisms (SNP) around the IL28B gene. HCV infecting chimeric mice were subcutaneously administered with peg-IFN-α for 2 weeks. RESULTS There were significant differences in the reduction of HCV-RNA levels after peg-IFN-α plus ribavirin therapy based on the IL28B SNP rs8099917 between TT (favourable) and TG/GG (unfavourable) genotypes in patients; the first-phase viral decline slope per day and second-phase slope per week in TT genotype were significantly higher than in TG/GG genotype. On peg-IFN-α administration to chimeric mice, however, no significant difference in the median reduction of HCV-RNA levels and the induction of antiviral ISG was observed between favourable and unfavourable human hepatocyte genotypes. CONCLUSIONS As chimeric mice have the characteristic of immunodeficiency, the response to peg-IFN-α associated with the variation in IL28B alleles in chronic HCV patients would be composed of the intact immune system.
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Affiliation(s)
- Tsunamasa Watanabe
- Department of Virology and Liver Unit, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan
| | - Fuminaka Sugauchi
- Department of Gastroenterology, Nagoya City Koseiin Medical Welfare Center, Nagoya, Japan
| | - Yasuhito Tanaka
- Department of Virology and Liver Unit, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan
| | - Kentaro Matsuura
- Department of Gastroenterology and Metabolism, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan
| | - Hiroshi Yatsuhashi
- Department of Therapeutic Research, National Hospital Organization (NHO) Nagasaki Medical Center, Nagasaki, Japan
| | - Shuko Murakami
- Department of Virology and Liver Unit, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan
| | - Sayuki Iijima
- Department of Virology and Liver Unit, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan
| | - Etsuko Iio
- Department of Gastroenterology and Metabolism, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan
| | - Masaya Sugiyama
- The Research Center for Hepatitis and Immunology, National Center for Global Health and Medicine, Ichikawa, Japan
| | | | | | | | - Masashi Mizokami
- The Research Center for Hepatitis and Immunology, National Center for Global Health and Medicine, Ichikawa, Japan
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Current treatment for chronic hepatitis C virus/HIV-infected individuals: the role of pegylated interferon-alpha and ribavirin. Curr Opin HIV AIDS 2012; 6:483-90. [PMID: 22001893 DOI: 10.1097/coh.0b013e32834bd257] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
PURPOSE OF REVIEW Liver disease is an important cause of morbidity and mortality in the era of combination antiretroviral therapy in HIV/hepatitis C virus (HCV) co-infected patients. This review highlights the role of pegylated interferon-alpha (peg-IFN) and ribavirin (RBV) therapy and examines factors associated with response and strategies to maximize responses. RECENT FINDINGS HCV viral clearance is lower in HIV co-infected patients than in HCV mono-infected patients. However, in patients who attain sustained response there is clinical benefit in terms of liver disease associated morbidity and mortality and treatment is costeffective. Predictors of response appear similar, although there are a number of modifiable patient-associated and HIV-associated factors that could be addressed. Moreover, the use of weight-based RBV and treatment length guided by early viral responses improve response rate. Avoidance of drug-drug interactions and use of haematopoietic growth factors reduce adverse events and dose reductions and ultimately increase response rates. Very early prediction of treatment futility is promising. Induction dosing strategies have not yielded positive results, though twice weekly peg-IFN-alpha-2a induction therapy merits further investigation. SUMMARY Peg-IFN/RBV therapy plays an important role in the management of HCV in HIV-infected patients. Efforts to maximize response to current therapy need to continue while we await new therapies.
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Berenguer M, Ortíz-Cantó C, Abellán JJ, Aguilera V, Rubín A, Prieto M, López-Labrador FX. Hepatitis C virus viral kinetics during α-2a or α-2b pegylated interferon plus ribavirin therapy in liver transplant recipients with different immunosuppression regimes. J Clin Virol 2012; 53:231-8. [PMID: 22222052 DOI: 10.1016/j.jcv.2011.12.005] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2011] [Revised: 11/09/2011] [Accepted: 12/08/2011] [Indexed: 12/16/2022]
Abstract
BACKGROUND Predictors of sustained virological response (SVR) to antiviral therapy post-liver transplantation (LT) for chronic hepatitis C are needed. In non-transplanted patients, viral kinetics can predict SVR. OBJECTIVES To determine the early viral kinetics in LT recipients with different immunosuppression (tacrolimus - Tac- vs. cyclosporine - CsA-) during treatment with peg-IFN+RBV. STUDY DESIGN Prospective pilot study in HCV-1b infected patients: (LT CsA n=8; Tac n=8; non-LT n=4), treated with IFN α-2a vs. α-2b (180 μg or 1.5 μg/kg, respectively) once weekly plus weight-based RBV. Median CsA or Tac baseline trough levels were 141 and 7.70 ng/mL, respectively. HCV-RNA was quantified before treatment and after 3, 6, 12h; days 1-6; and weeks 4, 12, 24, 48 and 78 (follow-up). RESULTS Different kinetics were observed: early viral load declines with shoulder phase (n=12), delayed monophasic without first phase (n=5, all CsA), and biphasic (n=1) or flat (n=1), without influence of IL28B rs12979860 donor/recipient alleles. In LT, median declines (log(10)UI/mL) at week 4 were -3.62 and -1.49 for Tac vs. CsA; and -2.10 vs.-1.50 for IFN α-2a vs. α-2b (NS), with a trend for faster declines in Tac patients. Generalized additive models suggested a cut-off for predicting response in LT patients of 30 days for Tac, but beyond day 40 for CsA. CONCLUSION In LT, the viral kinetics during peg-IFN+RBV treatment is delayed. HCV-RNA at 48 h. may not be predictive of response, and CsA-immunosupressed patients with delayed monophasic declines may potentially achieve ETVR and SVR despite unfavourable or absent early viral load declines.
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Affiliation(s)
- Marina Berenguer
- Hepatology-Liver Transplantation Unit, Digestive Medicine Service, Hospital Universitari La Fe, Spain
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Milazzo L, Cesari M. Early viral kinetics: a novel guide for optimal dosing frequency of pegylated interferon-α-2a in HIV/HCV-coinfected patients. Expert Rev Anti Infect Ther 2011; 9:859-62. [PMID: 21973297 DOI: 10.1586/eri.11.100] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The success rate in HCV treatment of HIV/HCV-coinfected patients is still unsatisfactory and new strategies are required to improve the effectiveness of current regimens and eventually optimize the oncoming new antiviral drugs. This article assesses the findings of a recently published paper comparing pharmacokinetics, pharmacodynamics and HCV decay with twice-weekly dosing of pegylated IFN-α-2a versus the standard weekly dosing, and weight-based ribavirin. A more rapid HCV-RNA decline was observed in the twice-weekly pegylated interferon arm and associated with a higher induction of interferon-stimulated genes, despite a similar pharmacokynetic profile between the two dosing schedules. This promising novel therapeutic approach to improve sustained virologic response in difficult-to-treat populations is discussed in relation to the key findings of the article.
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Affiliation(s)
- Laura Milazzo
- Department of Clinical Sciences, Section of Infectious Diseases and Immunopathology L. Sacco, Università degli Studi di Milano, Via GB Grassi 74, Milan, Italy.
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Baum MK, Sales S, Jayaweera DT, Lai S, Bradwin G, Rafie C, Page JB, Campa A. Coinfection with hepatitis C virus, oxidative stress and antioxidant status in HIV-positive drug users in Miami. HIV Med 2011; 12:78-86. [PMID: 20500231 DOI: 10.1111/j.1468-1293.2010.00849.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
BACKGROUND The pathogenesis of HIV/hepatitis C virus (HCV) coinfection is poorly understood. We examined markers of oxidative stress, plasma antioxidants and liver disease in HIV/HCV-coinfected and HIV-monoinfected adults. METHODS Demographics, medical history, and proof of infection with HIV, hepatitis A virus (HAV), hepatitis B virus (HBV) and HCV were obtained. HIV viral load, CD4 cell count, complete blood count (CBC), complete metabolic panel, lipid profile, and plasma concentrations of zinc, selenium, and vitamins A and E were determined. Malondialdehyde (MDA) and glutathione peroxidase concentrations were obtained as measures of oxidative stress. Aminotransferase to platelet ratio index (APRI) and fibrosis index (FIB-4) markers were calculated. RESULTS Significant differences were found between HIV/HCV-coinfected and HIV-monoinfected participants in levels of alanine aminotransferase (ALT) (mean±standard deviation: 51.4±50.6 vs. 31.9±43.1 U/L, respectively; P=0.014), aspartate aminotransferase (AST) (56.2±40.9 vs. 34.4±30.2 U/L; P<0.001), APRI (0.52±0.37 vs. 0.255±0.145; P=0.0001), FIB-4 (1.64±.0.91 vs. 1.03±0.11; P=0.0015) and plasma albumin (3.74±0.65 vs. 3.94±0.52 g/dL; P=0.038). There were no significant differences in CD4 cell count, HIV viral load or antiretroviral therapy (ART) between groups. Mean MDA was significantly higher (1.897±0.835 vs. 1.344± 0.223 nmol/mL, respectively; P=0.006) and plasma antioxidant concentrations were significantly lower [vitamin A, 39.5 ± 14.1 vs. 52.4±16.2 μg/dL, respectively (P=0.0004); vitamin E, 8.29±2.1 vs. 9.89±4.5 μg/mL (P=0.043); zinc, 0.61±0.14 vs. 0.67±0.15 mg/L (P=0.016)] in the HIV/HCV-coinfected participants than in the HIV-monoinfected participants, and these differences remained significant after adjusting for age, gender, CD4 cell count, HIV viral load, injecting drug use and race. There were no significant differences in glutathione peroxidase concentration, selenium concentration, body mass index (BMI), alcohol use or tobacco use between groups. Glutathione peroxidase concentration significantly increased as liver disease advanced, as measured by APRI (β=0.00118; P=0.0082) and FIB-4 (β=0.0029; P=0.0177). Vitamin A concentration significantly decreased (β=-0.00581; P=0.0417) as APRI increased. CONCLUSION HIV/HCV coinfection is associated with increased oxidative stress and decreased plasma antioxidant concentrations compared with HIV monoinfection. Research is needed to determine whether antioxidant supplementation delays liver disease in HIV/HCV coinfection.
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Affiliation(s)
- M K Baum
- Florida International University, R. Stempel College of Public Health and Social Work, Miami, FL 33199, USA.
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Dahari H, Guedj J, Perelson AS, Layden TJ. Hepatitis C Viral Kinetics in the Era of Direct Acting Antiviral Agents and IL28B. CURRENT HEPATITIS REPORTS 2011; 10:214-227. [PMID: 22180724 PMCID: PMC3237049 DOI: 10.1007/s11901-011-0101-7] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
In the last decade hepatitis C virus (HCV) kinetics has become an important clinical tool for the optimization of therapy with (pegylated)-interferon-α (IFN) and ribavirin (RBV). Mathematical models have generated important insights into HCV pathogenesis, HCV- host dynamics, and IFN and RBV's modes of action. Clinical trials with direct acting agents (DAAs) against various steps of the HCV life cycle have revealed new viral kinetic patterns that have not been observed with IFN±RBV. Very recently, studies have showed that single nucleotide polymorphisms (SNPs) in the IL28B gene region were associated with race/ethnicity and with response to IFN±RBV. Here we review our current knowledge of HCV kinetics and related mathematical models during IFN±RBV and/or DAA based therapies, HCV pathogenesis, and the role of IL28B polymorphism on early HCV kinetics. Better understanding of the mode of actions of drug(s) and viral kinetics may help to develop, in the near future, new individualized therapeutic regimens that include DAAs in combination with IFN+RBV.
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Affiliation(s)
- Harel Dahari
- Department of Medicine, Section of Hepatology, The University of Illinois at Chicago 840 S. Wood Street MC787, Chicago, IL 60612
- Theoretical Biology and Biophysics, MS-K710, Los Alamos National Laboratory, Los Alamos, NM 87545
| | - Jeremie Guedj
- Theoretical Biology and Biophysics, MS-K710, Los Alamos National Laboratory, Los Alamos, NM 87545
| | - Alan S. Perelson
- Theoretical Biology and Biophysics, MS-K710, Los Alamos National Laboratory, Los Alamos, NM 87545
| | - Thomas J. Layden
- Department of Medicine, Section of Hepatology, The University of Illinois at Chicago 840 S. Wood Street MC787, Chicago, IL 60612
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Araújo ESA, Dahari H, Neumann AU, de Paula Cavalheiro N, Melo CE, de Melo ES, Layden TJ, Cotler SJ, Barone AA. Very early prediction of response to HCV treatment with PEG-IFN-alfa-2a and ribavirin in HIV/HCV-coinfected patients. J Viral Hepat 2011; 18:e52-60. [PMID: 20738775 PMCID: PMC3075977 DOI: 10.1111/j.1365-2893.2010.01358.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
The objective of this study was to find very early viral kinetic markers to predict nonresponse to hepatitis C virus (HCV) therapy in a group of human immunodeficiency virus (HIV)/HCV-coinfected patients. Twenty-six patients (15 HCV genotype-1 and 11 genotype-3) were treated with a 48-week regimen of peginterferon-alfa-2a (PEG-IFN) (180 μg/week) and weight-based ribavirin (11 mg/kg/day). Samples were collected at baseline; 4, 8, 12, 18, 24, 30, 36 and 42 h; days 2, 3, 4, 7, 8, 15, 22, 29, 43 and 57 then weekly and monthly. Five patients discontinued treatment. Seven patients (27%) achieved a sustained virological response (SVR). Nadir HCV RNA levels were observed 1.6 ± 0.3 days after initiation of therapy, followed by a 0.3- to 12.9-fold viral rebound until the administration of the second dose of PEG-IFN, which were not associated with SVR or HCV genotype. A viral decline <1.19 log for genotype-1 and <0.97 log for genotype-3, 2 days after starting therapy, had a negative predictive value (NPV) of 100% for SVR. The day 2 virological response had a similar positive predictive value for SVR as a rapid virological response at week 4. In addition, a second-phase viral decline slope (i.e., measured from day 2 to 29) <0.3 log/week had a NPV = 100% for SVR. We conclude that first-phase viral decline at day 2 and second-phase viral decline slope (<0.3 log/week) are excellent predictors of nonresponse. Further studies are needed to validate these viral kinetic parameters as early on-treatment prognosticators of nonresponse in patients with HCV and HIV.
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Affiliation(s)
- Evaldo Stanislau A. Araújo
- University of São Paulo Hospital das Clínicas, São Paulo, Brazil
,Corresponding author: Hospital das Clínicas da Universidade de São Paulo Infectious Diseases Department- Hepatitis Unit-LIM 47 Av.Dr.Enéas de Carvalho Aguiar, 500 Sala 12 Cerqueira César 05401-000 São Paulo, SP, Brazil Tel/fax : ±55 (11) 30851601
| | - Harel Dahari
- Department of Medicine, University of Illinois at Chicago, Chicago, USA
| | | | | | | | | | - Thomas J. Layden
- Department of Medicine, University of Illinois at Chicago, Chicago, USA
| | - Scott J. Cotler
- Department of Medicine, University of Illinois at Chicago, Chicago, USA
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Laufer N, Bolcic F, Rolón MJ, Martinez A, Reynoso R, Pérez H, Salomón H, Cahn P, Quarleri J. HCV RNA decline in the first 24 h exhibits high negative predictive value of sustained virologic response in HIV/HCV genotype 1 co-infected patients treated with peginterferon and ribavirin. Antiviral Res 2011; 90:92-7. [PMID: 21376083 DOI: 10.1016/j.antiviral.2011.02.013] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2010] [Revised: 02/17/2011] [Accepted: 02/24/2011] [Indexed: 12/19/2022]
Abstract
BACKGROUND Treatment with Peg-interferon and ribavirin (PEG-IFN/RBV) for HIV patients co-infected with hepatitis C virus (HCV) genotype 1 has suboptimal rates of response. Viral kinetics has emerged as one of the best prognostic factors of treatment outcome. METHODS Twenty HIV/HCV genotype 1 co-infected patients in treatment with PEG-IFN/RBV, had blood drawn at baseline, 24 h, 4, 12, 24, 48, and 72 weeks. HCV-RNA levels were evaluated at each time point. ROC curves were used to evaluate the log10 HCV-RNA decay at 24 h that exhibits the best predictive value of achieving response. Genomic characterization of HCV NS5A at both interferon sensitivity-determining region (ISDR) and protein-kinase binding (PKRBD) domains were performed in order to evaluate its heterogeneity and association with 24 h HCV-RNA decay and SVR. RESULTS Non-responder patients exhibited a mean of 0.7 log10 (SD 0.74 log10) HCV-RNA decay at 24 h, whereas responder-patients presented 1.6 log10 (SD 0.28 log10), p = 0.04. A reduction in HCV viral load from baseline to 24 h of < 1.4 had a negative predictive value for achieving SVR of 100% and a positive predictive value of 50%. HCV genotype 1 isolates from patients with a decrease of HCV-RNA at 24 h > 1.4 log10, exhibited 3.1(SD 1.5) amino acids substitutions in ISDR and 4.8(SD 2.3) in PKRBD regions and 1.6(SD 0.7) and 2.4(SD 1.3), respectively, in those patients presenting lower reduction in HCV-RNA. CONCLUSIONS HIV/HCV genotype 1 co-infected patients with a decrease in HCV-VL at 24 h > 1.4 log10 are more likely to achieve SVR when treated with PEG-IFN/RBV than those with lower levels of HCV-RNA decay. Along with other host-related and viral-related prognostic factors in HIV/HCV co-infected patients, this very early time point of evaluation could be of relevance in the management of HCV-specific treatment.
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Affiliation(s)
- N Laufer
- Centro Nacional de Referencia para el SIDA, Universidad de Buenos Aires, Paraguay 2155, Buenos Aires, Argentina.
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Abstract
By mathematically describing early hepatitis C virus (HCV) RNA decay after initiation of interferon (IFN)-based antiviral therapy, crucial parameters of the in vivo viral kinetics have been estimated, such as the rate of production and clearance of free virus, and the rate of loss of infected cells. Furthermore, by suggesting mechanisms of action for IFN and ribavirin mathematical modelling has provided a means for evaluating and optimizing treatment strategies. Here, we review recent modelling developments for understanding complex viral kinetics patterns, such as triphasic HCV RNA declines and viral rebounds observed in patients treated with pegylated interferon and ribavirin. Moreover, we discuss new modelling approaches developed to interpret the viral kinetics observed in clinical trials with direct-acting antiviral agents, which induce a rapid decline of wild-type virus but also engender a higher risk for emergence of drug-resistant variants. Lastly, as in vitro systems have allowed a better characterization of the virus lifecycle, we discuss new modelling approaches that combine the intracellular and the extracellular viral dynamics.
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Affiliation(s)
- Jeremie Guedj
- Theoretical Biology and Biophysics, Los Alamos National Laboratory, Los Alamos 87545, USA
| | - Libin Rong
- Department of Mathematics and Statistics and Center for Biomedical Research, Oakland University, Rochester, Michigan 48309, USA
| | - Harel Dahari
- Department of Medicine, University of Illinois, Chicago, Illinois 60612, USA
| | - Alan S. Perelson
- Theoretical Biology and Biophysics, Los Alamos National Laboratory, Los Alamos 87545, USA,
Corresponding author: . Phone: 505-667-6829; Fax: 505-665-3493 Address: MS-K710, Los Alamos National Laboratory, NM 87545 USA
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Modeling subgenomic hepatitis C virus RNA kinetics during treatment with alpha interferon. J Virol 2009; 83:6383-90. [PMID: 19369346 DOI: 10.1128/jvi.02612-08] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Although replicons have been used to demonstrate hepatitis C virus (HCV) inhibition by alpha interferon (IFN-alpha), the detailed inhibition kinetics required to mathematically model HCV RNA decline have been lacking. Therefore, we measured genotype 1b subgenomic replicon (sg1b) RNA levels under various IFN-alpha concentrations to assess the inhibition kinetics of intracellular HCV RNA. During nine days of IFN-alpha treatment, sg1b RNA decreased in a biphasic, dose-dependent manner. Using frequent measurements to dissect these phases during IFN-alpha treatments of 100 and 250 U/ml revealed that the first-phase sg1b RNA decline began approximately 12 h posttreatment, continued for 2 to 4 days, and then exhibited a distinct flat or slower second phase. Based on these data, we developed a mathematical model of IFN-alpha-induced intracellular sg1b RNA decline, and we show that the mechanism(s) mediating IFN-alpha inhibition of HCV acts primarily by reducing sg1b RNA amplification, with an additional effect on HCV RNA stability/degradation detectable at a dose of 250 U/ml IFN-alpha. While the extremely slow or flat second phase of viral RNA inhibition observed in vitro, in which there is little or no cell death, supports the in vivo modeling prediction that the more profound second-phase decline observed in IFN-alpha-treated patients reflects immune-mediated death/loss of productively infected cells, the second-phase decline in viral RNA with a dose of 250 U/ml IFN-alpha suggests that a further inhibition of intracellular HCV RNA levels may contribute as well. As such, dissection of HCV IFN-alpha inhibition kinetics in vitro has brought us closer to understanding the mechanism(s) by which IFN-alpha may be inhibiting HCV in vivo.
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