1
|
Burgis NE, VanWormer K, Robbins D, Smith J. An ITPA Enzyme with Improved Substrate Selectivity. Protein J 2024; 43:62-71. [PMID: 38066288 PMCID: PMC10901923 DOI: 10.1007/s10930-023-10162-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/03/2023] [Indexed: 02/29/2024]
Abstract
Recent clinical data have identified infant patients with lethal ITPA deficiencies. ITPA is known to modulate ITP concentrations in cells and has a critical function in neural development which is not understood. Polymorphism of the ITPA gene affects outcomes for both ribavirin and thiopurine based therapies and nearly one third of the human population is thought to harbor ITPA polymorphism. In a previous site-directed mutagenesis alanine screen of the ITPA substrate selectivity pocket, we identified the ITPA mutant, E22A, as a gain-of function mutant with enhanced ITP hydrolysis activity. Here we report a rational enzyme engineering experiment to investigate the biochemical properties of position 22 ITPA mutants and find that the E22D ITPA has two- and four-fold improved substrate selectivity for ITP over the canonical purine triphosphates ATP and GTP, respectively, while maintaining biological activity. The novel E22D ITPA should be considered as a platform for further development of ITPA therapies.
Collapse
Affiliation(s)
- Nicholas E Burgis
- Department of Chemistry, Biochemistry & Physics, Eastern Washington University, Cheney, WA, 99004, USA.
| | - Kandise VanWormer
- Department of Chemistry, Biochemistry & Physics, Eastern Washington University, Cheney, WA, 99004, USA
| | - Devin Robbins
- Department of Chemistry, Biochemistry & Physics, Eastern Washington University, Cheney, WA, 99004, USA
| | - Jonathan Smith
- Department of Chemistry, Biochemistry & Physics, Eastern Washington University, Cheney, WA, 99004, USA
| |
Collapse
|
2
|
Vasanthakumar A, Davis JW, Abunimeh M, Söderholm J, Zha J, Dumas EO, Cohen DE, Waring JF, Lagging M. Reduced ITPase activity and favorable IL28B genetic variant protect against ribavirin-induced anemia in interferon-free regimens. PLoS One 2018; 13:e0198296. [PMID: 29851985 PMCID: PMC5979032 DOI: 10.1371/journal.pone.0198296] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2018] [Accepted: 05/16/2018] [Indexed: 12/21/2022] Open
Abstract
BACKGROUND Genetic variants of inosine triphosphatase (ITPA) that confer reduced ITPase activity are associated with protection against ribavirin(RBV)-induced hemolytic anemia in peginterferon(IFN)/RBV-based treatment of hepatitis C virus (HCV). Patients with reduced ITPase activity showed improved treatment efficacy when treated with IFN/RBV. In addition, a genetic polymorphism near the IL28B gene is associated with an improved response to IFN/RBV treatment. RBV has been an important component of IFN-containing regimens, and is currently recommended in combination with several IFN-free regimens for treatment of harder to cure HCV infections. AIM To evaluate whether genetic variations that reduce ITPase activity impact RBV-induced anemia in IFN-free/RBV regimens. METHODS In this study, genetic analyses were conducted in the PEARL-IV trial to investigate the effect of activity-reducing ITPA variants as well as IL28B polymorphism on anemia, platelet (PLT) counts, and virologic response in HCV genotype1a-infected patients treated with the direct-acting antiviral (DAA) regimen of ombitasvir/paritaprevir/ritonavir and dasabuvir±RBV. RESULTS Reduction in ITPase activity and homozygosity for the IL28Brs12979860 CC genotype protected against RBV-induced anemia. In patients receiving RBV, reduced ITPase activity was associated with reduced plasma RBV concentration and higher PLT counts. ITPase activity had no impact on response to DAA treatment, viral kinetics, or baseline IP-10 levels. CONCLUSIONS Our study demonstrates that genetics of ITPA and IL28B may help identify patients protected from RBV-induced anemia when treated with IFN-free regimens. Our work demonstrates for the first time that IL28B genetics may also have an impact on RBV-induced anemia. This may be of particular significance in patients with difficult-to-cure HCV infections, such as patients with decompensated cirrhosis where RBV-containing regimens likely will continue to be recommended.
Collapse
Affiliation(s)
| | - Justin W. Davis
- AbbVie Inc., North Chicago, Illinois, United States of America
| | - Manal Abunimeh
- AbbVie Inc., North Chicago, Illinois, United States of America
| | - Jonas Söderholm
- AbbVie Inc., North Chicago, Illinois, United States of America
| | - Jiuhong Zha
- AbbVie Inc., North Chicago, Illinois, United States of America
| | - Emily O. Dumas
- AbbVie Inc., North Chicago, Illinois, United States of America
| | - Daniel E. Cohen
- AbbVie Inc., North Chicago, Illinois, United States of America
| | | | - Martin Lagging
- Department of Infectious Diseases/Virology, Institute of Biomedicine, Sahlgrenska Academy, University of Gothenburg, Göteborg, Sweden
| |
Collapse
|
3
|
Liu Z, Wang S, Qi W, Wang X, Sun D, Wang H, Zhang Y, Li Z, Zhu L, Zhao P, Guo H, Zhou C, Wang J. The relationship between ITPA rs1127354 polymorphisms and efficacy of antiviral treatment in Northeast Chinese CHC patients. Medicine (Baltimore) 2017; 96:e7554. [PMID: 28723780 PMCID: PMC5521920 DOI: 10.1097/md.0000000000007554] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/06/2017] [Revised: 06/22/2017] [Accepted: 06/26/2017] [Indexed: 01/04/2023] Open
Abstract
This prospective study investigated the relationship between 2 inosine triphosphatase (ITPA) polymorphisms (rs7270101 and rs1127354) and the efficacy of ribavirin-based antiviral therapy in hepatitis C virus (HCV)-infected Chinese patients.A total of 906 patients diagnosed with chronic hepatitis C receiving pegylated interferon (PEG-IFN) plus ribavirin combination therapy between January 2011 and January 2014 from 5 hepatitis centers in Northeast China were enrolled. The patients were divided into genotype 1 and non-genotype 1 groups according to the genotype of infected HCV. ITPA single nucleotide polymorphism (SNP) genotyping was performed for all patients. Ribavirin-induced hemolytic anemia and virological response (VR) were monitored during treatment and follow-up. Multivariate regression analysis was used to analyze the predictors for sustained virological response (SVR).IPTA rs7270101 variants were not detected. IPTA rs1127354 variants were detected and showed no difference between the genotype 1 and non-genotype 1 groups. IPTA rs1127354 genotype CC was related to a higher incidence of ribavirin-induced hemolytic anemia. For patients who received >80% of the planned ribavirin dose, rs1127354 variants and related ITPase were related to better SVR. Multivariate analysis showed that IPTA rs1127354 non-genotype CC, HCV genotype, a baseline HCV RNA level <4 × 10 IU/mL, IL-28B rs12979860 genotype CC, and low liver fibrosis were independent predictors for SVR during the combination therapy.IPTA rs1127354 variants and related ITPase were not only related with ribavirin-induced hemolytic anemia but also directly affected the SVR to PEG-IFN plus ribavirin combination therapy in Chinese HCV-infected patients.
Collapse
Affiliation(s)
- Zhenhua Liu
- Department of Digestive of China-Japan Union Hospital affiliated to Jilin University
| | - Song Wang
- Department of Urology of First Hospital affiliated to Jilin University, Changchun
| | - Wenqian Qi
- Department of Digestive of China-Japan Union Hospital affiliated to Jilin University
| | - Xu Wang
- Department of Digestive of China-Japan Union Hospital affiliated to Jilin University
| | - Derong Sun
- Department of Digestive of the Second Hospital of Daqing
| | - Hongguang Wang
- Department of Digestive of the People's Hospital of Jilin City
| | - Yonggui Zhang
- Department of Digestive of China-Japan Union Hospital affiliated to Jilin University
| | - Zhongxie Li
- Department of Digestive of the People's Hospital of Hunchun City, Jilin
| | - Liying Zhu
- Department of Infectious Diseases of the Fourth Hospital of Harbin Medical University, Heilongjiang, China
| | - Ping Zhao
- Department of Digestive of China-Japan Union Hospital affiliated to Jilin University
| | - Honghua Guo
- Department of Digestive of China-Japan Union Hospital affiliated to Jilin University
| | - Changyu Zhou
- Department of Digestive of China-Japan Union Hospital affiliated to Jilin University
| | - Jiangbin Wang
- Department of Digestive of China-Japan Union Hospital affiliated to Jilin University
| |
Collapse
|
4
|
Burgis NE. A disease spectrum for ITPA variation: advances in biochemical and clinical research. J Biomed Sci 2016; 23:73. [PMID: 27770805 PMCID: PMC5075207 DOI: 10.1186/s12929-016-0291-y] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2016] [Accepted: 10/19/2016] [Indexed: 12/15/2022] Open
Abstract
Human ITPase (encoded by the ITPA gene) is a protective enzyme which acts to exclude noncanonical (deoxy)nucleoside triphosphates ((d)NTPs) such as (deoxy)inosine 5′-triphosphate ((d)ITP), from (d)NTP pools. Until the last few years, the importance of ITPase in human health and disease has been enigmatic. In 2009, an article was published demonstrating that ITPase deficiency in mice is lethal. All homozygous null offspring died before weaning as a result of cardiomyopathy due to a defect in the maintenance of quality ATP pools. More recently, a whole exome sequencing project revealed that very rare, severe human ITPA mutation results in early infantile encephalopathy and death. It has been estimated that nearly one third of the human population has an ITPA status which is associated with decreased ITPase activity. ITPA status has been linked to altered outcomes for patients undergoing thiopurine or ribavirin therapy. Thiopurine therapy can be toxic for patients with ITPA polymorphism, however, ITPA polymorphism is associated with improved outcomes for patients undergoing ribavirin treatment. ITPA polymorphism has also been linked to early-onset tuberculosis susceptibility. These data suggest a spectrum of ITPA-related disease exists in human populations. Potentially, ITPA status may affect a large number of patient outcomes, suggesting that modulation of ITPase activity is an important emerging avenue for reducing the number of negative outcomes for ITPA-related disease. Recent biochemical studies have aimed to provide rationale for clinical observations, better understand substrate selectivity and provide a platform for modulation of ITPase activity.
Collapse
Affiliation(s)
- Nicholas E Burgis
- Department of Chemistry and Biochemistry, Eastern Washington University, 226 Science Building, Cheney, WA, 99004, USA.
| |
Collapse
|
5
|
D'Avolio A, Cusato J, De Nicolò A, Allegra S, Di Perri G. Pharmacogenetics of ribavirin-induced anemia in HCV patients. Pharmacogenomics 2016; 17:925-41. [PMID: 27248282 DOI: 10.2217/pgs.16.22] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Dual therapy (pegylated interferon plus ribavirin) was considered the standard of care for hepatitis C virus (HCV) treatment until 2011, when the first-wave direct-acting antivirals were added to this regimen for HCV genotype-1 patients to increase the sustained virological response rate. The second-wave direct-acting antivirals entered the clinical use also in some ribavirin (RBV)- and/or interferon-free combinations. Nevertheless, since some of the new therapeutic regimens also include RBV and its use results still associated with hemolytic anemia, this requires countermeasures to be prevented. These include the identification of several host predictive factors involved in RBV absorption, distribution, metabolism, elimination and many others that might influence this toxic effect. For this reason, we provided an overview of the potential role of pharmacogenomics in predisposing RBV-treated HCV patients to anemia.
Collapse
Affiliation(s)
- Antonio D'Avolio
- Unit of Infectious Diseases, Department of Medical Sciences, Amedeo di Savoia Hospital, University of Turin, Turin, Italy
| | - Jessica Cusato
- Unit of Infectious Diseases, Department of Medical Sciences, Amedeo di Savoia Hospital, University of Turin, Turin, Italy
| | - Amedeo De Nicolò
- Unit of Infectious Diseases, Department of Medical Sciences, Amedeo di Savoia Hospital, University of Turin, Turin, Italy
| | - Sarah Allegra
- Unit of Infectious Diseases, Department of Medical Sciences, Amedeo di Savoia Hospital, University of Turin, Turin, Italy
| | - Giovanni Di Perri
- Unit of Infectious Diseases, Department of Medical Sciences, Amedeo di Savoia Hospital, University of Turin, Turin, Italy
| |
Collapse
|
6
|
About F, Oudot-Mellakh T, Niay J, Rabiéga P, Pedergnana V, Duffy D, Sultanik P, Cagnot C, Carrat F, Marcellin P, Zoulim F, Larrey D, Hézode C, Fontaine H, Bronowicki JP, Pol S, Albert ML, Theodorou I, Cobat A, Abel L. Impact of IL28B, APOH and ITPA Polymorphisms on Efficacy and Safety of TVR- or BOC-Based Triple Therapy in Treatment-Experienced HCV-1 Patients with Compensated Cirrhosis from the ANRS CO20-CUPIC Study. PLoS One 2015; 10:e0145105. [PMID: 26670100 PMCID: PMC4682920 DOI: 10.1371/journal.pone.0145105] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2015] [Accepted: 11/29/2015] [Indexed: 12/14/2022] Open
Abstract
BACKGROUND Human genetic factors influence the outcome of pegylated interferon and ribavirin hepatitis C therapy. We explored the role of IL28B, APOH and ITPA SNPs on the outcomes of triple therapy including telaprevir or boceprevir in patients with compensated cirrhosis chronically infected with HCV-1. PATIENTS AND METHODS A total of 256 HCV-1 Caucasian treatment-experienced patients with compensated cirrhosis from the ANRS CO20-CUPIC cohort were genotyped for a total of 10 candidate SNPs in IL28B (rs12979860 and rs368234815), APOH (rs8178822, rs12944940, rs10048158, rs52797880, rs1801689 and rs1801690) and ITPA (rs1127354 and rs7270101). We tested the association of IL28B and APOH SNPs with sustained virological response and of ITPA SNPs with anemia related phenotypes by means of logistic regression assuming an additive genetic model. RESULTS None of the six APOH SNPs were associated with sustained virological response. The favorable alleles of the IL28B SNPs rs12979860 and rs368234815 were associated with sustained virological response (rs12979860: OR = 2.35[1.50-3.70], P = 2x10(-4)). Refined analysis showed that the effect of IL28B SNPs on sustained virological response was restricted to prior PegIFN/RBV relapse (OR = 3.80[1.82-8.92], P = 8x10(-4)). We also confirmed the association between ITPA low activity alleles and protection against early hemoglobin decline in triple therapy (P = 2x10(-5)). CONCLUSION Our results suggest that the screening of rs12979860 may remain interesting for decision making in prior relapse HCV-1 Caucasian patients with compensated cirrhosis eligible for a telaprevir- or boceprevir-based therapy.
Collapse
Affiliation(s)
- Frédégonde About
- Laboratory of Human Genetics of Infectious Diseases, Necker Branch, Institut National de la Santé et de la Recherche Médicale (INSERM) U1163, Paris, France
- Paris Descartes University, Imagine Institute, Paris, France
| | - Tiphaine Oudot-Mellakh
- Laboratory of Immunity and Infection, Centre d’Immunologie et des Maladies Infectieuses de Paris (CIMI), INSERM U1135, Groupe Hospitalier Pitié Salpétrière, Assistance Publique-Hôpitaux de Paris (AP-HP), Paris, France
- Plateforme Génomique Inserm-ANRS, Groupe Hospitalier Pitié Salpétrière, AP-HP, UPMC Université Paris 6, Paris, France
| | - Jonathan Niay
- Laboratory of Immunity and Infection, Centre d’Immunologie et des Maladies Infectieuses de Paris (CIMI), INSERM U1135, Groupe Hospitalier Pitié Salpétrière, Assistance Publique-Hôpitaux de Paris (AP-HP), Paris, France
- Plateforme Génomique Inserm-ANRS, Groupe Hospitalier Pitié Salpétrière, AP-HP, UPMC Université Paris 6, Paris, France
| | - Pascaline Rabiéga
- Sorbonne Universités, UPMC Université Paris 06, INSERM, Institut Pierre Louis d’épidémiologie et de Santé Publique (IPLESP UMRS 1136), Paris, France
| | - Vincent Pedergnana
- Laboratory of Human Genetics of Infectious Diseases, Necker Branch, Institut National de la Santé et de la Recherche Médicale (INSERM) U1163, Paris, France
- Paris Descartes University, Imagine Institute, Paris, France
- Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, United Kingdom
| | - Darragh Duffy
- Centre for Human Immunology, Department of Immunology, Institut Pasteur, Paris, France
- The Laboratory of Dendritic Cell Biology, Department of Immunology, Institut Pasteur, INSERM U818, Paris, France
| | - Philippe Sultanik
- Département d'Hépatologie, Hôpital Cochin, AP-HP, Université Paris Descartes, Paris, France
- INSERM UMS20, Institut Pasteur, Paris, France
| | - Carole Cagnot
- Unit for Basic and Clinical research on Viral Hepatitis, Inserm-ANRS (France REcherche Nord & sud Sida-HIV Hépatites-FRENSH), Paris, France
| | - Fabrice Carrat
- Sorbonne Universités, UPMC Université Paris 06, INSERM, Institut Pierre Louis d’épidémiologie et de Santé Publique (IPLESP UMRS 1136), Paris, France
- Service de Santé Publique, Hôpital Saint Antoine, AP-HP, Paris, France
| | | | - Fabien Zoulim
- Centre de recherche en cancérologie de Lyon (CRCL), INSERM UMR I 1052/CNRS 5286, Lyon cedex 03, France
- Université Claude-Bernard Lyon 1, Villeurbanne, France
- Hospices civils de Lyon, Hôpital de la Croix-Rousse, service d'hépatologie et de gastroentérologie, Lyon, France
| | | | - Christophe Hézode
- Department of Hepatology and Gastroenterology, Hôpital Henri Mondor, AP-HP, Université Paris-Est Créteil (UPEC), Créteil, France
- Institut Mondor de Recherche Biomédicale (IMRB), INSERM U955, UPEC, Créteil, France
| | - Hélène Fontaine
- Département d'Hépatologie, Hôpital Cochin, AP-HP, Université Paris Descartes, Paris, France
- INSERM UMS20, Institut Pasteur, Paris, France
| | - Jean-Pierre Bronowicki
- Department of Hepatogastroenterology, INSERM U954, CHU de Nancy, Université de Lorraine, Vandoeuvre-Lès-Nancy, France
| | - Stanislas Pol
- Département d'Hépatologie, Hôpital Cochin, AP-HP, Université Paris Descartes, Paris, France
- INSERM UMS20, Institut Pasteur, Paris, France
| | - Matthew L. Albert
- Centre for Human Immunology, Department of Immunology, Institut Pasteur, Paris, France
- The Laboratory of Dendritic Cell Biology, Department of Immunology, Institut Pasteur, INSERM U818, Paris, France
- INSERM UMS20, Institut Pasteur, Paris, France
| | - Ioannis Theodorou
- Laboratory of Immunity and Infection, Centre d’Immunologie et des Maladies Infectieuses de Paris (CIMI), INSERM U1135, Groupe Hospitalier Pitié Salpétrière, Assistance Publique-Hôpitaux de Paris (AP-HP), Paris, France
- Plateforme Génomique Inserm-ANRS, Groupe Hospitalier Pitié Salpétrière, AP-HP, UPMC Université Paris 6, Paris, France
| | - Aurélie Cobat
- Laboratory of Human Genetics of Infectious Diseases, Necker Branch, Institut National de la Santé et de la Recherche Médicale (INSERM) U1163, Paris, France
- Paris Descartes University, Imagine Institute, Paris, France
| | - Laurent Abel
- Laboratory of Human Genetics of Infectious Diseases, Necker Branch, Institut National de la Santé et de la Recherche Médicale (INSERM) U1163, Paris, France
- Paris Descartes University, Imagine Institute, Paris, France
- St. Giles Laboratory of Human Genetics of Infectious Diseases, Rockefeller Branch, The Rockefeller University, New York, NY, United States of America
| | | |
Collapse
|
7
|
Coppola N, Pisaturo M, Sagnelli C, Onorato L, Sagnelli E. Role of genetic polymorphisms in hepatitis C virus chronic infection. World J Clin Cases 2015; 3:807-822. [PMID: 26380828 PMCID: PMC4568530 DOI: 10.12998/wjcc.v3.i9.807] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/27/2014] [Revised: 12/09/2014] [Accepted: 06/08/2015] [Indexed: 02/05/2023] Open
Abstract
AIM: To analyze the host genetics factors influencing the clinical course and the response to antiviral treatment in patients with chronic hepatitis C (CHC).
METHODS: We conducted an electronic search on the PubMed and MEDLINE (2000-2014) databases and Cochrane library (2000-2014). A total of 73 articles were retrieved and their data were extensively evaluated and discussed by the authors and then analyzed in this review article.
RESULTS: Several studies associated polymorphisms in the interleukin 28B gene on chromosome 19 (19q13.13) with a spontaneous viral clearance in acute hepatitis C and with the response to pegylated interferon (Peg-IFN)-based treatment in chronic hepatitis C patients. Other investigations demonstrated that inosine triphosphate pyrophosphatase genetic variants protect hepatitis C virus-genotype-1 CHC patients from ribavirin-induced anemia, and other studies that a polymorphism in the patatin-like phospholipase domain-containing protein 3 was associated with hepatic steatosis in CHC patients. Although not conclusive, some investigations suggested that the vitamin D-associated polymorphisms play an important role in the achievement of sustained virologic response in CHC patients treated with Peg-IFN-based antiviral therapy. Several other polymorphisms have been investigated to ascertain their possible impact on the natural history and on the response to treatment in patients with CHC, but the data are preliminary and warrant confirmation.
CONCLUSION: Several genetic polymorphisms seem to influence the clinical course and the response to antiviral treatment in patients with CHC, suggesting individualized follow up and treatment strategies.
Collapse
|
8
|
Shuldiner SR, Gong L, Muir AJ, Altman RB, Klein TE. PharmGKB summary: peginterferon-α pathway. Pharmacogenet Genomics 2015; 25:465-74. [PMID: 26111151 PMCID: PMC4757589 DOI: 10.1097/fpc.0000000000000158] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Affiliation(s)
| | - Li Gong
- Department of Genetics, Stanford University, Stanford, California
| | - Andrew J. Muir
- Duke Clinical Research Institute, Duke University, Durham, North Carolina, USA
| | - Russ B. Altman
- Department of Genetics, Stanford University, Stanford, California
- Department of Bioengineering, Stanford University, Stanford, California
| | - Teri E. Klein
- Department of Genetics, Stanford University, Stanford, California
| |
Collapse
|
9
|
Rembeck K, Lagging M. Impact of IL28B, ITPA and PNPLA3 genetic variants on therapeutic outcome and progression of hepatitis C virus infection. Pharmacogenomics 2015; 16:1179-88. [PMID: 26250055 DOI: 10.2217/pgs.15.65] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Chronic HCV infection comprises a broad spectrum of liver disease, ranging from no or minimal activity to active hepatitis that in time may progress to severe liver fibrosis, cirrhosis and hepatocellular carcinoma if left untreated. This review describes the impact of genetic variants of interleukin 28B (IL28B; also known as interferon-lambda 3), inosine triphosphate pyrophosphatase (ITPA) and patatin-like phospholipase domain-containing 3 (PNPLA3) on therapeutic outcome and liver disease severity in HCV-infected patients.
Collapse
Affiliation(s)
- Karolina Rembeck
- Department of Infectious Medicine, Institute of Biomedicine at Sahlgrenska Academy, University of Gothenburg, Guldhedsgatan 10B, SE-413 46, Gothenburg, Sweden
| | - Martin Lagging
- Department of Infectious Medicine, Institute of Biomedicine at Sahlgrenska Academy, University of Gothenburg, Guldhedsgatan 10B, SE-413 46, Gothenburg, Sweden
| |
Collapse
|
10
|
Ampuero J, Del Campo JA, Rojas L, Calleja JL, Cabezas J, Lens S, Crespo J, Forns X, Andrade RJ, Fernández I, Buti M, Millán R, Romero-Gómez M. Role of ITPA and SLC28A2 genes in the prediction of anaemia associated with protease inhibitor plus ribavirin and peginterferon in hepatitis C treatment. J Clin Virol 2015; 68:56-60. [PMID: 26071337 DOI: 10.1016/j.jcv.2015.05.010] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2015] [Revised: 05/07/2015] [Accepted: 05/11/2015] [Indexed: 01/26/2023]
Abstract
BACKGROUND Anaemia is a common side-effect of ribavirin (RBV) use that overwhelms management of hepatitis C when protease inhibitors are added. AIM To assess the pharmacogenomic impact of candidate genes SLC28A2, SLC28A3 and ITPA on anaemia in patients receiving triple therapy. METHODS Patients (n=161) with chronic hepatitis C genotype 1 treated with telaprevir (n=95) or boceprevir (n=66) were included. Using RT-PCR we genotyped ITPA (rs1127354, rs7270101) and SLC28A3 (rs56350726, rs10868138) and SLC28A2 (rs11854484). Clinically significant anaemia (CSA) was diagnosed when at least one of the following criteria was observed: (a) haemoglobin <8.5g/dL during treatment; (b) blood transfusion required; (c) erythropoietin administered. RESULTS CSA occurred in 44% (69/157) of patients and was associated with SLC28A2 rs11854484 [CC/CT genotypes: 33% (26/78) vs. TT genotype: 56% (36/64); p=0.006]. Further, the needed for blood transfusion was related to genotype [CC: 0% (0/18) vs. CT: 13% (8/61) vs. TT: 27% (17/64); p=0.016]. Similarly, ITPA rs1127354 genotypes [AA/AC: 19% (3/16) vs. CC: 45% (61/135; p=0.060] were linked to CSA. In multivariate analysis, SLC28A2 rs11854484 TT genotype (OR:2.33;95%CI:1.10-4.95; p=0.027), female sex (OR:2.54;95% CI:1.13-5.71;p=0.024) and Hb drop at week 4) OR: 1.36; 95CI%: 1.11-1.67; p=0.003) were independently associated with CSA. Similarly, ITPA rs1127354 genotypes [AA/AC: 16% (3/19) vs. CC: 63% (85/134); p=0.0001] and ITPA rs6051702 genotypes [CC/CA: 46% (26/57) vs. CC: 65% (60/93); p=0.023] were related to Hb drop of >3g/dL at week 4. CONCLUSIONS In patients receiving first generation protease inhibitors, genotype SLC28A2 rs11854484 predicts CSA, and helps to identify a subgroup of patients with better tolerance of triple therapy.
Collapse
Affiliation(s)
- Javier Ampuero
- Unit for the Clinical Management of Digestive Diseases, Valme University Hospital & CIBERehd, Sevilla, Spain
| | - José Antonio Del Campo
- Unit for the Clinical Management of Digestive Diseases, Valme University Hospital & CIBERehd, Sevilla, Spain
| | - Lourdes Rojas
- Unit for the Clinical Management of Digestive Diseases, Valme University Hospital & CIBERehd, Sevilla, Spain
| | | | - Joaquín Cabezas
- Digestive Department, Hospital Marqués de Valdecilla, Santander, Spain
| | - Sabela Lens
- Hepatology Unit, Hospital Clinic and IDIBAPS & CIBERehd, Barcelona, Spain
| | - Javier Crespo
- Digestive Department, Hospital Marqués de Valdecilla, Santander, Spain
| | - Xavier Forns
- Hepatology Unit, Hospital Clinic and IDIBAPS & CIBERehd, Barcelona, Spain
| | - Raúl J Andrade
- Digestive Unit, Hospital Virgen de la Victoria & CIBERehd, Málaga, Spain
| | | | - María Buti
- Hepatology Unit, Hospital Vall d'Hebron & CIBERehd, Barcelona, Spain
| | - Raquel Millán
- Unit for the Clinical Management of Digestive Diseases, Valme University Hospital & CIBERehd, Sevilla, Spain
| | - Manuel Romero-Gómez
- Unit for the Clinical Management of Digestive Diseases, Valme University Hospital & CIBERehd, Sevilla, Spain
| |
Collapse
|
11
|
Chen SH, Peng CY, Lai HC, Su WP, Lin CH, Li YF, Chuang PH, Chen CH. An index to predict ribavirin-induced anemia in asian patients with chronic genotype 1 hepatitis C. HEPATITIS MONTHLY 2015; 15:e27148. [PMID: 25834588 PMCID: PMC4377223 DOI: 10.5812/hepatmon.27148] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/22/2015] [Revised: 02/10/2015] [Accepted: 02/21/2015] [Indexed: 12/11/2022]
Abstract
BACKGROUND Single-nucleotide polymorphisms (SNP) in the inosine triphosphate pyrophosphatase (ITPA) gene correlate with ribavirin (RBV)-induced anemia in patients with chronic hepatitis C (CHC) receiving combination therapy. Managing anemia is an early priority in the treatment process. OBJECTIVES The aim was to develop a predictive index based on ITPA SNP status to identify CHC patients at risk of anemia. PATIENTS AND METHODS A total of 418 eligible East Asian patients diagnosed with CHC genotype 1 (G1) received combination therapy in this study. Participant DNA was genotyped for a functional ITPA SNP (C/C, A/A or C/A) on chromosome 20 at rs1127354. A predictive index was constructed by incorporating independent factors identified for severe anemia events (hemoglobin < 10 g/dL). Areas under the receiver-operating characteristic curves (AUCs) represented the diagnostic accuracies of the predictive index in randomly assigned development and validation cohorts. RESULTS Multiple logistic regressions identified age (≥ 50 y: OR = 9.7, 95% CI = 5.0 - 18.6), ITPA rs1127354 (C/C: OR = 3.3, 95% CI = 1.8 - 5.8) and baseline hemoglobin (< 14.0 g/dL: OR 6.4, 95% CI = 3.3 - 12.1; 14.0 - 14.9: OR = 2.4, 95% CI = 1.2 - 4.6) as predictors of severe anemia throughout the treatment. For severe anemia, the predictive index incorporating age, ITPA SNP status and baseline hemoglobin yielded diagnostic accuracies (AUCs) of 0.830 (95% CI = 0.783 - 0.871) in the development (n = 324) and 0.902 (0.826 - 0.925) in the validation (n = 81) cohorts. CONCLUSIONS In patients with CHC G1 and receiving combination therapy, ITPA SNP-based index was an accurate and practical solution for prediction of severe anemia.
Collapse
Affiliation(s)
- Sheng-Hung Chen
- Institute of Clinical Medical Science, School of Medicine, China Medical University, Taichung, Taiwan
- School of Medicine, China Medical University, Taichung, Taiwan
- Division of Hepatogastroenterology, Department of Internal Medicine, China Medical University Hospital, Taichung, Taiwan
| | - Cheng-Yuan Peng
- School of Medicine, China Medical University, Taichung, Taiwan
- Division of Hepatogastroenterology, Department of Internal Medicine, China Medical University Hospital, Taichung, Taiwan
- Corresponding Author: Cheng-Yuan Peng, Division of Hepatogastroenterology, Department of Internal Medicine, China Medical University Hospital, China Medical University, Taiwan. Tel: +88-6422052121, E-mail:
| | - Hsueh-Chou Lai
- Institute of Clinical Medical Science, School of Medicine, China Medical University, Taichung, Taiwan
- Division of Hepatogastroenterology, Department of Internal Medicine, China Medical University Hospital, Taichung, Taiwan
- College of Chinese Medicine, China Medical University, Taichung, Taiwan
| | - Wen-Pang Su
- Division of Hepatogastroenterology, Department of Internal Medicine, China Medical University Hospital, Taichung, Taiwan
| | - Chia-Hsin Lin
- Division of Hepatogastroenterology, Department of Internal Medicine, China Medical University Hospital, Taichung, Taiwan
| | - Yu-Fen Li
- Institute of Biostatistics, China Medical University, Taichung, Taiwan
| | - Po-Heng Chuang
- Division of Hepatogastroenterology, Department of Internal Medicine, China Medical University Hospital, Taichung, Taiwan
| | - Ching-Hsiang Chen
- Division of Hepatogastroenterology, Department of Internal Medicine, China Medical University Hospital, Taichung, Taiwan
| |
Collapse
|
12
|
Waldenström J, Nyström K, Lagging M. Do variations in the ITPA gene determine the risk of hepatitis C virus relapse? Future Microbiol 2014; 9:1009-12. [DOI: 10.2217/fmb.14.69] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Affiliation(s)
- Jesper Waldenström
- Department of Infectious Medicine/Virology, Institute of Biomedicine, Sahlgrenska Academy, University of Gothenburg, SE-413 46 Gothenburg, Sweden
| | - Kristina Nyström
- Department of Infectious Medicine/Virology, Institute of Biomedicine, Sahlgrenska Academy, University of Gothenburg, SE-413 46 Gothenburg, Sweden
| | - Martin Lagging
- Department of Infectious Medicine/Virology, Institute of Biomedicine, Sahlgrenska Academy, University of Gothenburg, SE-413 46 Gothenburg, Sweden
| |
Collapse
|
13
|
Rembeck K, Waldenström J, Hellstrand K, Nilsson S, Nyström K, Martner A, Lindh M, Norkrans G, Westin J, Pedersen C, Färkkilä M, Langeland N, Buhl MR, Mørch K, Christensen PB, Lagging M. Variants of the inosine triphosphate pyrophosphatase gene are associated with reduced relapse risk following treatment for HCV genotype 2/3. Hepatology 2014; 59:2131-9. [PMID: 24519039 DOI: 10.1002/hep.27009] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/07/2013] [Accepted: 01/09/2014] [Indexed: 12/30/2022]
Abstract
UNLABELLED The present study evaluated the impact of variations in the inosine triphosphate pyrophosphatase (ITPase) gene (ITPA) on treatment outcome in patients with hepatitis C virus (HCV) genotype 2/3 infection receiving peginterferon-α2a and lower, conventional 800 mg daily dose of ribavirin. Previous studies using higher, weight-based ribavirin dosing report that patients carrying polymorphisms encoding reduced predicted ITPase activity show decreased risk of ribavirin-induced anemia but increased risk of thrombocytopenia, with no impact on elimination of virus. In all, 354 treatment-naïve HCV genotype 2/3-infected patients, enrolled in a phase III trial (NORDynamIC), were genotyped for ITPA (rs1127354 and rs7270101). Homo- or heterozygosity at Ars1127354 or Crs7270101 , entailing reduced ITPase activity, was observed in 37% of patients and was associated with increased likelihood of achieving sustained virological response (SVR) (P = 0.0003 in univariate and P = 0.0002 in multivariate analyses) accompanied by a reduced risk of relapse among treatment-adherent patients. The association between ITPA variants and SVR remained significant when patients were subdivided by the 12- and 24-week treatment duration arms, HCV genotype, fibrosis stage, and IL28B genotype, and was not secondary to improved adherence to therapy or less pronounced anemia. Gene variants predicting reduced predicted ITPase activity were also associated with decreased risk of anemia (P < 0.0001), increased risk of thrombocytopenia (P = 0.007), and lower ribavirin concentrations (P = 0.02). CONCLUSION These findings demonstrate a novel ribavirin-like association between polymorphisms at ITPA and treatment efficacy in chronic hepatitis C mediated by reduced relapse risk. We hypothesize that patients (63%) being homozygous for both major alleles, leading to normal ITPase activity, may benefit more from the addition of ribavirin to present and future treatment regimens for HCV in spite of concomitant increased risk of anemia.
Collapse
Affiliation(s)
- Karolina Rembeck
- Department of Infectious Diseases/Virology, Institute of Biomedicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
14
|
Stättermayer AF, Scherzer T, Beinhardt S, Rutter K, Hofer H, Ferenci P. Review article: genetic factors that modify the outcome of viral hepatitis. Aliment Pharmacol Ther 2014; 39:1059-70. [PMID: 24654629 PMCID: PMC7159786 DOI: 10.1111/apt.12717] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/21/2013] [Revised: 12/10/2013] [Accepted: 03/01/2014] [Indexed: 12/16/2022]
Abstract
BACKGROUND Genetic factors can play an important role for treatment response and disease progression in chronic viral hepatitis. AIM To review the influence of host genetic factors on the clinical course as well as on treatment response in patients with viral hepatitis. METHODS Review of the literature. RESULTS A landmark genome-wide association study (GWAS) identified polymorphisms in the IL28B gene on chromosome 19 (19q13.13) associated with response to therapy with pegylated interferon-α (PEG-IFN) and ribavirin (RBV) and spontaneous viral clearance in acute hepatitis C. Furthermore, IL28B genotype is associated with changes of lipid metabolism and insulin resistance. A further GWAS demonstrated that ITPA genetic variants protect HCV genotype 1 patients from RBV-induced anaemia. Another polymorphism in the patatin-like phospholipase domain containing 3 (PNPLA3) is associated with hepatic steatosis. Difficult-to-treat hepatitis C patients homozygous for GG had an up to five-fold lower chance of viral clearance on PEG/RBV than non-GG patients. In chronic hepatitis B patients treated with PEG-IFN several retrospective analyses of IL28B rs12980275 and rs12979860 genotypes yielded conflicting results which can be explained by the heterogeneity between the study populations. Some variants of the HLA-DP locus (HLA-DPA1 A allele and HLA-DPB1) protect against progression of chronic hepatitis B infection. CONCLUSIONS The determination of IL28B polymorphisms may be useful to individualise treatment options when using PEG/RBV based therapies for chronic hepatitis C infection. In contrast, so far identified genetic factors play only a minor role in chronic hepatitis B infection.
Collapse
Affiliation(s)
- A. F. Stättermayer
- Division of Gastroenterology and HepatologyDepartment of Internal Medicine IIIMedical University of ViennaViennaAustria
| | - T. Scherzer
- Division of Gastroenterology and HepatologyDepartment of Internal Medicine IIIMedical University of ViennaViennaAustria
| | - S. Beinhardt
- Division of Gastroenterology and HepatologyDepartment of Internal Medicine IIIMedical University of ViennaViennaAustria
| | - K. Rutter
- Division of Gastroenterology and HepatologyDepartment of Internal Medicine IIIMedical University of ViennaViennaAustria
| | - H. Hofer
- Division of Gastroenterology and HepatologyDepartment of Internal Medicine IIIMedical University of ViennaViennaAustria
| | - P. Ferenci
- Division of Gastroenterology and HepatologyDepartment of Internal Medicine IIIMedical University of ViennaViennaAustria
| |
Collapse
|
15
|
Gatselis NK, Zachou K, Saitis A, Samara M, Dalekos GN. Individualization of chronic hepatitis C treatment according to the host characteristics. World J Gastroenterol 2014; 20:2839-53. [PMID: 24659876 PMCID: PMC3961989 DOI: 10.3748/wjg.v20.i11.2839] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/19/2013] [Revised: 11/19/2013] [Accepted: 01/06/2014] [Indexed: 02/06/2023] Open
Abstract
Hepatitis C virus (HCV) infection is a global health problem that affects more than 170 million people worldwide. It is a major cause of cirrhosis and hepatocellular carcinoma, making the virus the most common cause of liver failure and transplantation. The standard-of-care treatment for chronic hepatitis C (CHC) has been changed during the last decade and direct acting antiviral drugs have already been used. Besides, understanding of the pathogenesis of CHC has evolved rapidly during the last years and now several host factors are known to affect the natural history and response to treatment. Recent genome-wide association studies have shown the important role of interleukin-28B and inosine triphosphatase in HCV infection. The present review article attempts to summarize the current knowledge on the role of host factors towards individualization of HCV treatment.
Collapse
|
16
|
Kawaguchi-Suzuki M, Frye RF. The role of pharmacogenetics in the treatment of chronic hepatitis C infection. Pharmacotherapy 2014; 34:185-201. [PMID: 24114761 DOI: 10.1002/phar.1349] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Hepatitis C virus (HCV) chronically infects 170 million people worldwide. Until recently, combination therapy with peginterferon-α (pegIFN) and ribavirin (RBV) has been the standard of care. However, for many patients, especially those infected with the most common HCV genotype 1 (HCV-1), this treatment has resulted in unsatisfactory treatment response rates. Many clinical factors, including pharmacogenetics, influence the treatment response rate. Genetic variation in the interleukin 28B (IL28B) gene is the major determinant of treatment response, a finding that has been replicated in multiple independent cohorts. This review focuses on the association between pharmacogenetics and conventional pegIFN/RBV therapy in patients infected with HCV non-genotype 1; patients reinfected with HCV after liver transplantation; and patients coinfected with HCV and human immunodeficiency virus. We also review the pharmacogenetic data for boceprevir and telaprevir triple therapy in patients with HCV-1 infection, as well as viral genomic polymorphisms and genetic variants that may protect against anemia. Pharmacogenetic information offers a personalized medicine approach to help clinicians and patients make better informed decisions to maximize response and minimize toxicity for the treatment of chronic HCV infection.
Collapse
Affiliation(s)
- Marina Kawaguchi-Suzuki
- Department of Pharmacotherapy and Translational Research, College of Pharmacy, University of Florida, Gainesville, Florida
| | | |
Collapse
|
17
|
Lee TH, Tillmann HL, Patel K. Individualized therapy for hepatitis C infection: focus on the interleukin-28B polymorphism in directing therapy. Mol Diagn Ther 2014; 18:25-38. [PMID: 24022240 DOI: 10.1007/s40291-013-0053-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Hepatitis C virus—a major global cause of chronic hepatitis, cirrhosis, and hepatocellular carcinoma—affects millions of people worldwide. Pegylated interferon (Peg-IFN) and ribavirin (RBV) had been the standard treatment for a decade until availability of the protease inhibitors in 2011. However, current antiviral therapy is still IFN-based and is associated with significant side effects and variable treatment response. Thus, various host and viral factors have been evaluated before and during treatment for the prediction of sustained virologic response to antiviral therapy. In 2009, genome-wide association studies found the single-nucleotide polymorphisms, located near the host interleukin-28B (IL28B) gene that encodes IFN-λ3, to be the best pretreatment predictor of virologic response to Peg-IFN and RBV therapy in chronic hepatitis C genotype 1 patients. Additionally, inosine triphosphatase (ITPA) gene variants were found to be associated with RBV-induced hemolytic anemia, which could affect treatment dose for selected patients. IL28B, ITPA, and other treatment predictors allowed for a potential individualized approach to treat hepatitis C. In the era of increased overall virologic response rates and good tolerability of the rapidly developing non-IFN oral direct-acting antiviral therapy regimens, the need for individualized treatment is likely to diminish. Various predictors of response, including IL28B will likely be of reduced importance in the near future.
Collapse
|
18
|
Gall AD, Gall A, Moore AC, Aune MK, Heid S, Mori A, Burgis NE. Analysis of human ITPase nucleobase specificity by site-directed mutagenesis. Biochimie 2013; 95:1711-21. [PMID: 23770441 DOI: 10.1016/j.biochi.2013.05.016] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2012] [Accepted: 05/23/2013] [Indexed: 02/07/2023]
Abstract
Inosine triphosphate (ITP) pyrophosphohydrolase, or ITPase, is an intracellular enzyme that is responsible for the hydrolysis of the acidic anhydride bond between the alpha and beta phosphates in ITP, and other noncanonical nucleoside triphosphates, producing the corresponding nucleoside monophosphate and pyrophosphate. This activity protects the cell by preventing noncanonical nucleoside triphosphates from accumulating in (deoxy) nucleoside triphosphate ((d)NTP) pools and/or being integrated into nucleic acids. This enzyme is encoded by the ITPA gene in mammals. It has been reported that Itpa homozygous-null knock-out mice die before weaning and have gross cardiac abnormalities. Additionally, certain variations in the human ITPA gene have been linked to adverse reactions to the immunosuppressive prodrugs azathioprine and 6-mercaptopurine and protection against ribavirin-induced hemolytic anemia. These drugs are bioactivated to form noncanonical nucleoside triphosphates. Human ITPase enzymes engineered to modulate nucleobase specificity may be valuable tools for studying the role of ITPase in heart development and drug metabolism or developing gain-of-function mutants or inhibitory molecules. Based on x-ray crystallography and amino acid sequence data, a panel of putative human ITPase nucleobase specificity mutants has been generated. We targeted eight highly conserved amino acid positions within the ITPase sequence that correspond to amino acids predicted to directly interact with the nucleobase or help organize the nucleobase binding pocket. The ability of the mutants to protect against exogenous and endogenous noncanonical purines was tested with two Escherichia coli complementation assays. Nucleobase specificity of the mutants was investigated with an in vitro biochemical assay using ITP, GTP and ATP as substrates. This methodology allowed us to identify gain-of-function mutants and categorize the eight amino acid positions according to their ability to protect against noncanonical purines as follows: Glu-22, Trp-151 and Arg-178, essential for protection; Phe-149, Asp-152, Lys-172 and Ser-176, intermediate protection; His-177, dispensable for protection against noncanonical purines.
Collapse
Affiliation(s)
- Amanda D Gall
- Department of Chemistry and Biochemistry, Eastern Washington University, 226 Science Building, Cheney, WA 99004, USA
| | | | | | | | | | | | | |
Collapse
|
19
|
Fujino T, Aoyagi Y, Takahashi M, Yada R, Yamamoto N, Ohishi Y, Nishiura A, Kohjima M, Yoshimoto T, Fukuizumi K, Nakashima M, Kato M, Kotoh K, Nakamuta M, Enjoji M. Association of ITPA polymorphism with outcomes of peginterferon-α plus ribavirin combination therapy. World J Gastrointest Pharmacol Ther 2013; 4:54-60. [PMID: 23919217 PMCID: PMC3729868 DOI: 10.4292/wjgpt.v4.i3.54] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/01/2013] [Revised: 04/11/2013] [Accepted: 05/19/2013] [Indexed: 02/06/2023] Open
Abstract
AIM: To analyzed the association between inosine triphosphatase (ITPA) (rs1127354) genotypes and sustained virological response (SVR) rates in peginterferon (Peg-IFN)α + ribavirin (RBV) treatment.
METHODS: Patients who underwent Peg-IFNα + RBV combination therapy were enrolled (n = 120) and they had no history of other IFN-based treatments. Variation in hemoglobin levels during therapy, cumulative reduction of RBV dose, frequency of treatment withdrawal, and SVR rates were investigated in each ITPA genotype.
RESULTS: In patients with ITPA CC genotype, hemoglobin decline was significantly greater and the percentage of patients in whom total RBV dose was < 60% of standard and/or treatment was withdrawn was significantly higher compared with CA/AA genotype. However, SVR rates were equivalent between CC and CA/AA genotypes, and within a subset of patients with Interleukin 28B (IL28B) (rs8099917) TT genotype, SVR rates tended to be higher in patients with ITPA CC genotype, although the difference was not significant.
CONCLUSION: ITPA CC genotype was a disadvantageous factor for Peg-IFNα + RBV treatment in relation to completion rates and RBV dose. However, CC genotype was not inferior to CA/AA genotype for SVR rates. When full-length treatment is accomplished, it is plausible that more SVR is achieved in patients with ITPA CC variant, especially in a background of IL28B TT genotype.
Collapse
|
20
|
Hynicka LM, Heil EL. Anemia management in patients with chronic viral hepatitis C. Ann Pharmacother 2013; 47:228-36. [PMID: 23386076 DOI: 10.1345/aph.1r513] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
OBJECTIVE To review the literature regarding current strategies for the management of anemia associated with treatment for chronic viral hepatitis C (HCV) in adults. DATA SOURCES The MEDLINE/PubMed, EMBASE, and Cochrane databases were searched (January 1980-October 2012) for articles in English using the search terms anemia, ribavirin, dose reduction, erythropoietin stimulating agents, hepatitis C, HIV, liver transplant, telaprevir, and boceprevir. STUDY SELECTION AND DATA EXTRACTION All relevant original studies, meta-analyses, systematic reviews, guidelines, and review articles were assessed for inclusion. References from pertinent articles were examined for additional content not found during the initial search. DATA SYNTHESIS Standard of care for patients infected with HCV genotype 1 now requires a triple therapy regimen including an HCV NS3 protease inhibitor. These regimens lead to significantly higher rates of anemia compared to prior dual therapy regimens. Development of an optimal management strategy should begin with risk stratification. Ribavirin dose reductions have been recommended in the package inserts for the pegylated interferon products and studies have demonstrated the need for maintenance of 80% of the initial ribavirin dose to achieve optimal sustained virologic response (SVR) with dual therapy. The use of erythropoietin-stimulating agents has been shown to be effective for anemia caused by peginterferon and ribavirin without compromising SVR rates. Limited data have been published regarding the management of anemia with triple therapy; however, efficacy studies for boceprevir and telaprevir have used ribavirin dose reduction and erythropoietin-stimulating agents to successfully manage anemia. CONCLUSIONS Anemia is a common adverse event associated with the use of ribavirin, and, more recently, the new HCV protease inhibitors. Ribavirin dose reduction should continue to be used as an initial anemia management strategy, with the use of erythropoietin alfa 40,000 units once weekly reserved for patients whose hemoglobin does not adequately respond to initial management strategies.
Collapse
|