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Rios-Usuga C, Martinez-Gutierrez M, Ruiz-Saenz J. Antiviral Potential of Azathioprine and Its Derivative 6- Mercaptopurine: A Narrative Literature Review. Pharmaceuticals (Basel) 2024; 17:174. [PMID: 38399389 PMCID: PMC10892228 DOI: 10.3390/ph17020174] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2023] [Revised: 01/20/2024] [Accepted: 01/24/2024] [Indexed: 02/25/2024] Open
Abstract
The use of azathioprine (AZA) in human medicine dates back to research conducted in 1975 that led to the development of several drugs, including 6-mercaptopurine. In 1958, it was shown that 6-mercaptopurine decreased the production of antibodies against earlier administered antigens, raising the hypothesis of an immunomodulatory effect. AZA is a prodrug that belongs to the thiopurine group of drugs that behave as purine analogs. After absorption, it is converted into 6-mercaptopurine. Subsequently, it can be degraded through various enzymatic pathways into inactive compounds and biologically active compounds related to the mechanism of action, which has been the subject of study to evaluate a possible antiviral effect. This study aims to examine the metabolism, mechanism of action, and antiviral potential of AZA and its derivatives, exploring AZA impact on antiviral targets and adverse effects through a narrative literature review. Ultimately, the review will provide insights into the antiviral mechanism, present evidence of its in vitro effectiveness against various DNA and RNA viruses, and suggest in vivo studies to further demonstrate its antiviral effects.
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Affiliation(s)
- Carolina Rios-Usuga
- Grupo de Investigación en Ciencias Animales—GRICA, Facultad de Medicina Veterinaria y Zootecnia, Universidad Cooperativa de Colombia, Bucaramanga 680002, Colombia; (C.R.-U.); (M.M.-G.)
| | - Marlen Martinez-Gutierrez
- Grupo de Investigación en Ciencias Animales—GRICA, Facultad de Medicina Veterinaria y Zootecnia, Universidad Cooperativa de Colombia, Bucaramanga 680002, Colombia; (C.R.-U.); (M.M.-G.)
- Grupo de Investigación en Microbiología Veterinaria, Escuela de Microbiología, Universidad de Antioquia UdeA, Medellín 050001, Colombia
| | - Julian Ruiz-Saenz
- Grupo de Investigación en Ciencias Animales—GRICA, Facultad de Medicina Veterinaria y Zootecnia, Universidad Cooperativa de Colombia, Bucaramanga 680002, Colombia; (C.R.-U.); (M.M.-G.)
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2
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Liquid chromatographic methods in the determination of inosine monophosphate dehydrogenase enzyme activity: a review. Bioanalysis 2022; 14:1453-1470. [PMID: 36705020 DOI: 10.4155/bio-2022-0212] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
Inosine monophosphate dehydrogenase (IMPDH) is a crucial enzyme involved in the de novo synthesis of purine nucleotides. IMPDH activity is used to evaluate the pharmacodynamics/pharmacokinetics of immunosuppressant drugs such as mycophenolic acid and thiopurines. These drugs are often used to prevent organ transplant rejection and as steroid-sparing agents in autoinflammatory diseases such as inflammatory bowel disease and rheumatoid arthritis. Numerous analytical techniques have been employed to evaluate IMPDH activity in biological matrices. However, hyphenated LC techniques were most widely used in the literature. This review focuses on hyphenated LC methods used to measure IMPDH activity and provides detailed insight into the sample preparation techniques, chromatographic conditions, enzymatic assay conditions, detectors and normalization factors employed in those methods.
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3
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Aluko A, Ranganathan P. Pharmacogenetics of Drug Therapies in Rheumatoid Arthritis. Methods Mol Biol 2022; 2547:527-567. [PMID: 36068476 DOI: 10.1007/978-1-0716-2573-6_19] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Rheumatoid arthritis (RA) is a chronic systemic inflammatory disorder that can lead to severe joint damage and is often associated with a high morbidity and disability. Disease-modifying anti-rheumatic drugs (DMARDs) are the mainstay of treatment in RA. DMARDs not only relieve the clinical signs and symptoms of RA but also inhibit the radiographic progression of disease and reduce the effects of chronic systemic inflammation. Since the introduction of biologic DMARDs in the late 1990s, the therapeutic range of options for the management of RA has significantly expanded. However, patients' response to these agents is not uniform with considerable variability in both efficacy and toxicity. There are no reliable means of predicting an individual patient's response to a given DMARD prior to initiation of therapy. In this chapter, the current published literature on the pharmacogenetics of traditional DMARDS and the newer biologic DMARDs in RA is highlighted. Pharmacogenetics may help individualize drug therapy in patients with RA by providing reliable biomarkers to predict medication toxicity and efficacy.
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Affiliation(s)
- Atinuke Aluko
- Division of Rheumatology, Department of Medicine, Washington University School of Medicine, St. Louis, MO, USA
| | - Prabha Ranganathan
- Division of Rheumatology, Department of Medicine, Washington University School of Medicine, St. Louis, MO, USA.
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4
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Labarile N, Ghosh S, Ng SC, Walters J, Iacucci M. Tests that now deserve to be more widely adopted in IBD clinical practice. Therap Adv Gastroenterol 2020; 13:1756284820944088. [PMID: 32782481 PMCID: PMC7385848 DOI: 10.1177/1756284820944088] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/26/2020] [Accepted: 06/30/2020] [Indexed: 02/04/2023] Open
Abstract
Inflammatory bowel diseases are chronic relapsing immune-mediated diseases of the intestinal tract with multifaceted manifestations and treatment related morbidity. Faecal and blood tests, radiological, endoscopic and histologic investigations are now widely used for managing both ulcerative colitis and Crohn's disease. Over the years, a number of new investigations have been proposed but not widely adopted yet. Patients with Crohn's disease may have multiple causes of diarrhoea, not always attributable to disease exacerbation, but sometimes linked to bile acid malabsorption; we have a reliable serum test, C4, that allows us to recognize and treat this cause of diarrhoea efficaciously and not empirically, but it is not available or used widely. There is genetic inter-individual variability in drug responses, in terms of both efficacy and toxicity, leading to high rates of therapeutic failure. Patients treated with thiopurine or, more rarely, 5-aminosalicylic acid may suffer from unpredictable and serious adverse events, some of these with pathogenesis related to genetic variants: myelosuppression, acute pancreatitis and nephrotoxicity. The identification of pre-treatment genetic tests can optimize therapeutic choice and avoid adverse events. With regard to biological drugs, patients can experience primary non-response or loss of response due to induction of immune responses to the drugs affecting drug efficacy and determining hypersensitivity reactions. We have specifically reviewed a number of investigations, whose use is currently limited, and highlighted four tests that deserve to be more widely incorporated in clinical practice as these could improve medical decision-making and patient outcomes.
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Affiliation(s)
| | - Subrata Ghosh
- Institute Translational of Medicine, Institute of Immunology and Immunotherapy and NIHR Birmingham Biomedical Research Centre, University Hospitals NHS Foundation Trust and University of Birmingham, Birmingham, UK
| | - Siew C Ng
- Department of Medicine and Therapeutics, Institute of Digestive Disease, State Key Laboratory of Digestive Diseases, Li Ka Shing Institute of Health Science, The Chinese University of Hong Kong, Hong Kong, China
| | - Julian Walters
- Division of Digestive Diseases, Imperial College London, Imperial College Healthcare, London, UK
| | - Marietta Iacucci
- Institute Translational of Medicine, Institute of Immunology and Immunotherapy and NIHR Birmingham Biomedical Research Centre, University Hospitals NHS Foundation Trust and University of Birmingham, Birmingham, UK
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5
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Zhou Y, Wang L, Zhai XY, Wen L, Tang F, Yang F, Liu XT, Dong L, Zhi LJ, Shi HY, Hao GX, Zheng Y, Jacqz-Aigrain E, Wang TY, Zhao W. Precision therapy of 6-mercaptopurine in Chinese children with acute lymphoblastic leukaemia. Br J Clin Pharmacol 2020; 86:1519-1527. [PMID: 32077136 DOI: 10.1111/bcp.14258] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2019] [Revised: 01/27/2020] [Accepted: 01/29/2020] [Indexed: 01/02/2023] Open
Abstract
AIMS Chinese children are more susceptible to the development of thiopurine-induced leukopenia compared with Caucasian populations. The aim of our study was to establish a 6-mercaptopurine (6-MP) dose-concentration-response relationship through exploration of pharmacogenetic factors involved in the thiopurine-induced toxicities in Chinese paediatric patients afflicted by acute lymphoblastic leukaemia (ALL). METHODS Blood samples were obtained from ALL children treated with 6-MP. We determined the metabolite steady-state concentrations of 6-MP in red blood cells (RBCs) by using high-performance liquid chromatography. Pharmacogenetic analysis was carried out on patients' genomic DNA using the MassArray genotyping platform. RESULTS Sixty children afflicted by ALL who received 6-MP treatment were enrolled in this study. The median concentration of 6-thioguanine in patients afflicted by leukopenia was 235.83 pmol/8 × 108 RBCs, which was significantly higher than for patients unafflicted by leukopenia (178.90 pmol/8 × 108 RBCs; P = 0.029). We determined the population special target 6-thioguanine threshold to have equalled 197.50 pmol/8 × 108 RBCs to predict leukopenia risk in Chinese paediatric patients afflicted by ALL. Among 36 candidate single nucleotide polymorphisms, our results indicated that NUDT15 (rs116855232) and IMPDH1 (rs2278293) were correlated with a 5.50-fold and 5.80-fold higher risk of leukopenia, respectively. MTHFR rs1801133 variants were found to have had a 4.46-fold significantly higher risk of hepatotoxicity vs wild-type genotype. CONCLUSION Our findings support the idea that predetermination of genotypes and monitoring of thiopurine metabolism for Chinese paediatric patients afflicted by ALL is necessary to effectively predict the efficacy of treatments and to minimize the adverse effects of 6-MP maintenance therapy.
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Affiliation(s)
- Yue Zhou
- Department of Clinical Pharmacy, School of Pharmaceutical Sciences, Shandong University, Jinan, China
| | - Li Wang
- Department of Paediatric Haematology-Oncology, Children's Hospital of Hebei Province affiliated to Hebei Medical University, Shijiazhuang, China
| | - Xiao-Ying Zhai
- Department of Paediatric Haematology-Oncology, Children's Hospital of Hebei Province affiliated to Hebei Medical University, Shijiazhuang, China
| | - Li Wen
- Department of Paediatric Haematology-Oncology, Children's Hospital of Hebei Province affiliated to Hebei Medical University, Shijiazhuang, China
| | - Fang Tang
- Big data Center, Shandong Provincial Qianfoshan Hospital, the First Hospital Affiliated with Shandong First Medical University, Jinan, China
| | - Fan Yang
- Department of Clinical Pharmacy, School of Pharmaceutical Sciences, Shandong University, Jinan, China
| | - Xi-Ting Liu
- Department of Clinical Pharmacy, School of Pharmaceutical Sciences, Shandong University, Jinan, China
| | - Lei Dong
- Department of Pharmacy, Children's Hospital of Hebei Province affiliated to Hebei Medical University, Shijiazhuang, China
| | - Li-Juan Zhi
- Department of Paediatric Haematology-Oncology, Children's Hospital of Hebei Province affiliated to Hebei Medical University, Shijiazhuang, China
| | - Hai-Yan Shi
- Department of Pharmacy, Shandong Provincial Qianfoshan Hospital, the First Hospital Affiliated with Shandong First Medical University, Jinan, China
| | - Guo-Xiang Hao
- Department of Clinical Pharmacy, School of Pharmaceutical Sciences, Shandong University, Jinan, China
| | - Yi Zheng
- Department of Clinical Pharmacy, School of Pharmaceutical Sciences, Shandong University, Jinan, China
| | | | - Tian-You Wang
- Beijing Key Laboratory of Pediatric Hematology Oncology, National Key Discipline of Pediatrics (Capital Medical University), Key Laboratory of Major Diseases in Children, Ministry of Education, Beijing, China.,Hematology Oncology Center, Beijing Children's Hospital, Capital Medical University, National Center for Children's Health, Beijing, China
| | - Wei Zhao
- Department of Clinical Pharmacy, School of Pharmaceutical Sciences, Shandong University, Jinan, China.,Department of Pharmacy, Shandong Provincial Qianfoshan Hospital, the First Hospital Affiliated with Shandong First Medical University, Jinan, China
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6
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Weeramange C, Lansakara A, Dallman J, Nguyen T, Hulangamuwa W, Rafferty RJ. New methods to assess 6-thiopurine toxicity and expanding its therapeutic application to pancreatic cancer via small molecule potentiators. MEDCHEMCOMM 2019; 10:717-725. [PMID: 31191862 DOI: 10.1039/c9md00010k] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/08/2019] [Accepted: 03/14/2019] [Indexed: 01/16/2023]
Abstract
6-Thiopurine (6TP) is a potent cytotoxic agent that is a clinically prescribed anti-metabolite employed in the treatment of numerous blood cancers since 1952. However, its reported severe toxicities limit its general usage in the clinic. We previously have undertaken investigations into identifying the mode of toxicity for 6TP, and have found that the oxidative metabolites of 6TP, specifically 6-thiouric acid (6TU), is responsible for the in vitro inhibition of UDP-glucose dehydrogenase (UDPGDH) in a UV-vis method. In this method, inhibition was quantified through the quantification of NADH production, however, purines absorb at the same wavelength and thereby can interfere with the NADH detection. Herein, we report a HPLC method that allows for direct quantification of UDP-glucuronic acid, product from UDPGDH, for the assessment of inhibition towards UDPGDH with no interference from purines. In this method it was revealed that 6TP possesses a greater inhibitory properties than previously observed; 111 vs. 288 μM. Building upon the data collected from a previously performed rat hepatocyte study, which correlated our in vitro to in vivo inhibition theories about UDPGDH, we have developed a bio-mimic in vitro assay to aid in the inhibitory assessment of 6TP and analogs. In our efforts to expand the use of 6TP, and analogs constructed, our laboratory has undertaken a screening campaign to identify small molecule potentiators that work in synergy with 6TP in other types of cancers. Three chalcone-based compounds have been discovered through our total synthesis campaign of uvaretin, and it has been found that 11c has strong synergism with 6TP in the pancreatic cancer cell line MIA PaCa-2. Through the work presented herein, we reveal new methods to assess toxicity of 6TP and future analogs and new small molecules that work in synergy to expand the therapeutic applications of this neglected cytotoxic agent.
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Affiliation(s)
- Chamitha Weeramange
- Department of Chemistry , Kansas State University , 1212 Mid-Campus Drive North , Manhattan , KS 66506 , USA
| | - Ashabha Lansakara
- Department of Chemistry , Kansas State University , 1212 Mid-Campus Drive North , Manhattan , KS 66506 , USA
| | - Johnathan Dallman
- Department of Chemistry , Kansas State University , 1212 Mid-Campus Drive North , Manhattan , KS 66506 , USA
| | - Thi Nguyen
- Department of Chemistry , Kansas State University , 1212 Mid-Campus Drive North , Manhattan , KS 66506 , USA
| | - Wasundara Hulangamuwa
- Department of Chemistry , Kansas State University , 1212 Mid-Campus Drive North , Manhattan , KS 66506 , USA
| | - Ryan J Rafferty
- Department of Chemistry , Kansas State University , 1212 Mid-Campus Drive North , Manhattan , KS 66506 , USA
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7
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Citterio-Quentin A, El Mahmoudi A, Perret T, Conway A, Ryan A, Beringer A, Lachaux A, Boulieu R. Red Blood cell IMPDH activity in adults and children with or without azathioprine: Relationship between thiopurine metabolites, ITPA and TPMT activities. Basic Clin Pharmacol Toxicol 2018; 124:600-606. [PMID: 30451390 DOI: 10.1111/bcpt.13176] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2018] [Accepted: 11/11/2018] [Indexed: 01/11/2023]
Abstract
Inosine monophosphate dehydrogenase (IMPDH) is considered as the limiting enzyme of thiopurine metabolism for the formation of 6-thioguanine nucleotides (6-TGN). No data are available on the influence of RBC IMPDH activity on the metabolism of thiopurine drugs in individuals with IBD. The aims of this study were as follows: (a) to carry out a phenotypic study of RBC IMPDH activity in adults and children treated or not with azathioprine (AZA) for autoimmune diseases, and (b) to investigate the relationship between the activities of IMPDH, thiopurine metabolites, inosine triphosphatase (ITPA) and thiopurine methyltransferase (TPMT). IMPDH activity was determined in 97 adults and 67 children treated or not with AZA. 6-Thioguanine nucleotides (6-TGN), 6-methylmercaptopurine nucleotide (6-MeMPN) levels, and ITPA as well as TPMT activities were measured in RBCs by HPLC. Using the Gaussian mixture model, distribution of IMPDH activity was evaluated. Influence of age, sex and AZA treatment on IMPDH activity was also assessed. A bimodal distribution in IMPDH activity was found with 87% of patients exhibiting normal activity and 13% of patients with high activity. No influence of age, sex and AZA therapy was found. There is no relationship between TPMT, ITPA and IMPDH activities. A negative correlation between IMPDH activity and 6-MeMPN was shown in adults and children (rs = -0.335 P = 0.014 and rs = -0.383 P = 0.012, respectively). Our results suggest that AZA-treated patients exhibiting lower IMPDH activity could have higher Me-6MPN levels with higher risk of hepatotoxicity. We demonstrated that RBC matrix could be an interesting alternative to lymphocyte matrix to monitor thiopurine metabolites and enzyme activity.
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Affiliation(s)
- Antony Citterio-Quentin
- Clinical Pharmacy, Pharmacokinetics and Drug Evaluation, Université de Lyon, Université Lyon 1, France.,Edouard Herriot Hospital, Laboratory of Medical Biology Multisites of University Hospital of Lyon, Pharmaco-Toxicology Unit, Hospices Civils de Lyon, Lyon, France
| | - Amal El Mahmoudi
- Clinical Pharmacy, Pharmacokinetics and Drug Evaluation, Université de Lyon, Université Lyon 1, France.,Edouard Herriot Hospital, Laboratory of Medical Biology Multisites of University Hospital of Lyon, Pharmaco-Toxicology Unit, Hospices Civils de Lyon, Lyon, France
| | - Thibault Perret
- Clinical Pharmacy, Pharmacokinetics and Drug Evaluation, Université de Lyon, Université Lyon 1, France.,Edouard Herriot Hospital, Laboratory of Medical Biology Multisites of University Hospital of Lyon, Pharmaco-Toxicology Unit, Hospices Civils de Lyon, Lyon, France
| | - Anthony Conway
- Clinical Pharmacy, Pharmacokinetics and Drug Evaluation, Université de Lyon, Université Lyon 1, France.,School of Pharmacy and Pharmaceuticals Sciences, Trinity College Dublin, Dublin, Ireland
| | - Aishling Ryan
- Clinical Pharmacy, Pharmacokinetics and Drug Evaluation, Université de Lyon, Université Lyon 1, France.,School of Pharmacy and Pharmaceuticals Sciences, Trinity College Dublin, Dublin, Ireland
| | - Audrey Beringer
- Clinical Pharmacy, Pharmacokinetics and Drug Evaluation, Université de Lyon, Université Lyon 1, France.,Edouard Herriot Hospital, Laboratory of Medical Biology Multisites of University Hospital of Lyon, Pharmaco-Toxicology Unit, Hospices Civils de Lyon, Lyon, France
| | - Alain Lachaux
- Pediatric Gastroenterology Unit, Hôpital Femme Mère Enfant (HFME), Lyon, France
| | - Roselyne Boulieu
- Clinical Pharmacy, Pharmacokinetics and Drug Evaluation, Université de Lyon, Université Lyon 1, France.,Edouard Herriot Hospital, Laboratory of Medical Biology Multisites of University Hospital of Lyon, Pharmaco-Toxicology Unit, Hospices Civils de Lyon, Lyon, France
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8
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Torres Hernandez AX, Weeramange CJ, Desman P, Fatino A, Haney O, Rafferty RJ. Efforts in redesigning the antileukemic drug 6-thiopurine: decreasing toxic side effects while maintaining efficacy. MEDCHEMCOMM 2018; 10:169-179. [PMID: 30774864 DOI: 10.1039/c8md00463c] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/14/2018] [Accepted: 12/15/2018] [Indexed: 01/14/2023]
Abstract
6-Thiopurine (6TP) is a currently prescribed drug in the treatment of diseases ranging from Crohn's disease to acute lymphocytic leukemia. While its potent mode of action is through incorporation into DNA as a thiol mimic of deoxyguanosine, severe toxicities are associated with its administration which hinder the potential therapeutic application. We have previously reported in vitro that the oxidative metabolites of 6TP, specifically 6-thiouric acid (6TU, K i 7 μM), are potent inhibitors of UDP-glucose dehydrogenase (UDPGDH), an enzyme that is responsible for the formation of UDP-glucuronic acid (UDPGA), an essential substrate that is used in detoxification processes in the liver. An in vivo investigation was undertaken to probe if 6TU inhibits UDPGDH in rat hepatocytes, and it was observed that 6TU does greatly suppress the conjugation of bilirubin with UDPGA. The failed excretion of bilirubin is linked to a majority of the reported toxicities associated with 6TP administration. Efforts were undertaken for the construction of 6TP analogs, substituted at the C8 position, to reduce inhibition of UDPGDH while retaining therapeutic efficacy. Three new 6TP analogs bearing a halogen (Br, Cl, and F) at the C8 position have been achieved over five-synthetic steps in overall yields of 16 to 32%. Each of these analogs were shown to have reduced inhibition towards UDPGDH, with K i values of 192, 163, 215 μM, respectively. In addition, the bromine, chlorine, and fluorine analogs were shown to possess cytotoxicity towards the REH cell line (acute lymphocytic leukemia) having IC50 values of 9.54 μM (±0.97), 3.95 μM (±1.94), and 4.71 μM (±1.40), respectively. These three new 6TP analogs represent the first steps in the redesign of this potent anticancer agent into a better drug that possesses reduced toxic side effects while retaining therapeutic potency.
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Affiliation(s)
- Arnaldo X Torres Hernandez
- Department of Chemistry , Pontifical Catholic University of Puerto Rico , 2250 Boulevard Luis A. Ferré Aguayo, Suite 626 , Ponce , PR 00717-0777 , Puerto Rico.,Department of Chemistry , Kansas State University , 1212 Mid-Campus Drive North , Manhattan , KS 66506 , USA .
| | - Chamitha J Weeramange
- Department of Chemistry , Kansas State University , 1212 Mid-Campus Drive North , Manhattan , KS 66506 , USA .
| | - Prathibha Desman
- Department of Chemistry , Kansas State University , 1212 Mid-Campus Drive North , Manhattan , KS 66506 , USA .
| | - Anthony Fatino
- Department of Chemistry , Kansas State University , 1212 Mid-Campus Drive North , Manhattan , KS 66506 , USA .
| | - Olivia Haney
- Department of Chemistry , Kansas State University , 1212 Mid-Campus Drive North , Manhattan , KS 66506 , USA .
| | - Ryan J Rafferty
- Department of Chemistry , Kansas State University , 1212 Mid-Campus Drive North , Manhattan , KS 66506 , USA .
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9
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Lim SZ, Chua EW. Revisiting the Role of Thiopurines in Inflammatory Bowel Disease Through Pharmacogenomics and Use of Novel Methods for Therapeutic Drug Monitoring. Front Pharmacol 2018; 9:1107. [PMID: 30349479 PMCID: PMC6186994 DOI: 10.3389/fphar.2018.01107] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2018] [Accepted: 09/10/2018] [Indexed: 12/12/2022] Open
Abstract
Azathioprine and 6-mercaptopurine, often referred to as thiopurine compounds, are commonly used in the management of inflammatory bowel disease. However, patients receiving these drugs are prone to developing adverse drug reactions or therapeutic resistance. Achieving predefined levels of two major thiopurine metabolites, 6-thioguanine nucleotides and 6-methylmercaptopurine, is a long-standing clinical practice in ensuring therapeutic efficacy; however, their correlation with treatment response is sometimes unclear. Various genetic markers have also been used to aid the identification of patients who are thiopurine-sensitive or refractory. The recent discovery of novel Asian-specific DNA variants, namely those in the NUDT15 gene, and their link to thiopurine toxicity, have led clinicians and scientists to revisit the utility of Caucasian biomarkers for Asian individuals with inflammatory bowel disease. In this review, we explore the limitations associated with the current methods used for therapeutic monitoring of thiopurine metabolites and how the recent discovery of ethnicity-specific genetic markers can complement thiopurine metabolites measurement in formulating a strategy for more accurate prediction of thiopurine response. We also discuss the challenges in thiopurine therapy, alongside the current strategies used in patients with reduced thiopurine response. The review is concluded with suggestions for future work aiming at using a more comprehensive approach to optimize the efficacy of thiopurine compounds in inflammatory bowel disease.
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Affiliation(s)
| | - Eng Wee Chua
- Faculty of Pharmacy, Universiti Kebangsaan Malaysia, Kuala Lumpur, Malaysia
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10
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ITPA Activity in Adults and Children Treated With or Without Azathioprine: Relationship Between TPMT Activity, Thiopurine Metabolites, and Co-medications. Ther Drug Monit 2018. [PMID: 28650902 DOI: 10.1097/ftd.0000000000000430] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND The implication of inosine triphosphate pyrophosphatase (ITPA) on thiopurine drug response variability has been investigated but little data are available on its role on thiopurine metabolites. The ability of ITPA to modify the thiopurine metabolite levels is currently used to optimize azathioprine (AZA) therapy in relation to thiopurine S-methyltransferase (TPMT) activity, the aim of this study is to investigate ITPA phenotype in a large population and to evaluate the relation between ITPA and TPMT activities and thiopurine metabolites. METHODS ITPA activity was determined in 183 adults and 138 children with or without AZA therapy. 6-thioguanine nucleotides (6-TGN), 6-methylmercaptopurine nucleotides (6-MeMPN) levels, and ITPA as well as TPMT activities were measured in red blood cells. Using the Gaussian mixture model, distribution of ITPA activity was evaluated. Intraindividual variability and influence of age, sex, AZA treatment and associated co-medications on ITPA activity were also assessed. RESULTS This retrospective study shows a quadrimodal distribution in ITPA activity. No influence of age, sex, AZA therapy, and co-medications was found. In adults, ITPA activity was not significantly associated with 6-TGN or 6-MeMPN concentrations, whereas a weak negative correlation was observed with 6-MeMPN levels in pediatric populations (rs = -0.261; P = 0.024). A weak positive correlation was observed between ITPA and TPMT activities in children (rs = 0.289; P = 0.001). CONCLUSIONS ITPA activity was poorly influenced by nongenetic parameters and has no influence on 6-TGN and 6-MeMPN concentrations in adults and only a weak correlation with 6-MeMPN and TPMT activity in children. These results demonstrate that ITPA is not a rate-limiting enzyme in the formation of 6-TGN but suggest that a decrease in ITPA activity in children may be a risk factor for accumulation of 6-MeMPN in cells.
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11
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Kakuta Y, Kinouchi Y, Shimosegawa T. Pharmacogenetics of thiopurines for inflammatory bowel disease in East Asia: prospects for clinical application of NUDT15 genotyping. J Gastroenterol 2018; 53:172-180. [PMID: 29192347 PMCID: PMC5846876 DOI: 10.1007/s00535-017-1416-0] [Citation(s) in RCA: 60] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/19/2017] [Accepted: 11/19/2017] [Indexed: 02/06/2023]
Abstract
The thiopurine drugs 6-mercaptopurine (6-MP) and azathiopurine (AZA) are widely used to treat inflammatory bowel disease. However, the incidence of adverse reactions is high, particularly in Asia, and the mechanisms of toxicity in Asian populations remain unclear. Thiopurine S-methyltransferase (TPMT) is a well-known enzyme that inactivates AZA or 6-MP through methylation and is one of the few pharmacogenetic predictors used in clinical settings in Western countries. Individuals carrying TPMT-deficient genetic variants require reduced drug doses, but this treatment modification is are not applicable to East Asian populations. Several genes code thiopurine-metabolizing enzymes, including TPMT, multidrug-resistance protein 4, and inosine triphosphatase. These genes have been studied as candidate pharmacogenetic markers; however, it remains unclear why Asian populations seem to be more intolerant than other ethnic groups to a full dose of thiopurines. A genome-wide association approach to identify Asian-specific pharmacogenetic markers in Korean patients with Crohn's disease revealed that a non-synonymous single nucelotide polymorphism in nucleoside diphosphate-linked moiety X-type motif 15 (NUDT15) which causes p.Arg139Cys was strongly associated with thiopurine-induced early leukopenia. Six common haplotypes of NUDT15 were reported, and five variants showed medium-to-low enzyme activities, compared with the wild haplotype. NUDT15 hydrolyzes the thiopurine active metabolites 6-thio-GTP and 6-thio-dGTP; variants of NUDT15 had lower enzyme activities, causing higher levels of thiopurine active metabolites, resulting in thiopurine-induced leukopenia. In clinical application, NUDT15 genotyping is a good candidate for predicting thiopurine toxicity in East Asian populations. However, the association of NUDT15 diplotypes with thiopurine toxicity remains unclear. Further analyses with large cohorts to confirm the clinical effects of each haplotype are planned.
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Affiliation(s)
- Yoichi Kakuta
- Division of Gastroenterology, Tohoku University Graduate School of Medicine, 1-1 Seiryo, Aoba, Sendai, 980-8574 Japan
| | - Yoshitaka Kinouchi
- Institute for Excellent in Higher Education, Tohoku University, Sendai, Japan
| | - Tooru Shimosegawa
- Division of Gastroenterology, Tohoku University Graduate School of Medicine, 1-1 Seiryo, Aoba, Sendai, 980-8574 Japan
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12
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Inhibition of UDP-glucose dehydrogenase by 6-thiopurine and its oxidative metabolites: Possible mechanism for its interaction within the bilirubin excretion pathway and 6TP associated liver toxicity. J Pharm Biomed Anal 2017; 151:106-115. [PMID: 29324279 DOI: 10.1016/j.jpba.2017.12.058] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2017] [Revised: 12/24/2017] [Accepted: 12/29/2017] [Indexed: 02/07/2023]
Abstract
6-Thiopurine (6TP) is an actively prescribed drug in the treatment of various diseases ranging from Crohn's disease and other inflammatory diseases to acute lymphocytic leukemia and non-Hodgkin's leukemia. While 6TP has beneficial therapeutic uses, severe toxicities are also reported with its use, such as jaundice and liver toxicity. While numerous investigations into the mode in which toxicity originates has been undertaken. None have investigated the effects of inhibition towards UDP-Glucose Dehydrogenase (UDPGDH), an oxidative enzyme responsible for UDP-glucuronic acid (UDPGA) formation or UDP-Glucuronosyl transferase (UGT1A1), which is responsible for the conjugation of bilirubin with UDPGA for excretion. Failure to excrete bilirubin leads to jaundice and liver toxicity. We proposed that either 6TP or its primary oxidative excretion metabolites inhibit one or both of these enzymes, resulting in the observed toxicity from 6TP administration. Inhibition analysis of these purines revealed that 6-thiopurine has weak to no inhibition towards UDPGDH with a Ki of 288 μM with regard to varying UDP-glucose, but 6-thiouric (primary end metabolite, fully oxidized at carbon 2 and 8, and highly retained by the body) has a near six-fold increased inhibition towards UDPGDH with a Ki of 7 μM. Inhibition was also observed by 6-thioxanthine (oxidized at carbon 2) and 8-OH-6TP with Ki values of 54 and 14 μM, respectively. Neither 6-thiopurine or its excretion metabolites were shown to inhibit UGT1A1. Our results show that the C2 and C8 positions of 6TP are pivotal in said inhibition towards UDPGDH and have no effect upon UGT1A1, and that blocking C8 could lead to new analogs with reduced, if not eliminated jaundice and liver toxicities.
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13
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Yin D, Xia X, Zhang J, Zhang S, Liao F, Zhang G, Zhang Y, Hou Q, Yang X, Wang H, Ma Z, Wang H, Zhu Y, Zhang W, Wang Y, Liu B, Wang L, Xu H, Shu Y. Impact of NUDT15 polymorphisms on thiopurines-induced myelotoxicity and thiopurines tolerance dose. Oncotarget 2017; 8:13575-13585. [PMID: 28088792 PMCID: PMC5355121 DOI: 10.18632/oncotarget.14594] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2016] [Accepted: 01/04/2017] [Indexed: 02/05/2023] Open
Abstract
Thiopurines are widely used as anticancer and immunosuppressive agents. However, life-threatening myelotoxicity has been noticed and largely explained by genetic variations, including NUDT15 polymorphisms (e.g., rs116855232). In this study, we conduct a meta-analysis to investigate the impact of rs116855232 on thiopurines-induced myelotoxicity susceptibility (1752 patients from 7 independent cohorts), as well as on thiopurines intolerance dose (2745 patients from 13 cohorts). Variant allele of rs116855232 contributes 7.86-fold (P < 0.00001, 95% CI: 6.13–10.08) higher risk to develop leucopenia with high specificity (91.74%) and sensitivity (43.19%), and lower thiopurines intolerance dose (P < 0.00001). Through bioinformatics prediction, amino acid changes induced by genetic variants are considered to reduce the stability, and break an α helix of NUDT15, which is part of the thiopurine binding pocket. Additionally, we conduct an expression quantitative trait loci (eQTL) analysis for NUDT15, and find a promoter-located eQTL signal (rs554405994), which may act as a potential marker to predict thiopurines-induced myelotoxicity. In conclusion, genetic polymorphisms in NUDT15 are strongly associated with adverse drug reaction (ADR) of thiopurines, although more evidences are needed to determine values of all functional NUDT15 polymorphisms for clinical regimen, rs116855232 should be considered as a highly credible pharmacogenetic indicator for thiopurines using espcially is Asians.
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Affiliation(s)
- Dandan Yin
- Department of Laboratory Medicine, National Key Laboratory of Biotherapy/Collaborative Innovation Center of Biotherapy and Precision Medicine Key Laboratory of Sichuan Province, West China Hospital, Sichuan University, Chengdu, Sichuan, China
| | - Xuyang Xia
- Department of Laboratory Medicine, National Key Laboratory of Biotherapy/Collaborative Innovation Center of Biotherapy and Precision Medicine Key Laboratory of Sichuan Province, West China Hospital, Sichuan University, Chengdu, Sichuan, China
| | - Junlong Zhang
- Department of Laboratory Medicine/Research Center of Clinical Laboratory Medicine, West China Hospital, Sichuan University, Chengdu, Sichuan, China
| | - Shouyue Zhang
- Department of Laboratory Medicine, National Key Laboratory of Biotherapy/Collaborative Innovation Center of Biotherapy and Precision Medicine Key Laboratory of Sichuan Province, West China Hospital, Sichuan University, Chengdu, Sichuan, China
| | - Fei Liao
- Department of Laboratory Medicine, National Key Laboratory of Biotherapy/Collaborative Innovation Center of Biotherapy and Precision Medicine Key Laboratory of Sichuan Province, West China Hospital, Sichuan University, Chengdu, Sichuan, China
| | - Ge Zhang
- Department of Pediatric Hematology/Oncology, West China Second Hospital Sichuan University, Chengdu, Sichuan, China
| | - Yan Zhang
- Department of Thoracic Oncology, Cancer Center, National Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, Sichuan, China
| | - Qianqian Hou
- Department of Laboratory Medicine, National Key Laboratory of Biotherapy/Collaborative Innovation Center of Biotherapy and Precision Medicine Key Laboratory of Sichuan Province, West China Hospital, Sichuan University, Chengdu, Sichuan, China
| | - Xue Yang
- Integrated Biomedical Sciences Program, University of Tennessee Health Science Center, Memphis, TN, USA
| | - Hong Wang
- Integrated Biomedical Sciences Program, University of Tennessee Health Science Center, Memphis, TN, USA
| | - Zhigui Ma
- Department of Pediatric Hematology/Oncology, West China Second Hospital Sichuan University, Chengdu, Sichuan, China
| | - Heyao Wang
- Department of Precision Medicine, China-Japan Friendship Hospital, Beijing, China
| | - Yiping Zhu
- Department of Pediatric Hematology/Oncology, West China Second Hospital Sichuan University, Chengdu, Sichuan, China
| | - Wei Zhang
- Department of Clinical Pharmacology, Hunan Key Laboratory of Pharmacogenetics, Xiangya Hospital, Central South University, Changsha, China
| | - Yuelan Wang
- Department of Laboratory Medicine, National Key Laboratory of Biotherapy/Collaborative Innovation Center of Biotherapy and Precision Medicine Key Laboratory of Sichuan Province, West China Hospital, Sichuan University, Chengdu, Sichuan, China
| | - Bo Liu
- Department of Laboratory Medicine, National Key Laboratory of Biotherapy/Collaborative Innovation Center of Biotherapy and Precision Medicine Key Laboratory of Sichuan Province, West China Hospital, Sichuan University, Chengdu, Sichuan, China
| | - Lanlan Wang
- Department of Laboratory Medicine/Research Center of Clinical Laboratory Medicine, West China Hospital, Sichuan University, Chengdu, Sichuan, China
| | - Heng Xu
- Department of Laboratory Medicine, National Key Laboratory of Biotherapy/Collaborative Innovation Center of Biotherapy and Precision Medicine Key Laboratory of Sichuan Province, West China Hospital, Sichuan University, Chengdu, Sichuan, China.,Department of Laboratory Medicine/Research Center of Clinical Laboratory Medicine, West China Hospital, Sichuan University, Chengdu, Sichuan, China
| | - Yang Shu
- Department of Laboratory Medicine, National Key Laboratory of Biotherapy/Collaborative Innovation Center of Biotherapy and Precision Medicine Key Laboratory of Sichuan Province, West China Hospital, Sichuan University, Chengdu, Sichuan, China
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Combination treatment with 6-mercaptopurine and allopurinol in HepG2 and HEK293 cells - Effects on gene expression levels and thiopurine metabolism. PLoS One 2017; 12:e0173825. [PMID: 28278299 PMCID: PMC5344510 DOI: 10.1371/journal.pone.0173825] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2016] [Accepted: 02/26/2017] [Indexed: 12/13/2022] Open
Abstract
Combination treatment with low-dose thiopurine and allopurinol (AP) has successfully been used in patients with inflammatory bowel disease with a so called skewed thiopurine metabolite profile. In red blood cells in vivo, it reduces the concentration of methylated metabolites and increases the concentration of the phosphorylated ones, which is associated with improved therapeutic efficacy. This study aimed to investigate the largely unknown mechanism of AP on thiopurine metabolism in cells with an active thiopurine metabolic pathway using HepG2 and HEK293 cells. Cells were treated with 6-mercaptopurine (6MP) and AP or its metabolite oxypurinol. The expression of genes known to be associated with thiopurine metabolism, and the concentration of thiopurine metabolites were analyzed. Gene expression levels were only affected by AP in the presence of 6MP. The addition of AP to 6MP affected the expression of in total 19 genes in the two cell lines. In both cell lines the expression of the transporter SLC29A2 was reduced by the combined treatment. Six regulated genes in HepG2 cells and 8 regulated genes in HEK293 cells were connected to networks with 18 and 35 genes, respectively, present at known susceptibility loci for inflammatory bowel disease, when analyzed using a protein-protein interaction database. The genes identified as regulated as well as the disease associated interacting genes represent new candidates for further investigation in the context of combination therapy with thiopurines and AP. However, no differences in absolute metabolite concentrations were observed between 6MP+AP or 6MP+oxypurinol vs. 6MP alone in either of the two cell lines. In conclusion; the effect of AP on gene expression levels requires the presence of 6MP, at least in vitro. Previously described AP-effects on metabolite concentrations observed in red blood cells in vivo could not be reproduced in our cell lines in vitro. AP’s effects in relation to thiopurine metabolism are complex. The network-identified susceptibility genes represented biological processes mainly associated with purine nucleotide biosynthetic processes, lymphocyte proliferation, NF-KB activation, JAK-STAT signaling, and apoptotic signaling at oxidative stress.
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Beringer A, Citterio-Quentin A, Otero RO, Gustin C, Clarke R, Salvi JP, Boulieu R. Determination of inosine 5'-monophosphate dehydrogenase activity in red blood cells of thiopurine-treated patients using HPLC. J Chromatogr B Analyt Technol Biomed Life Sci 2017; 1044-1045:194-199. [PMID: 28110955 DOI: 10.1016/j.jchromb.2017.01.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2016] [Revised: 12/30/2016] [Accepted: 01/05/2017] [Indexed: 01/25/2023]
Abstract
Thiopurine drugs are commonly used in immune diseases and to a lesser extent, in transplant rejection prophylaxis: however interindividual variability in drug response and in the occurrence of adverse events is observed. Genetic variation in thiopurine S-methyltransferase (TPMT) doesn't completely explain the occurrence of all adverse events and drug response variability. The potential implication of other enzymes involved in thiopurine metabolism, such as ITPA, has been investigated over the last decade but little data is available on inosine 5'-monophosphate dehydrogenase (IMPDH) in patients treated with thiopurine drugs. The authors reported a HPLC method to determine IMPDH activity in the red blood cells (RBCs) of thiopurine-treated patients. IMPDH activity was evaluated by enzymatic conversion of inosine 5'-monophosphate (IMP) to xanthosine 5'-monophosphate (XMP). The XMP formed was analyzed on a Luna® NH2 stationary phase, a weak anion exchange phase that exhibits both ionic and hydrophobic properties. XMP was eluted below 15min. Intra-assay and inter-assay precisions were below 9% for RBCs supplemented with 2, 40 and 80μmol/L of XMP. IMPDH activity was measured in adults without thiopurine treatment as well as in adult and paediatric patients treated with thiopurines. A wide interindividual variability in IMPDH activity in RBCs was observed. No difference in IMPDH activity was found between untreated subjects and adult and paediatric patients on thiopurine therapy (median value 11.8, 7.9 and 7.7nmol XPM/g Hb/h respectively). The method described is useful in the determination of IMPDH phenotype from patients on thiopurine therapy and in the investigation of the potential relationship between IMPDH activity in RBCs and the occurrence of adverse events and drug response variability.
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Affiliation(s)
- Audrey Beringer
- Université de Lyon, Université Lyon 1, UMR CNRS 5305, Pharmacie Clinique, Pharmacocinétique et Evaluation du Médicament, Lyon, France; Hospices Civils de Lyon, Groupement Hospitalier Edouard Herriot, Laboratoire de Biologie Médicale Multi Sites du CHU de Lyon, unité de Pharmacocinétique Clinique, Lyon, France
| | - Antony Citterio-Quentin
- Université de Lyon, Université Lyon 1, UMR CNRS 5305, Pharmacie Clinique, Pharmacocinétique et Evaluation du Médicament, Lyon, France; Hospices Civils de Lyon, Groupement Hospitalier Edouard Herriot, Laboratoire de Biologie Médicale Multi Sites du CHU de Lyon, unité de Pharmacocinétique Clinique, Lyon, France
| | - Rebeca Obenza Otero
- Université de Lyon, Université Lyon 1, UMR CNRS 5305, Pharmacie Clinique, Pharmacocinétique et Evaluation du Médicament, Lyon, France
| | - Clémence Gustin
- Université de Lyon, Université Lyon 1, UMR CNRS 5305, Pharmacie Clinique, Pharmacocinétique et Evaluation du Médicament, Lyon, France; Hospices Civils de Lyon, Groupement Hospitalier Edouard Herriot, Laboratoire de Biologie Médicale Multi Sites du CHU de Lyon, unité de Pharmacocinétique Clinique, Lyon, France
| | - Rebecca Clarke
- Université de Lyon, Université Lyon 1, UMR CNRS 5305, Pharmacie Clinique, Pharmacocinétique et Evaluation du Médicament, Lyon, France; School of Pharmacy and Pharmaceuticals Sciences, Trinity College Dublin, Dublin, Ireland
| | - Jean-Paul Salvi
- Université de Lyon, Université Lyon 1, UMR CNRS 5305, Pharmacie Clinique, Pharmacocinétique et Evaluation du Médicament, Lyon, France
| | - Roselyne Boulieu
- Université de Lyon, Université Lyon 1, UMR CNRS 5305, Pharmacie Clinique, Pharmacocinétique et Evaluation du Médicament, Lyon, France; Hospices Civils de Lyon, Groupement Hospitalier Edouard Herriot, Laboratoire de Biologie Médicale Multi Sites du CHU de Lyon, unité de Pharmacocinétique Clinique, Lyon, France.
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16
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Moon W, Loftus EV. Review article: recent advances in pharmacogenetics and pharmacokinetics for safe and effective thiopurine therapy in inflammatory bowel disease. Aliment Pharmacol Ther 2016; 43:863-883. [PMID: 26876431 DOI: 10.1111/apt.13559] [Citation(s) in RCA: 72] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/24/2015] [Revised: 08/26/2015] [Accepted: 01/26/2016] [Indexed: 12/16/2022]
Abstract
BACKGROUND Azathioprine and mercaptopurine have a pivotal role in the treatment of inflammatory bowel disease (IBD). However, because of their complex metabolism and potential toxicities, optimal use of biomarkers to predict adverse effects and therapeutic response is paramount. AIM To provide a comprehensive review focused on pharmacogenetics and pharmacokinetics for safe and effective thiopurine therapy in IBD. METHODS A literature search up to July 2015 was performed in PubMed using a combination of relevant MeSH terms. RESULTS Pre-treatment thiopurine S-methyltransferase typing plus measurement of 6-tioguanine nucleotides and 6-methylmercaptopurine ribonucleotides levels during treatment have emerged with key roles in facilitating safe and effective thiopurine therapy. Optimal use of these tools has been shown to reduce the risk of adverse effects by 3-7%, and to improve efficacy by 15-30%. For the introduction of aldehyde oxidase (AOX) into clinical practice, the association between AOX activity and AZA dose requirements should be positively confirmed. Inosine triphosphatase assessment associated with adverse effects also shows promise. Nucleoside diphosphate-linked moiety X-type motif 15 variants have been shown to predict myelotoxicity on thiopurines in East Asian patients. However, the impact of assessments of xanthine oxidase, glutathione S-transferase, hypoxanthine guanine phosphoribosyltransferase and inosine monophosphate dehydrogenase appears too low to favour incorporation into clinical practice. CONCLUSIONS Measurement of thiopurine-related enzymes and metabolites reduces the risk of adverse effects and improves efficacy, and should be considered part of standard management. However, this approach will not predict or avoid all adverse effects, and careful clinical and laboratory monitoring of patients receiving thiopurines remains essential.
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Affiliation(s)
- W Moon
- Division of Gastroenterology and Hepatology, Mayo Clinic, Rochester, MN, USA.,Department of Internal Medicine, Kosin University College of Medicine, Busan, Korea
| | - E V Loftus
- Division of Gastroenterology and Hepatology, Mayo Clinic, Rochester, MN, USA
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17
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LaDuke KE, Ehling S, Cullen JM, Bäumer W. Effects of azathioprine, 6-mercaptopurine, and 6-thioguanine on canine primary hepatocytes. Am J Vet Res 2016; 76:649-55. [PMID: 26111096 DOI: 10.2460/ajvr.76.7.649] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
OBJECTIVE To investigate the cytotoxic effects of azathioprine, 6-mercaptopurine, and 6-thioguanine on canine hepatocytes. SAMPLE Commercially available cryopreserved canine primary hepatocytes. PROCEDURES The study consisted of 2 trials. In trial 1, hepatocytes were incubated with azathioprine, 6-mercaptopurine, or 6-thioguanine at 1 of 6 concentrations (0.468, 0.937, 1.875, 3.750, 7.500, or 15.000 μmol/L) for 24, 48, or 72 hours. At each time, cell viability and lactate dehydrogenase (LDH) activity were determined for each thiopurine-concentration combination, and alanine aminotransferase (ALT) activity was determined for cells incubated with each thiopurine at a concentration of 15 μmol/L. In trial 2, hepatocytes were incubated with azathioprine, 6-mercaptopurine, or 6-thioguanine at 1 of 3 concentrations (18.75, 37.50, or 75.00 μmol/L) for 24 hours, after which the free glutathione concentration was determined for each thiopurine-concentration combination and compared with that for hepatocytes incubated without a thiopurine (control). RESULTS Incubation of hepatocytes with each of the 3 thiopurines adversely affected cell viability in a time- and concentration-dependent manner; however, this decrease in cell viability was not accompanied by a concurrent increase in LDH or ALT activity. Likewise, free glutathione concentration for hepatocytes incubated for 24 hours with supratherapeutic thiopurine concentrations (> 18.75 μmol/L) did not differ significantly from that of control cells. CONCLUSIONS AND CLINICAL RELEVANCE Results indicated that thiopurines adversely affected the viability of canine hepatocytes in a time- and concentration-dependent manner but had a nonsignificant effect on the LDH and ALT activities and free glutathione depletion of those hepatocytes.
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NUDT15 R139C-related thiopurine leukocytopenia is mediated by 6-thioguanine nucleotide-independent mechanism in Japanese patients with inflammatory bowel disease. J Gastroenterol 2016; 51:22-9. [PMID: 26590936 DOI: 10.1007/s00535-015-1142-4] [Citation(s) in RCA: 77] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/27/2015] [Accepted: 10/27/2015] [Indexed: 02/04/2023]
Abstract
BACKGROUND NUDT15 R139C (rs116855232) is a recently identified genetic factor responsible for thiopurine-induced leukocytopenia and hair loss. In this study, we investigated the association of NUDT15 R139C with 6-thioguanine nucleotide (6-TGN) levels and thiopurine-induced leukocytopenia in Japanese patients with inflammatory bowel disease (IBD). METHODS Two hundred and sixty-four subjects (103 healthy volunteers and 161 IBD patients treated with thiopurines) were enrolled. Genotyping for NUDT15 R139C was performed using Custom TaqMan® SNP genotyping assays. RESULTS The NUDT15 C/C, C/T, and T/T genotypes were 80.7, 18.2, and 1.1 %, respectively. The allelic frequency was 10.2 %. Among 161 IBD patients, there was no significant difference in 6-TGN levels among the NUDT15 genotypes. Forty-five patients (27.9 %) developed leukocytopenia (WBC <3000/μl), and the C/T and T/T genotypes were significantly associated with the development of leukocytopenia (P = 1.7 × 10(-5)). In these patients, 6-TGN levels were not significantly different between NUDT15 genotypes. NUDT15 R139C was significantly associated with early (<8 weeks) (P = 1.03 × 10(-4)) and late (>8 weeks) leukocytopenia (P = 4.3 × 10(-4)). The decrease in WBC count at 2 and 4 weeks was significantly higher in patients with the C/T or T/T genotypes as compared to the patients with the C/C genotype. All patients with the T/T genotype (n = 2) developed early severe hair loss and severe leukocytopenia (<1000/μl). The logistic regression analysis revealed that NUDT15 R139C was the sole genetic factor responsible for the thiopurine-induced leukocytopenia (P = 0.001). CONCLUSIONS These results suggest that NUDT15 R139C-related thiopurine-induced leukocytopenia is mediated by a 6-TGN-independent mechanism.
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Impact of Genetic Polymorphisms on 6-Thioguanine Nucleotide Levels and Toxicity in Pediatric Patients with IBD Treated with Azathioprine. Inflamm Bowel Dis 2015; 21:2897-908. [PMID: 26332308 DOI: 10.1097/mib.0000000000000570] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
BACKGROUND Thiopurine-related toxicity results in discontinuation of therapy in up to 30% of patients with inflammatory bowel disease. Although thiopurine S-methyltransferase (TPMT) is implicated in toxicity, not all toxicity can be attributed to TPMT polymorphisms. We investigated the effects of polymorphisms of genes involved in thiopurine and folate metabolism pathways on 6-thioguanine nucleotide levels and toxicity. METHODS Retrospective clinical data and blood samples were collected from 132 pediatric patients with inflammatory bowel disease treated with azathioprine. Eighty-seven genetic polymorphisms of 30 genes were screened using the MassARRAY system, and 70 polymorphisms of 28 genes were selected for further analysis. RESULTS TPMT genotype (P < 0.001), concurrent use of mesalazine (P = 0.006), ABCC5 (rs2293001) (P < 0.001), ITPA (rs2236206 and rs8362) (P = 0.010 and P = 0.003), and ABCB1 (rs2032582) (P = 0.028) were all associated with the ratio of 6-thioguanine nucleotides to azathioprine dose. ADK (rs10824095) (P = 0.004, odds ratio [OR] = 6.220), SLC29A1 (rs747199) (P = 0.016, OR = 5.681), and TYMS (rs34743033) (P = 0.045, OR = 3.846) were associated with neutropenia. ABCC1 (rs2074087) (P = 0.022, OR = 3.406), IMPDH1 (rs2278294) (P = 0.027, OR = 0.276), and IMPDH2 (rs11706052) (P = 0.034, OR = 3.639) had a significant impact on lymphopenia. CONCLUSIONS This study describes genetic polymorphisms in genes whose products may affect pharmacokinetics and which may predict the relative likelihood of benefit or risk from thiopurine treatment. These findings may serve as a basis for personalized thiopurine therapy in pediatric patients with inflammatory bowel disease, although our data need to be validated in further studies.
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Hareedy MS, El Desoky ES, Woillard JB, Thabet RH, Ali AM, Marquet P, Picard N. Genetic variants in 6-mercaptopurine pathway as potential factors of hematological toxicity in acute lymphoblastic leukemia patients. Pharmacogenomics 2015; 16:1119-34. [PMID: 26237184 DOI: 10.2217/pgs.15.62] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
AIM We investigated the associations between variants in genes coding for enzymes and transporters related to the 6-mercaptopurine pathway and clinical outcomes in pediatric patients with acute lymphoblastic leukemia. MATERIALS & METHODS Statistical association between gender, age and genotypes of selected SNPs, and the risks of hematological toxicity and relapse were investigated using a Cox proportional hazard model in 70 acute lymphoblastic leukemia patients from upper Egypt. RESULTS We found significant associations between ITPA, IMPDH1, SLC29A1, SLC28A2, SLC28A3 and ABCC4 SNPs and one or more of the hematological toxicity manifestations (neutropenia, agranulocytosis and leukopenia); age was significantly related to relapse. CONCLUSION Genetic polymorphisms in enzymes and transporters involved in the 6-mercaptopurine pathway should be considered during its use to avoid hematological toxicity.
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Affiliation(s)
- Mohammad Salem Hareedy
- Department of Pharmacology, Faculty of Medicine, Assiut University, 71515 Assiut, Egypt.,Inserm, UMR-850, Limoges, France
| | - Ehab S El Desoky
- Department of Pharmacology, Faculty of Medicine, Assiut University, 71515 Assiut, Egypt
| | - Jean-Baptiste Woillard
- Inserm, UMR-850, Limoges, France.,Department of Pharmacology, Toxicology & Pharmacovigilance, CHU Limoges, Limoges, France.,Faculty of Medicine, Laboratory of Medical Pharmacology, University of Limoges, Limoges, France
| | - Romany Helmy Thabet
- Department of Pharmacology, Faculty of Medicine, Assiut University, 71515 Assiut, Egypt
| | | | - Pierre Marquet
- Inserm, UMR-850, Limoges, France.,Department of Pharmacology, Toxicology & Pharmacovigilance, CHU Limoges, Limoges, France.,Faculty of Medicine, Laboratory of Medical Pharmacology, University of Limoges, Limoges, France
| | - Nicolas Picard
- Inserm, UMR-850, Limoges, France.,Department of Pharmacology, Toxicology & Pharmacovigilance, CHU Limoges, Limoges, France.,South Egypt Cancer Institute, Assiut University, Assiut, Egypt
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Abstract
PURPOSE This study aimed to assess the role of thiopurine S-methyltransferase (TPMT) and 6-thioguanine nucleotide (6-TGN) as predictors of clinical response and side effects to azathioprine (AZA), and estimate the optimal AZA dose in Korean pediatric inflammatory bowel disease (IBD) patients. MATERIALS AND METHODS One hundred and nine pediatric IBD patients in whom AZA treatment was required were enrolled. Thiopurine metabolites were monitored since September 2010. Among them, 83 patients who had prescribed AZA for at least 3 months prior to September 2010 were enrolled and followed until October 2011 to evaluate optimal AZA dose, adverse effects and disease activity before and after thiopurine metabolite monitoring. RESULTS The result of the TPMT genotype was that 102 patients were *1/*1 (wild type), four were *1/*3C, one was *1/*6, one was *1/*16 (heterozygote) and one was *3C/*3C (homozygote). Adverse effects happened in 31 patients pre-metabolite monitoring and in only nine patients post-metabolite monitoring. AZA dose was 1.4±0.31 mg/kg/day before monitoring and 1.1±0.46 mg/kg/day after monitoring (p<0.001). However, there were no statistical differences in disease activity during metabolite monitoring period (p=0.34). Adverse effects noticeably decreased although reduction of the AZA dose since monitoring. CONCLUSION TPMT genotype and thiopurine metabolite monitoring could be helpful to examine TPMT genotypes before administering AZA and to measure 6-TGN concentrations during prescribing AZA in IBD patients.
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Affiliation(s)
- Mi Jin Kim
- Department of Pediatrics, Ilsan Paik Hospital, Inje University College of Medicine, Goyang, Korea
| | - Soo Youn Lee
- Department of Laboratory Medicine and Genetics, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - Yon Ho Choe
- Department of Pediatrics, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
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New genetic biomarkers predicting azathioprine blood concentrations in combination therapy with 5-aminosalicylic acid. PLoS One 2014; 9:e95080. [PMID: 24762746 PMCID: PMC3999094 DOI: 10.1371/journal.pone.0095080] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2013] [Accepted: 03/23/2014] [Indexed: 01/29/2023] Open
Abstract
BACKGROUND AND AIMS Azathioprine (AZA) is widely used for the treatment of inflammatory bowel disease (IBD) patients. AZA is catabolized by thiopurine S-methyltransferase (TPMT), which exhibits genetic polymorphisms. It has also been reported that 5-aminosalicylic acid (5-ASA) inhibits TPMT activity, and that increased 6-thioguanine nucleotide (6-TGN, a metabolite of AZA) blood concentrations result in an increased number of ADRs. In this study, single nucleotide polymorphisms (SNPs) related to differential gene expression affecting AZA drug metabolism in combination therapy with 5-ASA were examined. METHODS To identify genetic biomarkers for the prediction of 6-TGN blood concentration, ExpressGenotyping analysis was used. ExpressGenotyping analysis is able to detect critical pharmacogenetic SNPs by analyzing drug-induced expression allelic imbalance (EAI) of premature RNA in HapMap lymphocytes. We collected blood samples on 38 patients with inflammatory bowel disease treated with AZA and corroboration of the obtained SNPs was attempted in clinical samples. RESULTS A large number of SNPs with AZA/5-ASA-induced EAI within the investigated HapMap lymphocytes was identified by ExpressGenotyping analysis. The respective SNPs were analyzed in IBD patients' blood samples. Among these SNPs, several that have not yet been described to be induced by AZA/5-ASA were found. SNPs within SLC38A9 showed a particular correlation with patients' 6-TGN blood concentrations. CONCLUSIONS Based on these results, ExpressGenotyping analysis and genotyping of patients appears to be a useful way to identify inter-individual differences in drug responses and ADRs to AZA/5-ASA. This study provides helpful information on genetic biomarkers for optimized AZA/5-ASA treatment of IBD patients.
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Blaker PA, Arenas-Hernandez M, Smith MA, Shobowale-Bakre EA, Fairbanks L, Irving PM, Sanderson JD, Marinaki AM. Mechanism of allopurinol induced TPMT inhibition. Biochem Pharmacol 2013; 86:539-47. [PMID: 23770457 DOI: 10.1016/j.bcp.2013.06.002] [Citation(s) in RCA: 77] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2013] [Revised: 06/04/2013] [Accepted: 06/05/2013] [Indexed: 12/16/2022]
Abstract
Up to 1/5 of patients with wildtype thiopurine-S-methyltransferase (TPMT) activity prescribed azathioprine (AZA) or mercaptopurine (MP) demonstrate a skewed drug metabolism in which MP is preferentially methylated to yield methylmercaptopurine (MeMP). This is known as thiopurine hypermethylation and is associated with drug toxicity and treatment non-response. Co-prescription of allopurinol with low dose AZA/MP (25-33%) circumvents this phenotype and leads to a dramatic reduction in methylated metabolites; however, the biochemical mechanism remains unclear. Using intact and lysate red cell models we propose a novel pathway of allopurinol mediated TPMT inhibition, through the production of thioxanthine (TX, 2-hydroxymercaptopurine). In red blood cells pre-incubated with 250 μM MP for 2h prior to the addition of 250 μM TX or an equivalent volume of Earle's balanced salt solution, there was a significant reduction in the concentration of MeMP detected at 4h and 6h in cells exposed to TX (4 h, 1.68, p=0.0005, t-test). TX acts as a direct TPMT inhibitor with an apparent Ki of 0.329 mM. In addition we have confirmed that the mechanism is relevant to in vivo metabolism by demonstrating raised urinary TX levels in patients receiving combination therapy. We conclude that the formation of TX in patients receiving combination therapy with AZA/MP and allopurinol, likely explains the significant reduction of methylated metabolites due to direct TPMT inhibition.
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Affiliation(s)
- P A Blaker
- Department of Gastroenterology, Guy's and St Thomas' NHS Hospitals Foundation Trust, London, UK.
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Kim MJ, Choe YH. Monitoring and safety of azathioprine therapy in inflammatory bowel disease. Pediatr Gastroenterol Hepatol Nutr 2013; 16:65-70. [PMID: 24010109 PMCID: PMC3760698 DOI: 10.5223/pghn.2013.16.2.65] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/04/2013] [Accepted: 06/08/2013] [Indexed: 12/20/2022] Open
Abstract
Azathioprine is the most common drug used to maintain clinical remission in inflammatory bowel disease. This drug is also important as a steroid-sparing agent in steroid-dependent and chronically active inflammatory bowel disease. Nevertheless, many questions remain concerning the optimal treatment regimens of azathioprine. The dose of azathioprine has to be reduced or the therapy has to be discontinued frequently because of drug-induced toxicity. In this review, we discuss monitoring of thiopurines, adverse events, malignant complications and how to use azathioprine safely and usefully.
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Affiliation(s)
- Mi Jin Kim
- Department of Pediatrics, Ilsan Paik Hospital, Inje University College of Medicine, Goyang, Korea
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Gene expression and thiopurine metabolite profiling in inflammatory bowel disease - novel clues to drug targets and disease mechanisms? PLoS One 2013; 8:e56989. [PMID: 23437289 PMCID: PMC3578787 DOI: 10.1371/journal.pone.0056989] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2012] [Accepted: 01/16/2013] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND AND AIMS Thiopurines are effective to induce and maintain remission in inflammatory bowel disease (IBD). The methyl thioinosine monophosphate (meTIMP)/6-thioguanine nucleotide (6-TGN) concentration ratio has been associated with drug efficacy. Here we explored the molecular basis of differences in metabolite profiles and in relation to disease activity. METHODS Transcriptional profiles in blood samples from an exploratory IBD-patient cohort (n = 21) with a normal thiopurine S-methyltransferase phenotype and meTIMP/6-TGN ratios >20, 10.0-14.0 and ≤4, respectively, were assessed by hybridization to microarrays. Results were further evaluated with RT qPCR in an expanded patient cohort (n = 54). Additionally, 30 purine/thiopurine related genes were analysed separately. RESULTS Among 17 genes identified by microarray-screening, there were none with a known relationship to pathways of purines/thiopurines. For nine of them a correlation between expression level and the concentration of meTIMP, 6-TGN and/or the meTIMP/6-TGN ratio was confirmed in the expanded cohort. Nine of the purine/thiopurine related genes were identified in the expanded cohort to correlate with meTIMP, 6-TGN and/or the meTIMP/6-TGN ratio. However, only small differences in gene expression levels were noticed over the three different metabolite profiles. The expression levels of four genes identified by microarray screening (PLCB2, HVCN1, CTSS, and DEF8) and one purine/thiopurine related gene (NME6) correlated significantly with the clinical activity of Crohn's disease. Additionally, 16 of the genes from the expanded patient cohort interacted in networks with candidate IBD susceptibility genes. CONCLUSIONS Seventeen of the 18 genes which correlated with thiopurine metabolite levels also correlated with disease activity or participated in networks with candidate IBD susceptibility genes involved in processes such as purine metabolism, cytokine signaling, and functioning of invariant natural killer T cells, T cells and B cells. Therefore, we conclude that the identified genes to a large extent are related to drug targets and disease mechanisms of IBD.
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Nagamine A, Takenaka M, Aomori T, Okada Y, Hiromura K, Nojima Y, Araki T, Nakamura T, Yamamoto K. Effect of genetic polymorphisms on effectiveness of low-dose azathioprine in Japanese patients with systemic lupus erythematosus. Am J Health Syst Pharm 2012; 69:2072-8. [DOI: 10.2146/ajhp120179] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Affiliation(s)
- Ayumu Nagamine
- Department of Pharmacy Gunma University Hospital, Showa-machi, Maebashi, Japan
| | - Miki Takenaka
- Department of Pharmacy Gunma University Hospital, Showa-machi, Maebashi, Japan
| | - Tohru Aomori
- Department of Clinical Pharmacology, Graduate School of Medicine, Gunma University, Showa-machi
| | - Yuko Okada
- Faculty of Pharmacy, Takasaki University of Health and Welfare, Nakaoorui-machi, Takasaki, Japan
| | | | | | | | | | - Koujirou Yamamoto
- Department of Clinical Pharmacology, Graduate School of Medicine, Gunma University
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Blaker PA, Arenas-Hernandez M, Marinaki AM, Sanderson JD. The pharmacogenetic basis of individual variation in thiopurine metabolism. Per Med 2012; 9:707-725. [DOI: 10.2217/pme.12.85] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Thiopurines are an important class of immunosuppressive therapy, which have been used in clinical practice for over 50 years. Despite this extensive experience many of the pharmacodynamic and pharmacokinetic properties of these drugs remain unknown. As a consequence there is often no clear explanation for the individual variation in response to treatment, both in terms of efficacy or adverse drug reactions. This review, which emphasizes practice in gastroenterology, summarizes the current understanding of thiopurine drug metabolism and highlights the role of nongenetic and genetic factors other than TPMT, which should be a focus for future research. Correlation of polymorphic variations in these genes with clinical outcomes is expected to clarify the basis for interindividual differences in thiopurine metabolism and enable a more personalized approach to therapy.
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Affiliation(s)
- Paul Andrew Blaker
- Department of Gastroenterology, 1st Floor College House, St Thomas’ Hospital, Westminster Bridge Road, London, SE1 7EH, London, UK
| | - Monica Arenas-Hernandez
- The Purine Research Laboratory, Guy’s & St Thomas’ Hospitals NHS Foundation Trust , London, UK
| | - Anthony Marin Marinaki
- The Purine Research Laboratory, Guy’s & St Thomas’ Hospitals NHS Foundation Trust , London, UK
| | - Jeremy David Sanderson
- Department of Gastroenterology, 1st Floor College House, St Thomas’ Hospital, Westminster Bridge Road, London, SE1 7EH, London, UK
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Pharmacogenetic determinants of mercaptopurine disposition in children with acute lymphoblastic leukemia. Eur J Clin Pharmacol 2012; 68:1233-42. [PMID: 22421815 DOI: 10.1007/s00228-012-1251-4] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2011] [Accepted: 02/14/2012] [Indexed: 12/15/2022]
Abstract
BACKGROUND The backbone of drug therapy used in acute lymphoblastic leukemia (ALL) in children includes 6-mercaptopurine (6-MP). Intracellular metabolism of this prodrug is a key component of the therapeutic response. Many metabolizing enzymes are involved in 6-MP disposition and active 6-MP metabolites are represented by 6-thioguanine nucleotides (6-TGN) and methylated metabolites primarily methylated by the thiopurine S-methyltransferase enzyme (TPMT). The genetic polymorphism affecting TPMT activity displays an important inter-subject variability in metabolites pharmacokinetics and influences the balance between 6-MP efficacy and toxicity: patients with high 6-TGN levels are at risk of myelosuppression while patients with high levels of methylated derivates are at hepatotoxic risk. However, the genetic TPMT polymorphism does not explain all 6-MP adverse events and some severe toxicities leading to life-threatening conditions remain unexplained. Additional single nucleotide polymorphisms (SNPs) in genes encoding enzymes involved in 6-MP metabolism and 6-MP transporters may also be responsible for this inter-individual 6-MP response variability. AIM This review presents the pharmacogenetic aspects of 6-MP metabolism in great detail. We have focused on published data on ALL treatment supporting the great potential of 6-MP pharmacogenetics to improve efficacy, tolerance, and event-free survival rates in children with ALL.
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Ding L, Zhang FB, Liu H, Gao X, Bi HC, Wang XD, Chen BL, Zhang Y, Zhao LZ, Zhong GP, Hu PJ, Chen MH, Huang M. Hypoxanthine guanine phosphoribosyltransferase activity is related to 6-thioguanine nucleotide concentrations and thiopurine-induced leukopenia in the treatment of inflammatory bowel disease. Inflamm Bowel Dis 2012; 18:63-73. [PMID: 21381155 DOI: 10.1002/ibd.21676] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/16/2010] [Accepted: 01/13/2011] [Indexed: 12/15/2022]
Abstract
BACKGROUND Thiopurine drugs are widely used in the treatment of inflammatory bowel disease (IBD). The polymorphic enzyme thiopurine S-methyltransferase (TPMT) is of importance for thiopurine metabolism and adverse events occurrence. The role of other thiopurine-metabolizing enzymes is less well known. This study investigated the effects of TPMT and hypoxanthine guanine phosphoribosyltransferase (HPRT) activities on 6-thioguanine nucleotides (6-TGNs) concentrations and thiopurine-induced leukopenia in patients with IBD. METHODS Clinical data and blood samples were collected from 120 IBD patients who were receiving azathioprine (AZA)/6-mercaptopurine (6-MP) therapy. Erythrocyte TPMT, HPRT activities and 6-TGNs concentrations were determined. HPRT activity and its correlation with TPMT activity, 6-TGNs level, and leukopenia were evaluated. RESULTS The HPRT activity of all patients ranged from 1.63-3.33 (2.31 ± 0.36) μmol/min per g Hb. HPRT activity was significantly higher in patients with leukopenia (27, 22.5%) than without (P < 0.001). A positive correlation between HPRT activity and 6-TGNs concentration was found in patients with leukopenia (r = 0.526, P = 0.005). Patients with HPRT activity > 2.70 μmol/min per g Hb could have an increased risk of developing leukopenia (odds ratio = 7.47, P < 0.001). No correlation was observed between TPMT activity and HPRT activity, 6-TGNs concentration, or leukopenia. CONCLUSIONS High levels of HPRT activity could be a predictor of leukopenia and unsafe 6-TGN concentrations in patients undergoing AZA/6-MP therapy. This could partly explain the therapeutic response or toxicity that could not be adequately explained by the polymorphisms of TPMT.
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Affiliation(s)
- Liang Ding
- Institute of Clinical Pharmacology, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou, PR China
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The role of inosine-5'-monophosphate dehydrogenase in thiopurine metabolism in patients with inflammatory bowel disease. Ther Drug Monit 2011; 33:200-8. [PMID: 21311411 DOI: 10.1097/ftd.0b013e31820b42bb] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
BACKGROUND There is a large interindividual variability in thiopurine metabolism. High concentrations of methylthioinosine-5'-monophosphate (meTIMP) and low concentrations of 6-thioguanine nucleotides (6-TGNs) have been associated with a lower response rate and an increased risk of adverse events. In this study, the role of inosine-5'-monophosphate dehydrogenase (IMPDH) for differences in metabolite patterns of thiopurines was investigated. METHODS IMPDH activity and thiopurine metabolite concentrations were determined in patients with inflammatory bowel disease and a normal thiopurine methyltransferase (TPMT) phenotype and meTIMP/6-TGN concentration ratio > 20 (n = 26), in patients with a metabolite ratio ≤ 20 (n = 21), in a subgroup with a metabolite ratio <4 (n = 6), and in 10 patients with reduced TPMT activity. In vitro studies were conducted on human embryonic kidney cells (HEK293) with genetically engineered IMPDH and TPMT activities. RESULTS Patients with metabolite ratios >20 had lower IMPDH activity than those with ratios ≤ 20 (P < 0.001). Metabolite ratios >20 were only observed in patients with normal TPMT activity. Downregulation of IMPDH activity in HEK293 cells was associated with an increase in the concentration of meTIMP (fold change: 17 up to 93, P < 0.001) but, unexpectedly, also of 6-thioguanosine monophosphate (fold change: 2.6 up to 5.0, P < 0.001). CONCLUSIONS These data question the general view of IMPDH as the rate-limiting enzyme in the phosphorylation of thiopurines. Investigations of other mechanisms are needed to more fully explain the various metabolite patterns and outcomes in patients under treatment.
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Osaki R, Imaeda H, Ban H, Aomatsu T, Bamba S, Tsujikawa T, Sasaki M, Fujiyama Y, Andoh A. Accuracy of genotyping using the TaqMan PCR assay for single nucleotide polymorphisms responsible for thiopurine sensitivity in Japanese patients with inflammatory bowel disease. Exp Ther Med 2011; 2:783-786. [PMID: 22977575 PMCID: PMC3440725 DOI: 10.3892/etm.2011.287] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2011] [Accepted: 06/09/2011] [Indexed: 12/14/2022] Open
Abstract
Thiopurine drugs are the most common drugs used to maintain clinical remission in inflammatory bowel disease (IBD). Three single-nucleotide polymorphisms (SNPs), TPMT A719G (rs1142345), inosine triphosphate pyrophosphatase (ITPase) C94A (rs1127354) and multidrug resistance protein 4 MRP4 G2269A (rs3765534), have been reported to account for heightened sensitivity to thiopurine drugs in the Japanese population. We investigated the usefulness of the TaqMan(®) PCR assay (Applied Biosystems) for the rapid detection of these SNPs to improve the safety of thiopurine therapy. We enrolled 44 healthy volunteers and 235 IBD patients. Genotyping of the SNPs was performed using Custom TaqMan SNP genotyping assays, direct sequencing and PCR-RFLP. Genotyping for MRP4 G2269A by the TaqMan PCR assay was successfully achieved in all samples. Comparison with our previous data using direct sequencing indicated one discordant result, and re-sequencing showed that the TaqMan PCR assay was correct. The overall accuracy of the TaqMan assay for MRP4 G2269A was 100%. The TaqMan PCR genotyping for TPMT A719G and ITPase C94A was successfully performed in all samples. The results of TPMT A719G by the TaqMan assay were identical with those of PCR-RFLP. In ITPase C94A, a comparison of the TaqMan assay and PCR-RFLP yielded 12 discordant results, and direct sequencing showed that the TaqMan PCR assay was correct. The allelic frequency determined by the TaqMan assay was 0.145 for MRP4 G2269A, 0.009 for TPMT A719G and 0.121 for ITPase C94A, respectively. In conclusion, the TaqMan(®) PCR assay is useful for genotyping of SNPs responsible for thiopurine sensitivity in Japanese IBD patients.
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Glander P, Hambach P, Liefeldt L, Budde K. Inosine 5'-monophosphate dehydrogenase activity as a biomarker in the field of transplantation. Clin Chim Acta 2011; 413:1391-7. [PMID: 21889500 DOI: 10.1016/j.cca.2011.08.027] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2011] [Revised: 07/09/2011] [Accepted: 08/16/2011] [Indexed: 11/25/2022]
Abstract
Inosine 5'monophosphate dehydrogenase (IMPDH) is the rate limiting enzyme in the de novo synthesis of guanine nucleotides. The direct determination of target enzyme activity as a biomarker of mycophenolic acid (MPA) may help to estimate better the individual response to the immunosuppressant. However, the assessment of the clinical utility of this approach is limited by the diversity of the assay systems, which has not yet allowed the prospective assessment of this enzyme in larger patient cohorts. A recently validated and standardized assay allows the investigation of IMPDH activity in larger clinical studies. Although descriptive results from observational studies hold promise for a more individualized therapy in transplant medicine, more studies are needed to prospectively validate this approach.
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Affiliation(s)
- Petra Glander
- Charite-Universitätsmedizin Berlin, Department of Nephrology, Berlin, Germany.
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Loit E, Tricco AC, Tsouros S, Sears M, Ansari MT, Booth RA. Pre-analytic and analytic sources of variations in thiopurine methyltransferase activity measurement in patients prescribed thiopurine-based drugs: A systematic review. Clin Biochem 2011; 44:751-7. [PMID: 21402061 DOI: 10.1016/j.clinbiochem.2011.03.022] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2010] [Revised: 02/16/2011] [Accepted: 03/04/2011] [Indexed: 12/13/2022]
Abstract
OBJECTIVES Low thiopurine S-methyltransferase (TPMT) enzyme activity is associated with increased thiopurine drug toxicity, particularly myelotoxicity. Pre-analytic and analytic variables for TPMT genotype and phenotype (enzyme activity) testing were reviewed. DESIGN AND METHODS A systematic literature review was performed, and diagnostic laboratories were surveyed. RESULTS Thirty-five studies reported relevant data for pre-analytic variables (patient age, gender, race, hematocrit, co-morbidity, co-administered drugs and specimen stability) and thirty-three for analytic variables (accuracy, reproducibility). TPMT is stable in blood when stored for up to 7 days at room temperature, and 3 months at -30°C. Pre-analytic patient variables do not affect TPMT activity. Fifteen drugs studied to date exerted no clinically significant effects in vivo. Enzymatic assay is the preferred technique. Radiochemical and HPLC techniques had intra- and inter-assay coefficients of variation (CVs) below 10%. CONCLUSION TPMT is a stable enzyme, and its assay is not affected by age, gender, race or co-morbidity.
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Affiliation(s)
- Evelin Loit
- Department of Biochemistry, Microbiology and Immunology, Faculty of Medicine, University of Ottawa, Ottawa, Ontario, Canada
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Miheller P, Lakatos PL. Thiopurines in Crohn's disease, is there something new? Expert Opin Drug Metab Toxicol 2010; 6:1505-14. [PMID: 20919963 DOI: 10.1517/17425255.2010.525505] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
IMPORTANCE OF THE FIELD traditional immunosuppressants, including azathioprine, remain the mainstay of therapy in steroid dependent/refractory patients with inflammatory bowel diseases (IBD). The main limitations of its use are its side effects appearing in about a fifth of the patients, including myelosuppression and liver toxicity. Major complications occur in patients with low thiopurine-S-methyltransferase (TPMT) enzyme activity; however, the clinical relevance of these tests remains conflictive. AREAS COVERED IN THIS REVIEW in this review, the authors aim to summarize the new data regarding the relationship between the pharmacology of thiopurines and pathogenesis of adverse events. WHAT THE READER WILL GAIN readers will gain an understanding of the metabolism of thiopurines, side effect profile, pharmacological background of side effects, importance of metabolite monitoring, clinical relevance of inherited differences in drug metabolism and other conditions (e.g., concomitant use of allopurinol) which can modify enzyme activity. By gaining an understanding of the pharmacology and metabolism of thiopurines, clinicians will be able to optimize thiopurine therapy in IBD. TAKE HOME MESSAGE TPMT testing and metabolite monitoring are still not considered the standard of care, and clinicians will continue to choose the approach that best suits their clinical practice and patient needs. Regardless of what strategy is chosen, patients need to be carefully monitored and well informed about the potential risks.
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Affiliation(s)
- Pal Miheller
- Semmelweis University, 2nd Department of Medicine, Budapest, Koranyi, Hungary
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The multidrug-resistance protein 4 polymorphism is a new factor accounting for thiopurine sensitivity in Japanese patients with inflammatory bowel disease. J Gastroenterol 2010; 45:1014-21. [PMID: 20393862 DOI: 10.1007/s00535-010-0248-y] [Citation(s) in RCA: 84] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/27/2010] [Accepted: 03/29/2010] [Indexed: 02/04/2023]
Abstract
BACKGROUND Multidrug resistance protein 4 (MRP4) functions as an efflux pump of nucleoside monophosphate analogs, such as 6-mercaptopurine (6-MP) and 6-thioguanine nucleotide (6-TGN). A single-nucleotide polymorphism in human MRP4 (rs3765534) dramatically reduces MRP4 function and results in the intracellular accumulation of 6-TGN. In this study, we investigated the association between MRP4 G2269A polymorphism and thiopurine sensitivity in Japanese IBD patients. METHODS Direct sequencing of the MRP4 exon 18 was performed. The TPMT A719G and ITPase C94A polymorphisms were determined by polymerase-chain reaction-restriction fragment length polymorphism analyses. RESULTS Of the 279 samples analyzed (44 healthy volunteers and 235 IBD patients), 68 samples showed a heterozygote of MRP4 G2269A and 7 carried a homozygote. The allelic frequency of MRP4 G2269A was 14.7%. In 130 IBD patients treated with azathioprine/6-MP, the white blood cell count was significantly lower in patients with theMRP4 variant alone (n = 26) than in patients with a wild allelotype (n = 74) (P = 0.014) or in patients with the ITPase variant alone (n = 22) (P = 0.0095). The 6-TGN levels were significantly higher in patients with the MRP4 variant alone than in patients with the wild allelotype(P = 0.049). Of the 15 patients who experienced leucopenia (<3 x 10⁹/l), 7 patients carried the MRP4 variant.The odds ratio of carrying the MRP4 variant alone and having leukopenia was 3.30 (95% confidence interval 1.03–10.57, P = 0.036). CONCLUSIONS These results suggest that MRP4 G2269A might be a new factor accounting for thiopurine sensitivity in Japanese patients with IBD.
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Feng J, Sun J, Wang MZ, Zhang Z, Kim ST, Zhu Y, Sun J, Xu J. Compilation of a comprehensive gene panel for systematic assessment of genes that govern an individual’s drug responses. Pharmacogenomics 2010; 11:1403-25. [DOI: 10.2217/pgs.10.99] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Aims: Polymorphisms of genes involved in the pharmacokinetic and pharmacodynamic processes underlie the divergent drug responses among individuals. Despite some successes in identifying these polymorphisms, the candidate gene approach suffers from insufficient gene coverage whereas the genome-wide association approach is limited by less than ideal coverage of SNPs in some important genes. To expand the potential of the candidate approach, we aim to delineate a comprehensive network of drug-response genes for in-depth genetic studies. Materials & methods: Pharmacologically important genes were extracted from various sources including literatures and web resources. These genes, along with their homologs and regulatory miRNAs, were organized based on their pharmacological functions and weighted by literature evidence and confidence levels. Their coverage was evaluated by analyzing three commercial SNP chips commonly used for genome-wide association studies: Affymetrix SNP array 6.0, Illumina HumanHap1M and Illumina Omni. Results: A panel of drug-response genes was constructed, which contains 923 pharmacokinetic genes, 703 pharmacodynamic genes and 720 miRNAs. There are only 16.7% of these genes whose all known SNPs can be directly or indirectly (r2 > 0.8) captured by the SNP chips with coverage of more than 80%. This is possibly because these SNPs chips have notably poor performance over rare SNPs and miRNA genes. Conclusion: We have compiled a panel of candidate genes that may be pharmacologically important. Using this knowledgebase, we are able to systematically evaluate genes and their variants that govern an individual’s response to a given pharmaceutical therapy. This approach can serve as a necessary complement to genome-wide associations.
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Affiliation(s)
- Junjie Feng
- Center for Cancer Genomics, Wake Forest University School of Medicine, Winston-Salem, NC, USA
| | - Jielin Sun
- Center for Cancer Genomics, Wake Forest University School of Medicine, Winston-Salem, NC, USA
| | - Michael Zhuo Wang
- Division of Pharmacotherapy & Experimental Therapeutics, Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, NC, USA
| | - Zheng Zhang
- Center for Cancer Genomics, Wake Forest University School of Medicine, Winston-Salem, NC, USA
| | - Seong-Tae Kim
- Center for Cancer Genomics, Wake Forest University School of Medicine, Winston-Salem, NC, USA
| | - Yi Zhu
- Center for Cancer Genomics, Wake Forest University School of Medicine, Winston-Salem, NC, USA
| | - Jishan Sun
- Center for Cancer Genomics, Wake Forest University School of Medicine, Winston-Salem, NC, USA
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Kuriyama M, Kato J, Suzuki H, Akita M, Hiraoka S, Okada H, Yamamoto K. Tolerability and usefulness of mercaptopurine in azathioprine-intolerant Japanese patients with ulcerative colitis. Dig Endosc 2010; 22:289-96. [PMID: 21175481 DOI: 10.1111/j.1443-1661.2010.01009.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
BACKGROUND AND AIM Azathioprine (AZA) and mercaptopurine (6-MP) are established as effective therapeutic drugs for the induction and maintenance of remission in patients with ulcerative colitis (UC). However, AZA is often intolerable due to adverse effects. Evidence regarding the approach of switching from AZA to 6-MP in patients of Asian ethnicity is lacking. We assessed the tolerability and usefulness of 6-MP in Japanese UC patients who had shown intolerance to AZA. METHODS One-hundred and ten UC patients who had been treated with AZA and/or 6-MP from January 1985 to October 2008 were examined retrospectively. RESULTS Among 110 patients, 107 were treated first with AZA; only three were treated first with 6-MP. Thirty-five (33%) of the 107 patients were intolerant of AZA, with adverse effects including myelosuppression (8/35, 23%), hepatotoxicity (8/35, 23%), and abdominal symptoms (6/35, 17%). Among 35 AZA-intolerant patients, 23 were switched to 6-MP treatment. The cumulative probability of colectomy was significantly higher in patients not treated with 6-MP than in patients treated with 6-MP (log-rank test, P =0.0002). Among the 26 patients (23 AZA-intolerant and three AZA-untreated) treated with 6-MP, 22 (85%) could tolerate the therapy. Adverse effects due to 6-MP were abdominal symptoms (2/4), myelosuppression (1/4), and rash (1/4). The median initial dose of 6-MP was 20 mg/day, and the median final dose was 30 mg/day. CONCLUSIONS 6-MP was tolerated in 83% of AZA-intolerant patients, and it was effective for maintenance therapy of UC patients. 6-MP treatment should be considered in AZA-intolerant patients.
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Affiliation(s)
- Motoaki Kuriyama
- Department of Gastroenterology and Hepatology, Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, Okayama, Japan
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Abstract
Pharmacokinetic drug monitoring has been used for many years to relate immunosuppressant dose to drug exposure in vivo. However, this conventional therapeutic drug monitoring of blood immunosuppressant levels may not necessarily predict the pharmacologic effects on immune cells. The direct determination of target enzyme activity (eg, calcineurin activity, inosine-5'-monophospahte dehydrogenase [IMPDH] activity, p70S6 kinase) may help to better assess the individual response to the immunosuppressant. However, its use is limited by the difficulties of the assay systems, which did not allow yet the prospective assessment of these enzymes in larger patient cohorts with the establishment of validated pharmacodynamic drug monitoring. The most progress regarding a robust and reproducible test system has been achieved with the determination of IMPDH activity as a specific pharmacodynamic parameter of mycophenolic acid activity. This recently validated and standardized assay allows the investigation of IMPDH activity in larger clinical studies. Although the determination of target enzyme activity, eg, by the determination of IMPDH activity, holds promise for a more individualized therapy in transplant medicine, more studies are needed to prospectively validate this approach.
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Almer S. Novel strategies in the thiopurine treatment of inflammatory bowel disease. NUCLEOSIDES NUCLEOTIDES & NUCLEIC ACIDS 2010; 29:267-77. [PMID: 20544506 DOI: 10.1080/15257771003729559] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Thiopurine drugs are widely used as immunomodulatory and corticosteroid-sparing agents in inflammatory bowel disease. Despite being old drugs, a renewed research and clinical interest in their application has emerged during the last decade. The application of pharmacogenetic insights and metabolic monitoring, together with treatment strategies in combination with anti-TNFalpha-antibodies and possibilities to modulate their metabolism, has paved the way to a "modern" use of the thiopurines. These aspects are briefly overviewed herein.
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Affiliation(s)
- S Almer
- Division of Gastroenterology and Hepatology, IKE, Linköping University, Linköping, Sweden.
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Smith MA, Marinaki AM, Sanderson JD. Pharmacogenomics in the treatment of inflammatory bowel disease. Pharmacogenomics 2010; 11:421-37. [PMID: 20235796 DOI: 10.2217/pgs.10.4] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
In recent years, the benefits of early aggressive treatment paradigms for inflammatory bowel disease have emerged. Symptomatic improvement is no longer considered adequate; instead, the aim of treatment has become mucosal healing and altered natural history. Nonetheless, we still fail to achieve these end points in a large number of our patients. There are many reasons why patients fail to respond or develop toxicity when exposed to drugs used for inflammatory bowel disease, but genetic variation is likely to account for a significant proportion of this. Some examples, notably thiopurine methyltransferase polymorphism in thiopurine treatment, are already established in clinical practice. We present a review of the expanding literature in this field, highlighting many interesting developments in pharmacogenomics applied to inflammatory bowel disease and, where possible, providing guidance on the translation of these developments into clinical practice.
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Affiliation(s)
- Melissa A Smith
- Department of Gastroenterology, 1st Floor, College House, St Thomas' Hospital, Lambeth Palace Road, London, SE1 7EH, UK
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41
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Monitoring of Thiopurine Metabolites in Patients With Inflammatory Bowel Disease-What Is Actually Measured? Ther Drug Monit 2009; 31:345-50. [DOI: 10.1097/ftd.0b013e3181a1ea58] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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42
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Kudo M, Saito Y, Sasaki T, Akasaki H, Yamaguchi Y, Uehara M, Fujikawa K, Ishikawa M, Hirasawa N, Hiratsuka M. Genetic variations in the HGPRT, ITPA, IMPDH1, IMPDH2, and GMPS genes in Japanese individuals. Drug Metab Pharmacokinet 2009; 24:557-64. [PMID: 20045992 DOI: 10.2133/dmpk.24.557] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Thiopurines (such as azathioprine and 6-mercaptopurine) are widely used for the treatment of patients suffering from malignancies, rheumatic disease, inflammatory bowel disease and solid organ transplant rejection. These drugs are activated and eliminated by a number of enzymes in the human body. This analyzes all the exons and exon-intron junctions of 5 enzyme genes (hypoxanthine-guanine phosphoribosyltransferase, HGPRT; inosine triphosphate pyrophosphatase, ITPA; inosine monophosphate dehydrogenases 1 and 2, IMPDH1 and IMPDH2 and guanosine monophosphate synthetase, GMPS) involved in the metabolism of thiopurine drugs. Twelve novel single nucleotide polymorphisms (SNPs) (HGPRT: IVS6-12C>A (frequency:0.003); ITPA: 569T>C (Phe189Phe, 0.003); IMPDH1: IVS8-15C>A (0.003), IVS9+227A>G (0.003), IVS17+115C>T (0.003), and 930C>T (Thr310Thr, 0.005); IMPDH2: IVS1+50G>T (0.003), IVS2+15G>A (0.010), IVS3-20G>A (0.003), 609C>T (Arg203Arg, 0.003), and 1534C>T (Arg512Trp, 0.003); and GMPS: 1563T>C (Gly521Gly, 0.003)) and 7 known SNPs (ITPA: 94C>A (Pro32Thr, 0.005), 138G>A (Gln46Gln, 0.586), and 563G>A (Glu187Glu, 0.433); IMPDH1: 987G>C (Leu329Leu, 0.113) and 1575A>G (Ala525Ala, 0.620) and GMPS: IVS5-7T>C (0.153), 993A>G (Thr331Thr, 0.153)) were identified in 200 Japanese subjects. These data should provide useful information for thiopurine therapy in the Japanese and as well as other Asian populations.
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Affiliation(s)
- Mutsumi Kudo
- Department of Clinical Pharmaceutics, Tohoku Pharmaceutical University, Sendai, Miyagi 980-8578, Japan
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Peyrin-Biroulet L, Cadranel JF, Nousbaum JB, Oussalah A, Seddik M, Canva V, Cortot A, Sogni P, Gueant JL, Bigard MA, Roblin X, Bronowicki JP. Interaction of ribavirin with azathioprine metabolism potentially induces myelosuppression. Aliment Pharmacol Ther 2008; 28:984-93. [PMID: 18657132 DOI: 10.1111/j.1365-2036.2008.03812.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
BACKGROUND The interaction of ribavirin, an inosine monophosphate dehydrogenase inhibitor, with azathioprine metabolism, potentially leading to myelotoxicity, remains unexplored. AIM To underline the interaction of ribavirin, an inosine monophosphate dehydrogenase inhibitor, with azathioprine metabolism, potentially leading to myelotoxicity. METHODS The medical records of eight patients who developed severe pancytopenia following concomitant use of azathioprine and ribavirin were retrospectively reviewed. RESULTS Bone marrow suppression reached nadir after a mean interval of 4.6 +/- 1.6 weeks following HCV therapy initiation in seven patients. At the time of pancytopenia, the mean platelet count was 69.75 +/- 82.8 x 10(-3)/mm(3), mean haemoglobin level 7.75 +/- 1.3 g/dL and mean neutrophil count 0.45 +/- 0.26 x 10(-3)/mm(3). All patients had normal thiopurine methyltransferase genotype. In two patients, a prospective monitoring of azathioprine metabolites was available. Myelotoxicity was accompanied by elevated total methylated metabolite levels (16,500 and 15,000 pmol/8 x 10(8) erythrocytes) with a concomitant decrease in 6-tioguanine nucleotide levels; 1 month after azathioprine, pegylated interferon alfa and ribavirin were discontinued and full blood count returned to normal in both patients. No haematological toxicity occurred after the reintroduction of peginterferon plus ribarivin or azathioprine alone in eight patients. CONCLUSION Collectively, the benefit/risk ratio favours avoidance of inosine monophosphate dehydrogenase inhibitors in purine analogue-treated patients with normal thiopurine methyltransferase activity, a situation frequently encountered in clinical practice.
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Affiliation(s)
- L Peyrin-Biroulet
- INSERM, U724, and Department of Hepato-Gastroenterology, University Hospital of Nancy, Vandoeuvre-les-Nancy, France
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Andoh A, Tsujikawa T, Ban H, Hashimoto T, Bamba S, Ogawa A, Sasaki M, Saito Y, Fujiyama Y. Monitoring 6-thioguanine nucleotide concentrations in Japanese patients with inflammatory bowel disease. J Gastroenterol Hepatol 2008; 23:1373-7. [PMID: 18662197 DOI: 10.1111/j.1440-1746.2008.05419.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
BACKGROUND AND AIM There have been no reports on 6-thioguanine nucleotide (6-TGN) concentrations in Japanese patients with inflammatory bowel disease (IBD) undergoing azathioprine (AZA) or 6-mercaptopurine (6-MP) therapy. The aim of this study was to assess 6-TGN concentrations in Japanese IBD patients. METHODS Eighty-three patients with Crohn's disease (n = 42) and ulcerative colitis (n = 41) were enrolled. In 69 patients, AZA was prescribed at 50 mg/day, and seven patients were given 75 (n = 5) or 100 mg/day (n = 2). 6-MP was administered at 30 mg/day (n = 7). The 6-TGN concentrations were then assayed by high-performance liquid chromatography. RESULTS The mean 6-TGN concentrations of the entire study population (n = 83) were 277.9 +/- 179.8 pmol/8 x 10(8) red blood cells (RBC). The mean 6-TGN concentrations in those patients with active disease (n = 38) and those in remission (n = 45) were 232.9 +/- 159.7(mean +/- SD) and 342.8 +/- 184.6 pmol/8 x 10(8) RBC, respectively (P < 0.05). The odds ratio of being in remission and having a 6-TGN value >235 pmol/8 x 10(8) RBC was 2.6 (95% CI 1.05-6.2). A significant inverse correlation was found between the white blood cell (WBC) counts and 6-TGN concentrations (r = -0.301, P < 0.05, n = 83); the mean WBC counts of the active patients (6780 +/- 2412) were significantly higher than the patients in clinical remission (5468 +/- 1920, P < 0.05). Three patients with severe leukopenia and 10 patients with high 6-TGN concentrations had no thiopurine S-methyl transferase mutations. CONCLUSION The 6-TGN concentrations in Japanese patients with IBD on low-dose AZA and 6-MP therapy were comparable to those reported from Western countries. The monitoring of 6-TGN concentrations may be helpful for developing a therapeutic strategy for Japanese IBD patients.
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Affiliation(s)
- Akira Andoh
- Department of Medicine, Shiga University of Medical Science, Seta Tukinowa, Japan.
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Roberts RL, Gearry RB, Kennedy MA, Barclay ML. Beyond TPMT: genetic influences on thiopurine drug responses in inflammatory bowel disease. Per Med 2008; 5:233-248. [PMID: 29783500 DOI: 10.2217/17410541.5.3.233] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Azathioprine and 6-mercaptopurine are widely used in the management of inflammatory bowel disease (IBD). However, approximately 25% of IBD patients experience toxicity, and up to 10% show resistance to these thiopurine drugs. The importance of genetic variability in determining thiopurine toxicity was first recognized over 25 years ago with the discovery of the thiopurine S-methyltransferase (TPMT) polymorphism and the occurrence of azathioprine-induced myelosuppression in TPMT-deficient patients. In the intervening period, TPMT has become the foremost example of pharmacogenetics, and TPMT deficiency represents one of the few pharmacogenetic phenomena that have successfully made the transition from the research laboratory to diagnostics. While TPMT activity predicts some cases of myelosuppression, deficiency in this enzyme is neither predictive of other adverse drug reactions, nor resistance to thiopurine therapy. As myelosuppression only accounts for approximately 2.5% of adverse reactions in IBD patients, researchers are increasingly turning their attention to other enzymes involved in thiopurine metabolism to find molecular explanations for intolerance and resistance to azathioprine and 6-mercaptopurine. In this review, we summarize the current state of knowledge with regards to TPMT, and also explore genetic variability, beyond TPMT, that may contribute to thiopurine response in IBD patients.
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Affiliation(s)
| | - Richard B Gearry
- Department of Medicine, University of Otago, Christchurch 8140, New Zealand.,Department of Gastroenterology, Christchurch Hospital, Private Bag 151, Christchurch 8140, New Zealand
| | - Martin A Kennedy
- Department of Pathology, University of Otago, Christchurch 8140, New Zealand
| | - Murray L Barclay
- Department of Medicine, University of Otago, Christchurch 8140, New Zealand.,Department of Gastroenterology, Christchurch Hospital, Private Bag 151, Christchurch 8140, New Zealand
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