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Fehily SR, Al-Ani AH, Abdelmalak J, Rentch C, Zhang E, Denholm JT, Johnson D, Ng SC, Sharma V, Rubin DT, Gibson PR, Christensen B. Review article: latent tuberculosis in patients with inflammatory bowel diseases receiving immunosuppression-risks, screening, diagnosis and management. Aliment Pharmacol Ther 2022; 56:6-27. [PMID: 35596242 PMCID: PMC9325436 DOI: 10.1111/apt.16952] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/28/2021] [Revised: 04/14/2022] [Accepted: 04/18/2022] [Indexed: 12/15/2022]
Abstract
BACKGROUND One quarter of the world's population has latent tuberculosis infection (LTBI). Systemic immunosuppression is a risk factor for LTBI reactivation and the development of active tuberculosis. Such reactivation carries a risk of significant morbidity and mortality. Despite the increasing global incidence of inflammatory bowel disease (IBD) and the use of immune-based therapies, current guidelines on the testing and treatment of LTBI in patients with IBD are haphazard with a paucity of evidence. AIM To review the screening, diagnostic practices and medical management of LTBI in patients with IBD. METHODS Published literature was reviewed, and recommendations for testing and treatment were synthesised by experts in both infectious diseases and IBD. RESULTS Screening for LTBI should be performed proactively and includes assessment of risk factors, an interferon-gamma releasing assay or tuberculin skin test and chest X-ray. LTBI treatment in patients with IBD is scenario-dependent, related to geographical endemicity, travel and other factors. Ideally, LTBI therapy should be used prior to immune suppression but can be applied concurrently where urgent IBD medical treatment is required. Management is best directed by a multidisciplinary team involving gastroenterologists, infectious diseases specialists and pharmacists. Ongoing surveillance is recommended during therapy. Newer LTBI therapies show promise, but medication interactions need to be considered. There are major gaps in evidence, particularly with specific newer therapeutic approaches to IBD. CONCLUSIONS Proactive screening for LTBI is essential in patients with IBD undergoing immune-suppressing therapy and several therapeutic strategies are available. Reporting of real-world experience is essential to refining current management recommendations.
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Affiliation(s)
- Sasha R Fehily
- Gastroenterology Department, St Vincent's Hospital, Melbourne, Victoria, Australia.,Department of Medicine, University of Melbourne, Parkville, Victoria, Australia
| | - Aysha H Al-Ani
- Department of Medicine, University of Melbourne, Parkville, Victoria, Australia.,Gastroenterology Department, Royal Melbourne Hospital, Parkville, Victoria, Australia
| | - Jonathan Abdelmalak
- Gastroenterology Department, Alfred Hospital, Melbourne, Victoria, Australia
| | - Clarissa Rentch
- Gastroenterology Department, Royal Melbourne Hospital, Parkville, Victoria, Australia
| | - Eva Zhang
- Gastroenterology Department, Royal Melbourne Hospital, Parkville, Victoria, Australia
| | - Justin T Denholm
- Department of Medicine, University of Melbourne, Parkville, Victoria, Australia.,Infectious Diseases Department, Royal Melbourne Hospital, Parkville, Victoria, Australia.,Victorian Tuberculosis Program, Melbourne, Victoria, Australia.,Department of Infectious Diseases, Doherty Institute, Parkville, Victoria, Australia
| | - Douglas Johnson
- Department of Medicine, University of Melbourne, Parkville, Victoria, Australia.,Infectious Diseases Department, Royal Melbourne Hospital, Parkville, Victoria, Australia
| | - Siew C Ng
- Department of Medicine and Therapeutics, Institute of Digestive Disease, The Chinese University of Hong Kong, Hong Kong SAR, China
| | - Vishal Sharma
- Department of Gastroenterology, Postgraduate Institute of Medical Education and Research, Chandigarh, India
| | - David T Rubin
- University of Chicago Medicine Inflammatory Bowel Disease Center, University of Chicago Medicine, Chicago, Illinois, USA
| | - Peter R Gibson
- Department of Gastroenterology, Monash University and Alfred Health, Melbourne, Victoria, Australia
| | - Britt Christensen
- Department of Medicine, University of Melbourne, Parkville, Victoria, Australia.,Gastroenterology Department, Royal Melbourne Hospital, Parkville, Victoria, Australia
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Leeder JS. Ontogeny of Pediatric Pharmacogenetics: Celebrating the Past and Vision for the Future. J Pediatr Pharmacol Ther 2022; 27:4-11. [PMID: 35002553 DOI: 10.5863/1551-6776-27.1.4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2021] [Indexed: 11/11/2022]
Affiliation(s)
- J Steven Leeder
- Children's Mercy Research Institute, Children's Mercy Kansas City, Kansas City, MO
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3
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Khaeso K, Komvilaisak P, Chainansamit SO, Nakkam N, Suwannaying K, Kuwatjanakul P, Hikino K, Dornsena A, Kanjanawart S, Laoaroon N, Vannaprasaht S, Taketani T, Tassaneeyakul W. NUDT15 is a key genetic factor for prediction of hematotoxicity in pediatric patients who received a standard low dosage regimen of 6-mercaptopurine. Drug Metab Pharmacokinet 2021; 43:100436. [PMID: 35016134 DOI: 10.1016/j.dmpk.2021.100436] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2021] [Revised: 11/21/2021] [Accepted: 11/25/2021] [Indexed: 12/25/2022]
Abstract
6-Mercaptopurine (6-MP) is commonly used for treatment of acute lymphoblastic leukemia (ALL). The incidence of hematotoxicity caused by this drug is quite high in Asians even using a standard low dosage regimen. The present study was aimed to elucidate the impact of thiopurine S-methyltransferase (TPMT), a nucleoside diphosphate-linked moiety X-type motif 15 (NUDT15), inosine triphosphatase (ITPA) and ATP Binding Cassette Subfamily C Member 4 (ABCC4) polymorphisms on hematotoxicity in pediatric patients who received a standard low starting dose of 6-MP. One hundred and sixty-nine pediatric patients were enrolled and their genotypes were determined. Patients who carried NUDT15∗3 and NUDT15∗2 genotypes were at a 10-15 fold higher risk of severe neutropenia than those of the wild-type during the early months of the maintenance phase. Risk of neutropenia was not significantly increased in patients with other NUDT15 variants as well as in patients with TPMT, ITPA or ABCC4 variants. These results suggest that NUDT15 polymorphisms particularly, NUDT15∗3 and NUDT15∗2, play major roles in 6-MP-induced severe hematotoxicity even when using a standard low dosage of 6-MP and genotyping of these variants is necessary in order to obtain precise tolerance doses and avoid severe hematotoxicity in pediatric patients.
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Affiliation(s)
- Kanyarat Khaeso
- Department of Pharmacology, Faculty of Medicine, Khon Kaen University, Thailand
| | | | | | - Nontaya Nakkam
- Department of Pharmacology, Faculty of Medicine, Khon Kaen University, Thailand
| | - Kunanya Suwannaying
- Department of Pediatrics, Faculty of Medicine, Khon Kaen University, Thailand
| | | | - Keiko Hikino
- Laboratory for Pharmacogenomics, RIKEN Center for Integrative Medical Sciences, Yokohama City, Kanagawa, Japan
| | - Areerat Dornsena
- Department of Pharmacology, Faculty of Medicine, Khon Kaen University, Thailand
| | - Sirimas Kanjanawart
- Department of Pharmacology, Faculty of Medicine, Khon Kaen University, Thailand
| | - Napat Laoaroon
- Department of Pediatrics, Faculty of Medicine, Khon Kaen University, Thailand
| | - Suda Vannaprasaht
- Department of Pharmacology, Faculty of Medicine, Khon Kaen University, Thailand
| | - Takeshi Taketani
- Department of Pediatrics, Faculty of Medicine, Shimane University, Izumo, Japan
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4
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Geck RC, Boyle G, Amorosi CJ, Fowler DM, Dunham MJ. Measuring Pharmacogene Variant Function at Scale Using Multiplexed Assays. Annu Rev Pharmacol Toxicol 2021; 62:531-550. [PMID: 34516287 DOI: 10.1146/annurev-pharmtox-032221-085807] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
As costs of next-generation sequencing decrease, identification of genetic variants has far outpaced our ability to understand their functional consequences. This lack of understanding is a central challenge to a key promise of pharmacogenomics: using genetic information to guide drug selection and dosing. Recently developed multiplexed assays of variant effect enable experimental measurement of the function of thousands of variants simultaneously. Here, we describe multiplexed assays that have been performed on nearly 25,000 variants in eight key pharmacogenes (ADRB2, CYP2C9, CYP2C19, NUDT15, SLCO1B1, TMPT, VKORC1, and the LDLR promoter), discuss advances in experimental design, and explore key challenges that must be overcome to maximize the utility of multiplexed functional data. Expected final online publication date for the Annual Review of Pharmacology and Toxicology, Volume 62 is January 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.
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Affiliation(s)
- Renee C Geck
- Department of Genome Sciences, University of Washington, Seattle, Washington 98195, USA; ,
| | - Gabriel Boyle
- Department of Genome Sciences, University of Washington, Seattle, Washington 98195, USA; ,
| | - Clara J Amorosi
- Department of Genome Sciences, University of Washington, Seattle, Washington 98195, USA; ,
| | - Douglas M Fowler
- Department of Genome Sciences, University of Washington, Seattle, Washington 98195, USA; , .,Department of Bioengineering, University of Washington, Seattle, Washington 98195, USA
| | - Maitreya J Dunham
- Department of Genome Sciences, University of Washington, Seattle, Washington 98195, USA; ,
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5
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Kamojjala R, Bostrom B. Allopurinol to Prevent Mercaptopurine Adverse Effects in Children and Young Adults With Acute Lymphoblastic Leukemia. J Pediatr Hematol Oncol 2021; 43:95-100. [PMID: 33750748 DOI: 10.1097/mph.0000000000002117] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/01/2020] [Accepted: 01/19/2021] [Indexed: 11/25/2022]
Abstract
Mercaptopurine (6MP) is used to treat acute lymphoblastic leukemia (ALL) and is metabolized by hypoxanthine guanine phosphoribosal transferase to form 6-thioguanine nucleotide (6TGN). It is also metabolized by thiopurine methyl-transferase to produce 6-methylmercaptopurine (6MMP). Elevated levels of 6MMP have been associated with toxic effects that may interfere with therapy. Allopurinol is known to inhibit thiopurine methyl-transferase which reduces red cell 6MMP and increases 6TGN. Allopurinol has been utilized successfully in adult and pediatric patients with inflammatory bowel disease who have experienced 6MMP related gastrointestinal toxicity. Between August 2015 and August 2018 we started 25 patients with ALL in maintenance on allopurinol in combination with a reduced dose of 6MP. They all had unacceptable side-effects from elevated 6MMP, including abdominal pain, nausea, vomiting, decreased appetite, hypoglycemia, fatigue, and liver toxicity. In addition many had a facial rash. All patients showed resolution of symptoms within a few weeks after starting allopurinol. The red cell levels of 6MMP rapidly declined in the first month. The red cell levels of 6TGN transiently increased in spite of the lower 6MP dose. There was no decrease in absolute neutrophil count or hemoglobin. Platelets decreased slightly not requiring therapy modification. Elevated bilirubin normalized, and alanine aminotransferase decreased significantly with most normalizing. All patients continued on allopurinol with reduced dose 6MP until completing therapy. Allopurinol, in conjunction with a reduced dose of 6MP, effectively resolves 6MMP related side-effects in ALL patients on maintenance chemotherapy. This approach may lead to increased adherence to oral 6MP during ALL maintenance in patients with 6MMP induced side-effects.
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Moyer AM. NUDT15: A bench to bedside success story. Clin Biochem 2021; 92:1-8. [PMID: 33675810 DOI: 10.1016/j.clinbiochem.2021.02.007] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2021] [Revised: 02/10/2021] [Accepted: 02/14/2021] [Indexed: 12/13/2022]
Abstract
Recently, the enzyme nudix hydrolase 15 (NUDT15) has been identified as an additional component of the thiopurine metabolism pathway. NUDT15 (also known as MTH2) catalyzes the dephosphorylation of 6-thioguanosine triphosphate (6-TGTP) and 6-thio-deoxyguanosine triphosphate (6-TdGTP), which is the active metabolite of thiopurine medications. Thiopurine compounds, which were first synthesized in the 1950s, are widely used in the treatment of childhood leukemia, inflammatory bowel disease, and autoimmune disorders. For many years, TPMT has been recognized as an enzyme that is involved in thiopurine metabolism, and interindividual variation in TPMT activity has been known to contribute to differences in risk of thiopurine toxicity. Genetic variation that leads to decreased NUDT15 activity has been recognized as an additional contributor, beyond TPMT, to thiopurine toxicity. In some populations, including Asian and Latino populations, NUDT15 genetic variants are more common than TPMT variants, making this a significant biomarker of toxicity. Clinical genetic testing is now available for a subset of NUDT15 variants, representing a remarkably fast translation from bench to bedside. This review will focus on NUDT15 - from discovery to clinical implementation.
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Affiliation(s)
- Ann M Moyer
- Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN 55905, United States.
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7
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Optimization of azathioprine dose in combined treatment with anti-TNF-alpha in inflammatory bowel disease. GASTROENTEROLOGIA Y HEPATOLOGIA 2020; 44:337-345. [PMID: 33272733 DOI: 10.1016/j.gastrohep.2020.10.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Revised: 09/28/2020] [Accepted: 10/01/2020] [Indexed: 11/22/2022]
Abstract
INTRODUCTION The dose of thiopurine drugs in combined treatments with anti-TNF in inflammatory bowel disease (IBD) has not been clearly established. The purpose of this study is to assess whether the dose of azathioprine influences clinical and biochemical response/remission rates, and anti-TNF drug levels/antibody formation. MATERIAL AND METHODS Patients with IBD on combined maintenance treatment with azathioprine and infliximab or adalimumab were selected. Based on the dose of azathioprine, two groups were defined (standard: 2-2.5mg/kg/day; and decreased: less than 2mg/kg/day). RESULTS In the IFX group, there were no statistically significant differences (p=0.204) in the rates of remission (39% vs 41.3%), response (10% vs 21.7%) or failure (51.5% vs 37%) depending on the dose of thiopurine drugs. No differences were found between AZA-dose dependent IFX levels (2.46 vs 3.21μg/mL; p=0.211). In the adalimumab group, there were no statistically significant differences (p=0.83) in the rates of remission (66% vs 56%), response without remission (15.38% vs 25%) or failure (18% vs 18%) depending on the dose of thiopurines. With respect to ADA-levels, no differences were found in both groups (7.69 vs 8.23μg/mL; p=0.37). CONCLUSION In our experience, no statistically significant differences were found in either anti-TNF levels or clinical-biological response/remission rates based on doses of azathioprine.
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Zimdahl Kahlin A, Helander S, Wennerstrand P, Vikingsson S, Mårtensson LG, Appell ML. Pharmacogenetic studies of thiopurine methyltransferase genotype-phenotype concordance and effect of methotrexate on thiopurine metabolism. Basic Clin Pharmacol Toxicol 2020; 128:52-65. [PMID: 32865889 PMCID: PMC7821157 DOI: 10.1111/bcpt.13483] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Revised: 08/14/2020] [Accepted: 08/21/2020] [Indexed: 12/30/2022]
Abstract
The discovery and implementation of thiopurine methyltransferase (TPMT) pharmacogenetics has been a success story and has reduced the suffering from serious adverse reactions during thiopurine treatment of childhood leukaemia and inflammatory bowel disease. This MiniReview summarizes four studies included in Dr Zimdahl Kahlin's doctoral thesis as well as the current knowledge on this field of research. The genotype‐phenotype concordance of TPMT in a cohort of 12 663 individuals with clinically analysed TPMT status is described. Notwithstanding the high concordance, the benefits of combined genotyping and phenotyping for TPMT status determination are discussed. The results from the large cohort also demonstrate that the factors of gender and age affect TPMT enzyme activity. In addition, characterization of four previously undescribed TPMT alleles (TPMT*41, TPMT*42, TPMT*43 and TPMT*44) shows that a defective TPMT enzyme could be caused by several different mechanisms. Moreover, the folate analogue methotrexate (MTX), used in combination with thiopurines during maintenance therapy of childhood leukaemia, affects the metabolism of thiopurines and interacts with TPMT, not only by binding and inhibiting the enzyme activity but also by regulation of its gene expression.
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Affiliation(s)
- Anna Zimdahl Kahlin
- Division of Drug Research, Department of Biomedical and Clinical Sciences, Linköping University, Linköping, Sweden
| | - Sara Helander
- Division of Drug Research, Department of Biomedical and Clinical Sciences, Linköping University, Linköping, Sweden
| | - Patricia Wennerstrand
- Division of Chemistry, Department of Physics, Chemistry, and Biology, Linköping University, Linköping, Sweden
| | - Svante Vikingsson
- Division of Drug Research, Department of Biomedical and Clinical Sciences, Linköping University, Linköping, Sweden
| | - Lars-Göran Mårtensson
- Division of Chemistry, Department of Physics, Chemistry, and Biology, Linköping University, Linköping, Sweden
| | - Malin Lindqvist Appell
- Division of Drug Research, Department of Biomedical and Clinical Sciences, Linköping University, Linköping, Sweden
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9
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Jonason DE, Sievers T, Trocke L, Abraham JM, Vaughn BP. Normal Ranges of Thiopurine Methyltransferase Activity Do Not Affect Thioguanine Nucleotide Concentrations With Azathioprine Therapy in Inflammatory Bowel Disease. CROHN'S & COLITIS 360 2020; 2:otaa058. [PMID: 36776499 PMCID: PMC9802184 DOI: 10.1093/crocol/otaa058] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/22/2020] [Indexed: 11/14/2022] Open
Abstract
Background Thiopurine methyltransferase (TPMT) activity influences azathioprine conversion into active metabolite 6-thioguanine nucleotide (6-TGN). Low TPMT activity correlates with high 6-TGN and risk for myelosuppression. Conversely, normal-to-high TPMT activity may be associated with low 6-TGN and drug resistance, the so-called hypermetabolizers. Our aim was to identify the effect of normal-to-high TPMT activity on 6-TGN concentrations in an inflammatory bowel disease population. Methods A retrospective chart review of patients aged ≥18 with inflammatory bowel disease, on azathioprine, with documented TPMT activity and 6-TGN concentration was performed. Correlations were evaluated via the Spearman rho correlation coefficient. Linear regression was used to determine the effect of TPMT activity on 6-TGN accounting for confounders. Relationships between TPMT activity, drug dose, and 6-TGN levels were defined via average causal mediation effects. Results One hundred patients were included. No correlation was observed between TPMT activity, azathioprine dosing, and metabolite concentrations. Overall, 39% of the cohort had a therapeutic 6-TGN level of >230 pmol/8 × 108 red blood cells (RBCs). No patient under 1 mg/kg achieved a therapeutic 6-TGN level, whereas 42% of patients taking 2.5 mg/kg did. The median 6-TGN concentration was higher for those in remission (254 pmol/8 × 108 RBCs, interquartile range: 174, 309) versus those not in remission (177 pmol/8 × 108 RBCs, interquartile range: 94.3, 287.8), though not significantly (P = 0.08). Smoking was the only clinical factor associated with 6-TGN level. On multivariate linear regression, only age, azathioprine dose, and obese body mass index were predictive of metabolite concentration. Conclusions Variations within the normal range of TPMT activity do not affect 6-TGN concentration.
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Affiliation(s)
- David E Jonason
- Department of Internal Medicine, University of Minnesota, Minneapolis, Minnesota, USA
| | - Tyson Sievers
- Inflammatory Bowel Disease Program, Division of Gastroenterology, Hepatology and Nutrition, Department of Medicine, University of Minnesota, Minneapolis, Minnesota, USA
| | - Lindsay Trocke
- Inflammatory Bowel Disease Program, M Health Fairview, Minneapolis, Minnesota, USA
| | - James M Abraham
- Inflammatory Bowel Disease Program, Division of Gastroenterology, Hepatology and Nutrition, Department of Medicine, University of Minnesota, Minneapolis, Minnesota, USA,Present address: Division of Gastroenterology and Hepatology, Department of Medicine, University of Michigan, Ann Arbor, Michigan, USA
| | - Byron P Vaughn
- Inflammatory Bowel Disease Program, Division of Gastroenterology, Hepatology and Nutrition, Department of Medicine, University of Minnesota, Minneapolis, Minnesota, USA,Address correspondence to: Byron P. Vaughn, MD, MS, Inflammatory Bowel Disease Program, Division of Gastroenterology, Hepatology and Nutrition, Department of Medicine, University of Minnesota, 420 Delaware Street MMC 36, Minneapolis, MN 55455 ()
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Daniel LL, Dickson AL, Chung CP. Precision medicine for rheumatologists: lessons from the pharmacogenomics of azathioprine. Clin Rheumatol 2020; 40:65-73. [PMID: 32617765 DOI: 10.1007/s10067-020-05258-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2020] [Revised: 06/16/2020] [Accepted: 06/22/2020] [Indexed: 12/13/2022]
Abstract
Precision medicine aims to personalize treatment for both effectiveness and safety. As a critical component of this emerging initiative, pharmacogenomics seeks to guide drug treatment based on genetics. In this review article, we give an overview of pharmacogenomics in the setting of an immunosuppressant frequently prescribed by rheumatologists, azathioprine. Azathioprine has a narrow therapeutic index and a high risk of adverse events. By applying candidate gene analysis and unbiased approaches, researchers have identified multiple variants associated with an increased risk for adverse events associated with azathioprine, particularly bone marrow suppression. Variants in two genes, TPMT and NUDT15, are widely recognized, leading drug regulatory agencies and professional organizations to adopt recommendations for testing before initiation of azathioprine therapy. As more gene-drug interactions are discovered, our field will continue to face the challenge of balancing benefits and costs associated with genetic testing. However, novel approaches in genomics and the integration of clinical and genetic factors into risk scores offer unprecedented opportunities for the application of pharmacogenomics in routine practice. Key Points • Pharmacogenomics can help us understand how individuals' genetics may impact their response to medications. • Azathioprine is a success story for the clinical implementation of pharmacogenomics, particularly the effects of TPMT and NUDT15 variants on myelosuppression. • As our knowledge advances, testing and dosing recommendations will continue to evolve, with our field striving to balance costs and benefits to patients. • As we aim toward the goals of precision medicine, future research may integrate increasingly individualized traits-including clinical and genetic characteristics-to predict the safety and efficacy of particular medications for individual patients.
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Affiliation(s)
- Laura L Daniel
- Department of Medicine, Division of Rheumatology, Vanderbilt University Medical Center (LLD, ALD, CPC), Nashville, TN, 37232, USA
| | - Alyson L Dickson
- Department of Medicine, Division of Rheumatology, Vanderbilt University Medical Center (LLD, ALD, CPC), Nashville, TN, 37232, USA
| | - Cecilia P Chung
- Department of Medicine, Division of Rheumatology, Vanderbilt University Medical Center (LLD, ALD, CPC), Nashville, TN, 37232, USA. .,Tennessee Valley Healthcare System-Nashville Campus (CPC), Nashville, TN, USA. .,Vanderbilt Genetics Institute, Vanderbilt University School of Medicine (CPC), Nashville, TN, USA.
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11
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Czaja AJ. Review article: opportunities to improve and expand thiopurine therapy for autoimmune hepatitis. Aliment Pharmacol Ther 2020; 51:1286-1304. [PMID: 32363674 DOI: 10.1111/apt.15743] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/16/2020] [Revised: 03/07/2020] [Accepted: 03/31/2020] [Indexed: 12/14/2022]
Abstract
BACKGROUND Thiopurines in combination with glucocorticoids are used as first-line, second-line and maintenance therapies in autoimmune hepatitis and opportunities exist to improve and expand their use. AIMS To describe the metabolic pathways and key factors implicated in the efficacy and toxicity of the thiopurine drugs and to indicate the opportunities to improve outcomes by monitoring and manipulating metabolic pathways, individualising dosage and strengthening the response. METHODS English abstracts were identified in PubMed by multiple search terms. Full-length articles were selected for review, and secondary and tertiary bibliographies were developed. RESULTS Thiopurine methyltransferase activity and 6-tioguanine (6-thioguanine) nucleotide levels influence drug efficacy and safety, and they can be manipulated to improve treatment response and prevent myelosuppression. Methylated thiopurine metabolites are associated with hepatotoxicity, drug intolerance and nonresponse and their production can be reduced or bypassed. Universal pre-treatment assessment of thiopurine methyltransferase activity and individualisation of dosage to manipulate metabolite thresholds could improve outcomes. Early detection of thiopurine resistance by metabolite testing, accurate estimations of drug onset and strength by surrogate markers and adjunctive use of allopurinol could improve the management of refractory disease. Dose-restricted tioguanine (thioguanine) could expand treatment options by reducing methylated metabolites, increasing the bioavailability of 6-tioguanine nucleotides and ameliorating thiopurine intolerance or resistance. CONCLUSIONS The efficacy and safety of thiopurines in autoimmune hepatitis can be improved by investigational efforts that establish monitoring strategies that allow individualisation of dosage and prediction of outcome, increase bioavailability of the active metabolites and demonstrate superiority to alternative agents.
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Affiliation(s)
- Albert J Czaja
- Division of Gastroenterology and Hepatology, Mayo Clinic College of Medicine and Science, Rochester, MN, USA
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12
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Pashazadeh P, Marjani A, Asadi J, Khoshnia M. Thiopurine Methyltransferase Genetic Polymorphisms and Activity and Metabolic Products of Azathioprine in Patients with Inflammatory Bowel Disease. Endocr Metab Immune Disord Drug Targets 2018; 19:541-547. [PMID: 30451123 DOI: 10.2174/1871530318666181119153522] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/12/2018] [Revised: 10/01/2018] [Accepted: 10/04/2018] [Indexed: 12/07/2022]
Abstract
BACKGROUND Thiopurine S-methyltransferase (TPMT) is a cytoplasmic enzyme that catalyzes thiopurine drugs such as 6-mercaptopurine, 6-thioguanine, and azathioprine. There is a correlation between thiopurine drug metabolism, response, and toxicity and genetic polymorphism of TPMT. The aim of this study is to assess TPMT genetic polymorphisms activity and metabolic products of AZA in patients with IBD. METHODS Blood samples were obtained from 50 IBD unrelated patients from a private laboratory. We used polymerase chain reaction-restriction length polymorphism (PCR-RFLP) and allele-specific PCRbased assays to determine the TPMT gene for the different variants. A high-performance liquid chromatography system (HPLC) was carried out to determine the whole blood 6-TGN concentration. Determination of serum TMPT activity was done by ELISA kit. RESULTS In IBD patients, 46/50 (92%) subjects were homozygous for the wild-type allele (TPMT*1/*1). Mutant TPMT*1/*2 and TPMT*1/*3C alleles were found in 4/46 (8%) and 3/47 (6%) of IBD patients, respectively. TPMT*1/*3B variant was not detected in any of the IBD patients. TPMT enzyme activity was higher in wild-type than that mutant variants TPMT*1/*2 and TPMT*1/*3C, suggesting that there are statistically significant differences between 6-TG levels and polymorphisms of TMPT enzyme. 6-TG levels significantly increased in IBD patients mutant variants TPMT*1/*2 and TPMT*1/*3C. CONCLUSIONS Our results showed that TPMT polymorphisms are associated with 6-TGN levels in patients using AZA. This study suggests that AZA dosage may be determined according to the high or low prevalence of a TPMT genotype. Moreover, the results present the determination of metabolite for assessing possible safe effective dosage of the drug.
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Affiliation(s)
- Paria Pashazadeh
- Metabolic Disorders Research Center, Department of Biochemistry and Biophysics, Gorgan Faulty of Medicine, Golestan University of Medical Sciences, Gorgan, Golestan Province, Iran
| | - Abdoljalal Marjani
- Metabolic Disorders Research Center, Department of Biochemistry and Biophysics, Gorgan Faulty of Medicine, Golestan University of Medical Sciences, Gorgan, Golestan Province, Iran
| | - Jahanbakhash Asadi
- Metabolic Disorders Research Center, Department of Biochemistry and Biophysics, Gorgan Faulty of Medicine, Golestan University of Medical Sciences, Gorgan, Golestan Province, Iran
| | - Masoud Khoshnia
- Golestan Research Center of Gasteroenterolgy and Hepatology, Golestan University of Medical Sciences, Gorgan, Golestan Province, Iran
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Jensen CH, Tiu J, Catalanotti JS. Azathioprine-induced pancytopenia with normal TPMT activity presenting with HSV oral ulcers. BMJ Case Rep 2018; 2018:bcr-2018-225209. [PMID: 30002211 DOI: 10.1136/bcr-2018-225209] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
A 65-year-old man with treatment-resistant psoriatic arthritis, hypertension, dyslipidaemia and benign prostatic hyperplasia (BPH) presented with herpes simplex virus (HSV) oral ulcers and a recent 15 lb weight loss due to reduced consumption. Five weeks previously, his methotrexate was tapered and he had begun taking azathioprine. The patient's thiopurine S-methyltransferase (TPMT) activity level was normal prior to starting azathioprine. He was found to have pancytopenia with normal folate levels and azathioprine was discontinued. His pancytopenia worsened, with a nadir 8 days after stopping azathioprine, before returning to normal levels. His oral ulcers improved and he was able to tolerate solid food. This case illustrates that decreased TPMT activity is not the only risk factor for pancytopenia as an adverse reaction to azathioprine. Furthermore, HSV stomatitis may be the presenting symptom of pancytopenia. The timeline of improvement in cell counts illustrated in this patient has implications for the management of suspected azathioprine-induced pancytopenia.
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Affiliation(s)
- Caroline H Jensen
- School of Medicine and Health Sciences, George Washington University, Washington, District of Columbia, USA
| | - John Tiu
- Department of Medicine, George Washington University, Washington, District of Columbia, USA
| | - Jillian S Catalanotti
- Department of Medicine, George Washington University, Washington, District of Columbia, USA
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14
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Guillotin V, Galli G, Viallard JF. [Usefulness of thiopurine methyltransferase polymorphism study and metabolites measurement for patients treated by azathioprine]. Rev Med Interne 2018; 39:421-426. [PMID: 29370945 DOI: 10.1016/j.revmed.2017.12.007] [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] [Received: 07/01/2017] [Revised: 12/18/2017] [Accepted: 12/28/2017] [Indexed: 11/18/2022]
Abstract
Azathioprine is widely used in internal medicine and frequently implicated in occurrence of adverse events. Among these adverse events the bone marrow suppression, a dose-related one, is the most serious because of is potential morbidity and mortality. Severe myelosuppression, associated with abnormal AZA metabolism, is linked to the thiopurine methyltransferase (TPMT) genetic polymorphism that results in a high variability of its activity with 89% of patients with a normal activity, 11% with an intermediate activity, and 0.3% with very low activity leading to a very high risk of bonne marrow suppression. TPMT status can be assessed prior to AZA treatment by measuring enzyme activity or genotyping techniques to identify patients for which the standard dose is not advisable. Furthermore, azathioprine metabolites monitoring is helpful for the follow up of patients, especially in therapeutic failure, to distinguish non-compliant patients from under-dosed, "shunters" or resistant patients.
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Affiliation(s)
- V Guillotin
- Laboratoire d'immunologie de l'hôpital Pellegrin, place Amélié-Raba-Léon, 33000 Bordeaux, France.
| | - G Galli
- Service de médecine interne et immunologie clinique, Hôpital Saint-André, rue Jean-Burguet, 33000 Bordeaux, France
| | - J-F Viallard
- Service de médecine interne, hôpital du Haut-Lévêque, avenue Magellan, 33604 Pessac, France
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15
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Wall GC, Muktar H, Effken C, Mahajan PB. Addition of Allopurinol for Altering Thiopurine Metabolism to Optimize Therapy in Patients with Inflammatory Bowel Disease. Pharmacotherapy 2018; 38:259-270. [PMID: 29197117 DOI: 10.1002/phar.2067] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Thiopurine drugs, including azathioprine and 6-mercaptopurine, are used commonly in patients with inflammatory bowel disease for maintenance of remission. Although generally well tolerated, adverse effects lead to discontinuation in a significant minority of patients. Pharmacogenomic studies have suggested that metabolic breakdown of azathioprine in an individual is genetically determined. Coupled with the fact that certain thiopurine metabolites, notably 6-thioguanine nucleotide and 6-methylmercaptopurine, are associated with antiinflammatory effects and adverse effects, respectively, some investigators have examined intentionally shunting the metabolism of azathioprine toward increasing 6-thioguanine nucleotide levels by using low doses of the xanthine oxidoreductase inhibitor allopurinol to improve efficacy and decrease toxicity of azathioprine in patients with inflammatory bowel disease. We performed a search of the MEDLINE and Embase databases for basic and clinical research reports of this modality. Pertinent articles were retrieved, reviewed, and assessed by the authors. Case series, cohort studies, and one randomized trial have investigated adding allopurinol to azathioprine therapy in patients with inflammatory bowel disease. Most reports primarily examined metabolite levels in these patients. In general, the literature suggests that this modality was successful at significantly increasing 6-thioguanine nucleotide levels while decreasing 6-methylmercaptopurine levels. Several small reports have suggested that patients with increased 6-thioguanine nucleotide levels had improved symptoms or symptom remission. Adverse effects and discontinuation rates remained similar or were improved in patients who were taking a thiopurine and started allopurinol. In conclusion, the addition of allopurinol may be an option for optimizing thiopurine metabolite production in select patients with low 6-thioguanine nucleotide levels. Appropriate care and monitoring of these patients are mandatory to prevent neutropenia or other adverse effects.
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Affiliation(s)
- Geoffrey C Wall
- Drake University College of Pharmacy and Health Sciences, Des Moines, Iowa.,Iowa Methodist Medical Center-University of Iowa Medical Residency Program, Des Moines, Iowa
| | - Hamid Muktar
- Iowa Methodist Medical Center-University of Iowa Medical Residency Program, Des Moines, Iowa
| | - Cassandra Effken
- Drake University College of Pharmacy and Health Sciences, Des Moines, Iowa
| | - Pramod B Mahajan
- Drake University College of Pharmacy and Health Sciences, Des Moines, Iowa
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16
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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: 53] [Impact Index Per Article: 8.8] [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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Roblin X, Paul S, Nancey S, Flourie B. Letter: thiopurines - is less really more? Authors' reply. Aliment Pharmacol Ther 2018; 47:150. [PMID: 29226415 DOI: 10.1111/apt.14385] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/08/2022]
Affiliation(s)
- X Roblin
- Department of Gastroenterology, University Hospital Saint Etienne, France
| | - S Paul
- Department of Gastroenterology, University Hospital Saint Etienne, France
| | - S Nancey
- Department of Gastroenterology, University Hospital Lyon, Lyon, France
| | - B Flourie
- Department of Gastroenterology, University Hospital Lyon, Lyon, France
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18
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Prevalence of thiopurine S-methyltransferase gene polymorphisms in patients with inflammatory bowel disease from the island of Crete, Greece. Eur J Gastroenterol Hepatol 2017; 29:1284-1289. [PMID: 28857898 DOI: 10.1097/meg.0000000000000947] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/10/2022]
Abstract
BACKGROUND There is evidence that genotyping for the thiopurine S-methyltransferase (TPMT) gene variants is useful for the prediction of response to thiopurine analogs (azathioprine and 6-mercaptopurine) in patients with inflammatory bowel disease (IBD). The aim of the present study was to determine the prevalence of TPMT gene polymorphisms in a genetic homogenous population of IBD patients in Crete and to correlate the results with adverse reactions to thiopurine drugs. PATIENTS AND METHODS Genotyping for the most common TPMT variants TPMT*2, TPMT*3A, TPMT3*C, and TPMT*3B was performed using the PCR-restriction fragment length polymorphism method in 223 consecutive IBD patients and 119 age-matched and sex-matched healthy controls. The hospital medical records were reviewed for thiopurine use in these patients and related adverse events. RESULTS The prevalence of TPMT variants TPMT*2, TPMT*3A, TPMT*3B, and TPMT*3C was 1.8, 2.7, 1.3, and 1.8%, respectively. The G238C mutation was detected in four (1.8%) out of 223 patients, three (1.3%) patients were carriers of the G460A mutation, four (1.8%) of the A719G mutation, and six (2.7%) of both G460A and A719G mutations. In healthy controls, only one (0.8%) carried both the G460A and the A719G mutation, whereas TPMT*2, TPMT*3C, and TPMT*3B were not detected. None of the genotypes was homozygous. A statistically significant correlation between the presence of the G460A mutation and the development of leucopenia after the administration of thiopurines was observed (P=0.048). CONCLUSION This study showed a lower frequency of total TPMT variants and a higher frequency of TPMT*3B in Cretan IBD patients compared with other Caucasian populations. The presence of the G460A mutation is associated with the development of leukopenia.
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Pecher D, Dokupilová S, Zelinková Z, Peppelenbosch M, Mikušová V, Mikuš P. Determination of thiopurine S-methyltransferase activity by hydrophilic interaction liquid chromatography hyphenated with mass spectrometry. J Pharm Biomed Anal 2017; 142:244-251. [PMID: 28525791 DOI: 10.1016/j.jpba.2017.05.016] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2017] [Revised: 05/05/2017] [Accepted: 05/08/2017] [Indexed: 12/18/2022]
Abstract
Thiopurine S-methyltransferase (TPMT) plays an important role in the metabolism of thiopurines used in the therapy of inflammatory bowel diseases (IBD). In this work a new progressive method for the determination of TPMT activity in red blood cells lysates was developed. Analysis was carried out by means of hydrophilic interaction liquid chromatography (HILIC) hyphenated with mass spectrometry (MS). In comparison with reversed-phase high-performance liquid chromatography (RP-HPLC), that has been typically applied in determination of TPMT activity, the HILIC significantly improved the analytical signal provided by MS, shortened analysis time, and improved chromatographic resolution. The HILIC-HPLC-MS method was optimized and validated, providing favorable parameters of detection and quantitation limits (5.5 and 16.5pmol/mL, respectively), linearity (coefficient of determination 0.9999 in the range of 0.01-1.0nmol/mL), recovery and precision (93.25-100.37% with RSD 1.06-1.32% in the whole concentration range of QC samples). Moreover, in contrast to the conventional RP-HPLC-UV approach, the complex phenotype TPMT profiles can be reliably and without interferences monitored using the HILIC-HPLC-MS method. Such advanced monitoring can provide valuable detail information on the thiopurines (e.g. evaluating ratio of methylated and non-methylated 6-mercaptopurine) and, by that, TPMT action in biological systems before and during the therapy of IBD.
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Affiliation(s)
- Daniel Pecher
- Department of Pharmaceutical Analysis and Nuclear Pharmacy, Faculty of Pharmacy, Comenius University in Bratislava, Odbojárov 10, SK-832 32 Bratislava, Slovak Republic; Toxicological and Antidoping center, Faculty of Pharmacy, Comenius University in Bratislava, Odbojárov 10, SK-832 32 Bratislava, Slovak Republic
| | - Svetlana Dokupilová
- Department of Pharmaceutical Analysis and Nuclear Pharmacy, Faculty of Pharmacy, Comenius University in Bratislava, Odbojárov 10, SK-832 32 Bratislava, Slovak Republic; Toxicological and Antidoping center, Faculty of Pharmacy, Comenius University in Bratislava, Odbojárov 10, SK-832 32 Bratislava, Slovak Republic
| | - Zuzana Zelinková
- Department of Gastroenterology, St Michael's Hospital, Bratislava, Slovak Republic
| | | | - Veronika Mikušová
- Toxicological and Antidoping center, Faculty of Pharmacy, Comenius University in Bratislava, Odbojárov 10, SK-832 32 Bratislava, Slovak Republic; Department of Cell and Molecular Biology of Drugs, Faculty of Pharmacy, Comenius University in Bratislava, Odbojárov 10, SK-832 32 Bratislava, Slovak Republic
| | - Peter Mikuš
- Department of Pharmaceutical Analysis and Nuclear Pharmacy, Faculty of Pharmacy, Comenius University in Bratislava, Odbojárov 10, SK-832 32 Bratislava, Slovak Republic; Toxicological and Antidoping center, Faculty of Pharmacy, Comenius University in Bratislava, Odbojárov 10, SK-832 32 Bratislava, Slovak Republic.
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20
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Bhattacharyya K, Datta A. Visible-Light-Mediated Excited State Relaxation in Semi-Synthetic Genetic Alphabet: d5SICS and dNaM. Chemistry 2017; 23:11494-11498. [PMID: 28675549 DOI: 10.1002/chem.201702583] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2017] [Indexed: 12/17/2022]
Abstract
The excited state dynamics of an unnatural base pair (UBP) d5SICS/dNaM were investigated by accurate ab-initio calculations. Time-dependent density functional and high-level multireference calculations (MS-CASPT2) were performed to elucidate the excitation of this UBP and its excited state relaxation mechanism. After excitation to the bright state S2 (ππ*), it decays to the S1 state and then undergoes efficient intersystem crossing to the triplet manifold. The presence of sulfur atom in d5SICS leads to strong spin-orbit coupling (SOC) and a small energy gap that facilitates intersystem crossing from S1 (ns π*) to T2 (ππ*) followed by internal conversion to T1 state. Similarly in dNaM, the deactivation pathway follows analogous trends. CASPT2 calculations suggest that the S1 (ππ*) state is a dark state below the accessible S2 (ππ*) bright state. During the ultrafast deactivation, it exhibits bond length inversion. From S1 state, significant SOC leads the population transfer to T3 due to a smaller energy gap. Henceforth, fast internal conversion occurs from T3 to T2 followed by T1 . From time-dependent trajectory surface hopping dynamics, it is found that excited state relaxation occurs on a sub-picosecond timescale in d5SICS and dNaM. Our findings strongly suggest that there is enough energy available in triplet state of UBP to generate reactive oxygen species and induce phototoxicity with respect to cellular DNA.
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Affiliation(s)
- Kalishankar Bhattacharyya
- Department of Spectroscopy, Indian Association for the Cultivation of Science, 2A and 2B Raja S. C. Mullick Road, Jadavpur, 700032, Kolkata, West Bengal, India
| | - Ayan Datta
- Department of Spectroscopy, Indian Association for the Cultivation of Science, 2A and 2B Raja S. C. Mullick Road, Jadavpur, 700032, Kolkata, West Bengal, India
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21
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Dart RJ, Irving PM. Optimising use of thiopurines in inflammatory bowel disease. Expert Rev Clin Immunol 2017; 13:877-888. [DOI: 10.1080/1744666x.2017.1351298] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Affiliation(s)
- Robin J. Dart
- IBD Centre, Department of Gastroenterology, St Thomas’ Hospital, London, UK
- Immunosurveillance Lab, Francis Crick Institute, London, UK
- Immunobiology, DIIID, King’s College London, Guy’s Hospital, London, UK
| | - Peter M. Irving
- IBD Centre, Department of Gastroenterology, St Thomas’ Hospital, London, UK
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Roblin X, Boschetti G, Williet N, Nancey S, Marotte H, Berger A, Phelip JM, Peyrin-Biroulet L, Colombel JF, Del Tedesco E, Paul S, Flourie B. Azathioprine dose reduction in inflammatory bowel disease patients on combination therapy: an open-label, prospective and randomised clinical trial. Aliment Pharmacol Ther 2017; 46:142-149. [PMID: 28449228 DOI: 10.1111/apt.14106] [Citation(s) in RCA: 55] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/17/2017] [Revised: 02/09/2017] [Accepted: 03/26/2017] [Indexed: 01/14/2023]
Abstract
BACKGROUND Infliximab (IFX) combined with azathioprine (AZA) is more effective than IFX monotherapy in inflammatory bowel disease (IBD). AIM To identify the AZA optimal dose that is required for efficacy when receiving combination therapy. METHODS Patients with IBD in durable remission on combination therapy were enrolled in a 1-year, open-label, prospective trial after randomisation into three groups: AZA steady (2-2.5 mg/kg/day, n=28) vs AZA down (dose was halved 1-1.25 mg/kg/day, n=27) vs AZA stopped (n=26). Primary endpoint was failure defined as occurrence of a clinical relapse and/or any change in IBD therapy. RESULTS Eighty-one patients were included. Five (17.9%), 3 (11.1%), and 8 (30.8%) patients experienced failure at 1 year in groups AZA steady, AZA down and AZA stopped, respectively (P=.1 across the groups). The median trough levels of IFX at inclusion were close to those measured at the end of follow-up in group AZA steady (3.65 vs 3.45 μg/mL, P=.9) and in group AZA down (3.95 vs 3.60 μg/mL, P=.5), whereas these levels dropped from 4.25 to 2.15 μg/mL (P=.02) in group AZA stopped. Four (14.3%), four (14.8%) and 11 (42.3%) patients experienced an unfavourable evolution of IFX pharmacokinetics in groups AZA steady, AZA down and AZA stopped, respectively. A threshold of 6-TGN <105 pmoles/8.108 RBC was associated with an unfavourable evolution of IFX pharmacokinetics. CONCLUSIONS Under combination therapy, AZA dose reduction, but not withdrawal, appears to be as effective as continuation of AZA at full dose.
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Affiliation(s)
- X Roblin
- Department of Gastroenterology, University Hospital of Saint Etienne, Saint Etienne, France
| | - G Boschetti
- Department of Gastroenterology, Hospices Civils de Lyon, INSERM U1111, Lyon, France
| | - N Williet
- Department of Gastroenterology, University Hospital of Saint Etienne, Saint Etienne, France
| | - S Nancey
- Department of Gastroenterology, Hospices Civils de Lyon, INSERM U1111, Lyon, France
| | - H Marotte
- Department of Rheumatology, University Hospital of Saint Etienne, Saint Etienne, France
| | - A Berger
- Department of Immunology, CIC1408, GIMAP EA3064, University Hospital of Saint Etienne, Saint Etienne, France
| | - J M Phelip
- Department of Gastroenterology, University Hospital of Saint Etienne, Saint Etienne, France
| | - L Peyrin-Biroulet
- Department of Gastroenterology, University Hospital of Nancy, Nancy, France
| | - J F Colombel
- Division of Gastroenterology, Inflammatory Bowel Disease Center, Icahn School of Medicine, Mount Sinai Hospital, New York, NY, USA
| | - E Del Tedesco
- Department of Gastroenterology, University Hospital of Saint Etienne, Saint Etienne, France
| | - S Paul
- Department of Immunology, CIC1408, GIMAP EA3064, University Hospital of Saint Etienne, Saint Etienne, France
| | - B Flourie
- Department of Gastroenterology, Hospices Civils de Lyon, INSERM U1111, Lyon, France
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Abaji R, Krajinovic M. Thiopurine S-methyltransferase polymorphisms in acute lymphoblastic leukemia, inflammatory bowel disease and autoimmune disorders: influence on treatment response. PHARMACOGENOMICS & PERSONALIZED MEDICINE 2017; 10:143-156. [PMID: 28507448 PMCID: PMC5428801 DOI: 10.2147/pgpm.s108123] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The thiopurine S-methyltransferase (TPMT) gene encodes for the TPMT enzyme that plays a crucial role in the metabolism of thiopurine drugs. Genetic polymorphisms in this gene can affect the activity of the TPMT enzyme and have been correlated with variability in response to treatment with thiopurines. Advances in the pharmacogenetics of TPMT allowed the development of dosing recommendations and treatment strategies to optimize and individualize prescribing thiopurine in an attempt to enhance treatment efficacy while minimizing toxicity. The influence of genetic polymorphisms in the TPMT gene on clinical outcome has been well-documented and replicated in many studies. In this review, we provide an overview of the evolution, results, conclusions and recommendations of selected studies that investigated the influence of TPMT pharmacogenetics on thiopurine treatment in acute lymphoblastic leukemia, inflammatory bowel disease and autoimmune disorders. We focus mainly on prospective studies that explored the impact of individualized TPMT-based dosing of thiopurines on clinical response. Together, these studies demonstrate the importance of preemptive TPMT genetic screening and subsequent dose adjustment in mitigating the toxicity associated with thiopurine treatment while maintaining treatment efficacy and favorable long-term outcomes. In addition, we briefly address the cost-effectiveness of this pharmacogenetics approach and its impact on clinical practice as well as the importance of recent breakthrough advances in sequencing and genotyping techniques in refining the TPMT genetic screening process.
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Affiliation(s)
| | - Maja Krajinovic
- Departments of Pediatrics and Pharmacology, CHU Sainte-Justine Research Center, University of Montreal, Montreal, QC, Canada
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Zhang AL, Yang J, Wang H, Lu JL, Tang S, Zhang XJ. Association of NUDT15 c.415C>T allele and thiopurine-induced leukocytopenia in Asians: a systematic review and meta-analysis. Ir J Med Sci 2017; 187:145-153. [PMID: 28470355 DOI: 10.1007/s11845-017-1608-x] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2016] [Accepted: 03/25/2017] [Indexed: 12/11/2022]
Abstract
BACKGROUND Thiopurines, commonly used to treat autoimmune conditions and cancer, can be limited by life-threatening leucopenia. However, whether NUDT15 (nucleoside diphosphate-linked moiety X-type motif 15) is associated with thiopurine-induced leucopenia in Asians is controversial. METHODS Relevant studies in English that were published until July 10, 2016 were identified through PubMed, EMbase, and other web knowledge databases. Study quality was assessed according to the Newcastle-Ottawa Scale (NOS) criteria. Summary risk ratio (RR) and 95% confidence intervals (CI) were estimated based on a fixed-effects model or a random-effects model, depending on the absence or presence of significant heterogeneity. RESULTS Seven studies of 1138 patients met our inclusion criteria. Random-effects model meta-analysis provided evidence that T carriers of NUDT15 c.415C>T were significantly correlated with high incidences of thiopurine-induced leukocytopenia [CT + TT vs. CC: RR = 3.79, 95%CI (2.64 ~ 5.44), P < 0.00001]. This correlation was especially strong in TT patients, where it was found to be significantly increased by 6.54-fold compared with CC patients [TT vs. CC: RR = 6.54, 95%CI (3.34 ~ 12.82), P < 0.00001]. We also found that the NUDT15 c.415C>T variant was common in Asians and Hispanics, but rare in Europeans and Africans; the frequency of the NUDT15 c.415C>T distribution varied substantially by race/ethnicity. CONCLUSION The results of this meta-analysis confirm that NUDT15 c.415C>T may be an important predictor of thiopurine-induced leukocytopenia in Asians. Genotype targeting of NUDT15 c.415C>T before initiating thiopurine treatment may be useful to limit leukocytopenia.
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Affiliation(s)
- A L Zhang
- Department of Pharmacy, The First Affiliated Hospital of Zhengzhou University, NO.1 Jianshe Road, Erqi District, 450052, Zhengzhou, People's Republic of China
| | - J Yang
- Department of Pharmacy, The First Affiliated Hospital of Zhengzhou University, NO.1 Jianshe Road, Erqi District, 450052, Zhengzhou, People's Republic of China
| | - H Wang
- Department of Pharmacy, The First Affiliated Hospital of Zhengzhou University, NO.1 Jianshe Road, Erqi District, 450052, Zhengzhou, People's Republic of China
| | - J L Lu
- Department of Pharmacy, The First Affiliated Hospital of Zhengzhou University, NO.1 Jianshe Road, Erqi District, 450052, Zhengzhou, People's Republic of China
| | - S Tang
- Department of Pharmacy, The First Affiliated Hospital of Zhengzhou University, NO.1 Jianshe Road, Erqi District, 450052, Zhengzhou, People's Republic of China
| | - X J Zhang
- Department of Pharmacy, The First Affiliated Hospital of Zhengzhou University, NO.1 Jianshe Road, Erqi District, 450052, Zhengzhou, People's Republic of China.
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Determination of Concentrations of Azathioprine Metabolites 6-Thioguanine and 6-Methylmercaptopurine in Whole Blood With the Use of Liquid Chromatography Combined With Mass Spectrometry. Transplant Proc 2017; 48:1836-9. [PMID: 27496503 DOI: 10.1016/j.transproceed.2016.01.084] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2015] [Accepted: 01/21/2016] [Indexed: 11/20/2022]
Abstract
BACKGROUND 6-Mercaptopurine (6-MP) and its prodrug azathioprine (AZA) are used in many autoimmune diseases and after solid-organ transplantation. Their properties are mediated by active metabolites, 6-thioguanine nucleotides (6-TGN), and 6-methylmercaptopurine (6-MMP). The most common adverse effects are myelo- and hepato-toxicity. The aim of the study was quantification of 6-TG and 6-MMP, with the use of liquid chromatography combined with tandem mass spectrometry (LC/MS/MS) in solid-organ transplant recipients. METHODS In 33 patients, kidney transplant recipient (n = 25) and liver transplant recipient (n = 8) intra-erythrocyte concentrations of 6-TG and 6-MMP were measured with the use of LC/MS/MS. RESULTS The mean concentration of 6-TG was 205.35 ± 157.62 pmol/8 × 10(8) red blood cells (RBC); median concentration of 6-MMP was 1064.1 (35.78-11,552.9) pmol/8 × 10(8) RBC. There were no correlations between 6-TG levels and peripheral blood parameters (white blood cell count, WBC; hemoglobin, Hb concentration; PLT, blood platelet count) or alanine aminotransferase activity (AlAT) activity. Relationships between 6-MMP concentrations and peripheral blood parameters (WBC, Hb, PLT) or AlAT activity have not been found. Subgroups with leukopenia, anemia, thrombocytopenia, and liver dysfunction did not differ in concentrations of 6-TG or 6-MMP. We have observed a negative correlation between daily azathioprine dose and WBC count (r = -0.37, P = .04). CONCLUSIONS Relationships between concentrations of azathioprine metabolites and myelotoxicity or hepatotoxicity have not been confirmed. Further studies on larger groups of patients would be helpful in a more accurate understanding of the impact of azathioprine metabolites on parameters of bone marrow and liver function.
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Pharmacogénétique des immunosuppresseurs : état des connaissances et des pratiques – recommandations du Réseau national de pharmacogénétique (RNPGx). Therapie 2017; 72:269-284. [DOI: 10.1016/j.therap.2016.09.011] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2016] [Accepted: 09/02/2016] [Indexed: 12/18/2022]
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Woillard JB, Chouchana L, Picard N, Loriot MA. Pharmacogenetics of immunosuppressants: State of the art and clinical implementation - recommendations from the French National Network of Pharmacogenetics (RNPGx). Therapie 2017; 72:285-299. [PMID: 28318610 DOI: 10.1016/j.therap.2016.09.016] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2016] [Accepted: 09/02/2016] [Indexed: 12/21/2022]
Abstract
Therapeutic drug monitoring is already widely used for immunosuppressive drugs due to their narrow therapeutic index. This article summarizes evidence reported in the literature regarding the pharmacogenetics of (i) immunosuppressive drugs used in transplantation and (ii) azathioprine used in chronic inflammatory bowel disease. The conditions of use of currently available major pharmacogenetic tests are detailed and recommendations are provided based on a scale established by the RNPGx scoring tests as "essential", "advisable" and "potentially useful". Other applications for which the level of evidence is still debated are also discussed.
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Affiliation(s)
- Jean-Baptiste Woillard
- Service de pharmacologie, toxicologie et pharmacovigilance, centre de biologie et de recherche en santé, CHU de Limoges, 87042 Limoges, France; Université de Limoges UMR_S850, 87000 Limoges, France.
| | - Laurent Chouchana
- Service de pharmacologie, hôpital Cochin, Assistance publique-Hôpitaux de Paris (AP-HP), 75014 Paris, France
| | - Nicolas Picard
- Service de pharmacologie, toxicologie et pharmacovigilance, centre de biologie et de recherche en santé, CHU de Limoges, 87042 Limoges, France; Université de Limoges UMR_S850, 87000 Limoges, France
| | - Marie-Anne Loriot
- Inserm UMR_S1147, centre universitaire des Saints-Pères, 75006 Paris, France; Université Paris Descartes, Sorbonne Paris Cité, 75006 Paris, France; Service de biochimie, hôpital européen Georges-Pompidou, Assistance publique-Hôpitaux de Paris (AP-HP), 75015 Paris, France
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Lee DK, Chang VY, Kee T, Ho CM, Ho D. Optimizing Combination Therapy for Acute Lymphoblastic Leukemia Using a Phenotypic Personalized Medicine Digital Health Platform: Retrospective Optimization Individualizes Patient Regimens to Maximize Efficacy and Safety. SLAS Technol 2016; 22:276-288. [PMID: 27920397 DOI: 10.1177/2211068216681979] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Acute lymphoblastic leukemia (ALL) is a blood cancer that is characterized by the overproduction of lymphoblasts in the bone marrow. Treatment for pediatric ALL typically uses combination chemotherapy in phases, including a prolonged maintenance phase with oral methotrexate and 6-mercaptopurine, which often requires dose adjustment to balance side effects and efficacy. However, a major challenge confronting combination therapy for virtually every disease indication is the inability to pinpoint drug doses that are optimized for each patient, and the ability to adaptively and continuously optimize these doses to address comorbidities and other patient-specific physiological changes. To address this challenge, we developed a powerful digital health technology platform based on phenotypic personalized medicine (PPM). PPM identifies patient-specific maps that parabolically correlate drug inputs with phenotypic outputs. In a disease mechanism-independent fashion, we individualized drug ratios/dosages for two pediatric patients with standard-risk ALL in this study via PPM-mediated retrospective optimization. PPM optimization demonstrated that dynamically adjusted dosing of combination chemotherapy could enhance treatment outcomes while also substantially reducing the amount of chemotherapy administered. This may lead to more effective maintenance therapy, with the potential for shortening duration and reducing the risk of serious side effects.
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Affiliation(s)
- Dong-Keun Lee
- 1 Division of Oral Biology and Medicine, School of Dentistry, UCLA, Los Angeles, CA, USA
| | - Vivian Y Chang
- 2 Division of Pediatric Hematology and Oncology, David Geffen School of Medicine, UCLA, Los Angeles, CA, USA.,3 Jonsson Comprehensive Cancer Center, UCLA, Los Angeles, CA, USA
| | - Theodore Kee
- 4 Department of Bioengineering, Henry Samueli School of Engineering and Applied Science, UCLA, Los Angeles, CA, USA
| | - Chih-Ming Ho
- 3 Jonsson Comprehensive Cancer Center, UCLA, Los Angeles, CA, USA.,4 Department of Bioengineering, Henry Samueli School of Engineering and Applied Science, UCLA, Los Angeles, CA, USA.,5 Department of Mechanical and Aerospace Engineering, Henry Samueli School of Engineering and Applied Science, UCLA, Los Angeles, CA, USA
| | - Dean Ho
- 1 Division of Oral Biology and Medicine, School of Dentistry, UCLA, Los Angeles, CA, USA.,3 Jonsson Comprehensive Cancer Center, UCLA, Los Angeles, CA, USA.,4 Department of Bioengineering, Henry Samueli School of Engineering and Applied Science, UCLA, Los Angeles, CA, USA.,6 Jane and Jerry Weintraub Center for Reconstructive Biotechnology, UCLA, Los Angeles, CA, USA.,7 California NanoSystems Institute, UCLA, Los Angeles, CA, USA
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Kim MG, Ko M, Kim IW, Oh JM. Meta-analysis of the impact of thioprine S-methyltransferase polymorphisms on the tolerable 6-mercaptopurine dose considering initial dose and ethnic difference. Onco Targets Ther 2016; 9:7133-7139. [PMID: 27920553 PMCID: PMC5125793 DOI: 10.2147/ott.s110800] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
A meta-analysis was conducted to decide whether to reduce an initial 6-mercaptopurine (6-MP) dose in TPMT heterozygote in the case of an initial 6-MP dose of <75 mg/m2/d and to compare the tolerable 6-MP dose among different ethnic groups. The study was undertaken according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. The differences in mean values of the tolerable 6-MP dose were calculated by using Comprehensive Meta-Analysis version 3. The results of the meta-analysis indicated that the tolerable 6-MP dose was significantly lower in the TPMT heterozygote group (difference in mean values =11.729, 95% confidence interval =7.617-15.842, P<0.001) even when the initial 6-MP dose was <75 mg/m2/d. The TPMT*3C allele-dominant ethnic group (Asian) needed less reduction in mean 6-MP dose in comparison to the TPMT*3A allele-dominant ethnic group (Caucasian, Mediterranean, South American) (difference in mean values =8.884 vs 15.324). In conclusion, the initial 6-MP dose needs to be reduced in TPMT heterozygote when compared to the wild-type, and ethnic difference might influence the tolerable 6-MP dose in TPMT heterozygotes.
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Affiliation(s)
- Myeong Gyu Kim
- College of Pharmacy and Research Institute of Pharmaceutical Sciences, Seoul National University, Seoul, Korea
| | - Minoh Ko
- College of Pharmacy and Research Institute of Pharmaceutical Sciences, Seoul National University, Seoul, Korea
| | - In-Wha Kim
- College of Pharmacy and Research Institute of Pharmaceutical Sciences, Seoul National University, Seoul, Korea
| | - Jung Mi Oh
- College of Pharmacy and Research Institute of Pharmaceutical Sciences, Seoul National University, Seoul, Korea
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Gibaldi M. Pharmacogenetics: Part I. Ann Pharmacother 2016; 41:2042-7. [DOI: 10.1345/aph.140071] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Affiliation(s)
- Milo Gibaldi
- School of Pharmacy, University of Washington, Seattle, WA 98915
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Fakhoury M, Jacqz-Aigrain E, de Beaumais T, Médard Y. [Not Available]. Therapie 2016; 65:187-93. [PMID: 27392985 DOI: 10.2515/therapie/2010031] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2010] [Accepted: 03/23/2010] [Indexed: 12/25/2022]
Abstract
6-mercaptopurine, a key drug for the treatment of acute lymphoblastic leukaemia in children, is a prodrug metabolized into 6-thioguanine (6-TGN) which are the active compounds and into methylated metabolites, primary by thiopurine S-methyltransferase enzyme (TPMT). This enzyme displays important inter subject variability linked to a genetic polymorphism: when treated with standard doses of thiopurine, TPMT-deficient and heterozygous patients are at great risk for developing severe and potentially life-threatening toxicity (hematopoietic, hepatic, mucositis. . . ) but show a better survival rate while patients with high TPMT activity (wild type) present lower peripheral red blood cells 6-TGN concentrations and a higher risk of leukemia relapse. Genotyping remains crucial before 6-MP administration at diagnosis to identify patients with homozygous mutant TPMT genotype and therefore prevent severe and life-threatening toxicity, and to individualize therapy according to TMPT genotype. Follow-up of ALL treatment should preferentially be based on repeated determinations of intracellular active metabolites (6-thioguanine nucleotides) and methylated metabolites in addition to haematological surveillance.
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Affiliation(s)
- May Fakhoury
- Laboratoire de Pharmacologie Pédiatrique et Pharmacogénétique, Hôpital Robert Debré, Paris, France
| | - Evelyne Jacqz-Aigrain
- Laboratoire de Pharmacologie Pédiatrique et Pharmacogénétique, Hôpital Robert Debré, Paris, France.
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Coulthard SA, Berry P, McGarrity S, Ansari A, Redfern CPF. Liquid chromatography-mass spectrometry for measuring deoxythioguanosine in DNA from thiopurine-treated patients. J Chromatogr B Analyt Technol Biomed Life Sci 2016; 1028:175-180. [PMID: 27362994 PMCID: PMC4955110 DOI: 10.1016/j.jchromb.2016.06.017] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2016] [Revised: 05/26/2016] [Accepted: 06/12/2016] [Indexed: 01/14/2023]
Abstract
Thiopurines are effective immunosuppressant drugs. Monitoring of thiopurines is needed for research and clinical use. A sensitive assay of DNA-incorporated deoxythioguanosine is described. This method assays thiopurine nucleotides in DNA from nucleated blood cells.
Adverse reactions and non-response are common in patients treated with thiopurine drugs. Current monitoring of drug metabolite levels for guiding treatment are limited to analysis of thioguanine nucleotides (TGNs) in erythrocytes after chemical derivatisation. Erythrocytes are not the target tissue and TGN levels show poor correlations with clinical response. We have developed a sensitive assay to quantify deoxythioguanosine (dTG) without derivatisation in the DNA of nucleated blood cells. Using liquid chromatography and detection by tandem mass spectrometry, an intra- and inter-assay variability below 7.8% and 17.0% respectively were achieved. The assay had a detection limit of 0.0003125 ng (1.1 femtomoles) dTG and was quantified in DNA samples relative to endogenous deoxyadenosine (dA) in a small group of 20 patients with inflammatory bowel disease, all of whom had been established on azathioprine (AZA) therapy for more than 25 weeks. These patients had dTG levels of 20–1360 mol dTG/106 mol dA; three patients who had not started therapy had no detectable dTG. This method, comparable to previous methods in sensitivity, enables the direct detection of a cytotoxic thiopurine metabolite without derivatisation in an easily obtainable, stable sample and will facilitate a better understanding of the mechanisms of action of these inexpensive yet effective drugs.
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Affiliation(s)
- Sally A Coulthard
- Institute of Cellular Medicine, Newcastle University, Newcastle upon Tyne, UK.
| | - Phil Berry
- Northern Institute of Cancer Research, Newcastle University, Newcastle upon Tyne, UK
| | - Sarah McGarrity
- Northern Institute of Cancer Research, Newcastle University, Newcastle upon Tyne, UK
| | - Azhar Ansari
- Gastroenterology Dept., East Surrey Hospital, Redhill, East Surrey, UK
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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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Fangbin Z, Xiang G, Liang D, Hui L, Xueding W, Baili C, Huichang B, Yinglian X, Peng C, Lizi Z, Yanjun C, Feng X, Minhu C, Min H, Pinjin H. Prospective Evaluation of Pharmacogenomics and Metabolite Measurements upon Azathioprine Therapy in Inflammatory Bowel Disease: An Observational Study. Medicine (Baltimore) 2016; 95:e3326. [PMID: 27082580 PMCID: PMC4839824 DOI: 10.1097/md.0000000000003326] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Up to approximately 40% to 50% of patients discontinue thiopurine therapy during the course of inflammatory bowel disease (IBD). We investigated the role of the metabolite thiopurine in IBD treatment. This was a prospective study. IBD patients receiving azathioprine (AZA) were prospectively included. Thiopurine methyltransferase (TPMT) genotypes were examined before therapy, and thiopurine metabolite levels were examined at weeks 2, 4, 8, 12, 24, and 48. In total, 132 patients were included. The frequency of leucopenia increased at 6-thioguanine nucleotide (6-TGN) levels ≥420 pmol/8 × 10(8) RBC (odds ratio [OR] = 7.9; 95% confidence interval (95%CI): 3.5-18.0; P < 0.001) and increased more during the initial 12 weeks of thiopurine therapy (OR = 16.0; 95%CI: 5.7-44.9; P < 0.001). The patients with 6-TGN levels ≥420 pmol/8 × 10 RBC at weeks 4, 8, and 12 had an increased likelihood of leucopenia. Clinical response increased at 6-TGN levels ≥225 pmol/8 × 10(8) RBC (OR = 13.5; 95% CI: 3.7-48.9; P < 0.001) in Crohn disease (CD) patients. The CD patients with 6-TGN levels ≥225 pmol/8 × 10(8) RBC at weeks 8, 12, and 24 had an increased likelihood of successful clinical response. TPMT*3C had a specificity of 100%, but a sensitivity of 8% for predicting leucopenia.A 6-TGN level between 225 and 420 pmol/8 × 10(8) RBC could be a therapeutic window in patients receiving AZA therapy, and it could likely predict leucopenia in the initial 12 weeks of AZA therapy and a reasonable chance of successful clinical response in CD patients. The value of TPMT genotyping before thiopurine therapy is limited in Chinese patients with IBD, considering the low sensitivity of predicting leucopenia.
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Affiliation(s)
- Zhang Fangbin
- From the Department of Gastroenterology, the First Affiliated Hospital of Zhengzhou University, Zhengzhou (ZF, CP, CY, XF); Department of Gastroenterology, the First Affiliated Hospital, Sun Yat-sen University (ZF, GX, CB, XY, CM, HP); Department of Gastroenterology, the Sixth Affiliated Hospital of Sun Yat-sen University (GX, HP); Institute of Clinical Pharmacology, School of Pharmaceutical Sciences, Sun Yat-sen University (DL, LH, WX, BH, ZL, HM); and Department of Pharmacology, the First Affiliated Hospital of Jinan University (LH), Guangzhou, China)
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Burke MT, Isbel N, Barraclough KA, Jung JW, Wells JW, Staatz CE. Genetics and nonmelanoma skin cancer in kidney transplant recipients. Pharmacogenomics 2016; 16:161-72. [PMID: 25616102 DOI: 10.2217/pgs.14.156] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Kidney transplant recipients (KTRs) have a 65- to 250-fold greater risk than the general population of developing nonmelanoma skin cancer. Immunosuppressive drugs combined with traditional risk factors such as UV radiation exposure are the main modifiable risk factors for skin cancer development in transplant recipients. Genetic variation affecting immunosuppressive drug pharmacokinetics and pharmacodynamics has been associated with other transplant complications and may contribute to differences in skin cancer rates between KTRs. Genetic polymorphisms in genes encoding the prednisolone receptor, GST enzyme, MC1R, MTHFR enzyme and COX-2 enzyme have been shown to increase the risk of nonmelanoma skin cancer in KTRs. Genetic association studies may improve our understanding of how genetic variation affects skin cancer risk and potentially guide immunosuppressive treatment and skin cancer screening in at risk individuals.
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Affiliation(s)
- Michael T Burke
- Department of Nephrology, University of Queensland at the Princess Alexandra Hospital, Brisbane, Australia
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Marrone M, Schilsky RL, Liu G, Khoury MJ, Freedman AN. Opportunities for translational epidemiology: the important role of observational studies to advance precision oncology. Cancer Epidemiol Biomarkers Prev 2015; 24:484-9. [PMID: 25750251 DOI: 10.1158/1055-9965.epi-14-1086] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Within current oncology practice, several genomic applications are being used to inform treatment decisions with molecularly targeted therapies in breast, lung, colorectal, melanoma, and other cancers. This commentary introduces a conceptual framework connecting the full spectrum of biomedical research disciplines, including fundamental laboratory research, clinical trials, and observational studies in the translation of genomic applications into clinical practice. The conceptual framework illustrates the contribution that well-designed observational epidemiologic studies provide to the successful translation of these applications, and characterizes the role observational epidemiology plays in driving the dynamic and iterative bench-to-bedside, and bedside-to-bench translation continuum. We also discuss how the principles of this conceptual model, emphasizing integration of multidisciplinary research, can be applied to the evolving paradigm in "precision oncology" focusing on multiplex tumor sequencing, and we identify opportunities for observational studies to contribute to the successful and efficient translation of this paradigm.Cancer Epidemiol Biomarkers Prev; 24(3); 484-9. ©2015 AACR.
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Affiliation(s)
- Michael Marrone
- Epidemiology and Genomics Research Program, Division of Cancer Control and Population Sciences, National Cancer Institute, Bethesda, Maryland
| | | | - Geoff Liu
- Division of Medical Oncology, Princess Margaret Hospital, University Health Network, Toronto, Ontario, Canada
| | - Muin J Khoury
- Epidemiology and Genomics Research Program, Division of Cancer Control and Population Sciences, National Cancer Institute, Bethesda, Maryland. Office of Public Health Genomics, Centers for Disease Control and Prevention, Atlanta, Georgia
| | - Andrew N Freedman
- Epidemiology and Genomics Research Program, Division of Cancer Control and Population Sciences, National Cancer Institute, Bethesda, Maryland.
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Kotur N, Dokmanovic L, Janic D, Stankovic B, Krstovski N, Tosic N, Katsila T, Patrinos GP, Zukic B, Pavlovic S. TPMT gene expression is increased during maintenance therapy in childhood acute lymphoblastic leukemia patients in a TPMT gene promoter variable number of tandem repeat-dependent manner. Pharmacogenomics 2015; 16:1701-12. [PMID: 26411491 DOI: 10.2217/pgs.15.109] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
AIMS 6-mercaptopurine influences in vitro TPMT gene expression in a TPMT promoter variable number of tandem repeats (VNTR)-dependent manner. We studied TPMT expression following 6-mercaptopurine and methotrexate administration in childhood acute lymphoblastic leukemia (ALL) patients and the pharmacogenomic potential of the VNTR architecture. MATERIALS & METHODS TPMT gene expression was determined in childhood ALL patients at diagnosis (n = 57) and during the maintenance therapy (n = 27). RESULTS A threefold increase of TPMT gene expression was obtained during maintenance therapy, modulated by the architecture of the VNTR region. CONCLUSION The TPMT promoter genetic variants need to be considered at the very beginning of the maintenance therapy for childhood ALL patients. The TPMT promoter VNTR region may serve as a pharmacogenomic biomarker when introducing thiopurine therapy.
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Affiliation(s)
- Nikola Kotur
- Laboratory for Molecular Biomedicine, Institute of Molecular Genetics & Genetic Engineering, University of Belgrade, Serbia
| | - Lidija Dokmanovic
- University Children's Hospital, School of Medicine, University of Belgrade, Serbia
| | - Dragana Janic
- University Children's Hospital, School of Medicine, University of Belgrade, Serbia
| | - Biljana Stankovic
- Laboratory for Molecular Biomedicine, Institute of Molecular Genetics & Genetic Engineering, University of Belgrade, Serbia
| | - Nada Krstovski
- University Children's Hospital, School of Medicine, University of Belgrade, Serbia
| | - Natasa Tosic
- Laboratory for Molecular Biomedicine, Institute of Molecular Genetics & Genetic Engineering, University of Belgrade, Serbia
| | - Theodora Katsila
- Department of Pharmacy, University of Patras, School of Health Sciences, Patras, Greece
| | - George P Patrinos
- Department of Pharmacy, University of Patras, School of Health Sciences, Patras, Greece
| | - Branka Zukic
- Laboratory for Molecular Biomedicine, Institute of Molecular Genetics & Genetic Engineering, University of Belgrade, Serbia
| | - Sonja Pavlovic
- Laboratory for Molecular Biomedicine, Institute of Molecular Genetics & Genetic Engineering, University of Belgrade, Serbia
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Jayachandran D, Laínez-Aguirre J, Rundell A, Vik T, Hannemann R, Reklaitis G, Ramkrishna D. Model-Based Individualized Treatment of Chemotherapeutics: Bayesian Population Modeling and Dose Optimization. PLoS One 2015; 10:e0133244. [PMID: 26226448 PMCID: PMC4520687 DOI: 10.1371/journal.pone.0133244] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2014] [Accepted: 06/25/2015] [Indexed: 11/18/2022] Open
Abstract
6-Mercaptopurine (6-MP) is one of the key drugs in the treatment of many pediatric cancers, auto immune diseases and inflammatory bowel disease. 6-MP is a prodrug, converted to an active metabolite 6-thioguanine nucleotide (6-TGN) through enzymatic reaction involving thiopurine methyltransferase (TPMT). Pharmacogenomic variation observed in the TPMT enzyme produces a significant variation in drug response among the patient population. Despite 6-MP's widespread use and observed variation in treatment response, efforts at quantitative optimization of dose regimens for individual patients are limited. In addition, research efforts devoted on pharmacogenomics to predict clinical responses are proving far from ideal. In this work, we present a Bayesian population modeling approach to develop a pharmacological model for 6-MP metabolism in humans. In the face of scarcity of data in clinical settings, a global sensitivity analysis based model reduction approach is used to minimize the parameter space. For accurate estimation of sensitive parameters, robust optimal experimental design based on D-optimality criteria was exploited. With the patient-specific model, a model predictive control algorithm is used to optimize the dose scheduling with the objective of maintaining the 6-TGN concentration within its therapeutic window. More importantly, for the first time, we show how the incorporation of information from different levels of biological chain-of response (i.e. gene expression-enzyme phenotype-drug phenotype) plays a critical role in determining the uncertainty in predicting therapeutic target. The model and the control approach can be utilized in the clinical setting to individualize 6-MP dosing based on the patient's ability to metabolize the drug instead of the traditional standard-dose-for-all approach.
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Affiliation(s)
- Devaraj Jayachandran
- School of Chemical Engineering, Purdue University, 480 Stadium Mall Way, West Lafayette, IN, 47907, United States of America
| | - José Laínez-Aguirre
- School of Chemical Engineering, Purdue University, 480 Stadium Mall Way, West Lafayette, IN, 47907, United States of America
| | - Ann Rundell
- Weldon School of Biomedical Engineering, Purdue University, 206 South Martin Jischke Drive, West Lafayette, IN, 47907, United States of America
| | - Terry Vik
- Riley Hospital for Children, 702 Barnhill Drive, Indianapolis, IN, 46202, United States of America
| | - Robert Hannemann
- School of Chemical Engineering, Purdue University, 480 Stadium Mall Way, West Lafayette, IN, 47907, United States of America
- Weldon School of Biomedical Engineering, Purdue University, 206 South Martin Jischke Drive, West Lafayette, IN, 47907, United States of America
| | - Gintaras Reklaitis
- School of Chemical Engineering, Purdue University, 480 Stadium Mall Way, West Lafayette, IN, 47907, United States of America
| | - Doraiswami Ramkrishna
- School of Chemical Engineering, Purdue University, 480 Stadium Mall Way, West Lafayette, IN, 47907, United States of America
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Wojtuszkiewicz A, Barcelos A, Dubbelman B, De Abreu R, Brouwer C, Bökkerink JP, de Haas V, de Groot-Kruseman H, Jansen G, Kaspers GL, Cloos J, Peters GJ. Assessment of mercaptopurine (6MP) metabolites and 6MP metabolic key-enzymes in childhood acute lymphoblastic leukemia. NUCLEOSIDES NUCLEOTIDES & NUCLEIC ACIDS 2015; 33:422-33. [PMID: 24940700 DOI: 10.1080/15257770.2014.904519] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Pediatric acute lymphoblastic leukemia (ALL) is treated with combination chemotherapy including mercaptopurine (6MP) as an important component. Upon its uptake, 6MP undergoes a complex metabolism involving many enzymes and active products. The prognostic value of all the factors engaged in this pathway still remains unclear. This study attempted to determine which components of 6MP metabolism in leukemic blasts and red blood cells are important for 6MP's sensitivity and toxicity. In addition, changes in the enzymatic activities and metabolite levels during the treatment were analyzed. In a cohort (N=236) of pediatric ALL patients enrolled in the Dutch ALL-9 protocol, we studied the enzymes inosine-5'-monophosphate dehydrogenase (IMPDH), thiopurine S-methyltransferase (TPMT), hypoxanthine guanine phosphoribosyl transferase (HGPRT), and purine nucleoside phosphorylase (PNP) as well as thioguanine nucleotides (TGN) and methylthioinosine nucleotides (meTINs). Activities of selected enzymes and levels of 6MP derivatives were measured at various time points during the course of therapy. The data obtained and the toxicity related parameters available for these patients were correlated with each other. We found several interesting relations, including high concentrations of two active forms of 6MP--TGN and meTIN--showing a trend toward association with better in vitro antileukemic effect of 6MP. High concentrations of TGN and elevated activity of HGPRT were found to be significantly associated with grade III/IV leucopenia. However, a lot of data of enzymatic activities and metabolite concentrations as well as clinical toxicity were missing, thereby limiting the number of assessed relations. Therefore, although a complex study of 6MP metabolism in ALL patients is feasible, it warrants more robust and strict data collection in order to be able to draw more reliable conclusions.
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Kopylov U, Battat R, Benmassaoud A, Paradis-Surprenant L, Seidman EG. Hematologic indices as surrogate markers for monitoring thiopurine therapy in IBD. Dig Dis Sci 2015; 60:478-84. [PMID: 25236422 DOI: 10.1007/s10620-014-3362-5] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/12/2014] [Accepted: 09/08/2014] [Indexed: 12/24/2022]
Abstract
BACKGROUND Clinical efficacy and risk of complications are associated with intracellular levels of thiopurine metabolites 6-thioguanine nucleotides (6-TGN) and 6-methylmercaptopurines (6-MMP) in patients with Crohn's disease. Therapeutic monitoring of thiopurine metabolites is not widely available. Surrogate markers such as hematologic indices (MCV, leukopenia) have been proposed. AIMS To evaluate accuracy of hematologic indices for prediction of therapeutic levels of thiopurine metabolites. METHODS A retrospective cross-sectional study. We included patients treated with thiopurines for IBD between February 2008 and November 2013. Hematologic indices were correlated with thiopurine metabolites and compared to pre-treatment levels. RESULTS A total of 168 patients with 608 measurements were included. Macrocytosis was observed in 4.5 % of the patients. On multivariate analysis, macrocytosis was associated with 6-TGN levels >235 pmol/8 × 10(8) erythrocytes and 6-mmp levels >5,700 pmol/8 × 10(8) erythrocytes. Therapeutic 6-TGN levels were associated with MCV, ΔMCV, macrocytosis and lymphocyte count. Sensitivity and Spearman's r correlation for prediction of therapeutic metabolite levels were poor for all hematologic indices. CONCLUSION Although macrocytosis and an elevated MCV are associated with therapeutic 6-TGN levels, the correlation is weak. None of the evaluated hematologic indices is a reliable surrogate marker for thiopurine metabolite levels.
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Affiliation(s)
- Uri Kopylov
- Division of Gastroenterology, McGill University Health Centre, Montreal, QC, Canada,
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Chouchana L, Narjoz C, Roche D, Golmard JL, Pineau B, Chatellier G, Beaune P, Loriot MA. Interindividual variability in TPMT enzyme activity: 10 years of experience with thiopurine pharmacogenetics and therapeutic drug monitoring. Pharmacogenomics 2015; 15:745-57. [PMID: 24897283 DOI: 10.2217/pgs.14.32] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
BACKGROUND & AIMS TPMT activity and metabolite determination (6-thioguanine nucleotides [6-TGN] and 6-methylmercaptopurine nucleotides [6-MMPN]) remain controversial during thiopurine management. This study assessed associations between patient characteristics and TPMT activity, and their impact on metabolite levels. PATIENTS & METHODS A retrospective review of the laboratory database from a French university hospital identified 7360 patients referred for TPMT phenotype/genotype determination, and/or for 6-TGN/6-MMPN monitoring. RESULTS Four TPMT phenotypes were identified according to TPMT activity distribution: low, intermediate, normal/high and very high. Based on 6775 assays, 6-TGN concentrations were 1.6-fold higher in TPMT-deficient patients compared with TPMT-normal patients. Azathioprine dose and TPMT genotype were significant predictors of metabolite levels. Furthermore, 6-MMPN and 6-MMPN: 6-TGN ratios were, respectively, 1.6- and 2.2-fold higher in females than in males, despite similar TPMT, 6-TGN and azathioprine doses. An unfavorable ratio (≥20) was associated with a slightly higher TPMT activity. CONCLUSION These results illustrate the usefulness of pharmacogenomics and metabolite measurement to improve the identification of noncompliance and patients at high risk for toxicity or therapeutic resistance. Original submitted 13 November 2013; Revision submitted 30 January 2014.
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Host thiopurine methyltransferase status affects mercaptopurine antileukemic effectiveness in a murine model. Pharmacogenet Genomics 2014; 24:263-71. [PMID: 24710003 DOI: 10.1097/fpc.0000000000000044] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND Thiopurines are used for many cancers, including acute lymphoblastic leukemia (ALL). Patients with an inherited host defect in thiopurine methyltransferase (TPMT) are at high risk for life-threatening toxicity if treated with conventional dosages, but the impact on antileukemic efficacy is less clear. MATERIALS AND METHODS We treated thiopurine-sensitive BCR-ABL+Arf-null Tpmt+/+ ALL in Tpmt+/+, +/-, or -/- recipient mice to test the impact of the host polymorphism on antileukemic efficacy. RESULTS Median survival was similar in untreated mice of different Tpmt genotypes (16-18 days). However, in mice treated with low-dose mercaptopurine (such as tolerated by TPMT-/- patients), the difference in 30-day leukemia-free survival by Tpmt genotype was profound: 5% (±9%) for Tpmt+/+ mice, 47% (±26%) for Tpmt+/- mice, and 85% (±14%) for Tpmt-/- mice (P=5×10), indicating a substantial impact of host Tpmt status on thiopurine effectiveness. Among Tpmt+/+ recipient mice, leukemia-free survival improved with higher doses of mercaptopurine (similar to doses tolerated by wild-type patients) compared with lower doses, and at higher doses was comparable (P=0.6) to the survival of Tpmt-/- mice treated with the lower dose. CONCLUSIONS These findings support the notion that germline polymorphisms in Tpmt affect not only host tissue toxicity but also antitumor effectiveness.
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Vikingsson S, Andersson D, Almer S, Peterson C, Hindorf U. Novel assay to improve therapeutic drug monitoring of thiopurines in inflammatory bowel disease. J Crohns Colitis 2014; 8:1702-9. [PMID: 25239576 DOI: 10.1016/j.crohns.2014.08.009] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/10/2014] [Revised: 07/27/2014] [Accepted: 08/15/2014] [Indexed: 02/08/2023]
Abstract
BACKGROUND AND AIMS The thiopurines are widely used in the treatment of inflammatory bowel disease, but are limited by poor dose-effect relationship. The objective was to assess the ability of a novel assay, determining the mono-, di-, and triphosphates, of thioguanine as well as methylthioinosine as individual metabolites in erythrocytes, to predict clinical outcome compared to a routine assay, determining metabolites as sums. METHODS Samples from 79 patients with Crohn's disease or ulcerative colitis treated with azathioprine or mercaptopurine were analysed by both assays. Clinical status was determined by the Harvey-Bradshaw and Walmsley indices. The genotypes of thiopurine methyltransferase (TPMT) and inosine triphosphatase were determined. RESULTS TPMT wild-type patients with thioguanine nucleotide (TGN) levels below the cut-off level were more likely to have active disease when TGN was measured by the novel assay (p=0.02), and when thioguanosine triphosphate (TGTP) was measured separately (p=0.01). When TGN was measured by the routine assay the correlation was not evident (p=0.12). Neither TGN levels nor TGTP correlated to disease activity in TPMT deficient patients. Patients with methyl thioinosine nucleotide (meTIN) levels above 1500 pmol/8×10^8 RBCs were more likely to have active disease (p=0.07). We observed good correlations between the mono-, di-, and triphosphates and their respective sums (R(2)>0.88). CONCLUSIONS The novel TGN assay was better in predicting clinical outcome compared to the routine assay, while determination of TGTP had no clinical advantage and TGTP ratio was not correlated to disease activity.
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Affiliation(s)
- Svante Vikingsson
- Division of Drug Research, Clinical Pharmacology, Department of Medical and Health Sciences, Faculty of Health Sciences, Linköping University, Sweden.
| | - David Andersson
- Department of Gastroenterology, Skåne University Hospital, SE-22185 Lund, Sweden; Department of Medicine, Section of Gastroenterology and Hepatology, Danderyd Hospital, Stockholm, Sweden
| | - Sven Almer
- Division of Gastroenterology and Hepatology, Department of Clinical and Experimental Medicine, Faculty of Health Sciences, Linköping University, Linköping, Sweden; Karolinska Institutet, Department of Medicine, SE-171 76 Stockholm, Sweden; GastroCentrum, Karolinska University Hospital, Stockholm, Sweden
| | - Curt Peterson
- Division of Drug Research, Clinical Pharmacology, Department of Medical and Health Sciences, Faculty of Health Sciences, Linköping University, Sweden
| | - Ulf Hindorf
- Department of Gastroenterology, Skåne University Hospital, SE-22185 Lund, Sweden
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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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Gryn SE, Kim RB. Personalized medicine: importance of clinical interpretative skills for real-world patient care. Per Med 2014; 11:395-408. [PMID: 29783478 DOI: 10.2217/pme.14.16] [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: 11/21/2022]
Abstract
Sequencing of the human genome led to great hopes and expectations for a 'genomics revolution' where disease diagnosis as well as therapies would be based on an individual's genetic makeup. Although significant progress has been made, a number of challenging hurdles must be overcome prior to the broader adoption and implementation of pharmacogenomics and personalized medicine as a part of standard patient care. One aspect of pharmacogenomics-based personalized medicine that has not garnered as much attention, a key focus of this perspective, is the importance of interpreting pharmacogenomic test results in a patient-specific clinical context, and expert physicians and other allied health care providers with the requisite expertise in clinical pharmacology and genomics who are able to provide such services.
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Affiliation(s)
- Steven E Gryn
- Division of Clinical Pharmacology, Department of Medicine, Western University, London Health Sciences Centre-UH; 339 Windermere Road; London, ON. N6A 5A5; Canada
| | - Richard B Kim
- Division of Clinical Pharmacology, Department of Medicine, Western University, London Health Sciences Centre-UH; 339 Windermere Road; London, ON. N6A 5A5; Canada
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Revitalizing personalized medicine: respecting biomolecular complexities beyond gene expression. CPT-PHARMACOMETRICS & SYSTEMS PHARMACOLOGY 2014; 3:e110. [PMID: 24739991 PMCID: PMC4011166 DOI: 10.1038/psp.2014.6] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/12/2013] [Accepted: 01/27/2014] [Indexed: 02/05/2023]
Abstract
Despite recent advancements in "omic" technologies, personalized medicine has not realized its fullest potential due to isolated and incomplete application of gene expression tools. In many instances, pharmacogenomics is being interchangeably used for personalized medicine, when actually it is one of the many facets of personalized medicine. Herein, we highlight key issues that are hampering the advancement of personalized medicine and highlight emerging predictive tools that can serve as a decision support mechanism for physicians to personalize treatments.
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Zhang B, Xu XW, Zeng XJ, Li DK. Correlation of thiopurine methyltransferase activity and 6-thioguanine nucleotide concentration in Han Chinese patients treated with azathioprine 25 to 100 mg: A 1-year, single-center, prospective study. Curr Ther Res Clin Exp 2014; 67:270-82. [PMID: 24678102 DOI: 10.1016/j.curtheres.2006.07.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/02/2006] [Indexed: 11/29/2022] Open
Abstract
BACKGROUND Of the enzymes involved in the metabolism of azathioprine, thiopurine methyltransferase (TPMT) is the one characterized by genetic polymorphisms and ethnic variations. There have been several studies of the ethnic variations in phenotype and genotype of TPMT, although few have assessed the possible correlation between TPMT activity and 6-thioguanine nucleotide (6-TGN) concentrations. OBJECTIVE The aim of this study was to examine the relationship between TPMT activity and the steady-state concentration (Css) of 6-TGN, the primary active metabolite of azathioprine, in red blood cells (RBCs) in Han Chinese patients treated with azathioprine. METHODS Han Chinese patients aged 18 to 60 years with immunosuppression and normal hepatic and renal function who had been receiving a stable dose (25-100 mg/d) of oral azathioprine as a part of their regular anti-immunosuppression regimen for at least 10 days were recruited for this 1-year, single-center, prospective study. Azathioprine was administered PO QD in the morning, in combination with a stable regimen of other immunosuppressive drugs, for 1 year. At 1 year, blood samples were drawn just before the ingestion of azathioprine. TPMT activity and 6-TGN Css in RBCs were determined in our laboratory using high-performance liquid chromatography. Adverse drug events were monitored by a patient questionnaire and laboratory testing. Out of the initial cohort, several patients were concurrently enrolled in a subanalysis in which the effect of TPMT polymorphism on the pharmacokinetic properties of 6-mercaptopurine, the intermediate metabolite of azathioprine, was examined. RESULTS Nineteen patients (14 women, 5 men; mean [SD] age, 41 [9.6] years [range, 22-59 years]; mean [SD] weight, 62 [12] kg) were included in the study; 7 were included in the subanalysis. A significant negative correlation was found between TPMT activity and 6-TGN Css in RBCs (r = -0.712; P = 0.001); when the outlier data were removed, no significant correlation was found. Mean (SD) TPMT activity was 12.95 (3.07) nmol/h · mL(-1) RBCs and the interindividual CV was 23.68%. Mean (SD) 6-TGN CSS was 42.95 (41.98) ng/8 × 108 RBCs and the interindividual CV was 97.74% (N = 19), while the intraindividual CV of 6-TGNs within 8 hours after azathioprine ingestion was between 4.23% and 7.37% (n = 7). No significant correlation was found between 6-TGN Css in RBCs and the dose of azathioprine used. One patient's treatment was discontinued because her white blood cell count decreased to < 4 × 109 cells/L, indicating myelotoxicity; the t/12 of 6-TGNs in this patient was 5.85 days. Treatment was well tolerated by all other patients. CONCLUSION In this small study, a significant negative correlation was found between TPMT activity and 6-TGN concentration in the RBCs of these Han Chinese patients. However, the correlation was not significant when data from 1 patient with low TPMT activity were excluded.
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Affiliation(s)
- Bo Zhang
- Department of Pharmacy, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences-Peking Union Medical College, Beijing, China
| | - Xiao-Wei Xu
- Department of Pharmacy, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences-Peking Union Medical College, Beijing, China
| | - Xue-Jun Zeng
- Department of Rheumatology and Immunology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences-Peking Union Medical College, Beijing, China
| | - Da-Kui Li
- Department of Pharmacy, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences-Peking Union Medical College, Beijing, China
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Neuraz A, Chouchana L, Malamut G, Le Beller C, Roche D, Beaune P, Degoulet P, Burgun A, Loriot MA, Avillach P. Phenome-wide association studies on a quantitative trait: application to TPMT enzyme activity and thiopurine therapy in pharmacogenomics. PLoS Comput Biol 2013; 9:e1003405. [PMID: 24385893 PMCID: PMC3873228 DOI: 10.1371/journal.pcbi.1003405] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2013] [Accepted: 11/08/2013] [Indexed: 02/04/2023] Open
Abstract
Phenome-Wide Association Studies (PheWAS) investigate whether genetic polymorphisms associated with a phenotype are also associated with other diagnoses. In this study, we have developed new methods to perform a PheWAS based on ICD-10 codes and biological test results, and to use a quantitative trait as the selection criterion. We tested our approach on thiopurine S-methyltransferase (TPMT) activity in patients treated by thiopurine drugs. We developed 2 aggregation methods for the ICD-10 codes: an ICD-10 hierarchy and a mapping to existing ICD-9-CM based PheWAS codes. Eleven biological test results were also analyzed using discretization algorithms. We applied these methods in patients having a TPMT activity assessment from the clinical data warehouse of a French academic hospital between January 2000 and July 2013. Data after initiation of thiopurine treatment were analyzed and patient groups were compared according to their TPMT activity level. A total of 442 patient records were analyzed representing 10,252 ICD-10 codes and 72,711 biological test results. The results from the ICD-9-CM based PheWAS codes and ICD-10 hierarchy codes were concordant. Cross-validation with the biological test results allowed us to validate the ICD phenotypes. Iron-deficiency anemia and diabetes mellitus were associated with a very high TPMT activity (p = 0.0004 and p = 0.0015, respectively). We describe here an original method to perform PheWAS on a quantitative trait using both ICD-10 diagnosis codes and biological test results to identify associated phenotypes. In the field of pharmacogenomics, PheWAS allow for the identification of new subgroups of patients who require personalized clinical and therapeutic management. The use of underlying molecular mechanisms and other factors to describe and classify diseases is a major challenge for future treatment strategies. New methods are needed to achieve this goal. The phenome wide association study (PheWAS) methodology was initially developed to unveil unknown associations between a specific genetic status and phenotypic features (e.g. diagnoses from electronic health records). We initially propose to extend this method to assessment of the relationships between the levels of a quantitative trait and diagnosis codes. We also assess the relationships between this quantitative trait and the biological test results. We tested this method using the levels of enzymatic activity of thiopurine S-methyltransferase (TPMT) that is involved in the metabolism of thiopurine drugs used in inflammatory bowel diseases for example. We discovered an association between a very high TPMT activity and nutritional anemia and diabetes. These results could be used to describe a new subgroup of patients in order to optimize drug treatments.
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Affiliation(s)
- Antoine Neuraz
- Biomedical Informatics and Public Health Department, University Hospital HEGP, AP-HP, Paris, France
- INSERM UMR_S 872 Team 22: Information Sciences to support Personalized Medicine, Université Paris Descartes, Sorbonne Paris Cité, Faculté de Médecine, Paris, France
| | - Laurent Chouchana
- INSERM UMR-S 775, Université Paris Descartes, Sorbonne Paris Cité, Paris, France
| | - Georgia Malamut
- Gastroenterology Department, University Hospital HEGP, AP-HP, Paris, France
| | | | - Denis Roche
- Biochemistry, Pharmacogenetics and Molecular Oncology Unit, University Hospital HEGP, AP-HP, Paris, France
| | - Philippe Beaune
- INSERM UMR-S 775, Université Paris Descartes, Sorbonne Paris Cité, Paris, France
- Biochemistry, Pharmacogenetics and Molecular Oncology Unit, University Hospital HEGP, AP-HP, Paris, France
| | - Patrice Degoulet
- Biomedical Informatics and Public Health Department, University Hospital HEGP, AP-HP, Paris, France
- INSERM UMR_S 872 Team 22: Information Sciences to support Personalized Medicine, Université Paris Descartes, Sorbonne Paris Cité, Faculté de Médecine, Paris, France
| | - Anita Burgun
- Biomedical Informatics and Public Health Department, University Hospital HEGP, AP-HP, Paris, France
- INSERM UMR_S 872 Team 22: Information Sciences to support Personalized Medicine, Université Paris Descartes, Sorbonne Paris Cité, Faculté de Médecine, Paris, France
| | - Marie-Anne Loriot
- INSERM UMR-S 775, Université Paris Descartes, Sorbonne Paris Cité, Paris, France
- Biochemistry, Pharmacogenetics and Molecular Oncology Unit, University Hospital HEGP, AP-HP, Paris, France
| | - Paul Avillach
- Biomedical Informatics and Public Health Department, University Hospital HEGP, AP-HP, Paris, France
- INSERM UMR_S 872 Team 22: Information Sciences to support Personalized Medicine, Université Paris Descartes, Sorbonne Paris Cité, Faculté de Médecine, Paris, France
- * E-mail:
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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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Ebbesen MS, Nersting J, Jacobsen JH, Frandsen TL, Vettenranta K, Abramsson J, Wesenberg F, Schmiegelow K. Incorporation of 6-thioguanine nucleotides into DNA during maintenance therapy of childhood acute lymphoblastic leukemia-the influence of thiopurine methyltransferase genotypes. J Clin Pharmacol 2013; 53:670-4. [PMID: 23585236 DOI: 10.1002/jcph.81] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2012] [Accepted: 03/07/2013] [Indexed: 11/10/2022]
Affiliation(s)
- Maria S Ebbesen
- Department of Pediatrics and Adolescent Medicine, The University Hospital Rigshospitalet, Copenhagen, Denmark
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