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https://www.readbyqxmd.com/read/29210335/predictive-role-of-nudt15-variants-on-thiopurine-induced-myelotoxicity-in-asian-inflammatory-bowel-disease-patients
#1
Natalia Sutiman, Sylvia Chen, Khoon Lin Ling, Sai Wei Chuah, Wai Fook Leong, Vinayak Nadiger, Madeline Tjai, Chris San Choon Kong, Brian John Schwender, Webber Chan, Hang Hock Shim, Wee Chian Lim, Chiea Chuen Khor, Yin Bun Cheung, Balram Chowbay
BACKGROUND: Genetic variants of TPMT and NUDT15 have been reported to predict the inter-patient variability in response and toxicity profiles of patients receiving thiopurine therapy. However, the clinical utility of TPMT genotyping in guiding thiopurine doses has been questionable, in part due to underlying differences in the prevalence of TPMT variants in both Caucasian and Asian populations. Several NUDT15 variants have been associated with thiopurine-induced leukopenia, particularly in Asian cohorts...
December 6, 2017: Pharmacogenomics
https://www.readbyqxmd.com/read/29206869/measurements-of-6-thioguanine-nucleotide-levels-with-tpmt-and-nudt15-genotyping-in-patients-with-crohn-s-disease
#2
Ji Hyeon Lee, Tae Jun Kim, Eun Ran Kim, Sung Noh Hong, Dong Kyung Chang, Li-Hwa Choi, Hye In Woo, Soo-Youn Lee, Young-Ho Kim
The association between the 6-thioguanine nucleotide (6-TGN) level and clinical remission in Crohn's disease (CD) remains controversial. Thiopurine-induced leukopenia is a life-threatening complication of CD in Asians that was recently shown to strongly correlate with NUDT15 genetic variants. This study aimed to determine the relationship between thiopurine metabolite levels and therapeutic response, and to investigate the association of NUDT15, TPMT, and thiopurine metabolites with leukopenia in patients with CD...
2017: PloS One
https://www.readbyqxmd.com/read/29194039/validation-of-a-high-performance-liquid-chromatography-method-for-thiopurine-s-methyltransferase-activity-in-whole-blood-using-6-mercaptopurine-as-substrate
#3
Hannah Rieger, Patrik Schmidt, Elke Schaeffeler, Manabu Abe, Mira Schiffhauer, Matthias Schwab, Nicolas von Ahsen, Gabriela Zurek, Hartmut Kirchherr, Maria Shipkova, Eberhard Wieland
BACKGROUND: Variation in metabolism, toxicity and therapeutic efficacy of thiopurine drugs is largely influenced by genetic polymorphisms in the thiopurine S-methyltransferase (TPMT) gene. Determination of TPMT activity is routinely performed in patients to adjust drug therapy. METHODS: We further optimized a previously established high-performance liquid chromatography (HPLC) method by measuring TPMT activity in whole blood instead of isolated erythrocytes, which is based on conversion of 6-mercaptopurine to 6-methylmercaptopurine using S-adenosyl-methionine as methyl donor...
December 1, 2017: Clinical Chemistry and Laboratory Medicine: CCLM
https://www.readbyqxmd.com/read/29192347/pharmacogenetics-of-thiopurines-for-inflammatory-bowel-disease-in-east-asia-prospects-for-clinical-application-of-nudt15-genotyping
#4
REVIEW
Yoichi Kakuta, Yoshitaka Kinouchi, Tooru Shimosegawa
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...
November 30, 2017: Journal of Gastroenterology
https://www.readbyqxmd.com/read/29191122/association-between-tpmt-3c-and-decreased-thiopurine-s-methyltransferase-activity-in-patients-with-neuromyelitis-optica-spectrum-disorders-in-china
#5
Xiaoqing Gong, Shenghui Mei, Xindi Li, Xingang Li, Heng Zhou, Yonghong Liu, Anna Zhou, Li Yang, Zhigang Zhao, Xinghu Zhang
AIM OF THE STUDY: Thiopurines are effective drugs in treating neuromyelitis optica spectrum disorders and other diseases. Thiopurines' toxicity is mainly imputed to thiopurine S-methyltransferase activity. In Chinese population, the most common and important variation of thiopurine S-methyltransferase is TPMT*3C (rs1142345). This study aims to reveal the association between thiopurine S-methyltransferase activity and genetic polymorphisms of thiopurine S-methyltransferase in patients with neuromyelitis optica spectrum disorders in China...
December 1, 2017: International Journal of Neuroscience
https://www.readbyqxmd.com/read/29147133/allopurinol-in-combination-with-thiopurine-induces-mucosal-healing-and-improves-clinical-and-metabolic-outcomes-in-ibd
#6
Brigitte Moreau, Pierre Clement, Yves Theoret, Ernest G Seidman
Background: Thiopurines, azathioprine (AZA) and 6-mercaptopurine (6-MP) are common maintenance medications for inflammatory bowel disease (IBD). Excessive methylation via thiopurine methyltransferase (TPMT) frequently causes therapeutic failure. Allopurinol reduces excessive 6-methyl-mercaptopurine (6-MMP) while enhancing 6-thioguanine (6-TGN) levels. The aim of this study was to evaluate clinical, metabolic and endoscopic impact of allopurinol in combination with low-dose thiopurine in IBD...
November 2017: Therapeutic Advances in Gastroenterology
https://www.readbyqxmd.com/read/29065511/novel-tetra-primer-arms-pcr-assays-for-thiopurine-intolerance-susceptibility-mutations-nudt15-c-415c-t-and-tpmt-c-719a-g-tpmt-3c-in-east-asians
#7
Chi-Chun Ho, Wai-Ying Fong, Yuen-Hon Lee, Wing-Tat Poon
Thiopurines are clinically useful in the management of diverse immunological and malignant conditions. Nevertheless, these purine analogues can cause lethal myelosuppression, which may be prevented by prospective testing for variants in the thiopurine S-methyltransferase (TPMT) and, in East Asians, Nudix hydrolase 15 (NUDT15) genes. Two single-tube, tetra-primer amplification refractory mutation system polymerase chain reaction (ARMS-PCR) assays were developed to genotype the common loss-of-function variants NUDT15 c...
October 23, 2017: Genes
https://www.readbyqxmd.com/read/29059469/fat-free-muscle-mass-in-magnetic-resonance-imaging-predicts-acute-on-chronic-liver-failure-and-survival-in-decompensated-cirrhosis
#8
Michael Praktiknjo, Marius Book, Julian Luetkens, Alessandra Pohlmann, Carsten Meyer, Daniel Thomas, Christian Jansen, Andreas Feist, Johannes Chang, Jochen Grimm, Jennifer Lehmann, Christian P Strassburg, Juan Gonzalez Abraldes, Guido Kukuk, Jonel Trebicka
BACKGROUND: Muscle mass seems to be a prognostic marker in patients with liver cirrhosis. However, reported methods to quantify muscle mass are heterogeneous, consented cut-off values are missing and most studies used computed tomography (CT). This study evaluated fat-free muscle area as a marker of sarcopenia using magnetic resonance imaging (MRI) in decompensated cirrhotic patients with transjugular intrahepatic portosystemic shunt (TIPS). METHODS: The total erector spinae muscle area and the intramuscular fat tissue area were measured and subtracted to calculate the fat-free muscle area (FFMA) in 116 cirrhotic patients with TIPS and MRI...
October 23, 2017: Hepatology: Official Journal of the American Association for the Study of Liver Diseases
https://www.readbyqxmd.com/read/29050696/pharmacogenomics-in-acute-lymphoblastic-leukemia
#9
REVIEW
Shawn H R Lee, Jun J Yang
Pharmacogenomics is a fast-growing field of personalized medicine using a patient's genomic profile to determine drug disposition or response to drug therapy, in order to develop safer and more effective pharmacotherapy. Childhood acute lymphoblastic leukemia (ALL), being the most common malignancy in childhood, which is treated with uniform and standardized clinical trials, is remarkably poised for pharmacogenomic studies. In the last decade, unbiased genome-wide association studies have identified multiple germline risk factors that strongly modify host response to drug therapy...
September 2017: Best Practice & Research. Clinical Haematology
https://www.readbyqxmd.com/read/29035443/genetic-variants-of-pre-micrornas-a-499g-rs3746444-and-t-196a2c-rs11614913-with-ulcerative-colitis-uc-and-investigated-with-thiopurine-s-methyltransferase-tpmt-activity
#10
Farideh Ghobadi, Asad Vaisi-Raygani, Fariborz Bahrehmand, Maryam Tanhapour, Amir Kiani, Zohreh Rahimi, Tayebeh Pourmotabbed
BACKGROUND: Abnormal expression and different splicing of miRNAs are involved in several human inflammatory disorders. It has been suggested that gene variants of miRNAs may be associated with increased risk of ulcerative colitis (UC). We aimed to evaluate the association of two SNPs (miRNA-A-499G(rs3746444) and miRNA-T196a2C(rs11614913)) with the risk of UC and monitor their effect on thiopurine-S-methyltransferase (TPMT) activity in Kurdish population of Iran. METHODS: This case-control study was performed on 210 UC patients and 212 healthy individuals...
October 1, 2017: Clinical Laboratory
https://www.readbyqxmd.com/read/28966507/thiopurine-s-methyltransferase-polymorphisms-in-korean-dermatologic-patients
#11
Minseok Lee, Jimyung Seo, Dongsik Bang, Do Young Kim
BACKGROUND: Thiopurine S-methyltransferase (TPMT) is an important enzyme in the metabolism of thiopurines including azathioprine (AZA), 6-mercaptopurine, and 6-thioguanine. TPMT genotyping is widely used for screening of AZA-related toxicity during routine clinical practice in Korea. However, the data of TPMT genotypes and its AZA-related toxicity have not been studied in the field of dermatology. OBJECTIVE: The aim of this study was to evaluate the genetic basis of TPMT polymorphism in Korean dermatologic patients and subsequently to investigate the relationship between mutant TPMT and adverse responses to AZA treatment...
October 2017: Annals of Dermatology
https://www.readbyqxmd.com/read/28963908/emerging-role-of-nudt15-polymorphisms-in-6-mercaptopurine-metabolism-and-dose-related-toxicity-in-acute-lymphoblastic-leukaemia
#12
REVIEW
Minu Singh, Prateek Bhatia, Sanjeev Khera, Amita Trehan
Despite more than 80% long term survival in ALL, morbidity due to drug related myelotoxicity remains high. Germline variants of thiopurine metabolizing enzymes (TPMT and ITPA) have been described which are associated with increased drug toxicity during maintenance phase, but their prevalence in different ethnic groups is variable to account for relatively high myelotoxicity incidence. NUDT15 variant (rs116855232) has been recently identified as a novel polymorphism related with thiopurine-induced leucopenia in inflammatory bowel disease and ALL...
November 2017: Leukemia Research
https://www.readbyqxmd.com/read/28961694/a-severe-neonatal-lymphopenia-associated-with-administration-of-azathioprine-to-the-mother-in-a-context-of-crohn-s-disease
#13
C Thomas, C Monteil-Ganiere, S Mirallié, C Hémont, C Dert, A Léger, C Joyau, D Caldari, M Audrain
Azathioprine is commonly used in Crohn's Diseases. It has been administered to many pregnant women over many years without significant side effects. However, pancytopenia and Severe Combined Immune Deficiency-like disease have been reported in infants whose mothers received azathioprine throughout pregnancy. Moreover, myelotoxicity has been described in patients treated with azathioprine and having a low or absent thiopurine S-methyl transferase (TPMT) activity.Here, we describe the case of a new-born girl found highly lymphopenic (<300 CD3+ T cells) after a positive new-born screening for Severe Combined Immuno Deficiency...
September 2, 2017: Journal of Crohn's & Colitis
https://www.readbyqxmd.com/read/28950720/biomarkers-of-adverse-drug-reactions
#14
Daniel F Carr, Munir Pirmohamed
Adverse drug reactions can be caused by a wide range of therapeutics. Adverse drug reactions affect many bodily organ systems and vary widely in severity. Milder adverse drug reactions often resolve quickly following withdrawal of the casual drug or sometimes after dose reduction. Some adverse drug reactions are severe and lead to significant organ/tissue injury which can be fatal. Adverse drug reactions also represent a financial burden to both healthcare providers and the pharmaceutical industry. Thus, a number of stakeholders would benefit from development of new, robust biomarkers for the prediction, diagnosis, and prognostication of adverse drug reactions...
January 1, 2017: Experimental Biology and Medicine
https://www.readbyqxmd.com/read/28921647/pharmacogenomics-implementation-at-the-national-institutes-of-health-clinical-center
#15
Tristan M Sissung, Jon W McKeeby, Jharana Patel, Juan J Lertora, Parag Kumar, Willy A Flegel, Sharon D Adams, Ellen J Eckes, Frank Mickey, Teri M Plona, Stephanie D Mellot, Ryan N Baugher, Xiaolin Wu, Daniel R Soppet, Mary E Barcus, Vivekananda Datta, Kristen M Pike, Gary DiPatrizio, William D Figg, Barry R Goldspiel
The National Institutes of Health Clinical Center (NIH CC) is the largest hospital in the United States devoted entirely to clinical research, with a highly diverse spectrum of patients. Patient safety and clinical quality are major goals of the hospital, and therapy is often complicated by multiple cotherapies and comorbidities. To this end, we implemented a pharmacogenomics program in 2 phases. In the first phase, we implemented genotyping for HLA-A and HLA-B gene variations with clinical decision support (CDS) for abacavir, carbamazepine, and allopurinol...
October 2017: Journal of Clinical Pharmacology
https://www.readbyqxmd.com/read/28914560/thiopurine-metabolite-levels-in-patients-with-atopic-dermatitis-and-or-chronic-hand-foot-eczema-treated-with-azathioprine
#16
F M Garritsen, J van der Schaft, C A F Bruijnzeel-Koomen, R H van Schaik, M de Graaf, M P H van den Broek, M S de Bruin-Weller
BACKGROUND: Azathioprine is frequently used in severe eczema. It is converted in the liver into active metabolites, including 6-thioguanine nucleotide (6-TGN) and methylated 6-methylmercaptopurine (6-MMP). In the past, the therapeutic potential of azathioprine may have not been fully utilized. Recent investigations on inflammatory bowel disease have led to a better understanding of azathioprine metabolism and optimizing treatment. OBJECTIVE: To investigate whether measuring thiopurine metabolites in circulation can improve the effectiveness and safety of azathioprine treatment in patients with atopic dermatitis and/or chronic hand/foot eczema...
September 26, 2017: Journal of Dermatological Treatment
https://www.readbyqxmd.com/read/28914446/risk-factors-for-thiopurine-induced-myelosuppression-and-infections-in-inflammatory-bowel-disease-patients-with-a-normal-tpmt-genotype
#17
M M T J Broekman, M J H Coenen, G J Wanten, C J van Marrewijk, O H Klungel, A L M Verbeek, P M Hooymans, H-J Guchelaar, H Scheffer, L J J Derijks, D R Wong, D J de Jong
BACKGROUND: Leucopenia is a common side effect in patients treated with thiopurines. Variants in the thiopurine S-methyltransferase (TPMT) gene are the best-known risk factor, but only explain up to 25% of leucopenia cases. AIM: To identify the clinical risk factors for thiopurine-induced leucopenia in patients without a common TPMT variant, and explore if these patients are at increased risk for infections. METHODS: Post hoc analysis of the Thiopurine response Optimisation by Pharmacogenetic testing in Inflammatory bowel disease Clinics (TOPIC) trial...
November 2017: Alimentary Pharmacology & Therapeutics
https://www.readbyqxmd.com/read/28857898/prevalence-of-thiopurine-s-methyltransferase-gene-polymorphisms-in-patients-with-inflammatory-bowel-disease-from-the-island-of-crete-greece
#18
Constantina Coucoutsi, George Emmanouil, George Goulielmos, Ourania Sfakianaki, Ioannis E Koutroubakis, Elias A Kouroumalis
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...
November 2017: European Journal of Gastroenterology & Hepatology
https://www.readbyqxmd.com/read/28843236/a-practical-non-extraction-direct-liquid-chromatography-method-for-determination-of-thiopurine-s-methyltransferase-activity-in-inflammatory-bowel-disease
#19
Fariborz Bahrehmand, Amir Kiani, Asad Vaisi-Raygani, Homayoun Bashiri, Mehdi Zobeiri, Ali Moini, Tayebeh Pourmotabbed
Thiopurine drugs remain pivotal therapies for the wide varieties of diseases such as inflammatory bowel disease (IBD). Here, thiopurine S-methyltransferase (TPMT) phenotype, the main metabolizing enzyme of thiopurine-drugs, was studied. This is for the first time that TPMT activity is measured in Iranian IBD patients. We used an improved direct liquid chromatography assay without need for solvent extraction and minimize excess labor handling making it ideal for use in routine referral medical centers. TPMT activity in whole blood was determined by a non-extraction HPLC method...
June 2017: Acta Medica Iranica
https://www.readbyqxmd.com/read/28818801/development-and-validation-of-a-reliable-method-for-thiopurine-methyltransferase-tpmt-enzyme-activity-in-human-whole-blood-by-lc-ms-ms-an-application-for-phenotypic-and-genotypic-correlations
#20
Supaporn Wiwattanakul, Santirhat Prommas, Nuttawut Jenjirattithigarn, Siwalee Santon, Apichaya Puangpetch, Samart Pakakasama, Usanarat Anurathapan, Chonlaphat Sukasem
A liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed for the determination of thiopurine methyltransferase (TPMT) activity in human whole blood lysate, based on conversion of 6-mercaptopurine (6-MP) by TPMT to 6-methylmercaptopurine (6-MMP) using S-adenosyl-l-methionine (SAM) as the methyl donor. This method was improved from the previous laborious method for washing of red cell lysate preparation to develop whole blood EDTA lysate. In addition, the TPMT incubation was optimized and the chromatography was performed in a short runtime of 7min on a C18-column by detection via triple quadrupole mass spectrometry...
October 25, 2017: Journal of Pharmaceutical and Biomedical Analysis
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