Abstract
Thiopurine methyltransferase (TPMT) is a cytosolic enzyme involved in the metabolism of thiopurine medications that are used in the treatment of multiple malignant and nonmalignant immunologic conditions. Polymorphisms in the TPMT gene associated with low enzyme activity can produce pronounced pharmacologic effects during therapy. The determination of TPMT erythrocyte activity is a valuable adjunct test to genotyping for the assignment of TPMT phenotype, especially in the presence of indeterminate genotypes. We present a method for the determination TPMT activity in human erythrocytes whereby we utilize LC-MS/MS to measure the amount of 6-methylmercaptopurine formed in red blood cell (RBC) lysates using 6-mercaptopurine as substrate and S-adenosylmethionine (SAM) as methyl donor. This method has been successfully implemented and proven to be reliable for use in human specimens.
Access this chapter
Tax calculation will be finalised at checkout
Purchases are for personal use only
Similar content being viewed by others
References
Relling MV, Schwab M, Whirl-Carrillo M, Suarez-Kurtz G, Pui CH, Stein CM, Moyer AM, Evans WE, Klein TE, Antillon-Klussmann FG, Caudle KE, Kato M, Yeoh AEJ, Schmiegelow K, Yang JJ (2019) Clinical pharmacogenetics implementation consortium guideline for thiopurine dosing based on TPMT and NUDT15 genotypes: 2018 update. Clin Pharmacol Ther 105(5):1095–1105
Weinshilboum RM, Raymond FA, Pazmiño PA (1978) Human erythrocyte thiopurine methyltransferase: radiochemical microassay and biochemical properties. Clin Chim Acta 85(3):323–333
Indjova D, Shipkova M, Atanasova S, Niedmann PD, Armstrong VW, Svinarov D, Oellerich M (2003) Determination of thiopurine methyltransferase phenotype in isolated human erythrocytes using a new simple nonradioactive HPLC method. Ther Drug Monit 25(5):637–644
Lennard L, Chew TS, Lilleyman JS (2001) Human thiopurine methyltransferase activity varies with red blood cell age. Br J Clin Pharmacol 52:539–546
Ford LT, Berg JD (2010) Thiopurine S-methyltransferase (TPMT) assessment prior to starting thiopurine drug treatment; a pharmacogenomics test whose time has come. J Clin Pathol 63:288–295
Roy LM, Zur RM, Uleryk E, Carew C, Ito S, Ungar WJ (2016) Thiopurine S-methyltransferase testing for averting drug toxicity in patients receiving thiopurines: a systematic review. Pharmacogenomics 17:633–656
McLeod HL, Relling MV, Liu Q, Pui CH, Evans WE (1995) Polymorphic thiopurine methyltransferase in erythrocytes is indicative of activity in leukemic blasts from children with acute lymphoblastic leukemia. Blood 85(7):1897–1902. PMID: 7703493
Author information
Authors and Affiliations
Corresponding author
Editor information
Editors and Affiliations
Rights and permissions
Copyright information
© 2024 The Author(s), under exclusive license to Springer Science+Business Media, LLC, part of Springer Nature
About this protocol
Cite this protocol
Li, L., Atkinson, N., Crews, K.R., Molinelli, A.R. (2024). Determination of Thiopurine S-Methyltransferase (TPMT) Activity in Human Erythrocytes by Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS). In: Garg, U. (eds) Clinical Applications of Mass Spectrometry in Drug Analysis. Methods in Molecular Biology, vol 2737. Humana, New York, NY. https://doi.org/10.1007/978-1-0716-3541-4_43
Download citation
DOI: https://doi.org/10.1007/978-1-0716-3541-4_43
Published:
Publisher Name: Humana, New York, NY
Print ISBN: 978-1-0716-3540-7
Online ISBN: 978-1-0716-3541-4
eBook Packages: Springer Protocols