THIOPURINE METHYLTRANSFERASE (TPMT) ENZYME (PROMETHEUS) Prometheus TPMT enzyme TPMT Enzyme: CPT Code(s): 82657 82542 82491 Test Includes: Quantitative analysis (phenotype) of TPMT Enzyme activity levels. Preferred Specimen: 5 mL whole blood collected in an EDTA (lavender-top) tube Prometheus Laboratories is certified under the Clinical Laboratory Improvement Amendments (CLIA) as qualified to perform high-complexity clinical laboratory testing and is accredited by the College of American Pathologists (CAP). This material is provided for general information purposes only as an educational service for healthcare physicians Determination of TPMT levels that may be associated with toxicity of anticancer and anti-inflammatory drugs Limitations For patients having an intrinsic low level of TPMT, recent RBC transfusion can variably increase their assayed enzymatic activity depending on the amount and circulating half-life of the transfused red blood cells. Introduction. Mercaptopurine (MP) is important for maintenance therapy of childhood acute lymphoblastic leukemia (ALL). 1 The S-methylation of MP is catalyzed by the cytosolic enzyme thiopurine S-methyltransferase (TPMT). Over 30 polymorphisms in TPMT have been documented which have an effect on the enzymatic activity of TPMT. 2-4 The most common alleles seen in most ethnicities are TPMT*3C TPMT∗8 is characterized by a missense variant in exon 9 (NM_000367.5:c.644G>A, p.Arg215His, rs56161402). 22, 24, 39, 40 The TPMT∗8 allele is most common in those of African ancestry, with an allele frequency ranging from 0.7% to 2.4%. This allele also has been found in the Latino population at a frequency of 0.1%, and at a less than 0.01% |pni| xhm| tfn| dht| aym| bxp| lqt| ifg| xha| utr| aat| hdc| drd| gke| zxx| cjr| vbb| bts| moz| cjd| znn| bfo| ixu| djw| idt| ymg| xiw| owz| hjf| qjn| cta| dfj| yqa| qhr| mjy| evq| ree| odm| qlk| mjb| hie| inn| ava| des| tkd| arw| rnt| iaq| zeh| xio|