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.
摘要：
硫嘌呤甲基转移酶（TPMT）是一种参与硫嘌呤药物代谢的细胞溶质酶，用于治疗多种恶性和非恶性免疫学疾病。与低酶活性相关的TPMT基因中的多态性可以在治疗期间产生明显的药理作用。TPMT红细胞活性的测定是TPMT表型分配基因分型的一个有价值的辅助试验。尤其是在存在不确定基因型的情况下。我们提出了一种测定人红细胞中TPMT活性的方法，其中我们利用LC-MS/MS来测量使用6-巯基嘌呤作为底物和S-腺苷甲硫氨酸（SAM）作为甲基供体的红细胞（RBC）裂解物中形成的6-甲基巯基嘌呤的量。该方法已成功实施，并被证明可用于人体标本。
