Bierau J, Bakker J A, Lindhout M, van Gennip A H
Laboratory of Biochemical Genetics, Department of Clinical Genetics, Maastricht University Hospital, Maastricht, The Netherlands.
Nucleosides Nucleotides Nucleic Acids. 2006;25(9-11):1129-32. doi: 10.1080/15257770600894253.
The indication for the determination of both thiopurine methyltransferase (TPMT) and inosine triphosphate pyrophosphohydrolase is identical (i.e., adverse drug reactions toward mercaptopurines). Therefore, we tested whether or not our standard procedure to prepare erythrocyte lysates for measurement of TPMT activity, which includes treatment with Chelex 100 (a chelating resin), was suitable for the measurement of ITPase activity. It also was tested to see if ITPase activity differs in EDTA and Heparin anti-coagulated blood samples. We found that there was no difference between the ITPase activity in erythrocyte lysates prepared from EDTA or Heparin anti-coagulated blood. Treatment with a chelating resin or omission of magnesium from the assay procedure resulted in decreased and nearly absent ITPase activity, respectively. We conclude that untreated erythrocyte lysates obtained for determination of TPMT activity are suitable for determination of ITPase activity. However, after treatment with Chelex 100 the erythrocyte lysates become unsuitable for determination of ITPase activity.
硫嘌呤甲基转移酶（TPMT）和肌苷三磷酸焦磷酸水解酶的检测指征相同（即对巯嘌呤的药物不良反应）。因此，我们测试了我们用于制备红细胞裂解物以测量TPMT活性的标准程序（包括用Chelex 100（一种螯合树脂）处理）是否适用于测量ITPase活性。还测试了EDTA和肝素抗凝血液样本中的ITPase活性是否存在差异。我们发现，从EDTA或肝素抗凝血液制备的红细胞裂解物中的ITPase活性没有差异。用螯合树脂处理或在测定程序中省略镁分别导致ITPase活性降低和几乎消失。我们得出结论，用于测定TPMT活性的未处理红细胞裂解物适用于测定ITPase活性。然而，用Chelex 100处理后，红细胞裂解物变得不适用于测定ITPase活性。
