METHOD OF DETERMINING THIOPURINE METHYLTRANSFERASE (TPMT) ACTIVITY IN ERYTHROCYTES

摘要

The invention relates to a method of determining thiopurine methyltransferase activity in erythrocytes. The inventive method consists in: incubating a preparation of erythrocytes containing said TPMT enzyme in the presence of a suitable substrate and a methyl group donor, under conditions such that the product of the reaction catalysed by said enzyme forms; and extracting said reaction product with ethyl acetate and determining the content in said reaction product using high performance liquid chromatography (HPLC). Said method can be used to determine the TPMT activity in patients that may have to undergo treatment with azathioprine before beginning said treatment. In this way, patients with very low TPMT activity can be pinpointed and the azathioprine to be administered can be dosed in a personalised manner.