Method of determining thiopurine methyltransferase activity
US6576438B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | May 16, 2001 |
| Grant date | Jun 10, 2003 |
| Priority date | — |
| Expiry date | Oct 4, 2021 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N2333/91011
- WIPO fieldBiotechnology
- WIPO sectorChemistry
Abstract
The present invention provides a method of determining thiopurine methyltransferase (TPMT) activity in a subject. The method includes the steps of reacting sample obtained from the subject with a thiopurine derivative that is not 6-mercaptopurine to produce a methylated purine product; contacting the reacted sample with acid, thereby precipitating proteinaceous material from the reacted sample; separating supernatant from the precipitated proteinaceous material; and detecting in the supernatant the methylated purine product, where the amount of the methylated purine product indicates a level of thiopurine methyltransferase activity in the subject. In a method of the invention, the subject can be, for example, an inflammatory bowel disease patient. In one embodiment, the acid used to precipitate proteinaceous material is perchloric acid, for example, 70% perchloric acid. In another embodiment, the thiopurine derivative used as a substrate is 6-thioguanine. In a further embodiment, the methylated purine product is detected by fluorescence, which can be combined, if desired, with high performance liquid chromatography (HPLC).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.