Back to results
US 8,497,471 B2Granted
Mass spectrometry assay for thiopurine-S-methyl transferase activity and products generated thereby
AssigneeQuest Diagnostics Investments Incorporated
InventorsWilliam F. Haddon, Nigel J. Clarke
Life of this patent
Estimating the term…
Abstract
Methods are described for measuring the amount of a methylation TPMT enzyme product in a sample. More specifically, mass spectrometric methods are described for detecting and quantifying 6-MMP or isotopically labeled 6-MMP in a test sample utilizing mass spectrometric techniques and for using such methods to determine the activity of TPMT enzyme that is present in a sample.
Claims14
A method for determining thiopurine-S-methyl transferase (TPMT) activity in a patient prior to initiation of 6-MP administration, said method comprising:
- a. incubating a sample obtained from a patient for a specified period of time with an isotopically labeled substrate for TPMT under conditions suitable for the generation of an isotopically labeled 6-methylmercaptopurine (6-MMP) product by TPMT in the sample, thereby forming an incubated sample;
- b. ionizing said isotopically labeled 6-methylinercaptopurine (6-MMP) from said incubated sample under conditions suitable to produce one or more ions detectable by mass spectrometry;
- c. determining the amount of one or more ions by mass spectrometry;
- d. using the amount of said one or more ions to determine the amount of isotopically labeled 6-methylmercaptopurine (6-MMP) in said incubated sample;
- and
- e. using the amount of isotopically labeled 6-MMP determined in said incubated sample to determine TPMT activity in the patient.
3 more elements
Dependencies are inferred from the claim text.