1 x EDTA Blood
TPMT activity is measured at 37°C, pH 7.4 using 6-thioguanine as the substrate.
(NOTE Units are now mU/L as from 09/08/10, reference ranges have also changed from this date)
DEFICIENT Less than 10
HIGH Greater than 150
Assessment of patients who are considering Azothioprine therapy
Other information : TPMT is inducible by thiopurine drugs. If the patient has been receiving azathioprine or 6-mercaptopurine prior to the TPMT assay, the result may be raised above the basal level.
For genetic testing of the TPMT and NUDT15 genes to predict toxicity in patients treated with thiopurines and sample requirements, see https://www.exeterlaboratory.com/genetics/prediction-of-thiopurine-toxicity-tpmt-and-nudt15-testing/
Cannot be added on to an existing request
Dept of Chemical Pathology Sandwell & West Birmingham Hospital
There is no need to ever repeat this testSpecimen Labelling Procedure