5 - 8 days
Test Updated:
Thiopurine Methyltransferase (TPMT), Phenotype
TPMT Enzyme
TPMTPHE
TPMT Phenotype
Thiopurine Methyltransferase (TPMT), Erythrocytes, Enzyme Activity
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Test Overview
Phenotypic test that provides a quantitative measurement of TPMT enzyme activity levels to assist physicians with azathioprine (Imuran) or 6-MP (Purinethol) dosing strategies. Individuals with low thiopurine methyltransferase are at risk of excessive myelosuppression.
Normal TPMT Activity: >21.0 EU/mL; Intermediate TPMT Activity: 6.0-21.0 EU/mL; Low TPMT Activity: <6.0 EU/mL.
* Reference ranges may change over time. Please refer to the original patient report when evaluating results.