Thiopurine Metabolites (TPMT) Enzyme
Additional Codes
LAB7831
Performing Laboratory
PROMETHEUS Laboratories Inc.
Methodology
PROMETHEUS TPMT Enzyme testing provides a quantitative analysis of a patient’s thiopurine methyltransferase (TPMT) enzyme activity level. Because each patient metabolizes thiopurines differently, the efficacy and toxicity of thiopurines can vary widely from patient to patient. Knowledge of the TPMT enzyme phenotype may reduce time of response, allow physicians to individualize dosing, identify patients in whom thiopurine therapy should be avoided and help reduce the risk of leukopenia.
Specimen Requirements
Specimen Type: Whole blood
Container/Tube: Lavender top (EDTA)
Specimen Volume: 5 mL
Specimen Transport Temperature
Refrigerate 8 days/Ambient <24 hours OK/Frozen NO
Day(s) Test Set Up
Turnaround Time:
3 business days from date of receipt.
Reference Values
Normal TPMT Activity: >21.0 EU/mL
Intermediate TPMT Activity: 6.0-21.0 EU/mL
Low TPMT Activity: <6.0 EU/mL
Test Classification and CPT Coding
82657
82542