TPMT Activity Profile, RBC
Order Code:
TPMT3
Test Summary
Detection of individuals with low thiopurine methyltransferase (TPMT) activity who are at risk for excessive myelosuppression or severe hematopoietic toxicity when taking thiopurine drugs. Detection of individuals with hyperactive TPMT activity who have therapeutic resistance to thiopurine drugs and may develop hepatotoxicity if treated with these drugs.
Aliases
- TPMT Phenotype, Azathioprine toxicity, Imuran toxicity, Mercaptopurine (6-MP) toxicity
Specimen Collection
Special Instructions
N/A
Preferred Specimen
5 mL whole blood collected in an EDTA (lavender-top) tube
Minimum Volume
3 ml
Instructions
N/A
Patient Preparation
Thiopurine methyltransferase (TPMT) enzyme activity can be inhibited by several drugs and may contribute to falsely low results. Patients should abstain from the following drugs for at least 48 hours prior to TPMT testing: naproxen (Aleve), ibuprofen (Advil, Motrin), ketoprofen (Orudis), furosemide (Lasix), sulfasalazine (Azulfidine), mesalamine (Asacol), olsalazine (Dipentum), mefenamic acid (Ponstel), trimethoprim (Proloprim), methotrexate, thiazide diuretics, and benzoic acid inhibitors.
Storage
Lavender top tube (EDTA)
Transport Temperature
Refrigerated (cold packs)
Specimen Stability
- Room temperature: 6 days
- Refrigerated: 6 days
- Frozen: N/A
Limitations
N/A
Other Acceptable Specimens
Green top (sodium or lithium heparin), dark blue top (metal free sodium heparin), or plasma gel tubes
Unacceptable Specimens
Gross hemolysis
Order Code
TPMT3
EPIC (Premier) Code
LAB6822
Includes
N/A
CPT Code
- 80372
Billing Code
- 650068
CPT Statement
Methodology
Liquid Chromatography Tandem Mass Spectrometry (LC-MS/MS)
FDA Status
This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. It has not been cleared or approved by the US Food and Drug Administration.
Physician Attestation of Informed Consent
N/A
Testing Laboratory
Mayo Clinic Laboratories
200 First Street SW
Rochester MN, 55905
200 First Street SW
Rochester MN, 55905
Department
Reference Testing
Reference Range
N/A
Setup Schedule / Expected Turnaround Time
Monday, Wednesday, Friday; Report available: 4 - 7 days
Specimen Collection
Special Instructions
N/A
Preferred Specimen
5 mL whole blood collected in an EDTA (lavender-top) tube
Minimum Volume
3 ml
Instructions
N/A
Patient Preparation
Thiopurine methyltransferase (TPMT) enzyme activity can be inhibited by several drugs and may contribute to falsely low results. Patients should abstain from the following drugs for at least 48 hours prior to TPMT testing: naproxen (Aleve), ibuprofen (Advil, Motrin), ketoprofen (Orudis), furosemide (Lasix), sulfasalazine (Azulfidine), mesalamine (Asacol), olsalazine (Dipentum), mefenamic acid (Ponstel), trimethoprim (Proloprim), methotrexate, thiazide diuretics, and benzoic acid inhibitors.
Storage
Lavender top tube (EDTA)
Transport Temperature
Refrigerated (cold packs)
Specimen Stability
- Room temperature: 6 days
- Refrigerated: 6 days
- Frozen: N/A
Limitations
N/A
Other Acceptable Specimens
Green top (sodium or lithium heparin), dark blue top (metal free sodium heparin), or plasma gel tubes
Unacceptable Specimens
Gross hemolysis
Result Information
Methodology
Liquid Chromatography Tandem Mass Spectrometry (LC-MS/MS)
Testing Laboratory
N/A
Reference Range
N/A
Setup Schedule / Expected Turnaround Time
Monday, Wednesday, Friday; Report available: 4 - 7 days