A B C D E F G H I J K L M N O P Q R S T U V W X Y Z # |
TPMT Activity
MessageWHOLE BLOOD - DO NOT CENTRIFUGE
COLLECT TWO SEPARATE LAVENDER EDTA TUBES.
COLLECT TWO SEPARATE LAVENDER EDTA TUBES.
Test Code
18831
Alias/See Also
LAB00321
THIOPURINE METHLTRANSFERASE ACTIVITY
THIOPURINE METHLTRANSFERASE ACTIVITY
CPT Codes
84433
Preferred Specimen
4 mL whole blood collected in two of each separate tubes
Minimum Volume
2 mL (x2)
Instructions
Collect venous blood in 2 separate EDTA (lavender-top) tubes (4 mL in each tube). Ship at 2-8° C (refrigerated) within 24 hours of collection.
Blood is collected prior to azathioprine (Imuran) or 6-mercaptopurine (6-MP, Purinethol) therapy for screening purposes. The draw time is at physician's discretion.
Blood is collected prior to azathioprine (Imuran) or 6-mercaptopurine (6-MP, Purinethol) therapy for screening purposes. The draw time is at physician's discretion.
Transport Container
EDTA (lavender-top) tube(s)
Transport Temperature
Refrigerated (cold-packs)
Specimen Stability
Room temperature: 48 hours
Refrigerated: 9 days
Frozen: Unacceptable
Refrigerated: 9 days
Frozen: Unacceptable
Reject Criteria (Eg, hemolysis? Lipemia? Thaw/Other?)
Hemolysis • Clotted • Animal specimen • Forensic specimen • Received frozen
Methodology
Chromatography/Mass Spectrometry
FDA Status
This test was developed and its analytical performance characteristics have been determined by Quest Diagnostics. It has not been cleared or approved by FDA. This assay has been validated pursuant to the CLIA regulations and is used for clinical purposes.
Setup Schedule
Sun-Thurs
Report Available
5-7 days
Reference Range
>12 | Normal |
4-12 | Heterozygote or low metabolizer |
<4 | Homozygote Deficient Range |
Clinical Significance
Help prevent hepatotoxicity from thiopurine therapy.
This test helps identify individuals at increased risk of hepatotoxicity from thiopurine dose escalation. Patients with a TMPT activity of 4-12 nmol 6-MMP/hr/mL RBC (heterozygote/low metabolizer) are at increased risk and may require a lower dose of thiopurine drug.
This test helps identify individuals at increased risk of hepatotoxicity from thiopurine dose escalation. Patients with a TMPT activity of 4-12 nmol 6-MMP/hr/mL RBC (heterozygote/low metabolizer) are at increased risk and may require a lower dose of thiopurine drug.
Performing Laboratory
Quest Diagnostics Nichols Institute-San Juan Capistrano, CA |
33608 Ortega Highway |
San Juan Capistrano, CA 92675-2042 |