Thiopurine Metabolites 6MP

Synonyms

Allscripts (AEHR) Order Name

Thiopurine Metabolites

Sunrise Clinical Manager (SCM) Order Name

Thiopurine Metabolites

EPIC Order Name

Thiopurine Metabolites

Clinical Info

This assay measures the red-cell concentration of 6-MMP (formed from 6-MP by thiopurine methyltransferase) and also measures the concentration of the resulting 6-TG after removal of the mono-, di-, or tri-phosphates from the various 6-thioguanine nucleotides.

Specimen Type

Blood

Container

Lavender Top Tube

Collection Instructions

Container/Tube: EDTA Lavender top tube
Specimen: 3 mL EDTA whole blood (1 mL min)
Transport Temperature: Refrigerate
Stability: 14 Days Refrigerated
                Unstable Frozen
Note: Send specimen within14 days of collection.

Transport Instructions

Refrigerate

Specimen Stability

14 Days Refrigerated
                Unstable Frozen
Note: Send specimen within14 days of collection.

Methodology

Whole blood washing and red blood cell harvesting/counting. Liquid chromatography/tandem mass spectrometry (LC/MS-MS) after acidic hydrolysis.

Days Performed

TAT: 7-13 Days
Limitations
This test should only be performed for patients currently on thiopurine therapy. This therapy includes administration of azathioprine or mercaptopurine. This test may not be useful in patients with autoimmune hepatitis.

Performing Laboratory

LabCorp of America

CPT

80375
LOINC Code: 82869-9

PDM

5911041

Result Interpretation

 

6-TGN
For treatment of inflammatory bowel disease (IBD)*
Suboptimal dosing	<235 pmol 6-TGN/8×108 red blood cells
Optimal dosing	235−450 pmol 6-TGN/8×108 red blood cells
Increasing risk for myelotoxicity and leucopenia	>450 pmol 6-TGN/8×108 red blood cells
6-MMPN
Hepatotoxicity risk	>5700 pmol 6-MMPN/8×108 red blood cells

*Chevaux JB, Peyrin-Biroulet L, Sparrow MP. Optimizing thiopurine therapy in inflammatory bowel disease. Inflamm Bowel Dis. 2011 Jun; 17(6):1428-1435.

Forms