Home
HelpTest Code THIOP Thiopurine Metabolites, Whole Blood
Reporting Name
Thiopurine Metabolites, BUseful For
Aids physicians in dose adjustments, minimizing dose-dependent toxicity, and monitoring compliance of thiopurine drug therapy
Performing Laboratory
Mayo Clinic Laboratories in Rochester
Specimen Type
Whole Blood EDTAShipping Instructions
Specimen must be shipped refrigerated.
Specimen Required
Container/Tube: Lavender top (EDTA)
Specimen Volume: 3 mL
Collection Instructions: Send whole blood specimen in original tube. Do not aliquot, centrifuge, or freeze.
Specimen Minimum Volume
1.5 mL
Testing Algorithm
A red blood cell (RBC) count is performed followed by determined of thiopurine metabolite values by liquid chromatography-tandem mass spectrometry. Values are utilized to calculate and report a final result (unit of measure: pmol/8 x 10[8] RBC) for 6-thioguanine nucleotides and 6-methylmercaptopurine derivative analyte.
Specimen Stability Information
| Specimen Type | Temperature | Time | Special Container |
|---|---|---|---|
| Whole Blood EDTA | Refrigerated (preferred) | 8 days | |
| Ambient | 24 hours |
Reference Values
6-Thioguanine Nucleotides (6-TGN): 235-450 pmol/8x10(8) red blood cell (RBC)
6-Methylmercaptopurine (6-MMP): Less than or equal to 5700 pmol/8x10(8) RBC
Day(s) Performed
Monday through Friday
Test Classification
This test was developed, and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. This test has not been cleared or approved by the US Food and Drug Administration.CPT Code Information
80299LOINC Code Information
| Test ID | Test Order Name | Order LOINC Value |
|---|---|---|
| THIO | Thiopurine Metabolites, B | 82869-9 |
| Result ID | Test Result Name | Result LOINC Value |
|---|---|---|
| 49580 | 6-Thioguanine Nucleotides | 32660-3 |
| 49581 | 6-Methylmercaptopurine | 32654-6 |
Clinical Reference
1. Goel RM, Blaker P, Mentzer A, Fong SCM, Marinaki AM, Sanderson JD: Optimizing the use of thiopurines in inflammatory bowel disease. Ther Adv Chronic Dis. 2015 May;6(3):138-146
2. Shipkova M, Armstrong VM, Wieland E, Oellerich M: Differences in nucleotide hydrolysis contribute to the differences between erythrocyte 6-thioguanine nucleotide concentrations determined by two widely used methods. Clin Chem. 2003 Feb:49(2):260-268
3. Boulieu R, Dervieux T: High-performance liquid chromatographic determination of methyl 6-mercaptopurine nucleotides (Me6-MPN) in red blood cells: analysis of Me6-MPN per se or Me6-MPN derivative? J Chromatogr B Biomed Sci Appl. 1999 Jul 9;730(2):273-276
4. Kirchherr H, Shipkova M, von Ahsen N: Improved method for therapeutic drug monitoring of 6-thioguanine nucleotides and 6-methylmercaptopurine in whole-blood by LC/MSMS using isotope-labeled internal standards. Ther Drug Monit. 2013 Jun:35(3):313-321
Method Description
Red blood cell count is first performed and then the thiopurine metabolites values are determined by mass spectrometry.(Unpublished Mayo Method)
Report Available
2 to 4 daysReject Due To
| Gross hemolysis | Reject |
| Moderate hemolysis | Reject |
| Gross lipemia | OK |
| Gross icterus | OK |
| Clotted | Reject |
Method Name
Liquid Chromatography Tandem Mass Spectrometry (LC-MS/MS)
Forms
If not ordering electronically, complete, print, and send Gastroenterology and Hepatology Client Test Request (T728) with the specimen