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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 specimen in original tube. Do not aliquot, centrifuge, or freeze.
Specimen Minimum Volume
1.5 mL
Testing Algorithm
Red blood cell (RBC) count is first performed and then the thiopurine metabolites' values are determined by liquid chromatography-tandem mass spectrometry (LC-MS/MS). 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) RBC
6-Methylmercaptopurine (6-MMP): Less than or equal to 5700 pmol/8x10(8) RBC
Day(s) and Time(s) Performed
Monday through Friday, 2:30 p.m.
Saturday, 10 a.m.
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 U.S. 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, et al: Optimizing the use of thiopurines in inflammatory bowel disease. Ther Adv Chronic Dis. 2015;6(3):138-146
2. Shipkova M, Armstrong V, 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. 2003:49(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. 1999:730:273-274
4. Kirchherr H, Shipkova M, 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. 2013:35(3):313-321
Method Description
Red blood cell (RBC) count is first performed and then the thiopurine metabolites values are determined by mass spectrometry.(Unpublished Mayo Method)
Analytic Time
Same day/1 dayReject Due To
| Gross hemolysis | Reject |
| Gross lipemia | Reject |
| Gross icterus | Reject |
| Clotted | Reject |
Method Name
Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS)
Forms
If not ordering electronically, complete, print, and send a Gastroenterology and Hepatology Client Test Request (T728) with the specimen.