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Test Code
THIOP
Test Name
Thiopurine Metabolites by LC-MS/MS
CPT Codes
80299
Included Tests
  • 6-Thioguanine Nucleotides (6-TGN)
  • 6-Methylmercaptopurine (6-MMP)
Expected Turnaround Time
2 - 4 days
Clinical Utility

Aids physicians in dose adjustments, minimizing dose-dependent toxicity, and monitoring compliance of thiopurine drug therapy
Specimen and Container Info

Specimen Type: Whole Blood

Collection Container: Lavender Top (EDTA)

Desired Specimen Volume: 3 mL
Collection Instructions

This specimen cannot be shared with testing for tacrolimus, cyclosporine, sirolimus or everolimus. Testing for these must be ordered separately and separate specimens submitted.

  1. Collect a lavender top (EDTA) tube via venipuncture.
Processing and Submission Instructions
  1.  Transport 3 mL of whole blood in the original collection container. Do not aliquot.
Transport Instructions

Transport to the laboratory refrigerated. 
Stability Requirements

Room Temperature

24 hours

Refrigerated

8 days
Causes for Rejection
  • Hemolysis
  • Clotted specimen
Methodology
Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS)
Reference Intervals

See patient report.
Limitations

This test cannot be used to predict optimal starting dose. This test does not replace monitoring of patients using other laboratory tests (eg, complete blood cell count, liver function tests).
Reference Lab
Mayo Clinic Laboratories
Testing Schedule
Routine, 3 times per week
The American Medical Association (AMA) Current Procedural Terminology (CPT) codes published by HNL Lab Medicine are guidelines and are intended for informational purposes only. CPT coding is the exclusive responsibility of the billing entity. View the Terms.
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