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HelpTest Code LAB3246 Leflunomide Metabolite (Teriflunomide), Serum
Additional Codes
LEFLU
Reporting Name
Leflunomide Metabolite, SSCH Clinical System Name: Leflunomide Level
Useful For
Therapeutic monitoring of patients actively taking leflunomide
Assessment of elimination in patients requiring enhanced elimination of the drug
Performing Laboratory
Mayo Clinic Laboratories in Rochester
Specimen Type
Serum RedSpecimen Required
Supplies: Sarstedt Aliquot Tube, 5 mL (T914)
Collection Container/Tube:
Preferred: Red top
Acceptable: Serum gel
Submission Container/Tube: Plastic vial
Specimen Volume: 1 mL
Collection Instructions:
1. Draw blood no sooner than 12 hours (trough value) after last dose.
2. Within 2 hours of collection, centrifuge and aliquot serum into a plastic vial.
Collect 2.0 mL whole blood in a Red top.
Specimen Minimum Volume
0.3 mL
Specimen Stability Information
| Specimen Type | Temperature | Time | Special Container |
|---|---|---|---|
| Serum Red | Ambient (preferred) | 28 days | |
| Frozen | 28 days | ||
| Refrigerated | 28 days |
Reference Values
Therapeutic: >40 mcg/mL
Elimination: <0.020 mcg/mL
Day(s) Performed
Monday, Wednesday, Friday
TAT: 4 - 7 days
Test Classification
This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. It has not been cleared or approved by the US Food and Drug Administration.CPT Code Information
80193
LOINC Code Information
| Test ID | Test Order Name | Order LOINC Value |
|---|---|---|
| LEFLU | Leflunomide Metabolite, S | 44828-2 |
| Result ID | Test Result Name | Result LOINC Value |
|---|---|---|
| 60292 | Leflunomide Metabolite, S | 44828-2 |
Method Description
Serum samples are diluted in an aqueous solution containing deuterated teriflunomide as an internal standard. This is injected onto a liquid chromatography system with Cohesive turboflow to separate the drug from serum components and analyzed by negative-ion mode tandem mass spectrometry.(Unpublished Mayo method)
Report Available
3 to 5 daysReject Due To
| Gross hemolysis | OK |
| Gross lipemia | OK |
| Gross icterus | OK |
Method Name
High-Turbulence Liquid Chromatography Mass Spectrometry (HTLC-MS/MS)
Forms
If not ordering electronically, complete, print, and send a Therapeutics Test Request (T831) with the specimen.
Aliases: A77 1726; Arava; Leflunomide; Leflunomide metabolite; Teriflunomide