Sign in →

Test Code Billings Clinic: 9573 Mayo: LEFLU Leflunomide Metabolite (Teriflunomide), Serum

Reporting Name

Leflunomide Metabolite, S

Performing Laboratory

Mayo Clinic Laboratories in Rochester

Useful For

Therapeutic monitoring of patients actively taking leflunomide

 

Assessment of elimination in patients requiring enhanced elimination of the drug

Method Name

High-Turbulence Liquid Chromatography Mass Spectrometry (HTLC-MS/MS)


Specimen 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 serum

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.


Specimen Type

Serum Red

Specimen Minimum Volume

Serum: 0.3 mL

Specimen Stability Information

Specimen Type Temperature Time
Serum Red Ambient (preferred) 28 days
  Frozen  28 days
  Refrigerated  28 days

Reject Due To

Gross hemolysis OK
Gross lipemia OK
Gross icterus OK

Reference Values

Therapeutic: >40 mcg/mL

Elimination: <0.020 mcg/mL

Interpretation

Therapy: clinical targets for serum teriflunomide (leflunomide metabolite) concentrations are still being determined, but levels greater than 40 mcg/mL appear to correlate with better outcome.

 

Elimination: serum concentrations less than 0.020 mcg/mL (20 ng/mL) on two independent tests at least 2 weeks apart are preferred to minimize potential teratogenesis for patients considering pregnancy.

Day(s) Performed

Monday, Wednesday, Friday

Report Available

3 to 5 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

Forms

If not ordering electronically, complete, print, and send 1 of the following forms with the specimen:

-Therapeutics Test Request (T831)

-Neurology Specialty Testing Client Test Request (T732)