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Test Code LEFLU Leflunomide Metabolite (Teriflunomide), Serum

Additional Codes

Epic Ordering Code LAB3040466
NBS code LBC07518
Service code 36915

Reporting Name

Leflunomide Metabolite, S

Specimen Type

Serum Red


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.


National University Hospital-Singapore Note:

NUH Outreach Laboratories:
Specimen Requirements
Submit only one of the following:
Preferred: Red Top
Acceptable: Yellow Top
Collect specimen at least 12 hours (trough value) after last dose.
Processing Requirements
Centrifuge and aliquot serum into a Mayo plastic tube.
Specimen type: Serum
Volume: 1 mL
Storage/transport requirements: Refrigerated

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)

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

Method Name

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

Day(s) Performed

Monday, Wednesday, Friday

Report Available

3 to 5 days
National University Hospital-Singapore Note:

Please note that this is a referral test requiring transport to the external testing facility and an additional 3-5 days is required.

Reference Values

Therapeutic: >40 mcg/mL

Elimination: <0.020 mcg/mL

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

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

Secondary ID

60292

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.
National University Hospital-Singapore Additional Information:

Last updated 04/08/2026