Sign in →

Test Code 0298554 Tacrolimus, Blood

Additional Codes

 

Mayo Test ID
TAKRO

 

Performing Laboratory

Mayo Clinic Laboratories in Rochester

Useful For

Monitoring whole blood tacrolimus concentration during therapy, particularly in individuals coadministered CYP3A4 substrates, inhibitors, or inducers

 

Adjusting dose to optimize immunosuppression while minimizing toxicity

 

Evaluating patient compliance

Method Name

High-Performance Liquid Chromatography/Tandem Mass Spectrometry (HPLC-MS/MS)

Reporting Name

Tacrolimus, B

Specimen Type

Whole Blood EDTA


Specimen Required


Container/Tube: Lavender top (EDTA)

Specimen Volume: 3 mL

Collection Instructions: 

1. Draw blood immediately before a schedule dose.

2. Do not centrifuge.

3. Send specimen in original tube.

Additional Information: Therapeutic range applies to trough specimens drawn immediately prior to a.m. dose.


Specimen Minimum Volume

1 mL

Specimen Stability Information

Specimen Type Temperature Time
Whole Blood EDTA Refrigerated (preferred) 14 days
  Ambient  14 days
  Frozen  14 days

Reject Due To

Hemolysis

Mild OK; Gross OK

Lipemia

Mild OK; Gross OK

Icterus

Mild OK; Gross OK

Other

NA

Reference Values

5.0-15.0 ng/mL (Trough)

 

Target steady-state trough concentrations vary depending on the type of transplant, concomitant immunosuppression, clinical/institutional protocols, and time post-transplant. Results should be interpreted in conjunction with this clinical information and any physical signs/symptoms of rejection/toxicity.

Interpretation

Most individuals display optimal response to tacrolimus with trough whole blood levels of 5.0 to 15.0 ng/mL. Preferred therapeutic ranges may vary by transplant type, protocol, and comedications.

 

Therapeutic ranges are based on samples drawn at trough (ie, immediately before a scheduled dose). Blood drawn at other times will yield higher results.

 

The assay is specific for tacrolimus; it does not cross-react with cyclosporine, cyclosporine metabolites, sirolimus, sirolimus metabolites, or tacrolimus metabolites. Results by liquid chromatography with detection by tandem mass spectrometry are approximately 30% less than by immunoassay.

Day(s) and Time(s) Performed

Monday through Friday; Continuous until 3 p.m.

Saturday, Sunday; Continuous until 1 p.m.

Analytic Time

Same day/1 day

Specimen Retention Time

14 days

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

80197

LOINC Code Information

Test ID Test Order Name Order LOINC Value
TAKRO Tacrolimus, B 77348-1

 

Result ID Test Result Name Result LOINC Value
35145 Tacrolimus, B 77348-1

Forms

If not ordering electronically, complete, print, and send a General Request (T239) with the specimen.