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Test Code USTEK Ustekinumab Quantitation with Antibodies, Serum

Reporting Name

Ustekinumab QN with Antibodies, S

Performing Laboratory

Mayo Clinic Laboratories in Rochester

Useful For

Evaluation of loss of response to therapy

 

Quantification of ustekinumab in human serum

 

Trough level quantitation for evaluation of patients treated with ustekinumab

 

Detection of antibodies to ustekinumab in human serum

Method Name

Enzyme-Linked Immunosorbent Assay (ELISA)


Specimen Required


Supplies: Sarstedt Aliquot Tube, 5 mL (T914)

Collection Container/Tube:

Preferred: Serum gel

Acceptable: Red top

Submission Container/Tube: Plastic vial

Specimen Volume: 0.5 mL

Collection Instructions:

1. Draw blood immediately before the next dose of drug administration (trough level).

2. Centrifuge and aliquot serum into a plastic vial.


Specimen Type

Serum

Specimen Minimum Volume

0.35 mL

Specimen Stability Information

Specimen Type Temperature Time Special Container
Serum Refrigerated (preferred) 21 days
  Frozen  21 days

Reject Due To

Gross hemolysis OK
Gross lipemia OK
Gross icterus OK
Heat-inactivated specimen Reject

Reference Values

USTEKINUMAB QN, S:

Limit of quantitation is 0.3 mcg/mL

 

In inflammatory bowel disease, at post-induction measurement (week 8), concentrations above 3.5 mcg/mL are associated with good outcomes.

 

For maintenance stages:

Concentrations ≥1.0 mcg/mL are associated with clinical response and clinical remission

Concentrations ≥4.5 mcg/mL are associated with mucosal healing

 

USTEKINUMAB AB, S:

Limit of quantitation is 10 AU/mL

Absent: <10 AU/mL

Present: ≥10 AU/mL

Interpretation

Antibodies to ustekinumab (ATU) absent

ATU present

Ustekinumab quantification

<1.0 mcg/mL

For nonresponders:
Insufficient ustekinumab is present.
In the absence of ATU, consider optimizing therapy by increasing the dose or shortening the administration intervals, or by adding an immunomodulator to the therapeutic regimen.

For nonresponders:
Insufficient ustekinumab is present. Antibodies-to-ustekinumab detected can contribute to faster clearance of ustekinumab and treatment failure. Clinical evaluation is recommended.

Ustekinumab quantification

≥1.0 mcg/mL

For nonresponders:
If the sample was collected at trough ie, immediately before the next infusion, the results could suggest a mechanistic failure of ustekinumab. The provider may consider switching therapeutic regimen outside of the drug class.

For nonresponders:
If the sample was collected at trough ie, immediately before the next infusion, the results could suggest a mechanistic failure of ustekinumab. The provider may consider switching therapeutic regimen outside of the drug class.

Day(s) Performed

Monday, Wednesday, Friday

Report Available

2 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

80299

83520

LOINC Code Information

Test ID Test Order Name Order LOINC Value
USTEK Ustekinumab QN with Antibodies, S In Process

 

Result ID Test Result Name Result LOINC Value
USQN Ustekinumab QN, S 87408-1
USTAB Ustekinumab Ab, S 87409-9

Forms

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

-Gastroenterology and Hepatology Test Request (T728)

-Therapeutics Test Request (T831)

Profile Information

Test ID Reporting Name Available Separately Always Performed
USQN Ustekinumab QN, S No Yes
USTAB Ustekinumab Ab, S No Yes