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Test Code LAB0001884 Ustekinumab Quantitation with Antibodies, Serum

Additional Codes

Mayo Test ID
USTEK


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 Serum

Collection Instructions:

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

2. Centrifuge and aliquot serum into a plastic vial.


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)

Useful For

Evaluating patients for loss of response, partial response on initiation of therapy, autoimmune or hypersensitivity reactions, primary nonresponse, reintroduction after drug holiday, endoscopic/computed tomography enterography recurrence (in inflammatory bowel disease) and acute infusion reactions using trough level specimens

 

This test does not differentiate between the originator and biosimilar products.

Profile Information

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

Method Name

Enzyme-Linked Immunosorbent Assay (ELISA)

Reporting Name

Ustekinumab QN with Antibodies, S

Specimen Type

Serum

Specimen Minimum Volume

Serum: 0.35 mL

Specimen Stability Information

Specimen Type Temperature Time
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 QUANTITATION:

Limit of quantitation is 0.3 mcg/mL

 

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 ANTIBODIES:

Limit of quantitation is 10 AU/mL

Absent: <10 AU/mL

Present: ≥10 AU/mL

Interpretation

During maintenance stages in inflammatory bowel diseases (IBD), trough ustekinumab concentrations between 3 and 7 mcg/mL are associated with clinical response and remission. Reactive monitoring is employed when response is suboptimal. Subtherapeutic trough concentrations are most often due to increased drug clearance related to inflammatory burden or body weight and are commonly managed by dose interval shortening.

 

Ustekinumab quantification (mcg/mL)

Antibodies to ustekinumab absent

Antibodies to ustekinumab present

<1.0

For IBD nonresponders:
Insufficient ustekinumab is present.
In the absence of antibodies to ustekinumab (ATU), consider optimizing therapy by shortening the administration intervals.

For IBD nonresponders:
Insufficient ustekinumab is present. ATU detected can contribute to faster clearance of ustekinumab and treatment failure.

≥1.0

For IBD 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 shortening administration intervals to reach desired target or switching therapeutic regimen outside of the drug class.

For IBD 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 closely monitoring ATU for persistence before switching therapeutic regimen outside of the drug class.

Day(s) Performed

Monday, Wednesday, Friday

Report Available

2 to 5 days

Specimen Retention Time

14 days

Performing Laboratory

Mayo Clinic Laboratories in Rochester

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