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Order Code USTEK Ustekinumab Quantitation with Antibodies, Serum


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.


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

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

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

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

Method Description

Ustekinumab (UTK) quantitation and anti-ustekinumab antibody measurements are performed using enzyme-linked immunosorbent assay. Microwell strips are pre-coated with UTK or anti-UTK antibody . Calibrators, controls, and patient samples are added to separate wells, allowing either UTK or antibodies to ustekinumab (ATUs) to bind to immobilized antigen. Unbound sample is washed away, and a second horseradish peroxidase-labeled anti-UTK or UTK (conjugate) is added to each well. A second incubation step allows the conjugate to bind to the UTK or ATU that has become attached to the microwells. After washing away the excess of unbound conjugate, the remaining enzyme activity is determined by adding a substrate and measuring the intensity of the color that develops in a spectrophotometer. The signal obtained is proportional to the amount of UTK or ATUs in the patient sample.(Unpublished Mayo method)

Day(s) Performed

Monday, Wednesday, Friday

Performing Laboratory

Mayo Clinic Laboratories in Rochester

CPT Code Information

80299

83520