Test 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)
Secondary ID
609476Profile 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)
Specimen Type
SerumSpecimen Minimum Volume
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 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
Day(s) Performed
Monday, Wednesday, Friday
Report Available
2 to 5 daysPerforming Laboratory

CPT Code Information
80299
83520
Testing Algorithm
For more information see Ulcerative Colitis and Crohn Disease Therapeutic Drug Monitoring Algorithm.