Ustekinumab and Anti-Ustekinumab Antibody, DoseASSURE™ UST

CPT: 80299; 82397
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  • Anti-interleukin antibody drug, Anti-IL12, IL23 inhibitor
  • Biologic monitoring, therapeutic drug monitoring (TDM)
  • DoseASSURE
  • Immunogenicity testing, anti-drug antibody
  • Stelara

Test Includes

This test includes serial monitoring.

Expected Turnaround Time

11 - 25 days

Specimen Requirements


Serum (preferred) or plasma


3 mL

Minimum Volume

1 mL (Note: This volume does not allow for repeat testing.)


Red-top tube, gel-barrier tube, plasma EDTA tube, or plasma heparin tube


Allow a minimum clotting time of 30 to 60 minutes with serum separation within 2 hours of collection. Send serum in a plastic transport tube. To avoid delays in turnaround time when requesting multiple tests on frozen samples, please submit separate frozen specimens for each test requested.

Storage Instructions

Frozen (preferred) or refrigerated

Stability Requirements



Room temperature

14 days


14 days


14 days

Freeze/thaw cycles

Stable x6

Test Details


Provides ustekinumab drug concentration and anti‐ustekinumab antibodies in order to optimize treatment and facilitate clinical decision‐making.

This assay may be helpful in any patients on ustekinumab therapy for Crohn's disease, psoriasis, or other autoimmune conditions.


Drug concentration should be interpreted with confirmation of specimen collection timing.

Non‐trough concentrations may be misleading.

Trough blood collection (just before or within 24 hrs. of next dose) is suitable because target ranges and therapeutic cut‐offs have been established in clinical studies using trough concentration.

The drug half‐life should be taken into consideration when interpreting results from non‐perfect trough collections.

Some primary non‐responders have inadequate clinical response despite adequate trough levels.

As with other biologics, the optimal ustekinumab concentration depends upon patient‐specific factors including co‐morbidities, disease and desired therapeutic endpoint.

Positive anti‐ustekinumab antibodies should be interpreted in the context of the concomitant free ustekinumab drug level.

High serum biotin concentrations in patients taking biotin supplements may cause an interference in this assay. Patients may be advised to stop biotin consumption at least 72 hours prior to sample collection.


Electrochemiluminescence immunoassay (ECLIA)

Reference Interval

Ustekinumab drug level: <0.1 μg/mL

• Result ≥0.1 μg/mL indicates detection of ustekinumab

• In the presence of anti-ustekinumab antibodies, the ustekinumab drug level reflects the free, antibody-unbound fraction of ustekinumab in serum.

Anti-ustekinumab antibody: <40 ng/mL

• Result ≥40ng/mL indicates detection of anti-ustekinumab antibodies.

Additional Information

Drug Assay: The ustekinumab drug level typically reflects the antibody-unbound (the free fraction) of ustekinumab when serum anti-ustekinumab antibodies are present. In the absence of anti-ustekinumab antibodies, the ustekinumab drug level typically reflects the total ustekinumab concentration in serum.

Anti-drug Antibody Assay: This anti-ustekinumab antibody assay is “drug-tolerant,” that is, the presence of serum ustekinumab does not impede the detection and quantitation of anti-ustekinumab antibodies. This anti-ustekinumab antibody assay is specific; antibodies against other biologic drugs do not cross-react with this assay. All positive anti-ustekinumab antibody results are verified by a confirmatory test.

Both drug and anti-drug antibody assays have been developed and validated using the FDA guidance document Assay Development and Validation for Immunogenicity Testing of Therapeutic Protein Products (2016) as a reference.


Adedokun O, et al. P-007 Exposure-Response to SC Ustekinumab in Moderate–Severe Crohn’s Disease: Results From the IM-UNITI Maintenance Study. Advances in IBD meeting, Orlando, FL, abstract. Oct 2017.
Adedokun OJ, et al. Pharmacokinetics and Exposure-Response Relationships of Ustekinumab during IV Induction and SC Maintenance Treatment of Patients with Crohn’s Disease with UNITI-1, UNITI-2, and IM-UNITI Studies. Gastroenterology. 2016;150(4):S408.
Battat R, Kopylov U, Bessissow T, et al. Association Between Ustekinumab Trough Concentrations and Clinical, Biomarker, and Endoscopic Outcomes: Results in Patients with Crohn’s Disease. Clin Gastroenterol Hepatol. 2017 Sep;15(9):1427-1434.e2.28365485
Chiu H, Chu TW, Cheng YP, Tsai TF. The Association Between Clinical Response to Ustekinumab and Immunogenicity to Ustekinumab and Prior Adalimumab. PLoS One. doi:10:1371/journal.pone.0142930.26566272
Menting SP, van den Reek JM, Baerveldt EM, et al. The correlation of clinical efficacy, serum trough levels and antidrug antibodies in ustekinumab-treated patients with psoriasis in a clinical-practice setting. Br J Dermatol. 2015 Sep;173(3):855-857.25865153


Order Code Order Code Name Order Loinc Result Code Result Code Name UofM Result LOINC
504594 Ustekinumab Drug + Antibody 504595 Ustekinumab ug/mL 87408-1
504594 Ustekinumab Drug + Antibody 504596 Anti-Ustekinumab Antibody ng/mL 88992-3
Reflex Table for Anti-Ustekinumab Antibody
Order Code Order Name Result Code Result Name UofM Result LOINC
Reflex 1 506001 Serial Monitoring 000000 Serial Monitoring N/A
Reflex Table for Anti-Ustekinumab Antibody
Order Code Order Name Result Code Result Name UofM Result LOINC
Reflex 1 506001 Serial Monitoring 511958 PDF 80563-0

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