TEST CHANGE
Ustekinumab (Stelara) and Ustekinumab Antibodies
Order Code: FUKAU
CPT Code: 80299, 82397
Referral Laboratory: Mayo Medical Laboratories
REPLACEMENT TEST
Ustekinumab QN with Antibodies, Serum
Order Code: USEK
CPT Code: 80299, 83520
Referral Laboratory: Mayo Medical Laboratories
Effective October 14, 2020 MLabs will be discontinuing Ustekinumab (Stelara) and Ustekinumab Antibodies
(FUKAU) and replacing the test with Ustekinumab QN with Antibodies, Serum (USEK) per Mayo Medical Laboratories.
Collection Instructions: Collect approximately 1 mL of whole blood in a serum separator tube (SST) or red top immediately before next dose of drug administration (trough level). Centrifuge and aliquot the serum into a plastic tube and ship refrigerated (preferred) or frozen.
Methodology: Enzyme-Linked Immunosorbent Assay (ELISA)
Analytic Time: Test set up Tuesday and Friday, 1 day analytic time
Reference Range:
USTEKINUMAB QN, S:
Limit of quantitation is 0.3 mcg/mL
In inflammatory bowel disease, at post-induction measurement (week 8), concentrations above3.5 mcg/mL are associated with good outcomes
For maintenance stages:
Concentrations > or =1.0 mcg/mL are associated with clinical response and clinical remission
Concentrations > or =4.5 mcg/mL are associated with mucosal healing
USTEKINUMAB AB, S:
Limit of quantitation is 10 AU/mL
Absent: <10 AU/mL
Present: > or =10 AU/mL