Infliximab Quantitation with Reflex to Antibodies to Infliximab, Serum
Use
This test is useful for evaluating patients for loss of response, partial response on initiation of therapy, autoimmune or hypersensitivity reactions, primary nonresponse, reintroduction after a drug holiday, recurrence of disease in inflammatory bowel disease, acute infusion reactions, and proactive monitoring. It does not differentiate between the originator and biosimilar products.
Special Instructions
Draw blood immediately before the next scheduled dose (trough specimen). For 12 hours before specimen collection, patients should not take multivitamins or dietary supplements containing biotin (vitamin B7). Mayo Clinic may add reflex testing for antibodies to infliximab if infliximab levels are below 5.1 mcg/mL, with additional charges applied for this reflex test.
Limitations
The test cannot differentiate between the reference product Remicade and infliximab biosimilar products available, including Renflexis, Inflectra, Ixifi, and Avsola. Immunogenicity rates may vary between products, and anti-drug antibodies may still form. Clinical decisions should not be based solely on infliximab quantitation or ATI assessment without considering the complete clinical context.
New York Approved
Methodology
Mass Spectrometry (LC-MS/MS)
Biomarkers
LOINC Codes
- 39803-2
- 39803-2
- 59462-2
Result Turnaround Time
3-6 days
Related Documents
For more information, please review the documents below
Specimen
Serum
Volume
1 mL
Minimum Volume
0.5 mL
Container
Plastic vial
Collection Instructions
Within 2 hours of collection, centrifuge and aliquot serum into plastic vial.
Patient Preparation
Draw blood immediately before the next scheduled dose (trough specimen). For 12 hours before specimen collection, avoid multivitamins or dietary supplements containing biotin.
Causes for Rejection
Gross hemolysis and icterus
Stability Requirements
| Temperature | Period |
|---|---|
| Refrigerated | 28 days |
| Frozen | 28 days |