Infliximab Quantitation with Antibodies to Infliximab, Serum
Use
This test is useful for evaluating patients for loss of response, partial response upon initiation of therapy, autoimmune or hypersensitivity reactions, primary nonresponse, reintroduction after a drug holiday, endoscopic/computed tomography enterography recurrence in inflammatory bowel disease, acute infusion reactions, and for proactive monitoring. It helps to measure the concentration of infliximab, a monoclonal antibody against TNF-alpha, and identify antibodies against infliximab that might undermine treatment.
Special Instructions
When ordering this test, ensure to draw the blood immediately before the next scheduled dose (trough specimen). If not ordering electronically, complete and send the Gastroenterology and Hepatology Test Request form with the specimen. Note that there should be a 12-hour period before specimen collection during which the patient should refrain from biotin-containing supplements. This test cannot differentiate between the originator infliximab product and its biosimilars.
Limitations
The assays performed to determine infliximab levels and antibodies cannot distinguish between the originator and biosimilar infliximab products. Biotin levels exceeding 12.5 ng/mL can interfere with the antibody test. Variations in infliximab concentrations could occur during the induction phase of treatment as steady-state has not yet been achieved. Immunogenicity assays may not properly register when serum infliximab levels are high.
New York Approved
Methodology
Mass Spectrometry (LC-MS/MS)
Biomarkers
LOINC Codes
- 103791-0
- 59462-2
- 72623-2
- 39803-2
Result Turnaround Time
3-6 days
Related Documents
For more information, please review the documents below
Specimen
Serum
Volume
1.2 mL
Minimum Volume
0.5 mL
Container
Plastic vial
Collection Instructions
Draw blood immediately before next scheduled dose (trough specimen). Within 2 hours of collection, centrifuge and aliquot serum into a plastic vial.
Patient Preparation
For 12 hours before specimen collection, patient should not take multivitamins or dietary supplements containing biotin.
Causes for Rejection
Gross hemolysis, gross icterus, heat-treated specimens.
Stability Requirements
| Temperature | Period |
|---|---|
| Refrigerated | 28 days |
| Frozen | 28 days |