Infliximab Level for Rheumatic Diseases
Also known as: Anti-TNF-alpha Drug, TNF-alpha blocker, TNF-alpha inhibitor, Remicade®, Anti-TNF-alpha antibody
Use
When treatment of rheumatic diseases with infliximab or its biosimilar fails, a physician may need to consider adjusting dose or dosing intervals, switching to a different TNF blocker, or switching to a different drug agent (e.g., a non-TNF blocker). This assay specifically measures serum infliximab and infliximab‑dyyb (Inflectra) levels. Clinical studies suggest target infliximab trough concentrations of 2–8 mcg/mL or 2–10 mcg/mL in rheumatoid arthritis. Equivalence studies support applying infliximab clinical guidance to its biosimilars.
Special Instructions
Not provided.
Limitations
Not provided.
Methodology
Immunoassay (ELISA)
Biomarkers
Result Turnaround Time
2-3 days
Related Documents
For more information, please review the documents below
Specimen
Serum
Volume
1 mL
Minimum Volume
0.3 mL
Container
red‑top tube (no gel)
Collection Instructions
The blood should be drawn just before the next infusion of infliximab to measure the trough drug level.
Causes for Rejection
Serum separator tube (SST)
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | 48 hours |
| Refrigerated | 7 days |
| Frozen | -20 °C: 28 days; -70 °C: 70 days |