Provides infliximab drug concentration levels as well as levels of anti-infliximab antibodies.
In the absence of anti-infliximab antibodies, the infliximab drug level typically reflects the total infliximab concentration in serum. In the presence of anti-infliximab antibodies, the infliximab drug level typically reflects the antibody-unbound fraction of infliximab concentration in serum. The presence of infliximab drug, even at concentrations well above target treatment levels (>50 μg/mL), does not interfere with the anti-infliximab antibody detection. This assay may be helpful for any patients on infliximab therapy for diseases such as Crohn's disease, inflammatory bowel disease, ulcerative colitis, rheumatoid arthritis, or other autoimmune conditions.
Limitations Failure of infliximab therapy may not always be due to the presence of anti-infliximab antibodies. In addition, the absence of anti-infliximab antibodies does not guarantee positive response to treatment.
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.
Specimen Sources
Blood, ArterialBlood, CapillaryBlood, Central LineBlood, Venous
Specimen Types
Blood
Container
Gold Top Tube
Collection Instructions
Container/Tube: Gold top or Red top tube Specimen: 2 ml serum (1 mL min- does not allow for repeat testing) Transport Temperature: Refrigerated Stability: 7 Days Room Temperature 7 Days Refrigerated 359 Days Frozen
Note: Serum must be separated from cells within 45 minutes of venipuncture
Specimen Volume
2 ml serum (1 mL min- does not allow for repeat testing)
Transport Instructions
Refrigerated
Specimen Stability
7 Days Room Temperature 7 Days Refrigerated 359 Days Frozen
Note: Serum must be separated from cells within 45 minutes of venipuncture
Methodology
Electrochemiluminescence immunoassay (ECLIA)
Days Performed
Performing Laboratory
LabCorp of America
CPT
80299 82397
PDM
5963016
Only Orderable at Locations:
Orderable Everywhere
Results
Component Name
Base Name
Common Name
External Name
INFLIXIMAB DRUG LEVEL
INFLIXIMAD
INFLIXIMAB DRUG LEVEL
Infliximab Drug Level
ANTI-INFLIXIMAB ANTIBODY
INFLIXAB
ANTI INFLIXIMAB ANTIBODY
Anti-Infliximab Antibody
Result Interpretation
Infliximab drug level:
<0.4 µg/mL
• Result ≥0.4 µg/mL
indicates detection of infliximab.
• In the presence of anti-infliximab antibodies, the
infliximab drug level reflects the antibody-unbound fraction of
infliximab concentration in serum.
Anti-infliximab antibody:
<22 ng/mL
• Result ≥22 ng/mL indicates
detection of anti-infliximab antibodies.
