Infliximab and Anti-Infliximab Antibody, DoseASSURE™ IFX

Serum (preferred) or plasma

2 mL

1 mL (Note: This volume does not allow for repeat testing).

Red-top tube, gel-barrier tube or plasma from green-top tube

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 ug/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, rhematoid arthritis, or other autoimmune conditions. This test includes long-term serial monitoring of results.

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.

Electrochemiluminescence Immunoassay (ECLIA)