RIDASCREEN®Anti-IFX Antibodies

Intended use:

RIDASCREEN® Anti-IFX Antibodies is an enzyme linked immunoassay intended for the quantitative determination of antibodies to infliximab (ATI) in human serum and plasma.

Key features

• CE-marked versions of the ELISA tests of KU Leuven
• Highly specific antibodies
• Validated in clinical trials
• Validated on automated ELISA readers (e.g. DSX®)

Therapeutic Drug Monitoring
Infliximab (IFX) is a chimeric antibody that targets the pro-inflammatory cytokine TNF-alpha. The introduction of infliximab has revolutionized the treatment of chronic inflammatory diseases like inflammatory bowel disease (IBD), rheumatoid arthritis (RA) and spondyloarthritis. It has been shown that infliximab can induce deep remission and improve the patient’s quality of life. Some patients do not respond to infliximab therapy upon induction (primary non-responders), while others lose response over time (secondary non-responders).

Immunogenicity

Secondary loss of response is often due to the development of anti-infliximab antibodies (ATI), because of the immunogenic character of the drug. ATI can develop in any patient undergoing infliximab therapy and are primarily neutralizing the activity of infliximab through immunocomplex formation. In addition, these immunocomplexes are rapidly cleared from the system. Analytically, they are responsible for subtherapeutic infliximab concentrations. Therefore, in the case of very low trough concentrations of infliximab (< 1 μg/ml), subsequent measurement of ATI may be helpful to determine the optimal treatment strategy.

Diagnostic Value

The diagnostic value of the RIDASCREEN® Anti-IFX Antibodies lies in its ability to stratify patients with subtherapeutic infliximab concentrations (< 1 µg/ml) in patients who need dose intensification or a drug (class) switch. Patients with low infliximab concentrations (< 1 µg/ml) and low ATI titers can benefit from infliximab dose intensification, as shown in several studies. However, the ATI titer of patients with low ATI titers undergoing a dose intensified treatment regimen must be adequately monitored. Patients that have high ATI titers are preferably switched to another drug, both within class or out of class.