Utility of Measuring Free vs. Total Anti-Infliximab Antibodies in Assessing Clinical Response to Infliximab in Patients With Inflammatory Bowel Disease
Therapeutic drug monitoring (TDM) of Infliximab (IFX) has been in use in our centre since 2012 and has become increasingly widespread in the UK with the availability of several CE marked assays. TDM of IFX is useful in optimisation of therapy in patients with inflammatory bowel disease (IBD). The detection of antibodies against Infliximab can guide clinical decision making with regard to dose escalation, immunomodulation or drug switching / withdrawal. However the utility of measuring free versus total (IFX-complex + free) anti-Infliximab antibody (ADAb) remains debatable, further complicated by lack of assay standardisation.