Antibodies to infliximab (ATIs) have been associated with loss of clinical response and lower serum infliximab (IFX) levels in some studies of patients with inflammatory bowel disease (IBD). Lower drug levels can mean less effect ont eh disease. It is clinically useful to be able to assess and predict diminishing response. A recent meta-analysis concluded that the presence of ATIs is associated with a significantly higher risk of loss of clinical response to IFX and lower serum IFX levels in patients with IBD. However, most studies were flawed in that published studies on this topic lack uniform reporting of outcomes and high risk of bias was present in all the included studies.
Similar conclusions are reached by reviews that look at this question and are likewise limited in the same way. For example, a recent paper outlines why antibodies to infliximab (ATI) cannot be used as a surrogate marker for immunogenicity,
or to predict clinical outcome or safety. This is because up to half of patients still need dose adjustment for recurrent symptoms and 20% of patients lose response, even when treatment is optimised to avoid ATI through scheduled maintenance therapy or concomitant immunomodulators. The effects of ATI is, therefore, diluted statistically in these studies.
Thus far many questions persist about how useful ATI testing can be. Measurement of serum antibodies to infliximab has not received clearance by the FDA andthere is not sufficient peer-reviewed scientific literature that demonstrates that the procedure is effective.
For Professional version see here