ABSTRACT
Biological therapies have revolutionized the treatment of Crohns disease (CD) ever since their introduction in 1998. Infusion or injection reactions, the development and implications of anti-drug antibodies, the role of concomitant immunomodulators, incidence of medication-induced lupus-like reaction, and issues regarding risk of neoplasm have been the subject of many investigations worldwide. It was the first biological therapy released for the treatment of CD. Infliximab is the only biological therapy to date with large clinical trials specifically designed to evaluate the response of CD related fistulas. Checking trough infliximab levels may be helpful when assessing for cause of loss of response; patients with low drug levels and no anti-infliximab antibodies can be treated with dose escalation; those who have developed antibodies should be switched to a different biological agent. The best results occur when agents are given together with a concomitant immunosuppressant, in part due to lower incidence of anti-drug antibodies and other acute reactions.
