Combined immunosuppression is more dangerous than monotherapy: what is fact and what is fiction?

A number of immunosuppressants are used in the treatment of IBD. They have different modes of action but most of them affect different cell types and all are able to increase the number of infections, in particular opportunistic infections. Some may also lead to an increased number of malignomas. This is of particular importance in a disease such as Crohn's disease, which seems to be at least in part due to an immune deficiency. Data with regard to the differences of the effects of immunosuppressant combinations versus monotherapy are rare. Combinations with steroids, particularly, seem to pose a problem; however, an increased risk most probably also exists for other combinations. Therefore, in order to downregulate inflammation, we should use combined immunosuppression only if really necessary and only for short periods of time. The ultimate goal of the restitution of epithelial integrity and the maintenance of the mucosal barrier will better be achieved by other approaches.