Infliximab-graded challenge in a patient with Crohn’s disease and adalimumab hypersensitivity

Background Infliximab and adalimumab are monoclonal antibodies to tumor necrosis factor alpha (TNF-á) used in the treatment of various inflammatory disorders. Infliximab, a chimeric monoclonal antibody, is postulated to be more immunogenic as it is not entirely humanized. Despite reports of adalimumab treatment in patients after an adverse reaction to infliximab, there is a paucity of literature reporting the converse – treatment with infliximab after adverse reaction to adalimumab. Thus, it is difficult to estimate the risk of cross-sensitization. Graded drug challenges are utilized for patients unlikely to be allergic to a specific drug, but where concern for a reaction remains.