Toxicity of infliximab in the course of treatment of Crohn's disease.

Infliximab is a monoclonal antibody directed against the pro-inflammatory mediator TNF-alpha, which was approved in the US in 1998 for treatment-resistant Crohn's disease. Since that time, the indications have dramatically expanded to include rheumatoid arthritis, ankylosing spondylitis, psoriasis and most recently, active ulcerative colitis. Although the safety profile in the initial studies was quite favourable, subsequent studies have shown that a small percentage of patients reported severe side effects, including pneumonia, tuberculosis, lymphoma, drug-induced lupus and hepatotoxicity. Although these complications are rare, it is important to properly screen patients for predisposing conditions before beginning treatment. Furthermore, concurrent use of other immunosuppresive agents, such as 6-mercaptopurine, may reduce the incidence of less serious side effects, such as arthralgias, myopathies and other antibody-associated diseases. Since its approval, infliximab has revolutionised the treatment of Crohn's disease and has shown benefit in a variety of other inflammatory conditions, but significant toxicities can occur that necessitate thorough screening protocols and periodic clinical evaluation.