Diffuse alveolar hemorrhage after infliximab treatment of Crohn's disease.

Infliximab (Remicade), a chimeric monoclonal antibody to tumor necrosis factor-alpha (anti-TNF-alpha), is being used with increasing frequency in the treatment of Crohn's disease. Infliximab's safety profile to date has been good with reported adverse events being mild to moderate. We report a case of diffuse alveolar hemorrhage after the second infliximab infusion in a patient with Crohn's disease. The mechanism by which infliximab may have caused the observed pulmonary insult remains unknown. Physicians should be aware of the possible association between infliximab treatment and the development of alveolar hemorrhage. Future cases should be reported.