Infliximab-Induced Nonspecific Interstitial Pneumonia

Infliximab has well-established complications including injection site and allergic reactions, cytopenias, induction of autoimmune and demyelinating diseases and malignancy, especially lymphoma. Pulmonary complications are well documented and include serious respiratory infections from tuberculosis, fungal and opportunistic pathogens. This has prompted a Food and Drug Administration black-box warning recommending close surveillance for these diseases. Nonspecific interstitial pneumonitis (NSIP) secondary to tumor necrosis factor-alpha inhibitor (TNF-alpha) therapy is less well described. Rarely, TNF-alpha inhibitor therapy has been reported to cause NSIP when used in conjunction with other immunosuppressive agents. Literature search revealed 12 independent patients with presumed infliximab-induced NSIP in 8 separate publications; all patients were on concomitant steroid sparing immunosuppressive agents, complicating cause and effect. The authors report a case in which infliximab is surmised to cause NSIP in the absence of other steroid sparing immunosuppressants in a young female with ulcerative colitis. Of importance, the patient was taking no additional steroid sparing immunomodulating agents. The diagnosis was based on clinical presentation and radiologic and histopathological data. Cessation of infliximab and high-dose steroid therapy resulted in complete resolution of the patient’s presenting signs and symptoms.