Development of interstitial pneumonia in a rheumatoid arthritis patient treated with infliximab, an anti-tumor necrosis factor alpha-neutralizing antibody.

Infliximab, an anti-tumor necrosis factor (TNF)-alpha antibody, was introduced to a 66-year-old woman with methotrexate (MTX)-resistant rheumatoid arthritis (RA). Although the TNF-blocking therapy was successful, she developed noninfectious interstitial pneumonia (IP) after a second infusion of infliximab. In most cases reported previously, infliximab-associated noninfectious IP occurred after a second or third infusion of infliximab, and this type of IP was more fatal in comparison with cases associated with MTX treatment alone. Keeping a sharp lookout on IP development during this period is crucial to the success of infliximab treatment. After MTX discontinuation and steroid pulse therapy, our patient made a dramatic recovery from IP.