[Two cases of respiratory infection complicating treatment with infliximab].

Infliximab, an anti-TNF-alpha agent, is highly effective against rheumatoid arthritis and Crohn's disease. However, respiratory infection can occur as a complication. We report two cases complicated by respiratory infection following administration of infliximab. The first case, a 67-year-old woman with rheumatoid arthritis, developed pneumocystis pneumonia after three courses of infliximab therapy. The second case, a 31-year-old man with Crohn's disease, developed pulmonary tuberculosis after four courses of infliximab therapy. Respiratory complications associated with anti-TNF therapy include infectious diseases such as pneumocystis pneumonia, tuberculosis, and bacterial pneumonia. They often lead a fulminant course, and early diagnosis is essential. The final report of a survey of the initial 5000 cases with rheumatoid arthritis treated with infliximab in Japan was released in April 2006; pulmonary infectious complications included 22 cases of pneumocystis pneumonia, 14 cases of tuberculosis, and 108 cases of bacterial pneumonia. The growing use of anti-TNF therapy might lead to increasing pulmonary complications. Accumulation of similar cases is expected to elucidate the mechanism of the complications and methods for effective prophylaxis.