[A case of interferon-alpha-induced pneumonitis]

We report a case of interferon-alpha-induced pneumonitis. A 61-year-old man was diagnosed as having recurrence of renal cell carcinoma and treated with 3 x 10(6) unit of interferon-alpha daily for 8 weeks. On the 55th injection, he presented with a high fever and mild dyspnea, and his chest CT films revealed diffuse reticulonodular shadows in both lung fields. We suspected interstitial pneumonitis due to interferon-alpha, and started steroid therapy. He showed rapid improvement of symptoms and diffusing capacity, and the pulmonary infiltrates in his chest CT were markedly reduced. Transbronchial lung biopsy (TBLB) revealed slightly thickened alveolar walls and small granulomatous-like lesions. These granulomatous-like lesions showed marked accumulation of macrophages. To our knowledge, this is the first report of interferon-alpha-induced pulmonary injury in Japan.