[M. kansasii lung infection occurring in a compromised host with idiopathic pulmonary fibrosis]

A 61-year-old man was admitted to our hospital because of persisting cough, sputum and shortness of breath for four months. Brushing specimens and BALF bronchoscopically obtained revealed acid-fast bacilli and TBLB showed pathological findings consistent with interstitial pneumonia. Based on these results, clinical symptoms, chest roentgenograms on admission and identification of M. kansasii, a diagnosis of M. kansasii lung infection occurred in idiopathic pulmonary fibrosis was made. The patient's symptoms consistent with M. kansasii lung infection and his sputum became negative 6 weeks after antituberculosis chemotherapy with INH, SM and RFP. Because of an increasing dyspnea due to pulmonary fibrosis, however, the patient received oxygen therapy. This case suggested an increasing tendency of compromised hosts associated with M. kansasii lung infection.