Mycobacterium kansasii lung infection associated with myelofibrosis - A case refractory to treatment with antitubercular agents

A case of Mycobacterium kanasasii lung infection associated with myelofibrosis is reported. A 32-year-old woman was admitted to Keio University Hospital because of fever. One year before admission, a diagnosis of myelofibrosis was made at another hospital. The initial chest X-ray film showed bilateral diffuse infiltrative shadows and right hilar enlargement. Sputum cultures yielded Mycobacterium kansasii on 3 occasions. A fever of 38°C or higher persisted for about 4 months despite the use of antitubercular agents, including INH, RFP, SM, and PZA. During the course of treatment, the hilar and mediastinal lymph node enlargement became more severe, and this was followed by calcification of the nodes. The fever and chest X-ray findings improved in response to the addition of treatment with EB, Ofloxacin, TH, and an increase in the doses of INH (from 300 to 500 mg/day) and RFP (from 450 to 600 mg/day). The patient was discharged 14 months after admission. It is rare especially in Japan for a Mycobacterium kansasii lung infection (not disseminated) to persist in spite of treatment with antitubercular drugs, including RFP or TH. The response to treatment may have been impaired by an immunological disorder associated with the myelofibrosis.