[Chronic eosinophilic pneumonia involving eosinophil cationic protein and bone marrow cells].

A 64-year-old women presented with a dry cough. The common cold was diagnosed and she was given medication, but the symptom did not resolve. She came to our hospital, and multiple patchy shadows were seen on a chest X-ray film. Bronchoalveolar lavage fluid contained an abnormally high percentage of eosinophils. Microscopic examination of transbronchial lung biopsy specimens showed infiltration of eosinophils into the alveoli and alveolar septa. Chronic eosinophilic pneumonia was diagnosed. Analysis of bone marrow cells showed high percentages of mature eosinophilic cells, and blood serum had a high concentration of eosinophil cationic protein. An inhalation challenge test with methacholine revealed bronchial hypersensitivity and hyperresponsiveness. Prednisolone (30 mg/day) was given and the symptoms resolved. After steroid treatment, the patient was asymptomatic, although airway hyperresponsiveness remained. The concentration of eosinophil cationic protein in serum and the results of the methacholine inhalation test reflected the degree of chronic eosinophilic pneumonia, and the production of eosinophils in bone marrow was suppressed by steroid medication.