Abstract
A 44-year-old Japanse man who had suffered from bronchial asthma since childhood was given the diagnosis of chronic eosinophilic pneumonia because of his symptoms, chest roentgenographic findings, and the results of a transbronchial lung biopsy. At the time of the onset of the disease, the pleural effusion contained 73% eosinophils. Symptoms were relieved and the laboratory findings returned forward normal after a short course of high-dose corticosteroids. The concentrations of IL-5, IL-6, and G-CSF in pleural fluid and in serum were very high; the concentrations of these cytokines were 3 times to 35 times higher in pleural fluid than in serum. In contrast, no IL-3 or GM-CSF was detected in any of these samples. The precise etiology of chronic eosinophilic pneumonia is still unclear, but this case suggests that inappropriate production of IL-5, IL-6 and G-CSF in the lung play a pivotal role in this disease. Inhibition of the production of these cytokines may be another therapeutic approach to this disease.