Chronic eosinophilic pneumonia progressing to lung fibrosis.

A 65 year old Japanese man was hospitalized with fever. Opacities distributed mainly in the subpleural regions were found on chest computed tomographic scan (CT), and these promptly cleared with corticosteroid therapy. Four years later, he presented with severe eosinophilia. Both chest X-ray and high resolution CT scan showed ground-glass opacities and honeycombing, suggesting lung fibrosis. A lung biopsy demonstrated intra-alveolar eosinophil infiltration, interstitial thickening with eosinophil infiltration, and a widely-distributed desquamative interstitial pneumonia-like reaction. With corticosteroid therapy, the ground-glass opacities decreased with a corresponding clinical improvement, although lung honeycombing and blood eosinophilia remained. In this case, circulating intercellular adhesion molecule-1 and circulating and bronchoalveolar lavage fluid eosinophil granule proteins were felt to be more effective markers for evaluating disease activity than the blood eosinophil number.