Detection of IL-5 and IL-1 receptor antagonist in bronchoalveolar lavage fluid in acute eosinophilic pneumonia.

BACKGROUND

Acute eosinophilic pneumonia is an idiopathic cause of respiratory failure, characterized by very high numbers of alveolar eosinophils without significant blood eosinophilia.

OBJECTIVE

The purpose of this study was to determine which cytokines are associated with acute eosinophilic pneumonia.

METHODS

Soluble IL-1 type II receptor and the cytokines IL-1 beta, IL-1ra, IL-3, IL-5, granulocyte-macrophage colony-stimulating factor, and tumor necrosis factor-alpha were measured in serum and in bronchoalveolar lavage fluid from two patients with acute eosinophilic pneumonia during both acute and convalescent phases.

RESULTS

Compared with patients with adult respiratory distress syndrome, the patients with acute eosinophilic pneumonia had high bronchoalveolar lavage fluid levels of IL-5, IL-1ra, and soluble type II IL-1 receptor but not IL-1 beta, tumor necrosis factor-alpha, IL-3, or granulocyte-macrophage colony-stimulating factor. Bronchoalveolar lavage fluid levels of IL-5 and IL-1ra fell after resolution of symptoms. In the serum of patients with acute eosinophilic pneumonia, IL-5 was not detectable, and IL-1ra was initially high but fell after corticosteroid treatment.

CONCLUSION

Acute eosinophilic pneumonia is characterized by locally high levels of IL-5, IL-1ra, and soluble type II IL-1 receptor in the alveolar space.