Sputum cell counts in airway disease: a useful sampling technique.

Quantitative sputum cell counts from patients with asthma and chronic bronchitis were performed and found to be reproducible. Sputum from carefully characterized subjects with asthma contained large numbers of eosinophils and formalin-sensitive metachromatic (mast) cells. In contrast, the macrophage was the dominant cell type in the sputum from smokers with chronic bronchitis. In a third group of patients with corticosteroid responsive-chronic cough and normal methacholine airway responsiveness the sputum contained eosinophils and metachromatic cells, similar to the asthmatic subjects. Sputum cell counts are a useful, noninvasive method for the identification of this pattern of inflammatory response in patients with airway diseases.