Relationship of cytomorphology to spirometric findings in cigarette smokers.

The objective of the study was to determine the relationship between sputum cytomorphology and pulmonary function. A cross-sectional correlation analysis of results from pulmonary function testing and eight cytomorphologic indices of inflammation and metaplasia was conducted in 143 smokers registered in a residential smoking-cessation program. Stepwise multiple regression analysis revealed that after adjusting for age and smoking history, lower levels of pulmonary function were related significantly to higher levels of macrophage pigmentation, neutrophils and metaplasia. Higher levels of macrophages were associated with higher levels of pulmonary function. The overall regression coefficient, 0.35, was highly significant (F[5,136] = 14.84, P = .0001). Categorical analyses revealed that smokers with high counts of neutrophils, macrophage pigmentation, columnar cells, spirals and metaplasia were two to three times more likely to have abnormal pulmonary function than were those with low counts. From these results we conclude that elevations in certain cytologic indices are associated with abnormal lung function. These findings may reflect the pathophysiology of obstructive lung disease. Longitudinal studies are required to determine whether cytomorphologic parameters can identify individuals at risk for functional deterioration at a stage amenable to intervention.