Cellular composition of fluid in the airways of patients with house dust sensitive asthma, classified by clinical symptoms.

The cellular composition of bronchoalveolar lavage (BAL) fluid was observed in 28 patients with house dust mite-sensitive asthma. The proportion of neutrophils in the BAL fluid was significantly higher in the patients between the ages of 50 and 59 and those over 60 than in the patients younger than age 39. There was a significant difference in the number of neutrophils in patients aged 30-39 years and in those over 40 at the onset of disease. The cellular composition varied among the three types of asthma; the mean percentage of cells in the BAL fluid was 1.1% neutrophils and 21.3% eosinophils in type Ia (simple bronchoconstriction), 9.1% neutrophils and 23.0% eosinophils in type Ib (bronchoconstriction + hypersecretion), and 34.4% neutrophils and 12.0% eosinophils in type II (bronchiolar obstruction). The results suggested that an increased frequency of both neutrophils and eosinophils correlates with the mechanism of hypersecretion, and that a marked increase in the proportion of neutrophils is involved in bronchiolar obstruction.