Serum neutrophil chemotactic activity and leukocyte count after house dust induced bronchospasm.

Neutrophil chemotactic activity of the serum, leukocyte count and total eosinophil count were determined before and after bronchial provocation with inhalation of house dust or acetylcholine. Airway parameters were determined by whole-body plethysmography. The airway conductance started to return to normal between 20 and 60 min after provocation as did the chemotactic activity. The largest increase of serum neutrophil chemotactic activity was measured 20 min after challenge with house dust, and the activity did not return to the initial value within 24 h, unlike specific airway conductance which was normalized at 24 h. No alteration of the leukocyte count was found. A significant decrease of the total eosinophil count was observed at 60 min, then a 1.5-fold increase was seen at 24 h. Positive correlation was found between the eosinophil count and the lung function. A putative pathophysiological role of the neutrophil chemotactic factor of mast cell origin in bronchial asthma is suggested.