Dissolution of eosinophil granules in bronchial lavage obtained from allergic asthmatics during bronchoprovocation and seasonal exposure

Bronchial lavage was used to assess changes in cell populations from the airways of allergic asthmatic patients who were exposed seasonally to allergens or challenged with aerosolized allergen. Bronchoprovocation (BPC) was used to elicit early and late asthmatic responses (LAR), and bronchial lavage was performed at baseline out of season or at either 2, 6, or 24 hours after challenge, and during the season in five mildly symptomatic patients. Four normal subjects were challenged with allergen and lavaged either 2 or 6 hours later. Bronchial lavage fluid and cells from subsegmental bronchi were immediately passed through 2 layers of gauze and cells were washed once with Hank's buffered salt solution and gently centrifuged. Cyto-preps of lavage cells were prepared and examined by light, microscopy with a Wright-Giemsa stain. These cells were then mixed with 50% Percoll and centrifuged at 1500 RPM for 20 minutes. This procedure was adopted to concentrate small numbers of cells such as eosinophils and mast cells into a pellet which contained relatively few macrophages.