Methods for Bronchoalveolar Lavage in Asthmatic Patients Following Bronchoprovocation and Local Antigen Challenge

¹ From the Divisions of Allergy-Immunology and Pulmonary Medicine, Department of Internal Medicine, Veterans Administration, and University of Iowa College of Medicine, Iowa City

We employed bronchoalveolar lavage (BAL) of subsegmental airways to study the local inflammatory effects of aeroallergen bronchoprovocation (BPC) and local instillation of allergen in allergic asthmatic patients, allergic rhinitis patients, and normal subjects. Two protocols were used: (1) BAL was performed in three subsegments following BPC or during spontaneous seasonal exposure, and (2) 5-ml aliquots of increasing doses of allergen were instilled into a single subsegment until there was at least 30 percent closure of the airway; the airway was then immediately lavaged. A subsegment in the opposite lung was lavaged as a control site. These same two segments were lavaged again two to 14 days later and the cells and fluid analyzed. Fifty-five lavages have been performed without complications. Pulmonary function tests (FEV₁) were not significantly disturbed by either local challenge or lavage procedures. Cells were examined using light and electron microscopy and showed inflammatory cells in alveolar airways and dissolution of mast cell and eosinophil granules. Using selected criteria, we were able to use these methods in mildly, seasonally asthmatic patients to obtain safely cells and fluid for analysis. These techniques may permit studies which further our understanding of the mechanisms responsible for allergic asthma.