Bronchial Lavage and Bronchoalveolar Lavage in Allergen-induced Single Early and Dual Asthmatic Responders

Abstract

The phenotypic cellular profile of bronchial lavage (BL) and bronchoalveolar lavage (BAL) was studied in 7 single early (SR) and 10 dual asthmatic responders (DR). Lavage was performed, after previously having determined bronchial hyperresponsiveness to histamine and the response to house dust mite (HDM) challenge. The recovered lavage fluid was separated in two fractions, BL and BAL. Total fluid recovery and cell number from the BL and BAL were comparable in both patient groups. Differential cell counting and immunocytochemistry were performed. DR had a significantly higher number of eosinophils and EG2+ cells in BL but not in their BAL. No differences could be found in CD4+, CD8+, and HLA-DR+ cells. A strong correlation was found between eosinophils in the BL+ and EG2+ cells in the BL (r = 0.79, p < 0.001) and between eosinophils in the BL and peripheral blood eosinophils (r = 0.70, p < 0.0025). The number of EG2+ cells and the number of epithelial cells in both BL and BAL showed a correlation (r = 0.55, p < 0.05). Dual responders had a higher total IgE (p < 0.01), and total serum IgE correlated well with the eosinophils in the BL (r = 0.85, p < 0.0001). Our observations demonstrate cellular differences in the lung on mainly a bronchial level between single early and dual asthmatic responders. A bronchial lavage eosinophil and EG2+ cell count and higher blood total IgE level are associated with the tendency to develop a dual asthmatic response.