The aim of the present study was to evaluate the release of some potential mediators of allergic reactions, such as histamine, peptide leukotrienes (LTs), LTB4 and prostaglandin D2 (PGD2), in bronchoalveolar lavage (BAL) fluids from 11 patients with respiratory allergy (eight with bronchial asthma and three with allergic rhinitis), who underwent specific endobronchial challenge. Histamine, peptide LT, and PGD2 levels in BAL fluids increased significantly after antigen stimulation both in patients with asthma and in patients with rhinitis. By contrast, LTB4 concentration was always below the limits of detection of the radioimmunoassay. In patients with asthma, histamine concentration increased from 5.3 ± 0.6 ng/ml in lavages obtained before provocation to 20.2 ± 5.8 ng/ml (mean ± SEM; p <0.04) 5 minutes after bronchoprovocation. Peptide LTs increased from 0.32 ± 0.08 to 0.82 ± 0.21 ng/ml (p <0.02) and PGD2 from 0.06 ± 0.01 ng/ml to 0.36 ± 0.09 ng/ml (p <0.02). Elevated histamine, peptide LT, and PGD2 concentrations were also found in the 15-minute postchallenge BAL fluids. Similar results were obtained in patients with rhinitis. Histamine concentration was 3.4 ± 0.6 ng/ml in prechallenge bronchial lavages and 11.3 ± 1.7 ng/ml in postchallenge lavages; peptide LTs increased from 0.13 ± 0.008 ng/ml to 0.73 ± 0.21 ng/ml, and PGD2 from 0.05 ± 0.01 ng/ml to 0.26 ± 0.06 ng/ml. Histamine, peptide LTs, and PGD2 were released into bronchial airways after local antigen challenge in all 11 subjects with respiratory allergy, whereas in three normal subjects (not allergic to the antigen used), there was no release of these mediators into BAL fluid above their basal concentrations. These findings, combined with known effects on human airways, suggest that histamine, peptide LTs, and PGD2 may be important in the pathogenesis of early antigen-induced asthmatic reactions.
ASJC Scopus subject areas
- Immunology and Allergy