Dynamics of eosinophil infiltration in the bronchial mucosa before and after the late asthmatic reaction.
We wanted to determine whether changes in bronchial hyperresponsiveness (BHR) following allergen challenge show a time relationship with inflammatory events in the airways of allergic asthmatic subjects. Lavage was performed and endobronchial biopsies were taken via the fiberoptic bronchoscope, before, and 3 and 24 h after, allergen challenge, on separate occasions, in nine dual asthmatic responders. The numbers of activated eosinophils, identified by immunohistochemistry, using the monoclonal anti-eosinophil cationic protein antibody, EG2, were significantly increased both at 3 h and at 24 h in the submucosa and bronchial lavage. A significant negative correlation was found between the number of EG2+ cells in the submucosa and in the bronchial lavage 24 h after the allergen challenge (r = -0.70). At 24 h, the amount of eosinophil cationic protein (ECP) was increased in the bronchial lavage. A significant correlation was observed between the amount of ECP at 3 h and the log provocative dose of house dust mite producing a 20% fall in forced expiratory volume in one second (PD20 HDM) (r = -0.63). The results suggest a recruitment of activated eosinophils to the submucosa and, further, to the epithelial lining, followed by degranulation. This process has already started 3 h after allergen challenge, and lasts for at least 24 h, which may result in mucosal damage and subsequent allergen-induced increase in BHR, before and after the late asthmatic reaction.
Aalbers
R
R
Depts of Allergology, University Hospital, Groningen, The Netherlands.
de Monchy
J G
JG
Kauffman
H F
HF
Smith
M
M
Hoekstra
Y
Y
Vrugt
B
B
Timens
W
W
D000328:Adult; D001249:Asthma / Q000276:immunology* / Q000473:pathology / Q000503:physiopathology; D001980:Bronchi / Q000276:immunology* / Q000473:pathology; D016535:Bronchial Hyperreactivity / Q000276:immunology* / Q000473:pathology / Q000503:physiopathology; D001985:Bronchial Provocation Tests; D001992:Bronchoalveolar Lavage Fluid; D001999:Bronchoscopy; D004804:Eosinophils / Q000276:immunology* / Q000502:physiology; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D007958:Leukocyte Count; D008297:Male; D009092:Mucous Membrane / Q000276:immunology / Q000473:pathology; D012129:Respiratory Function Tests; D013997:Time Factors