Inflammatory and T-cell profile of asthmatic airways 6 hours after local allergen provocation.
T cells in the airways are considered to play a key role in orchestrating the inflammatory response of asthma through the elaboration of specific cytokines. Using flow cytometry we have investigated the T-cell response of sensitized asthmatic airways 6 h after local allergen provocation. Twelve subjects with atopic asthma underwent bronchoalveolar lavage (BAL) before and 6 h after local instillation of allergen into the right middle lobe (RML) and saline into the right upper lobe (RUL). Allergen challenge produced a significant 26% fall in FEV1, an increase in eosinophils in BAL at 6 h, and at 24 h an increase in methacholine responsiveness compatible with late-phase airway inflammation. When compared with saline challenge, allergen produced an overall decrease in the number of BAL lymphocytes from 21.3 +/- 2.8% to 16.0 +/- 3.08% of total cells but no change in the proportion of CD4+, CD8+, CD25+, or HLA-DR+ cells. Allergen provocation reduced the proportion of T cells expressing the beta 2 integrin lymphocyte functional antigen-1 (LFA-1) from 72.5 +/- 30 to 43.9 +/- 9.1 mean fluorescent units (p < 0.01) and a similar trend in intercellular adhesion molecule-1 (ICAM-1) (p = 0.08). These results indicate that late-phase inflammatory events 6 h after local allergen provocation involve the selective retention of airway T cells expressing specific cell adhesion molecules.
Gratziou
C
C
University Medicine, Southampton General Hospital, United Kingdom.
Carroll
M
M
Montefort
S
S
Teran
L
L
Howarth
P H
PH
Holgate
S T
ST
D000328:Adult; D000485:Allergens; D015703:Antigens, CD / Q000032:analysis; D001249:Asthma / Q000276:immunology* / Q000473:pathology / Q000503:physiopathology; D001980:Bronchi / Q000276:immunology* / Q000473:pathology; D001985:Bronchial Provocation Tests; D001992:Bronchoalveolar Lavage Fluid / Q000276:immunology; D001999:Bronchoscopy; D018791:CD4 Lymphocyte Count; D018414:CD8-Positive T-Lymphocytes; D002452:Cell Count; D005260:Female; D005434:Flow Cytometry; D005541:Forced Expiratory Volume; D006684:HLA-DR Antigens / Q000032:analysis; D006801:Humans; D007249:Inflammation; D018799:Intercellular Adhesion Molecule-1 / Q000378:metabolism; D018655:Lymphocyte Count; D008297:Male; D016176:T-Lymphocyte Subsets; D013601:T-Lymphocytes / Q000378:metabolism
D000485:Allergens; D015703:Antigens, CD; D006684:HLA-DR Antigens; D018799:Intercellular Adhesion Molecule-1