LYMPHOCYTE AND MACROPHAGE ACTIVATION IN BRONCHOALVEOLAR LAVAGE FLUID IN NOCTURNAL ASTHMA

Citation
Y. Oosterhoff et al., LYMPHOCYTE AND MACROPHAGE ACTIVATION IN BRONCHOALVEOLAR LAVAGE FLUID IN NOCTURNAL ASTHMA, American journal of respiratory and critical care medicine, 151(1), 1995, pp. 75-81
Citations number
21
Categorie Soggetti
Emergency Medicine & Critical Care","Respiratory System
ISSN journal
1073449X
Volume
151
Issue
1
Year of publication
1995
Pages
75 - 81
Database
ISI
SICI code
1073-449X(1995)151:1<75:LAMAIB>2.0.ZU;2-I
Abstract
Increased nocturnal airway narrowing is thought to occur as a conseque nce of an intensification of inflammatory processes at night. Lymphocy te and alveolar macrophage (AM) activation are thought to be associate d with the clinical expression of asthma, and may be important in the occurrence of nocturnal asthma as well. The expression of CD25 and HLA -DR receptors on lymphocytes from bronchoalveolar lavage (BAL) and per ipheral blood (PB) CD4(+), as well as of CD14, IgG Fc, and CD11/CD18 l eukocyte adhesion receptors on AM in BAL fluid and monocytes in PB, we re determined at 16.00 and 04.00 h by flow cytometry. Their relationsh ip with the occurrence of nocturnal asthma was investigated in eight n onatopic controls (Group 1) and 17 atopic asthmatic subjects, prospect ively assigned to groups with a mean circadian peak expiratory flow (P EF) variation < 15% (Group 2) and greater than or equal to 15% (Group 3). The occurrence of an increased circadian variation in PEF in asthm atic subjects was on the whole not associated with a day-night fluctua tion in lymphocyte numbers and subsets in PB or BAL fluid, nor with da y-night changes in receptor expression on AM from BAL or monocytes fro m PB. The only exception was the presence of a greater day-night chang e in the proportion of HLA-DR-expressing CD4(+) lymphocytes in the BAL fluid along with an increasing circadian PEF rhythm in asthmatic subj ects (r = 0.68, p = 0.03). A further finding was that a lower number o f BAL CD4(+) lymphocytes at daytime was significantly related to a hig her circadian PEF variation in asthmatic subjects (r = -0.66, p = 0.01 ). Additionally, asthmatics in Group 3 showed a greater expression of CD11b on AM from BAL fluid at 16.00 h (p = 0.05), and a significantly positive correlation was found for this parameter with the circadian v ariation in PEF of all asthmatic subjects (r = 0.72, p = 0.03). These findings show that increased nocturnal airway obstruction in asthma is not associated with an increased influx of lymphocytes and macrophage s into BAL fluid at night, nor with marked activation of these cells. Daytime presence of enhanced AM CD11b expression may predispose to the occurrence of nocturnal asthma.