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
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.