Association between airway hyperreactivity and bronchial macrophage dysfunction
in individuals with mild asthma.
Alexis, Neil E, Joleen Soukup, Stefan Nierkens, and Susanne Becker.
1Center For Environmental Medicine and Lung Biology, University of North
Carolina, Chapel Hill 27599; and 2United States Environmental Protection Agency,
National Health and Environmental Effects Research Laboratory, RTP, North Carolina
27711
APStracts 7:0259L, 2000.
Little is known about the functional capabilities of bronchial macrophages (BM) and their
relationship to airway disease such as asthma. We hypothesize that BM from asthmatics
may be modulated in their function compared with similar cells from healthy individuals.
BM obtained by induced sputum from mild asthmatics (n = 20) and healthy individuals (
n = 20 ) were analyzed using flow cytometry for CD16, CD64, CD11b, CD14, and HLA-
DR expression, phagocytosis of IgG opsonized yeast, and oxidant production. Asthma
status was assessed by lung function (%predicted FVC and FEV1 ), percent sputum
eosinophils, and nonspecific airway responsiveness (PC20FEV1). Asthmatics with
>5% airway eosinophils (AEo+) had decreased AM CD64 expression and
phagocytosis compared with asthmatics with <5% eosinophils (AEo«minus»). Among
asthmatics, a significant correlation was found between CD64 expression and BM
phagocytosis (R = 0.7, P < 0.009). Phagocytosis was also correlated with PC20FEV1
(R = 0.6, P < 0.007), lung function (%predicted FEV1, R = 0.7, P < 0.002) and
percent eosinophils (R = «minus»0.6, P < 0.01). In conclusion, BM from asthmatics are
functionally modulated, possibly by Th-2 cytokines involved in asthma pathology.
Received 7 June 2000; accepted in final form 29 August 2000
APS Manuscript Number L167-0.
Article publication pending Am J Physiol Lung Cell Mol Physiol
ISSN 1080-4757 Copyright 2000 The American Physiological Society.
Published in APStracts on 30 November 2000