Specific pattern of inflammatory responses linked to airways obstruction in asthma
MedWire News: Chronic airways obstruction is associated
with decreased activation of T-helper (Th)1-like/cytotoxic and
interferon pathways in children who have suffered an asthma
attack.
Writing in the journal Mucosal Immunology, A Bosco
(University of Arizona, Tucson, USA) and colleagues explain that
many children with asthma have chronic airflow obstruction, as
indicated by deficits in the FEV1/forced vital capacity
(FVC) ratio, while others do not.
To investigate whether a specific pattern of inflammatory
responses in the airways during acute asthma exacerbations is
associated with chronic airway obstruction, the team studied sputum
samples collected during an acute asthma attack from 40 children
with mild-to-moderate persistent asthma.
Ten of these samples were selected from children with
significant pre-exacerbation chronic airway obstruction (mean
FEV1/FVC ratio=78.8%) and 10 from children without
pre-exacerbation chronic airway obstruction (mean
FEV1/FVC ratio=91.3%).
Gene co-expression network analysis of the samples revealed
decreased activation of Th1-like/cytotoxic and interferon signaling
pathways, involving 115 and 78 genes, respectively, in asthmatic
children with chronic airway obstruction relative to those without
chronic airway obstruction.
These associations were independent of atopy, the presence of
picornavirus infections, and the use of medications at the onset of
the exacerbation, the researchers note.
Bosco and team conclude: "Our findings for the first time
provide a global perspective of the immunological networks that are
operating during naturally occurring acute asthma exacerbations in
children, and broadly characterize variations in these networks
that are associated with deficits in baseline FEV1/FVC
ratios."
However, they caution: "Sputum induction was not performed
during severe exacerbations because it was deemed unsafe and
unethical, and thus the mechanisms operating in severe
exacerbations may be different from those reported herein."
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Springer Healthcare Limited. © Springer Healthcare Ltd;
2010
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