Inhaled corticosteroids in COPD - Author's reply (2)

AUTHORS’ REPLY We would like to thank Drs
Brightling and Pavord for their interesting
comments. As stated in our article, we
enrolled only patients with stable COPD,
diagnosed according to a recent European
Consensus Conference, and none of them
had a previous history of asthma.1 The
percentage of sputum eosinophils in the global
COPD study population (34 subjects;
mean (SE) 2.7 (0.7)) was not significantly
different from that of the healthy subjects (16
subjects; mean (SE) 0.98 (0.2)) by the
Mann-Whitney U test (p = 0.08). Indeed, if
we consider the treated and control groups
separately, a significant increase in the
proportion of sputum eosinophils is seen in
both COPD groups compared with the
healthy subjects (p = 0.02).
We suggest that the sputum eosinophilia in
our patients with smoking related COPD
could be explained by their current smoking
habit. In fact, recent experimental and
clinical data seem to support the hypothesis
that exposure to cigarette smoke can induce
eosinophilic airway inflammation both in
animals and humans.2 3
Although there was no overall change in
the sputum eosinophil count after two
months of treatment with beclomethasone
dipropionate, we have analysed separately the
seven subjects with eosinophils of >2% in the
treated group. In these subjects, not only
neutrophils but also sputum eosinophils
decreased (from a mean (SE) of 4.5 (1.2)%
to 2.0 (0.4)%) after two months of treatment,
although the difference did not reach statistical
significance (p = 0.06). Moreover, these
subjects did not show a significant increase in
FEV1 after two months of treatment with
inhaled corticosteroids (from 60.1 (5.6)% to
64.9 (4.1)% predicted).
We also analysed separately the subgroup of
treated patients with COPD with sputum
eosinophils <2% in order to verify the changes
in sputum neutrophils after two months of
treatment with inhaled beclomethasone dipropionate.
These patients showed a significant
reduction in both total cell and neutrophil
counts after treatment. In fact, the mean
difference from baseline of the total cell count
(cells/ml ´ 104) was 191 (51.8) (95% CI 68.5
to 314), and the mean difference from baseline
of the neutrophils was 27 (1.7) (95% CI 22.9
to 31.1).
We are grateful to the authors of this letter
for their careful consideration that provides a
good insight into our paper. Nevertheless, the
results of our study do not change since a
reduction in sputum neutrophils also occurred
after treatment with high dose inhaled
beclomethasone dipropionate in the subgroup subgroup
of patients with COPD without
sputum eosinophilia.