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Sputum cell counts and exhaled nitric oxide in patients with gastroesophageal reflux, and cough or asthma
K Parameswaran | CL Allen | D Kamada | A Efthimiadis | M Anvari | FE Hargreave
BACKGROUND:
Gastroesophageal reflux (GER) is commonly associated
with chronic cough and asthma, but there is little or
no information on the nature of any associated airway
inflammation.
OBJECTIVE:
To observe whether the association with GER worsens
airway inflammation in patients with chronic cough or
asthma.
PATIENTS
AND METHODS: The airway inflammatory indexes in
induced sputum and exhaled air were examined in a cross-sectional
study of 11 patients with cough and GER, nine patients
with mildly symptomatic asthma and GER, nine patients
with mildly symptomatic asthma without GER and nine
normal, healthy control subjects. GER was shown objectively
by 24 h ambulatory pH recording.
RESULTS:
The sputum total cell count, the proportion of neutrophils
and macrophages, and the fibrinogen level were normal
in all four groups, with no significant differences
among the groups. The sputum eosinophil and metachromatic
cell percentages, and eosinophil cationic protein levels
were normal in patients with cough and GER. They were
significantly increased in patients with asthma compared
with healthy subjects (P<0.01) and patients with cough
(P<0.01), but were not different between groups with
and without GER. Exhaled nitric oxide levels showed
similar results (P<0.01). The correlations between the
number of episodes of reflux and the proportion of sputum
eosinophils, neutrophils or exhaled nitric oxide were
modest but not significant.
CONCLUSIONS:
GER, when associated with cough or mildly symptomatic
asthma, does not cause or aggravate existing airway
inflammation as measured by induced sputum cell counts
and fibrinogen level, or by exhaled nitric oxide.
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