Background: Asthma and COPD are characterized by chronic airway inflammation that
results in chronic airway obstruction which is reversible in asthma and non-reversible or partially
reversible in COPD. The differential diagnosis between reversible or irreversible airflow obstruction
due to asthma or COPD is important in clinical practice because the prognosis and the response to
treatment of the two diseases are different. Nitric oxide (NO) is produced by many cells within the
respiratory tract. Endogenous NO may play an important signaling role in the physiological control
of airway function and in the pathophysiology of airway diseases. Measurement of airway inflammation
by means of FENO may be useful and convenient for asthma diagnosis, particularly when
bronchial challenges and/or spirometric maneuvers cannot be correctly performed. The increase in
the percentage of peripheral blood and sputum eosinophils was found in patients with asthma that
correlated with the clinical severity of asthma and pulmonary function. Elevated levels of C-reactive
protein (CRP) are established in COPD but, in asthma, the results have been inconsistent. The aim
of the present study was to evaluate differences in local (airway) and systemic inflammatory markers
among primary care patients with asthma and COPD using simple, rapid and easy to do tests.
Subjects and methods: One hundred and fifty patients and thirty control subjects were included
in this study. They were divided into three groups, ninety asthmatic patients diagnosed clinically
and physiologically as reversible airway obstruction (group I). Sixty COPD patients diagnosed
by clinical, physiological and laboratory tests to have irreversible or partially reversible airway
obstruction (group II). The third group is the control group with no airway obstruction (NAO)
including thirty subjects. Pulmonary function tests, FENO, hs-CRP, blood and sputum eosinophil
percentages were done to all subjects.
Results: FENO was positively correlated with all inflammatory markers in the asthmatic group
with highly significant differences (p 6 .001) and negatively correlated with age, BMI and PFTs. Inthe COPD group there was a positive correlation between FENO with all inflammatory markers
and PFT with highly significant differences (p 6 .001) with sputum and blood eosinophils and
not significantly correlated with hs-CRP and PFT.
Conclusion: It is concluded that there are significant differences in inflammatory patterns
between asthma and COPD. FENO and hs-CRP had the highest ability to discriminate between
patients with asthma and COPD. |
