A test commonly used to diagnose asthma patients may also work to differentiate people with both bronchiectasis (BE) and bronchial asthma from those with BE alone, researchers in China reported. The findings were published in the Journal of Thoracic Disease, in an article titled “Importance of fractional exhaled nitric oxide in diagnosis of bronchiectasis accompanied with bronchial asthma.“
Asthma and BE are common diseases of the airways and lungs, but exhibit different clinical characteristics. Approaches now used to distinguish patients with both asthma and BE, or with BE alone, often depend on clinical symptoms and pulmonary function test results, which are reliable but can induce severe bronchospasm in some patients.
Fractional exhaled nitric oxide (FeNO) measurement is a simple, rapid, highly reproducible, and noninvasive method to detect nitric oxide (NO) in the exhaled air, a useful marker of airway inflammation.
Researchers addressed whether FeNO levels could be used to differentiate BE patients from BE patients who also have asthma, and if these measures could be valuable in evaluating a patient’s response to treatments for these respiratory conditions.
The research team, led by Can-Mao Xie with Sun Yet-sen University, analyzed people diagnosed with BE through high-resolution computed tomography (HRCT), and performed FeNO measurements, along with conventional diagnostic tests, to detect asthma. A total of 99 patients were analyzed, out of which 20 were asthmatic and 79 were not.
Results from the FeNO measurement revealed that FeNO levels in asthmatic patients were significantly higher than those in the non-asthmatic group. Among the 20 asthmatic patients, 12 were treated with inhaled corticosteroids for 12 weeks to assess the accuracy of FeNO measurement during treatment. Interestingly, FeNO levels significantly decreased in these patients, suggesting that FeNO measurement is a potential test of asthma management.
“In conclusion, we found that FeNO measurement is an alternative diagnostic tool to conventional lung function tests for differentiating BE accompanied with asthma from BE alone. FeNO level exhibits high sensitivity and specificity. FeNO measurement is a simple, reproducible, and noninvasive method of monitoring patient responsiveness to specific treatments,” the researchers concluded. “However, additional large-scale prospective studies must be performed to expand the clinical applications of FeNO measurement.”