Exhaled nitric oxide reflects asthma severity and asthma control

Area of Science:

• Pediatric Pulmonology
• Respiratory Medicine
• Biomarkers

Background:

• Asthma severity assessment often relies on clinical evaluation and lung function tests.
• There is a need for objective, non-invasive markers to monitor asthma control and treatment adherence.
• Exhaled nitric oxide (fraction of exhaled nitric oxide [FENO]) is a potential biomarker for airway inflammation.

Purpose of the Study:

• To evaluate if FENO levels correlate with asthma severity based on established guidelines.
• To determine the utility of FENO, measured via a single-breath technique, for monitoring asthma control.
• To assess FENO's effectiveness in tracking patient compliance with steroid therapy.

Main Methods:

• Thirty pediatric asthma patients (ages 7-17) were classified by severity: mild (n=8), moderate (n=17), and severe (n=5).
• Data collected included asthma symptoms, medication use (beta-agonists, corticosteroids), steroid compliance, forced expiratory volume in 1 second (FEV1), and FENO measurements.
• Asthma control was assessed by a pulmonologist using symptoms, FEV1, and beta-agonist frequency.

Main Results:

• FENO levels significantly differed across mild, moderate, and severe asthma groups (30±12, 65±48, 104±68, respectively).
• FENO showed significant correlations with asthma severity (r=0.44, p=0.001), steroid compliance (r=-0.75, p=0.001), and asthma control (r=-0.51, p=0.001).
• No significant correlation was found between asthma severity and compliance or FEV1.

Conclusions:

• FENO is a practical tool for assessing asthma severity and monitoring control over time in pediatric patients.
• FENO can serve as a marker for steroid compliance, even in the absence of significant changes in FEV1.
• The single-breath exhalation technique for FENO measurement is a valuable addition to asthma management.