Association of the Fraction of Exhaled Nitric Oxide with Peripheral Eosinophilia in Asthma

Optimal asthma management focuses on controlling symptoms and preventing exacerbations. While serum and sputum eosinophil counts have traditionally been used to gauge eosinophilic airway inflammation, these measures are invasive and may not always be practical. The fraction of exhaled nitric oxide (FeNO) has emerged as a promising, non-invasive biomarker that reflects airway eosinophilia and may guide timely adjustments in inhaled corticosteroid therapy, particularly in patients with uncontrolle