Kambara R, et al. – Researchers in this study assessed lower airway inflammation by measuring the fractional concentration of exhaled nitric oxide (FeNO), as well as, they analyzed the effects of endoscopic sinus surgery (ESS) on FeNO in patients with eosinophilic CRS (ECRS) compared to non–ECRS. Elevated FeNO unearthed lower airway inflammation in ECRS patients, which was parallel to the Lund–Mackay CT scores. The blood eosinophils and FeNO were found to be decreased by ESS. It prompted an improvement of the occult pulmonary dysfunction in ECRS patients.

Methods

• This study consisted CRS patients with nasal polyps (23 with ECRS and 22 with non-ECRS).
• On the basis of definition proposed by the Japanese Epidemiological Survey of Refractory Eosinophilic Chronic Rhinosinusitis (JESREC) study group, ECRS was diagnosed.
• Between ECRS and non-ECRS, several clinical markers including blood eosinophil counts, percent of eosinophils in white blood cells (WBC), number of eosinophils in nasal polyps, JESREC scores, total IgE, FeNO, and Lund-Mackay paranasal sinus CT scores were compared.
• Before and 2 months after ESS, these markers were also tested.

Results

• As compared to non-ECRS patients, FeNO was significantly higher in patients with ECRS.
• A significant correlation was found between FeNO and eosinophilic markers including blood eosinophil counts, percent of eosinophils in WBC, number of eosinophils in nasal polyps, and JESREC scores, when all CRS patients were tested.
• Only in ECRS patients, FeNO significantly correlated to Lund-Mackay scores.
• In addition, blood eosinophil counts, percent of eosinophils in WBC, and FeNO decreased after ESS only in ECRS patients.