Exhaled nitric oxide measurement in patients affected by nasal polyposis

Nitric oxide (NO) is produced in the respiratory tract with a major contribution coming from paranasal sinuses and the nose. The pathophysiological role of NO in the airways has been debated. The aims of this study were to measure fraction of exhaled NO (FENO), a validated marker of airway inflammation, in patients affected by nasal polyposis with and without asthma; to assess the importance of FENO measurement in detecting subclinical involvement of lower airways in patients with clinical rhinosinusal symptoms; and to clarify the impact of endoscopic surgical removal of polyps on airway inflammation.

The study was conducted at the O.R.L. Clinic and Clinical Pharmacology Unit, University Hospital Agostino Gemelli, Rome, Italy.

Prospective study.

Concentrations of FENO were measured with the NIOX system (Aerocrine, Stockholm, Sweden) by using a single-breath online method, according to the American Thoracic Society guidelines.

Compared with those in healthy subjects (15 [11-19] ppb, n = 15; P < .0001), FENO values were elevated in patients with nasal polyposis (41 [21-77] ppb, n = 43). There was no significant difference in FENO concentrations between asthmatic and nonasthmatic patients with nasal polyposis (P = .73). Concentrations of FENO in patients with nasal polyposis were decreased after surgery (64.2 [30.0-132.7] ppb vs 56.0 [26.4-73.8] ppb, respectively; P = .03).

The fraction of exhaled NO is elevated in the inflammatory process involving both the rhinosinusal district and lower airways, supporting the one-airway disease hypothesis.