Influence of Atopy on Exhaled and Nasal Nitric Oxide in Cystic Fibrosis Patients

ABSTRACT

Nitric oxide (NO) levels are low in cystic fibrosis (CF). Fractional exhaled NO (FENO) rises in patients with atopy when they are exposed to a relevant allergen. CF patients can be sensitized by common allergens that potentially trigger respiratory exacerbations. We aimed to demonstrate that FENO and nasal NO are related to atopy in CF. Clinical data of 57 CF patients were collected. CF was confirmed by genetic analysis and positive sweat test (chloride >60 mM). FENO and nasal NO were measured using the NIOX analyzer® (Aerocrine®). Atopy was defined by at least one positive prick test to common aeroallergens. FENO and nasal NO were in normal range without any significant difference between atopic (n=22) and non-atopic patients (n=35). There was no difference between NO levels according to inhaled corticosteroid treatments. FE_NO and nasal NO were within the normal range, and atopy did not affect these results. These discrepancies might be explained by the difference in inflammatory pathways and difficulties in measuring NO in CF.