title: Study of nasal exhaled nitric oxide levels in diagnosis of allergic rhinitis in subjects with and without asthma.
abstract: BACKGROUND
  The measure of fractional exhaled nitric oxide (FENO) in the airways is a useful tool to guide the diagnosis and titration of inhaled corticosteroids in patients with asthma. However, its role in diagnosis of allergic rhinitis (AR), especially in subjects with asthma, is not well established.
  
  
  OBJECTIVE
  To study the cutoff of nasal FENO in the diagnosis of subjects with AR and AR-asthma compared to age-matched subjects without AR or asthma and its correlations with the clinical and functional characteristics.
  
  
  METHODS
  The study was cross sectional and descriptive. Subjects were grouped into control subjects, AR, and AR-asthma, based on the inclusion criteria. Exhaled NO (nasal FENO, bronchial FENO, and alveolar concentration of NO) was measured by multiple flow electro-luminescence device.
  
  
  RESULTS
  Six hundred twenty-eight subjects were included: 217 control subjects (children: n=98, 10±4 years; adults: n=119, 50±16 years), 168 subjects with AR (children: n=54, 10±3 years; adults: n=114, 49±15 years), and 243 subjects with AR-asthma (children: n=115, 10±3 years; adults: n=128, 51±14 years). Nasal peak inspiratory flow and peak expiratory flow were lower in subjects with AR and AR-asthma than in control subjects (P<0.01 andP<0.01; andP<0.05 andP<0.01, respectively). Nasal FENO levels were significantly higher in subjects with AR and AR-asthma than in control subjects (1614±629 and 1686±614 ppb vs 582±161 ppb;P<0.001 andP<0.001, respectively). In subjects with AR non-asthma, the cutoffs of nasal FENO for those diagnosed with AR were 775 ppb in children, 799 ppb in adults, and 799 in the general population (sensitivity: 92.68%, 92.63%, and 92.65%, respectively; specificity: 91.67%, 95.00%, and 96.87%, respectively). In subjects with AR-asthma, the cutoffs of nasal FENO were higher, especially in asthma children (1458 ppb; sensitivity: 72.97% and specificity: 95.83%).
  
  
  CONCLUSIONS
  Nasal FENO measurement is a useful technique for the diagnosis of AR in subjects with and without asthma.
authors.affiliation: Department of Respiratory Physiology, Cochin Hospital, Paris Descartes University, Sorbonne Paris Cité, Paris, France; Department of Medicine, Penn State University, Hershey, PA, USA; Bio-Medical Research Center, Lam Dong Medical College, Dalat.
authors.forename: Sy
authors.initials: S
authors.lastname: Duong-Quy
authors.affiliation: Department of Immuno-Allergology, ENT National Institute, Hanoi, Vietnam.
authors.forename: Thuc
authors.initials: T
authors.lastname: Vu-Minh
authors.affiliation: Department of Respiratory Physiology, Cochin Hospital, Paris Descartes University, Sorbonne Paris Cité, Paris, France.
authors.forename: Thong
authors.initials: T
authors.lastname: Hua-Huy
authors.affiliation: Bio-Medical Research Center, Lam Dong Medical College, Dalat.
authors.forename: Tram
authors.initials: T
authors.lastname: Tang-Thi-Thao
authors.affiliation: Bio-Medical Research Center, Lam Dong Medical College, Dalat.
authors.forename: Khiet
authors.initials: K
authors.lastname: Le-Quang
authors.affiliation: Bio-Medical Research Center, Lam Dong Medical College, Dalat.
authors.forename: Dinh
authors.initials: D
authors.lastname: Tran-Thanh
authors.affiliation: Bio-Medical Research Center, Lam Dong Medical College, Dalat.
authors.forename: Nhu
authors.initials: N
authors.lastname: Doan-Thi-Quynh
authors.affiliation: Department of Pulmonology, St Elisabeth Hospital, Namur, Belgium.
authors.forename: Nhat-Nam
authors.initials: NN
authors.lastname: Le-Dong
authors.affiliation: Department of Medicine, Penn State University, Hershey, PA, USA.
authors.forename: Timothy J
authors.initials: TJ
authors.lastname: Craig
authors.affiliation: Department of Respiratory Physiology, Cochin Hospital, Paris Descartes University, Sorbonne Paris Cité, Paris, France.
authors.forename: Anh-Tuan
authors.initials: AT
authors.lastname: Dinh-Xuan
keywords: FENO; NO; allergic rhinitis; asthma; nasal FENO; nitric oxide