Utility of nitric oxide for the diagnosis of asthma in an allergy clinic population

Danielle Cordeiro, Arjan Rudolphus, Erik Snoey, Gert-Jan Braunstahl
Allergy and Asthma Proceedings: 2011, 32 (2): 119-26
Fractionated exhaled nitric oxide (FeNO) expression is increased in airway inflammation and several studies have suggested that FeNO measurement can be useful in patients with asthma. Atopic individuals have increased FeNO levels, indicating that atopy may be a codeterminant in FeNO production. The aim of this study was to determine the discriminative value of FeNO for asthma and other atopic conditions in the general allergy clinic. Patients referred to the outpatient allergy clinic were screened. A standardized questionnaire was taken and atopic status was assessed (skin-prick test or specific plasma IgE). FeNO level and spirometry were measured. If the patient's history was suspect for asthma, a provocative concentration causing a 20% decrease in forced expiratory volume in 1 second (PC(20)) histamine challenge followed. One hundred fourteen steroid-naive patients were included. Forty-two subjects were diagnosed as asthmatic patients and 72 were diagnosed as nonasthmatic patients, comprising patients with allergic rhinitis (n = 32), nonallergic rhinitis (n = 11), urticaria (n = 11), eczema (n = 7), and other (n = 11). Asthmatic patients had a higher FeNO level than nonasthmatic patients (44 ppb versus 17 ppb; p < 0.001). Receiver operating characteristic curve analysis revealed the optimal FeNO level to distinguish asthma from nonasthma at 27 ppb, with a sensitivity of 78%, specificity of 92%, a positive predictive value of 86%, and a negative predictive value of 87%. Increased FeNO was positively correlated with the presence of respiratory symptoms (p < 0.01), airflow reversibility (p < 0.001), total IgE (p < 0.001), and negatively correlated with PC(20) histamine (p = 0.019). Multivariate analysis revealed that atopy was not a significant predictor of FeNO in asthmatic patients. Measuring FeNO is a simple and useful test to differentiate new asthma patients from those with other atopic conditions in a general allergy clinic.

Full Text Links

Find Full Text Links for this Article


You are not logged in. Sign Up or Log In to join the discussion.

Related Papers

Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"