title: Predictive value of exhaled nitric oxide in the management of asthma: a systematic review.
abstract: The clinical value of measuring fractional exhaled nitric oxide (FeNO) in asthma is not clear. We aimed to assess whether FeNO can reliably predict clinical outcomes in asthma treated with inhaled corticosteroids (ICS). We also evaluated whether its predictive role is influenced by different inflammatory phenotypes of asthma.We conducted a systematic review focusing on five clinically relevant questions. Two authors independently screened search results, extracted data and assessed quality of the included studies. Data were synthesised by qualitative methods.12 prospective studies were included, answering partly three of the five questions. In steroid-naïve asthma, a high FeNO level probably predicts good response to ICS. In ICS-treated asthmatics, a low FeNO level probably predicts low risk of exacerbation, and the patient is unlikely to benefit from increasing ICS dose. There were scarce data to conclude whether FeNO predicts exacerbations when ICS treatment is stopped in well-controlled asthma. Only one study reported results separately in different asthma phenotypes.The current evidence on the predictive value of FeNO and its role in the management of asthma is incomplete. Future studies should focus on clinically meaningful questions and probably target only eosinophilic phenotypes where FeNO is best associated with the activity of airway inflammation.
authors: Medical School, University of Tampere, Tampere, Finland Allergy Centre, Tampere University Hospital, Tampere, Finland lauri.lehtimaki@uta.fi.
authors: Lauri
authors: L
authors: Lehtimäki
authors: Terveystalo Healthcare Oy, Tampere, Finland.
authors: Péter
authors: P
authors: Csonka
authors: National Institute for Health and Welfare, Helsinki, Finland.
authors: Eeva
authors: E
authors: Mäkinen
authors: National Institute for Health and Welfare, Helsinki, Finland.
authors: Jaana
authors: J
authors: Isojärvi
authors: National Institute for Health and Welfare, Helsinki, Finland.
authors: Sirpa-Liisa
authors: SL
authors: Hovi
authors: National Institute for Health and Welfare, Helsinki, Finland.
authors: Anneli
authors: A
authors: Ahovuo-Saloranta
mesh_terms: D000293:Adolescent; D000305:Adrenal Cortex Hormones / Q000627:therapeutic use; D000328:Adult; D000368:Aged; D018927:Anti-Asthmatic Agents / Q000627:therapeutic use; D001249:Asthma / Q000503:physiopathology* / Q000628:therapy; D001944:Breath Tests / Q000379:methods; D002648:Child; D002675:Child, Preschool; D045853:Exhalation; D005260:Female; D006801:Humans; D007249:Inflammation; D008297:Male; D008875:Middle Aged; D009569:Nitric Oxide / Q000737:chemistry*; D010641:Phenotype; D011237:Predictive Value of Tests; D011379:Prognosis; D011446:Prospective Studies; D016896:Treatment Outcome; D055815:Young Adult
chemical_list: D000305:Adrenal Cortex Hormones; D018927:Anti-Asthmatic Agents; D009569:Nitric Oxide