Relationship between Methacholine Challenge Testing and exhaled nitric oxide in adult patients with suspected bronchial asthma

Eur Ann Allergy Clin Immunol. 2014 May;46(3):109-13.


Usually, hyperresponsiveness to inhaled methacholine is considered closely associated with a diagnosis of bronchial asthma. Recently, it has been clearly pointed out that bronchial hyperreactivity (BHR) is not a constant feature of asthma and that this condition is not always related to airways inflammation. In the present study we evaluated 42 Patients (21 positive and 21 negative for bronchial hyperreactivity, BHR) with the aim to determine the effect of Methacholine Challenge Testing (MCT) on the levels of exhaled nitric oxide (NO). Higher FeNO levels were found before methacholine provocation in the group that eventually resulted positive to the challenge, while after the challenge in both groups FeNO decreased in similar way, with no statistical difference. These data confirm that MCT is a relevant test for asthma diagnosis, but it is not always related to the severity of bronchial inflammation, while FeNO levels in our study have limited clinical significance when evaluated out of asthma exacerbation.

Keywords: Asthma; Bronchial Hyperreactivity (BHR); Exhaled Nitric Oxide (FeNO); Methacolin Challenge Testing (MCT).

MeSH terms

  • Adult
  • Age Factors
  • Asthma / diagnosis*
  • Asthma / metabolism
  • Asthma / physiopathology
  • Biomarkers / metabolism
  • Breath Tests*
  • Bronchial Hyperreactivity / diagnosis*
  • Bronchial Hyperreactivity / metabolism
  • Bronchial Hyperreactivity / physiopathology
  • Bronchial Provocation Tests*
  • Bronchoconstriction / drug effects*
  • Bronchoconstrictor Agents*
  • Disease Progression
  • Exhalation*
  • Female
  • Humans
  • Male
  • Methacholine Chloride*
  • Middle Aged
  • Nitric Oxide / metabolism*
  • Predictive Value of Tests
  • Prognosis
  • Severity of Illness Index
  • Young Adult


  • Biomarkers
  • Bronchoconstrictor Agents
  • Methacholine Chloride
  • Nitric Oxide