Exhaled nitric oxide and sputum eosinophil markers of inflammation in asthmatic children

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Published on: December 17, 2017

G L Piacentini1, A Bodini, S Costella

  • 1Clinica Pediatrica, Universitá di Verona, Italy.

The European Respiratory Journal
|August 13, 1999
PubMed

Insights

Exhaled nitric oxide and sputum eosinophils are reliable markers for assessing airway inflammation in children with mild-to-moderate asthma. However, inhaled steroid treatment may reduce the correlation between these asthma evaluation methods.

Area of Science:

  • Pediatric Pulmonology
  • Allergy and Immunology
  • Respiratory Medicine

Background:

  • Airway inflammation is a key feature of asthma.
  • Noninvasive markers like exhaled nitric oxide (FeNO) and sputum eosinophils are crucial for monitoring asthma control.
  • Understanding the relationship between these markers is essential for effective asthma management in children.

Purpose of the Study:

  • To investigate the correlation between exhaled nitric oxide (FeNO) and sputum eosinophil markers in children with mild-to-moderate asthma.
  • To assess the influence of inhaled corticosteroid treatment on the relationship between FeNO and sputum eosinophils.
  • To evaluate other markers like serum eosinophil cationic protein (ECP) and lung function (FEV1) in relation to FeNO and sputum eosinophils.

Main Methods:

  • A cross-sectional study involving 25 children (aged 6-13 years) with mild-to-moderate asthma.
  • Measurements included exhaled nitric oxide (FeNO), induced sputum analysis (eosinophil count and eosinophil cationic protein - ECP), serum ECP, and forced expiratory volume in one second (FEV1).
  • Ten patients were receiving inhaled steroid therapy.

Main Results:

  • A significant positive correlation was found between FeNO and sputum eosinophil counts (r=0.438, p=0.032).
  • Sputum eosinophils also correlated significantly with sputum ECP (r=0.532, p<0.01).
  • No significant correlations were observed between FeNO and serum ECP, sputum ECP, or FEV1. The correlations were diminished or absent in children treated with inhaled steroids.

Conclusions:

  • Exhaled nitric oxide and sputum eosinophil counts are concordant in evaluating airway inflammation in mild-to-moderate asthma in children.
  • The association between FeNO and sputum eosinophils is less pronounced in children receiving inhaled steroid treatment.
  • These noninvasive markers provide valuable insights into asthma inflammation, but treatment effects should be considered.

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