The relationship between airways inflammation and asthma severity

Am J Respir Crit Care Med. 2000 Jan;161(1):9-16. doi: 10.1164/ajrccm.161.1.9802048.


In order to investigate the relationship between airways inflammation and disease severity, and improve the understanding of persistent asthma, 74 asthmatics, with disease severity ranging from intermittent, to mild to moderate and severe persistent (classified according to the Global Initiative for Asthma [GINA] guidelines), and 22 nonatopic control subjects were studied using the method of induced sputum. Sputum was analyzed for total and differential cell counts concentrations of albumin, and levels of eosinophil cationic protein (ECP), myeloperoxidase (MPO), and tryptase, inflammatory mediators reflecting eosinophil, neutrophil, and mast cell activation. Asthma severity (assessed by FEV(1), peak expiratory flow [PEF] variability, and daily symptom scores) and methacholine airways responsiveness were related to sputum eosinophilia and ECP. In addition, sputum neutrophilia and MPO levels correlated, albeit weakly, with PEF variability and symptom scores, respectively. Tryptase concentrations were raised in mild to moderate asthmatics. Albumin concentrations were significantly raised across the spectrum of asthma severity and correlated with those of tryptase and ECP. Despite treatment with either high doses of inhaled corticosteroids or oral corticosteroids, prominent eosinophilic inflammation with raised ECP was noted. This study points to persistent, disease severity-related airways inflammation in asthma, involving eosinophils, mast cells, and neutrophils, which is evident despite treatment with corticosteroids.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Albumins / metabolism
  • Asthma / drug therapy
  • Asthma / metabolism
  • Asthma / physiopathology*
  • Biomarkers
  • Blood Proteins / metabolism
  • Bronchial Hyperreactivity / drug therapy
  • Bronchial Hyperreactivity / metabolism
  • Bronchial Hyperreactivity / physiopathology*
  • Chymases
  • Eosinophil Granule Proteins
  • Eosinophils / metabolism
  • Eosinophils / pathology
  • Female
  • Glucocorticoids / therapeutic use
  • Humans
  • Male
  • Mast Cells / enzymology
  • Mast Cells / pathology
  • Methacholine Compounds
  • Neutrophils / enzymology
  • Neutrophils / pathology
  • Peroxidase / metabolism
  • Respiratory Function Tests
  • Ribonucleases*
  • Serine Endopeptidases / metabolism
  • Severity of Illness Index
  • Sputum / cytology
  • Sputum / metabolism
  • Tryptases


  • Albumins
  • Biomarkers
  • Blood Proteins
  • Eosinophil Granule Proteins
  • Glucocorticoids
  • Methacholine Compounds
  • Peroxidase
  • Ribonucleases
  • Serine Endopeptidases
  • chymase 2
  • Chymases
  • Tryptases