Magnitude of late asthmatic response to allergen in relation to baseline and allergen-induced sputum eosinophilia in mild asthmatic patients

Ann Allergy Asthma Immunol. 2008 May;100(5):457-62. doi: 10.1016/S1081-1206(10)60471-1.


Background: Late asthmatic response (LAR) to allergen challenge is a validated method for studying the pathogenesis of and new treatments for asthma in the laboratory.

Objective: To evaluate the relationship between the magnitude of allergen-induced LAR and clinical and biological determinants, including sputum and blood eosinophil percentages and eosinophil cationic protein concentrations.

Methods: Thirty-eight untreated mild asthmatic patients (mean age, 21.2 years) were selected for the presence of allergen-induced early asthmatic response (EAR) and LAR. Each patient measured methacholine responsiveness (provocation dose that caused a decrease in forced expiratory volume in 1 second of 20% [PD20FEV1]) at baseline, differential blood cell counts and eosinophil cationic protein levels in blood and induced sputum, and serum neutrophil chemotactic activity at baseline and 24 hours after allergen challenge.

Results: A correlation was found between LAR (as area under the curve [AUC]) and sputum eosinophil percentages at baseline (r = 0.51; P = .001) and 24 hours after allergen challenge (r = 0.44; P < .007). Furthermore, we found significant correlations between AUC LAR and AUC EAR, baseline methacholine PD20FEV1, baseline blood eosinophil percentages, and baseline serum neutrophil chemotactic activity. A stepwise multiple regression analysis showed that the stronger determinants of AUC LAR were baseline sputum eosinophilia and AUC EAR.

Conclusion: Baseline sputum eosinophilia and functional findings are determinants of the magnitude of allergen-induced LAR.

MeSH terms

  • Adolescent
  • Adult
  • Allergens / administration & dosage
  • Allergens / immunology
  • Asthma / blood
  • Asthma / immunology*
  • Asthma / physiopathology
  • Bronchial Provocation Tests / methods*
  • Cell Count
  • Chemotaxis, Leukocyte / immunology
  • Eosinophil Cationic Protein / blood
  • Eosinophil Cationic Protein / metabolism
  • Eosinophilia / blood
  • Eosinophilia / immunology*
  • Eosinophils / cytology
  • Female
  • Forced Expiratory Volume / drug effects
  • Forced Expiratory Volume / physiology
  • Humans
  • Leukocyte Count
  • Macrophages, Alveolar / cytology
  • Male
  • Methacholine Chloride / pharmacology
  • Neutrophils / cytology
  • Sputum / cytology*
  • Sputum / immunology
  • Sputum / metabolism


  • Allergens
  • Methacholine Chloride
  • Eosinophil Cationic Protein
  • RNASE3 protein, human