Clinical & Experimental Allergy

The inflammatory response in asthma exacerbation: changes in circulating eosinophils, basophils and their progenitors

Authors

  • P. G. GIBSON,

    1. Asthma Research Group, Departments of Medicine and Paediatrics, McMaster University and St Joseph's Hospital, Hamilton, Ontario, Canada
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    • *Present address: Dr Peter G. Gibson. University of Newcastle, David Maddison Clinical Sciences Building, Royal Newcastle Hospital, Newcastle, NSW 2300, Australia.

  • J. DOLOVICH,

    1. Asthma Research Group, Departments of Medicine and Paediatrics, McMaster University and St Joseph's Hospital, Hamilton, Ontario, Canada
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  • A. GIRGIS-GABARDO,

    1. Asthma Research Group, Departments of Medicine and Paediatrics, McMaster University and St Joseph's Hospital, Hamilton, Ontario, Canada
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  • M. M. MORRIS,

    1. Asthma Research Group, Departments of Medicine and Paediatrics, McMaster University and St Joseph's Hospital, Hamilton, Ontario, Canada
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  • M. ANDERSON,

    1. Asthma Research Group, Departments of Medicine and Paediatrics, McMaster University and St Joseph's Hospital, Hamilton, Ontario, Canada
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  • F. E. HARGREAVE,

    1. Asthma Research Group, Departments of Medicine and Paediatrics, McMaster University and St Joseph's Hospital, Hamilton, Ontario, Canada
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  • J. A. DENBURG

    Corresponding author
    1. Asthma Research Group, Departments of Medicine and Paediatrics, McMaster University and St Joseph's Hospital, Hamilton, Ontario, Canada
      Dr J. A. Denburg, Departmenl of Medicine, Room 4H21, McMaster University, Health Sciences Centre, 1200 Main Street West, Haniillon, Ontario, Canada L8N 3Z5.
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Dr J. A. Denburg, Departmenl of Medicine, Room 4H21, McMaster University, Health Sciences Centre, 1200 Main Street West, Haniillon, Ontario, Canada L8N 3Z5.

Summary

Circulating eosinophils, basophils and eosinophil/basophil (Eo/B) progenitors were examined in 12 patients at the time of an exacerbation of asthma accompanied by sputum eosinophilia and after resolution of the exacerbation with inhaled corticosteroid treatment. Differential counts were performed and peripheral blood non-adherent mononuclear cells were cultured for 14 days in methyl-cellulose to determine the number of Eo/B and granulocyte-macrophage (GM) colonies without knowledge of the clinical conditions or findings. With resolution of the asthma exacerbation on beclomethasone therapy, there were significant falls in circulating eosinophils, basophils and Eo/B colonies whereas GM colonies were unchanged. To elucidate whether the observed changes could be due to systemic absorption or local action of inhaled corticosteroid, seven subjects with allergic rhinitis and no current evidence of lower airway inflammation (no symptoms of asthma and normal methacholine airway responsiveness) received 14 days' treatment with the same dose of inhaled beclomethasone or of placebo in a double-blind randomized cross-over study. No significant changes in airway function or in circulating cell counts were observed. The results suggest reduced production of eosinophils and basophils after the resolution of an exacerbation of asthma. This effect may be due to reduced levels of airway-derived eosinophil-basophil growth and differentiation factors.

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