Eosinophils, bronchial hyperreactivity and late-phase asthmatic reactions

Authors

  • S. R. DURHAM,

    1. Department of Allergy and Clinical Immunology, Cardiothoracic Institute, Brompton Hospital, London, U.K.
    Search for more papers by this author
    • *

      Osler Chest Unit, Churchill Hospital, Oxford, U.K.

  • A. B. KAY

    Corresponding author
    1. Department of Allergy and Clinical Immunology, Cardiothoracic Institute, Brompton Hospital, London, U.K.
    Search for more papers by this author

Professor A. B. Kay, Department of Allergy and Clinical Immunology, Cardithoracic Institute, Brompton Hospital, Fulham Road, London, SW3 6HP.

Summary

We have measured airways reactivity (methacholine PC20) and blood eosinophils in eleven asthmatics with allergen-induced late-phase reactions. Before challenge there was a significant (P<0.05) inverse correlation between blood eosinophils and the methacholine PC20. After allergen inhalation eosinophil counts were significantly (P<0.01) elevated at 24 hr. These increases in blood eosinophil counts were not observed in patients who developed single early responses. The magnitude of the changes in eosinophil counts (24 hr minus pre-challenge values) also correlated with the baseline methacholine PC20 (P<0.01) in the late-phase responders. These observations suggest that there may be a direct association between eosinophils and airway reactivity in subjects who develop late-phase asthmatic reactions.

Ancillary