Chronic cough resembles asthma with IL-5 and granulocyte-macrophage colony-stimulating factor gene expression in bronchoalveolar cells

J Allergy Clin Immunol. 1998 Mar;101(3):320-6. doi: 10.1016/S0091-6749(98)70242-8.


Background: Chronic cough is a multifactorial condition, which, like asthma, can be associated with eosinophilic airway inflammation. In asthma, airway eosinophilia is believed to be mediated by cytokines such as interleukin-5 and granulocyte-macrophage colony stimulating factor (GM-CSF). The role of these cytokines in chronic cough is unclear.

Objective: The aim of this study was to examine gene expression for IL-5 and GM-CSF in chronic cough and compare the results with those found in asthma.

Methods: We studied adults with asthma (n = 12), chronic cough responsive to inhaled corticosteroid (ICS-responsive cough) (n = 9), and chronic cough not responsive to inhaled corticosteroid (non-ICS-responsive cough) (n = 4). Bronchoalveolar lavage (BAL) was performed, and cytokine gene expression was assessed by using a semiquantitative reverse transcriptase polymerase chain reaction.

Results: IL-5 mRNA was expressed by BAL cells from nine of 12 asthmatic subjects and six of nine subjects with ICS-responsive chronic cough. IL-5 mRNA was not detected in subjects with non-ICS-responsive chronic cough (zero of four subjects, p < 0.05). GM-CSF mRNA was expressed in BAL cells from seven of 12 asthmatic subjects and six of nine subjects with ICS-responsive cough. GM-CSF mRNA was not detected in non-ICS responsive cough subjects (zero of four subjects, p < 0.05). GM-CSF gene expression was related to the degree of methacholine airway responsiveness in asthmatic subjects (r = -0.59).

Conclusion: We conclude that chronic cough, like asthma, is associated with airway inflammation and gene expression for IL-5 and GM-CSF. Ongoing expression of these cytokines is likely to be related to the persistence of airway inflammation and chronic cough.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Administration, Inhalation
  • Adrenal Cortex Hormones / administration & dosage
  • Adrenal Cortex Hormones / therapeutic use
  • Adult
  • Asthma / genetics
  • Asthma / immunology*
  • Bronchi / immunology
  • Bronchial Hyperreactivity / genetics
  • Bronchial Hyperreactivity / immunology
  • Bronchial Provocation Tests
  • Bronchoalveolar Lavage Fluid / cytology
  • Chronic Disease
  • Cough / drug therapy
  • Cough / genetics
  • Cough / immunology*
  • DNA Primers / genetics
  • DNA, Complementary / genetics
  • Female
  • Gene Expression
  • Granulocyte-Macrophage Colony-Stimulating Factor / genetics*
  • Granulocyte-Macrophage Colony-Stimulating Factor / immunology
  • Granulocyte-Macrophage Colony-Stimulating Factor / metabolism*
  • Humans
  • Inflammation / immunology
  • Interleukin-5 / genetics*
  • Interleukin-5 / immunology
  • Interleukin-5 / metabolism*
  • Male
  • Methacholine Chloride / pharmacology
  • Middle Aged
  • Polymerase Chain Reaction
  • RNA, Messenger / analysis
  • RNA, Messenger / metabolism
  • Skin Tests
  • Spirometry


  • Adrenal Cortex Hormones
  • DNA Primers
  • DNA, Complementary
  • Interleukin-5
  • RNA, Messenger
  • Methacholine Chloride
  • Granulocyte-Macrophage Colony-Stimulating Factor