Eosinophilic inflammation is associated with elevation of interleukin-5 in the airways of patients with spontaneous symptomatic asthma

Sanjiv Sur, Gerald J. Gleich, Mark C. Swansonb, Kathleen R. Bartemesb, David H. Broide

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69 Scopus citations


In vitro and in vivo studies have shown an important role for interleukin-5 (IL-5) in regulating eosinophil proliferation, survival, and effector function. Because eosinophilic inflammation is an important component of symptomatic episodes of asthma, we have investigated whether increased levels of IL-5 protein are present in bronchoalveolar lavage (BAL) fluid of patients with spontaneously symptomatic asthma (FEV1, 61% predicted; FEF25%-75%, 30% predicted) compared with patients with asymptomatic asthma (FEV1, 88% predicted; FEF25%-75%, 76% predicted). The percent of BAL eosinophils (10.5% vs 0.6%) (p = 0.0001) and eosinophil-derived neurotoxin (386.0 ng/ml vs 6.3 ng/ml) (p = 0.0001) was greater in BAL fluids derived from patients with symptomatic asthma compared with patients with asymptomatic asthma. Levels of IL-5 measured with an immunoradiometric assay were significantly higher in patients with symptomatic asthma (n = 26) compared with those with asymptomatic asthma (n = 18) (274 pg/ml vs <13 pg/ml) (p = 0.02). The increased IL-5 levels were noted in a subset of patients with symptomatic asthma with BAL absolute eosinophil counts greater than 106 (IL-5, 664 pg/ml; n = 10) as opposed to patients with symptomatic asthma with BAL eosinophil counts less than 106 (IL-5, <13 pg/ml; n = 16) (p = 0.005). This study suggests that IL-5 is not only induced in experimental models of allergen-induced asthma but can also be detected as asthma progresses from the asymptomatic to the clinically symptomatic state in subjects with significant BAL eosinophilia. (J ALLERGY CLIN IMMUNOL 1995;96:661-8.).

Original languageEnglish (US)
Pages (from-to)661-668
Number of pages8
JournalThe Journal of Allergy and Clinical Immunology
Issue number5
StatePublished - 1995
Externally publishedYes



  • asthma
  • eosinophil
  • eosinophil-derived neurotoxin
  • IL-5

ASJC Scopus subject areas

  • Immunology
  • Immunology and Allergy

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