Identification of airway mucosal type 2 inflammation by using clinical biomarkers in asthmatic patients

J Allergy Clin Immunol. 2017 Sep;140(3):710-719. doi: 10.1016/j.jaci.2016.11.038. Epub 2017 Jan 13.


Background: The Airways Disease Endotyping for Personalized Therapeutics (ADEPT) study profiled patients with mild, moderate, and severe asthma and nonatopic healthy control subjects.

Objective: We explored this data set to define type 2 inflammation based on airway mucosal IL-13-driven gene expression and how this related to clinically accessible biomarkers.

Methods: IL-13-driven gene expression was evaluated in several human cell lines. We then defined type 2 status in 25 healthy subjects, 28 patients with mild asthma, 29 patients with moderate asthma, and 26 patients with severe asthma based on airway mucosal expression of (1) CCL26 (the most differentially expressed gene), (2) periostin, or (3) a multigene IL-13 in vitro signature (IVS). Clinically accessible biomarkers included fraction of exhaled nitric oxide (Feno) values, blood eosinophil (bEOS) counts, serum CCL26 expression, and serum CCL17 expression.

Results: Expression of airway mucosal CCL26, periostin, and IL-13-IVS all facilitated segregation of subjects into type 2-high and type 2-low asthmatic groups, but in the ADEPT study population CCL26 expression was optimal. All subjects with high airway mucosal CCL26 expression and moderate-to-severe asthma had Feno values (≥35 ppb) and/or high bEOS counts (≥300 cells/mm3) compared with a minority (36%) of subjects with low airway mucosal CCL26 expression. A combination of Feno values, bEOS counts, and serum CCL17 and CCL26 expression had 100% positive predictive value and 87% negative predictive value for airway mucosal CCL26-high status. Clinical variables did not differ between subjects with type 2-high and type 2-low status. Eosinophilic inflammation was associated with but not limited to airway mucosal type 2 gene expression.

Conclusion: A panel of clinical biomarkers accurately classified type 2 status based on airway mucosal CCL26, periostin, or IL-13-IVS gene expression. Use of Feno values, bEOS counts, and serum marker levels (eg, CCL26 and CCL17) in combination might allow patient selection for novel type 2 therapeutics.

Keywords: Asthma; airway mucosal gene expression; biomarkers; phenotypes; type 2 inflammation.

Publication types

  • Controlled Clinical Trial

MeSH terms

  • Adolescent
  • Adult
  • Asthma / blood*
  • Asthma / immunology
  • Asthma / metabolism
  • Asthma / physiopathology
  • Biomarkers / blood
  • Biomarkers / metabolism
  • Cell Adhesion Molecules / immunology
  • Cell Line
  • Chemokine CCL17 / blood*
  • Chemokine CCL17 / immunology
  • Chemokine CCL26
  • Chemokines, CC / blood*
  • Chemokines, CC / immunology
  • Eosinophils / immunology
  • Female
  • Gene Expression
  • Humans
  • Interleukin-13 / genetics
  • Interleukin-13 / immunology
  • Leukocyte Count
  • Male
  • Middle Aged
  • Nitric Oxide / metabolism
  • Respiratory Function Tests
  • Respiratory Mucosa / immunology
  • Severity of Illness Index
  • Young Adult


  • Biomarkers
  • CCL17 protein, human
  • CCL26 protein, human
  • Cell Adhesion Molecules
  • Chemokine CCL17
  • Chemokine CCL26
  • Chemokines, CC
  • IL13 protein, human
  • Interleukin-13
  • POSTN protein, human
  • Nitric Oxide