Role of eosinophils in airway inflammation of chronic obstructive pulmonary disease

Int J Chron Obstruct Pulmon Dis. 2018 Jan 17;13:335-349. doi: 10.2147/COPD.S152291. eCollection 2018.


COPD is a significant cause of morbidity and mortality. In some patients with COPD, eosinophils contribute to inflammation that promotes airway obstruction; approximately a third of stable COPD patients have evidence of eosinophilic inflammation. Although the eosinophil threshold associated with clinical relevance in patients with COPD is currently subject to debate, eosinophil counts hold potential as biomarkers to guide therapy. In particular, eosinophil counts may be useful in assessing which patients may benefit from inhaled corticosteroid therapy, particularly regarding exacerbation prevention. In addition, several therapies targeting eosinophilic inflammation are available or in development, including monoclonal antibodies targeting the IL5 ligand, the IL5 receptor, IL4, and IL13. The goal of this review was to describe the biologic characteristics of eosinophils, their role in COPD during exacerbations and stable disease, and their use as biomarkers to aid treatment decisions. We also propose an algorithm for inhaled corticosteroid use, taking into consideration eosinophil counts and pneumonia history, and emerging eosinophil-targeted therapies in COPD.

Keywords: asthma; corticosteroids; lung disease; pneumonia; pulmonary diseases.

Publication types

  • Review

MeSH terms

  • Administration, Inhalation
  • Adrenal Cortex Hormones / administration & dosage
  • Animals
  • Eosinophils / drug effects
  • Eosinophils / immunology*
  • Eosinophils / metabolism
  • Humans
  • Inflammation Mediators / immunology
  • Inflammation Mediators / metabolism
  • Lung / drug effects
  • Lung / immunology*
  • Lung / metabolism
  • Lung / physiopathology
  • Pneumonia / drug therapy
  • Pneumonia / immunology*
  • Pneumonia / metabolism
  • Pneumonia / physiopathology
  • Pulmonary Disease, Chronic Obstructive / drug therapy
  • Pulmonary Disease, Chronic Obstructive / immunology*
  • Pulmonary Disease, Chronic Obstructive / metabolism
  • Pulmonary Disease, Chronic Obstructive / physiopathology
  • Pulmonary Eosinophilia / drug therapy
  • Pulmonary Eosinophilia / immunology*
  • Pulmonary Eosinophilia / metabolism
  • Pulmonary Eosinophilia / physiopathology
  • Signal Transduction
  • Treatment Outcome


  • Adrenal Cortex Hormones
  • Inflammation Mediators