Factors associated with plasma IL-33 levels in patients with chronic obstructive pulmonary disease

Int J Chron Obstruct Pulmon Dis. 2017 Jan 21:12:395-402. doi: 10.2147/COPD.S120445. eCollection 2017.


Background: Interleukin (IL)-33 promotes T helper (Th)2 immunity and systemic inflammation. The role of IL-33 in asthma has been widely investigated. IL-33 has also been suggested to play an important role in the pathogenesis of chronic obstructive pulmonary disease (COPD). This study investigated the clinical significance and usefulness of plasma IL-33 level in patients with COPD.

Methods: A total of 307 patients with stable COPD from 15 centers, who were in the Korean Obstructive Lung Disease cohort, were enrolled in this study. Plasma IL-33 levels were measured by enzyme-linked immunosorbent assay. We analyzed the association between IL-33 level and other clinical characteristics related to COPD. We also examined the features of patients with COPD who exhibited high IL-33 levels.

Results: IL-33 levels varied, but were very low in most patients. Eosinophil count was significantly correlated with a plasma IL-33 level. In addition, old age and current smoking were related to a low IL-33 level. Significantly more patients with a higher IL-33 level had chronic bronchitis compared with those with a low IL-33 level.

Conclusion: Plasma IL-33 level in patients with stable COPD was related to eosinophil count and chronic bronchitis phenotype. Further studies are needed to identify the precise mechanisms of IL-33/ST2 pathway in patients with COPD.

Keywords: biomarker; chronic bronchitis; cytokine; eosinophil; interleukin-33; pathogenesis.

Publication types

  • Multicenter Study

MeSH terms

  • Age Factors
  • Aged
  • Biomarkers / blood
  • Bronchitis, Chronic / blood*
  • Bronchitis, Chronic / diagnosis
  • Bronchitis, Chronic / immunology
  • Bronchitis, Chronic / physiopathology
  • Enzyme-Linked Immunosorbent Assay
  • Eosinophils / immunology
  • Female
  • Humans
  • Interleukin-33 / blood*
  • Leukocyte Count
  • Lung / immunology
  • Lung / physiopathology
  • Male
  • Phenotype
  • Predictive Value of Tests
  • Pulmonary Disease, Chronic Obstructive / blood*
  • Pulmonary Disease, Chronic Obstructive / diagnosis
  • Pulmonary Disease, Chronic Obstructive / immunology
  • Pulmonary Disease, Chronic Obstructive / physiopathology
  • Republic of Korea
  • Smoking / adverse effects
  • Smoking / blood


  • Biomarkers
  • IL33 protein, human
  • Interleukin-33