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


CONCLUSIONS
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.
Division of Pulmonary, Department of Internal Medicine, Yeouido St Mary's Hospital.
Sei Won
SW
Kim
Division of Pulmonary, Allergy and Critical Care Medicine, Department of Internal Medicine, Seoul St Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul.
Chin Kook
CK
Rhee
Department of Internal Medicine, Pusan National University, School of Medicine, Busan.
Ki Uk
KU
Kim
Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, St Paul's Hospital, College of Medicine, The Catholic University of Korea, Seoul.
Sang Haak
SH
Lee
Department of Internal Medicine, Soonchunhyang University Gumi Hospital, Gumi.
Hun Gyu
HG
Hwang
Division of Pulmonology, Department of Internal Medicine, Chonnam National University Hospital, Gwangju.
Yu Il
YI
Kim
Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, SMG-SNU Boramae Medical Center, Seoul National University College of Medicine.
Deog Kyeom
DK
Kim
Department of Pulmonary and Critical Care Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea.
Sang Do
SD
Lee
Department of Pulmonary and Critical Care Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea.
Yeon-Mok
YM
Oh
Division of Pulmonary, Department of Internal Medicine, Yeouido St Mary's Hospital.
Hyoung Kyu
HK
Yoon
D000367:Age Factors; D000368:Aged; D015415:Biomarkers / Q000097:blood; D029481:Bronchitis, Chronic / Q000097:blood* / Q000175:diagnosis / Q000276:immunology / Q000503:physiopathology; D004797:Enzyme-Linked Immunosorbent Assay; D004804:Eosinophils / Q000276:immunology; D005260:Female; D006801:Humans; D000067596:Interleukin-33 / Q000097:blood*; D007958:Leukocyte Count; D008168:Lung / Q000276:immunology / Q000503:physiopathology; D008297:Male; D010641:Phenotype; D011237:Predictive Value of Tests; D029424:Pulmonary Disease, Chronic Obstructive / Q000097:blood* / Q000175:diagnosis / Q000276:immunology / Q000503:physiopathology; D056910:Republic of Korea; D012907:Smoking / Q000009:adverse effects / Q000097:blood
D015415:Biomarkers; C506536:IL33 protein, human; D000067596:Interleukin-33
biomarker; chronic bronchitis; cytokine; eosinophil; interleukin-33; pathogenesis