Blood Eosinophil Count as a Predictor of Lung Function Decline in Healthy Individuals

So-Hee Lee; Kyung-Min Ahn; Suh-Young Lee; Sun-Sin Kim; Heung-Woo Park

doi:10.1016/j.jaip.2020.07.055

Blood Eosinophil Count as a Predictor of Lung Function Decline in Healthy Individuals

J Allergy Clin Immunol Pract. 2021 Jan;9(1):394-399.e1. doi: 10.1016/j.jaip.2020.07.055. Epub 2020 Aug 17.

Authors

So-Hee Lee¹, Kyung-Min Ahn², Suh-Young Lee², Sun-Sin Kim¹, Heung-Woo Park³

Affiliations

¹ Department of Internal Medicine, Seoul National University Hospital, Seoul, Republic of Korea; Seoul National University Hospital Healthcare System Gangnam Center, Seoul, Republic of Korea.
² Department of Internal Medicine, Seoul National University Hospital, Seoul, Republic of Korea; Institute of Allergy and Clinical Immunology, Seoul National University Medical Research Center, Seoul, Republic of Korea.
³ Department of Internal Medicine, Seoul National University Hospital, Seoul, Republic of Korea; Institute of Allergy and Clinical Immunology, Seoul National University Medical Research Center, Seoul, Republic of Korea; Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Republic of Korea. Electronic address: guinea71@snu.ac.kr.

PMID: 32818699
DOI: 10.1016/j.jaip.2020.07.055

Abstract

Background: Little is known about the effect of blood eosinophil count (BEC) on a decline in lung function in healthy individuals.

Objective: Using a well-established health screening database, we assessed the associations between BEC and a decline in lung function, measured as the forced expiratory volume in 1 second (FEV₁).

Methods: Serial BEC and FEV₁ data were analyzed using linear mixed models adjusted for gender, height, and smoking status. The association between BEC consistency and a decline in FEV₁ was evaluated in subpopulation analyses.

Results: A total of 4634 individuals were enrolled. The mean number of health screenings was 7.49 over an average of 11.74 years of observation. A higher log2-transformed BEC was significantly associated with a greater decline in FEV₁ that was stronger in nonsmokers (P = 8.56 × 10^-8) than in smokers (P = 1.52 × 10^-3). In subpopulation analyses of 2018 individuals with consistent BECs, those with BECs consistently ≥100/μL (P = 4.58 × 10^-6), ≥200/μL (P = 3.53 × 10^-7), and ≥300/μL (P = 1.12 × 10^-3) had a significantly higher dose-dependent FEV₁ decline than those with BECs consistently <100/μL. A BEC threshold of 100/μL in nonsmokers and 200/μL in smokers may predict an accelerated decline in FEV₁.

Conclusions: BEC is associated with a decline in FEV₁, and a consistently high BEC is an independent risk factor for an accelerated decline in FEV₁. These results suggest the use of the BEC to identify healthy individuals at high risk for developing chronic lung disease, which in turn may enable a tailored preventive strategy.

Keywords: Blood; Eosinophils; Forced expiratory volume; Healthy volunteers; Trajectory.

MeSH terms

Eosinophils*
Forced Expiratory Volume
Humans
Leukocyte Count
Lung*
Respiratory Function Tests