Baseline blood eosinophil counts ≥300 cells/µL were associated with greater 5-year emphysema progression versus <150 cells/µL (adjusted progression ratio 1.10; 95% CI 1.06-1.14).
Cohort (n=5,500)
No
Does higher baseline blood eosinophil count predict faster emphysema progression on serial CT in a health-screening cohort?
Higher baseline blood eosinophil count is independently associated with faster emphysema progression on serial CT, suggesting eosinophil-related inflammation may contribute to structural lung damage.
Effect estimate: adjusted 5-year progression ratio 1.10 (95% CI 1.06-1.14)
Absolute Event Rate: 1.15% vs 1.05%
Abstract Background Blood eosinophil count (BEC), a widely used biomarker of type 2 inflammation in chronic obstructive pulmonary disease (COPD), has been associated with COPD development and lung function decline. However, whether BEC is associated with longitudinal emphysema progression remains unclear. Method We conducted a retrospective cohort study among individuals who underwent ≥2 comprehensive health screening examinations at the Samsung Medical Center Health Promotion Center between 2010 and 2019 (N = 50,596). To enable image analyses, an 11% simple random subsample was selected, yielding 5,500 participants. Emphysema was quantified on chest CT as the emphysema index (EI), defined as the percentage of low attenuation area (LAA%) below -950 HU using automatic segmentation software (Aview, Coreline Soft, Seoul, Korea). The primary endpoint was EI progression, modeled as log-transformed EI (lnEI + 1). Linear mixed-effects models with random intercepts and slopes estimated annualized change by baseline BEC categories (150, 150-299, ≥300 cells/µL) adjusting for major confounders including smoking status, baseline EI and FEV1. Results Among 5,500 participants, the mean age was 53.2 years and 34.9% were men. Of these, 3,350 (60.9%) had BEC 150 cells/µL, 1,515 (27.5%) had 150-299 cells/µL, and 635 (11.6%) had ≥300 cells/µL. The mean baseline EI was 1.06(%) and was similar across group. Over a median follow-up of 7.2 years (IQR, 4.0 - 11.1) with a median number of 5 CTs per participant (IQR 3 - 7), the 5-year rates of emphysema progression were 1.05 (95% CI, 1.04-1.07), 1.10 (95% CI, 1.07-1.12), and 1.15 (95% CI, 1.11-1.18) for the 150, 150-299, and ≥300 cells/µL groups, respectively. In multivariable analyses, BEC 150-299 and ≥300 cells/µL groups showed significantly greater emphysema progression versus 150 cells/µL group, with adjusted 5-year progression ratios of 1.04 (95% CI, 1.02-1.07) and 1.10 (95% CI, 1.06-1.14), respectively. Spline analyses demonstrated a linear relationship between BEC and emphysema progression, with the lowest risk around 150 cells/µL and a monotonic increase at higher counts. Conclusion Higher baseline BEC was independently associated with faster emphysema progression on serial CT in this large health-screening cohort. These findings suggest that eosinophil-related inflammation may contribute to structural lung damage in COPD. Future prospective studies are warranted to determine whether targeting eosinophilic inflammation can modify the course of emphysema progression. This abstract is funded by: None.
Park et al. (Fri,) conducted a cohort in Emphysema progression (n=5,500). Blood eosinophil count ≥300 cells/µL vs. Blood eosinophil count <150 cells/µL was evaluated on Emphysema index (EI) progression (adjusted 5-year progression ratio 1.10, 95% CI 1.06-1.14). Baseline blood eosinophil counts ≥300 cells/µL were associated with greater 5-year emphysema progression versus <150 cells/µL (adjusted progression ratio 1.10; 95% CI 1.06-1.14).