Work

Longitudinal variability of blood eosinophils impact lung function decline in the general population

Year: 2025

Type: article

Abstract: Background Blood eosinophil counts (BECs) show moderate fluctuations over time but their long-term variability and clinical relevance in the general population remain unclear. We hypothesise a temporal variation of BECs over two visits (V1 and V2; 4.3±0.6 years) in the population-based Austrian LEAD study. Methods Adults (n=6932) were categorised by their BEC levels: consistently high (BEC HIGH , ≥210 cells·µL −1 at V1 and V2), consistently low–normal (BEC LOW/NORMAL , <210 cells·µL −1 at V1 and V2), variably increasing (BEC INCREASE , <210 cells·µL −1 at V1 and ≥210 cells·µL −1 at V2) and variably decreasing (BEC DECREASE , ≥210 cells·µL −1 at V1 and <210 cells·µL −1 at V2). Associations with lung function and respiratory conditions were analysed. Results Most individuals remain within their baseline BEC threshold (83.7% in BEC LOW/NORMAL and 67.3% in BEC HIGH ). BEC variability exceeded the normal range (−30 to 60 cells·µL −1 ) BEC INCREASE (+150 cells·µL −1 ) and BEC DECREASE (−144 cells·µL −1 ) groups. BEC variability significantly affected lung function (ΔFEV 1 −BEC DECREASE , 26.14 (95.75–46.52) and BEC INCREASE , −21.58 (−38.41– −4.75); and ΔFVC−BEC DECREASE , 28.74 (8.14–49.34) and BEC INCREASE , −20.78 (−37.73– −3.83)). BEC HIGH individuals were most associated with respiratory symptoms. Conclusions BEC is not a static biomarker; longitudinal variability predicts changes in lung function. Current guidelines rely on single time-point BEC measurements, but our findings suggest that repeated assessments and the use of thresholds to determine normal BEC variability over time may better guide treatment decisions in high-risk patients.

Source: ERJ Open Research

DOI: 10.1183/23120541.00368-2025

Authors: Charmaine J.M. Lim, Oliver Helk, Robab Breyer-Kohansal, Marie-Kathrin Breyer, Emiel F.M. Wouters, Sylvia Hartl