Blood eosinophils and clinical features of pneumoconiosis complicated with chronic obstructive pulmonary disease: A cross-sectional study

Abstract

Objective: To analyze the correlation between peripheral blood eosinophil (EOS) level and clinical characteristics of patients with pneumoconiosis complicated with chronic obstructive pulmonary disease (COPD) . Methods: From January 2007 to November 2020, newly diagnosed patients with pneumoconiosis complicated with COPD in Beijing Chaoyang Hospital, were retrospectively analyzed. These patients were stratified into EOS<100 cells/μl group and EOS≥100 cells/μl group, taking 100 cells/μl as the cut-off value. Demographic characteristics, clinical symptoms, lung function and laboratory indexes were compared between the two groups. Results: The median EOS count of patients with pneumoconiosis complicated with COPD was 100 (40, 180) cells/μl. 50.2% (160/319) had blood eosinophil counts ≥100 cells/μl, and 11.0% (35/319) had blood eosinophil counts ≥300 cells/μl. In comparison with EOS<100 cells/μl group, EOS≥100 cells/μl group were older (P=0.035), had higher body mass index (P=0.008), and had lower forced respiratory volume in the first second (P=0.017), had higher the ratio of residual volume to total lung volume (P=0.010), and had lower diffusing capacity of the lung for carbon monoxide (P=0.008). Arterial partial pressure of oxygen was significantly reduced in EOS≥100 cells/μl group (P=0.039). The peripheral blood EOS count was negatively correlated with forced vital capacity, forced breathing volume in the first second, carbon monoxide diffusion, peak expiratory flow, and maximum mid expiratory flow as a percentage of expected values (r(s)=-0.22, -0.18, -0.19, -0.19, -0.19, P=0.000, 0.001, 0.003, 0.008, 0.002), and positively correlated with the ratio of residual air volume to total lung volume (r(s)=0.17, P=0.002) . Conclusion: There was a correlation between blood EOS count and pulmonary function parameters, can proide reference for the diagnosis and treatment of chnoric obstuctive pulmmory disease in clinical practice.