Appearance of large scavenger receptor A-positive cells in peripheral blood: A potential risk factor for severe exacerbation of chronic obstructive pulmonary disease.

Fresh peripheral blood (PB) samples from 432 outpatients with stable chronic obstructive pulmonary disease (COPD) were examined. Patients were classified into Group A (large SRA+ cells were undetected) and Group B (large SRA+ cells were detected) and followed-up for 1 year. Patients were further subdivided according to Global Initiative for Chronic Obstructive Lung Disease (GOLD) stage. Cox proportional hazard model had shown that Gold, Group, home oxygen therapy (HOT), and treatment were significant predictors of severe exacerbation. Six of 353 patients in Group A and 29 of 79 in Group B developed severe exacerbation. The rates of severe exacerbation were significantly higher in Group B patients, GOLD stage 2 than Group A, GOLD stage 2; in Group B, GOLD stage 3 than Group A, GOLD stage 3; and in all of Group B compared with in all of Group A. The Kaplan-Meier curves of Group B, GOLD stages 1-4, and of all of Group B showed significantly worse rates of severe exacerbation than those of Group A, Gold 1-4, and all of Group A, respectively. The appearance of large SRA+ cells in the PB of patients with stable COPD may represent a useful biomarker for severe COPD exacerbation.