Eosinophilic phenotype was associated with better early clinical remission in elderly but not middle-aged patients with acute exacerbations of COPD.

Background There is limited evidence of the relationship between peripheral blood eosinophils and clinical remission of acute exacerbations of chronic obstructive pulmonary disease (AECOPD) at different ages, especially in elderly patients, which was the objective of the present study. Methods This retrospective study stratified patients by age (elderly patients >65 years old or middle-aged patients between 45 and 65 years old) and analyzed the relationship between blood eosinophils (≥2% or Results Of 703 AECOPD cases analyzed, 616 were elderly (>65 years), 312 of whom had eosinophilic exacerbations. There were statistically significant differences in leucocytes, eosinophils, neutrophils, lymphocytes, monocytes, high-sensitivity C-reactive protein levels (hs-CRP), hospital costs between groups (p 0.05). Among overall analysis through adjusted Cox proportional hazards model analysis, eosinophilic exacerbation was significantly associated with a higher cumulative remission rate in elderly patients at 7, 14, 21 days (all p 0.05). No significant association was observed in meddle-aged patients at any time points (all p>0.05). Conclusion Eosinophilic exacerbation was associated with better early clinical remission of AECOPD patients during hospitalization. As stratified by ages, similar results were observed in elderly but not middle-aged patients. Blood eosinophils at different ages may be valuable in personalized management for AECOPD.