Prevalence of persistent blood eosinophilia: relation to outcomes in patients with COPD
The impact of blood eosinophilia in chronic obstructive pulmonary disease (COPD) remains controversial.To evaluate the prevalence and stability of a high level of blood eosinophils (≥300 cells·μL-1) and its relationship to outcomes, we determined blood eosinophils at baseline and over 2 years in 424 COPD patients (forced expiratory volume in 1 s (FEV1) 60% predicted) and 67 smokers without COPD from the CHAIN cohort, and in 308 COPD patients (FEV1 60% predicted) in the BODE cohort. We related eosinophil levels to exacerbations and survival using Cox hazard analysis.In COPD patients, 15.8% in the CHAIN cohort and 12.3% in the BODE cohort had persistently elevated blood eosinophils at all three visits. A significant proportion (43.8%) of patients had counts that oscillated above and below the cut-off points, while the rest had persistent eosinophil levels <300 cells·μL-1 A similar eosinophil blood pattern was observed in controls. Exacerbation rates did not differ in patients with and without eosinophilia. All-cause mortality was lower in patients with high eosinophils compared with those with values <300 cells·μL-1 (15.8% versus 33.7%; p=0.026).In patients with COPD, blood eosinophils ≥300 cells·μL-1 persisting over 2 years was not a risk factor for COPD exacerbations. High eosinophil count was associated with better survival.
Casanova C, Celli BR, de-Torres JP, Martínez-Gonzalez C, Cosio BG, Pinto-Plata V, de Lucas-Ramos P, Divo M, Fuster A, Peces-Barba G, Calle-Rubio M, Solanes I, Aguero R, Feu-Collado N, Alfageme I, De Diego A, Romero A, Balcells E, Llunell A, Galdiz JB, Marin M, Moreno A, Cabrera C, Golpe R, Lacarcel C, Soriano JB, López-Campos JL, Soler-Cataluña JJ, Marin JM. Prevalence of persistent blood eosinophilia: relation to outcomes in patients with COPD. Eur Respir J. 2017 Nov 22;50(5). pii: 1701162.