Blood eosinophils could be useful as a biomarker in chronic obstructive pulmonary disease exacerbations

Abstract

Summary IntroductionThe aim of analysing the usefulness of the blood eosinophil count (BEC) as a prognostic marker in exacerbations of patients with Chronic Obstructive Pulmonary Disease (COPD), evaluating its relationship with hospital mortality, the length of stay and the early and late re‐admissions. Materials and MethodsWe have carried out a retrospective study including all patients who required hospital admission from 1 January 2008 to 31 December 2009, with a diagnosis on hospital discharge of COPD exacerbation. These patients were classified using three cut‐off points of BEC: less than 200 vs ≥ 200/µL, less than 300 vs ≥ 300/µL and less than 400 vs ≥ 400/µL. ResultsThere were a total of 1626 hospital admissions during the study period with the diagnosis of exacerbation of COPD. In this study we have included 358 patients. The probability of any late re‐admission increased with a BEC ≥ 300/µL (odds ratio: 1.684) and for those with a BEC ≥ 400/µL (odds ratio: 2.068). The BEC does not appear to be related to hospital mortality or the probability of early re‐admission after an exacerbation of COPD. ConclusionsIn our study an elevated BEC is associated with a higher incidence of late hospital readmissions in COPD exacerbations.

Elevated blood eosinophils in acute COPD exacerbations: better short- and long-term prognosis

“…Compatible with findings from previous studies, the eosinophilic group had significantly lower in-hospital and all-cause mortality compared to patients with nonelevated eosinophils [11,22,34,41,42]. Our results are, however, not in compliance with some authors that have reported no difference in the in-hospital mortality of eosinophilic and non-eosinophilic groups [5,6,32], these findings are, however, statistically not significant.…”

“…The wide difference between these findings depend on many factors, such as stability of COPD, eosinophil measurement methods and different threshold values, among others. For instance, some studies have reported eosinophils as differential count by cells per μL [6,12,33], some by percentage [14,34,35] and others have used both [31,32,36]. The different measurements of eosinophils can, however, result in vastly different prevalence of high blood eosinophils in COPD patients.…”

“…Many studies have linked high blood eosinophils and COPD exacerbations with subsequent events. The results of these studies are somewhat ambiguous, as some investigators have linked it to a higher rate of exacerbations [1][2][3][4], others with less frequent exacerbations [5][6][7] and some have reported no relationship [8][9][10]. Blood eosinophils have also been associated with longer hospital stay [11,12] and higher risk of mortality [13][14][15], however, some have shown no difference in the mortality [6,16,17].…”

“…The results of these studies are somewhat ambiguous, as some investigators have linked it to a higher rate of exacerbations [1][2][3][4], others with less frequent exacerbations [5][6][7] and some have reported no relationship [8][9][10]. Blood eosinophils have also been associated with longer hospital stay [11,12] and higher risk of mortality [13][14][15], however, some have shown no difference in the mortality [6,16,17]. More recently, there has also been an increasing interest in investigating the association between blood eosinophils and response to systemic steroids during an acute exacerbation of COPD [18][19][20], and studies have used blood eosinophils count to guide steroid treatment [12,19,20].…”

Factors Associated with Treatment Failure in Patients with Acute Exacerbation of COPD Admitted to the Emergency Department Observation Unit

“…Also, the data came from a single hospital and the results should not be generalized to other hospitals. Furthermore, other variable factors that may seem relevant to treatment failure, such as blood eosinophils, serum sodium, FEV1 <30% predicted, and treatment at discharge, were not obtained in this study [6,[29][30][31].…”