https://doi.org/10.4081/monaldi.2025.3298
Prognostic role of blood eosinophils in acute exacerbations of chronic obstructive pulmonary disease: systematic review and meta-analysis
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Published: 27 March 2025
Acute exacerbation of chronic obstructive pulmonary disease (AECOPD) is a major cause of hospitalization and mortality worldwide. While blood eosinophils have been suggested as a prognostic biomarker of COPD, their predictive value in AECOPD remains uncertain. This meta-analysis aims to evaluate the prognostic role of blood eosinophil counts in predicting mortality and hospital readmission in these patients. A systematic review and meta-analysis were conducted according to PRISMA guidelines. We included studies that evaluated the prognostic role of blood eosinophils in AECOPD, with predefined cut-offs. Data on mortality and readmission rates were extracted, and statistical analyses were performed to assess sensitivity, specificity, and likelihood ratios. A total of 14 studies with 23,625 patients were included. High blood eosinophil counts during AECOPD hospitalization had low sensitivity (28.1%) and specificity (66.2%) in predicting 12-month mortality and readmission. Positive and negative likelihood ratios were also suboptimal, with values of 0.8 and 1.1, respectively. Sensitivity analyses, including only high-quality studies, confirmed these findings. The results suggest that blood eosinophil counts have limited prognostic value in predicting mortality and readmission in AECOPD patients. The variability in eosinophil cut-offs and lack of consistent data across studies contribute to this limitation. Further large-scale prospective studies are needed to clarify the role of eosinophils as a prognostic marker in AECOPD. Consequently, routine measurement of blood eosinophils during acute exacerbations may not be warranted for prognostic purposes.
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Zhang HL, Tan M, Qiu AM, et al. Antibiotics for treatment of acute exacerbation of chronic obstructive pulmonary disease: a network meta-analysis. BMC Pulm Med 2017;17:196. DOI: https://doi.org/10.1186/s12890-017-0541-0
Ko FW, Chan KP, Hui DS, et al. Acute exacerbation of COPD. Respirology 2016;21:1152-65. DOI: https://doi.org/10.1111/resp.12780
Fermont JM, Masconi KL, Jensen MT, et al. Biomarkers and clinical outcomes in COPD: a systematic review and meta-analysis. Thorax 2019;74:439-46. DOI: https://doi.org/10.1136/thoraxjnl-2018-211855
Brusselle G, Pavord ID, Landis S, et al. Blood eosinophil levels as a biomarker in COPD. Respir Med 2018;138:21-31. DOI: https://doi.org/10.1016/j.rmed.2018.03.016
Brightling C, Greening N. Airway inflammation in COPD: progress to precision medicine. Eur Respir J 2019;54:1900651. DOI: https://doi.org/10.1183/13993003.00651-2019
Emami Ardestani M, Alavi-Naeini N. Evaluation of the relationship of neutrophil-to lymphocyte ratio and platelet-to-lymphocyte ratio with in-hospital mortality in patients with acute exacerbation of chronic obstructive pulmonary disease. Clin Respir J 2021;15:382-8. DOI: https://doi.org/10.1111/crj.13312
Page MJ, McKenzie JE, Bossuyt PM, et al. The PRISMA 2020 statement: an updated guideline for reporting systematic reviews. BMJ 2021;372:n71. DOI: https://doi.org/10.1136/bmj.n71
Stroup DF, Berlin JA, Morton SC, et al. Meta-analysis of observational studies in epidemiology: a proposal for reporting. Meta-analysis of observational studies in epidemiology (MOOSE) group. JAMA 2000;283:2008-12. DOI: https://doi.org/10.1001/jama.283.15.2008
Wells GA, Wells G, Shea B, et al. The Newcastle-Ottawa Scale (NOS) for assessing the quality of nonrandomised studies in meta-analyses. 2014.
Zwinderman AH, Bossuyt PM. We should not pool diagnostic likelihood ratios in systematic reviews. Stat Med 2008;27:687-97. DOI: https://doi.org/10.1002/sim.2992
Kostikas K, Papathanasiou E, Papaioannou AI, et al. Blood eosinophils as predictor of outcomes in patients hospitalized for COPD exacerbations: a prospective observational study, Biomarkers 2021;4:354-62. DOI: https://doi.org/10.1080/1354750X.2021.1903998
Martínez-Gestoso S, García-Sanz MT, Calvo-Álvarez U, et al. Variability of blood eosinophil count and prognosis of COPD exacerbations. Ann Med 2021;53:1152-8. DOI: https://doi.org/10.1080/07853890.2021.1949489
Peng J, Yu Q, Fan S, et al. High blood eosinophil and YKL-40 levels, as well as low CXCL9 levels, are associated with increased readmission in patients with acute exacerbation of chronic obstructive pulmonary disease. Int J Chron Obstruct Pulmon Dis 2021;16:795-806. DOI: https://doi.org/10.2147/COPD.S294968
Bélanger M, Couillard S, Courteau J, et al. Eosinophil counts in first COPD hospitalizations: a comparison of health service utilization. Int J Chron Obstruct Pulmon Dis 2018;13:3045-54. DOI: https://doi.org/10.2147/COPD.S170743
Couillard S, Larivée P, Courteau J, Vanasse A. Eosinophils in COPD exacerbations are associated with increased readmissions. Chest 2017;151:366-73. DOI: https://doi.org/10.1016/j.chest.2016.10.003
Wu CW, Lan CC, Hsieh PC, et al. Role of peripheral eosinophilia in acute exacerbation of chronic obstructive pulmonary disease. World J Clin Cases 2020;8:2727-37. DOI: https://doi.org/10.12998/wjcc.v8.i13.2727
Bafadhel M, Greening NJ, Harvey Dunstan TC, et al. Blood eosinophils and outcomes in severe hospitalized exacerbations of COPD. Chest 2016;150:320-8. DOI: https://doi.org/10.1016/j.chest.2016.01.026
Ko FWS, Chan KP, Ngai J, et al. Blood eosinophil count as a predictor of hospital length of stay in COPD exacerbations. Respirology 2020;25:259-66. DOI: https://doi.org/10.1111/resp.13660
Russell R, Beer S, Pavord ID, et al. The acute wheezy adult with airways disease in the emergency department: a retrospective case-note review of exacerbations of COPD. Int J Chron Obstruct Pulmon Dis 2019;14:971-7. DOI: https://doi.org/10.2147/COPD.S190085
Ruiying W, Zhaoyun, Jianying X. Clinical features and three-year prognosis of AECOPD patients with different levels of blood eosinophils. Heart Lung 2022;56:29-39. DOI: https://doi.org/10.1016/j.hrtlng.2022.05.012
Pu J, Yi Q, Luo Y, et al. Blood eosinophils and clinical outcomes in patients with acute exacerbation of chronic obstructive pulmonary disease: a prospective cohort study. Int J Chron Obstruct Pulmon Dis 2023;18:169-79. DOI: https://doi.org/10.2147/COPD.S396311
Hegewald MJ, Horne BD, Trudo F, et al. Blood eosinophil count and hospital readmission in patients with acute exacerbation of chronic obstructive pulmonary disease. Int J Chron Obstruct Pulmon Dis 2020;15:2629-41. DOI: https://doi.org/10.2147/COPD.S251115
Hasegawa K, Camargo CA Jr. Prevalence of blood eosinophilia in hospitalized patients with acute exacerbation of COPD. Respirology 2016;21:761-4. DOI: https://doi.org/10.1111/resp.12724
Cui Y, Zhan Z, Zeng Z, et al. Blood eosinophils and clinical outcomes in patients with acute exacerbation of chronic obstructive pulmonary disease: a propensity score matching analysis of real-world data in China. Front Med 2021;8:653777. DOI: https://doi.org/10.3389/fmed.2021.653777
Yun JH, Lamb A, Chase R, et al. Blood eosinophil count thresholds and exacerbations in patients with chronic obstructive pulmonary disease. J Allergy Clin Immunol 2018;141:2037-47.e10.
Kim VL, Coombs NA, Staples KJ, et al. Impact and associations of eosinophilic inflammation in COPD: analysis of the AERIS cohort. Eur Respir J 2017;50:1700853. DOI: https://doi.org/10.1183/13993003.00853-2017
Vedel-Krogh S, Nielsen SF, Lange P, et al. Blood eosinophils and exacerbations in COPD: the Copenhagen general population study. Am J Respir Crit Care Med 2016;193:965-74. DOI: https://doi.org/10.1164/rccm.201509-1869OC
Bafadhel M, McKenna S, Terry S, et al. Acute exacerbations of chronic obstructive pulmonary disease: identification of biologic clusters and their biomarkers. Am J Respir Crit Care Med 2011;184:662-71. DOI: https://doi.org/10.1164/rccm.201104-0597OC
Pascoe S, Locantore N, Dransfield MT, et al. Blood eosinophil counts, exacerbations, and response to the addition of inhaled fluticasone furoate to vilanterol in patients with chronic obstructive pulmonary disease: a secondary analysis of data from two parallel randomised controlled trials. Lancet Respir Med 2015;3:435-42. DOI: https://doi.org/10.1016/S2213-2600(15)00106-X
Siddiqui SH, Guasconi A, Vestbo J, et al. Blood eosinophils: a biomarker of response to extrafine beclomethasone/formoterol in chronic obstructive pulmonary disease. Am J Respir Crit Care Med 2015;192:523-5. DOI: https://doi.org/10.1164/rccm.201502-0235LE
Håkansson KEJ, Ulrik CS, Godtfredsen NS, et al. High suPAR and low blood eosinophil count are risk factors for hospital readmission and mortality in patients with COPD. Int J Chron Obstruct Pulmon Dis 2020;15:733-43. DOI: https://doi.org/10.2147/COPD.S229904
Reddel HK, Gerhardsson de Verdier M, Agustí A, et al. Prospective observational study in patients with obstructive lung disease: NOVELTY design. ERJ Open Res 2019;5:00036-2018. DOI: https://doi.org/10.1183/23120541.00036-2018
Woodruff PG, Agusti A, Roche N, et al. Current concepts in targeting chronic obstructive pulmonary disease pharmacotherapy: making progress towards personalised management. Lancet 2015;385:1789-98. DOI: https://doi.org/10.1016/S0140-6736(15)60693-6
Brightling CE, Bleecker ER, Panettieri RA Jr, et al. Benralizumab for chronic obstructive pulmonary disease and sputum eosinophilia: a randomised, double-blind, placebo-controlled, phase 2a study. Lancet Respir Med 2014;2:891-901. DOI: https://doi.org/10.1016/S2213-2600(14)70187-0
Mao Y, Qian Y, Sun X, Li N, Huang H. Eosinopenia predicting long-term mortality in hospitalized acute exacerbation of COPD patients with community-acquired pneumonia-a retrospective analysis. Int J Chron Obstruct Pulmon Dis 2021;16:3551-9. DOI: https://doi.org/10.2147/COPD.S347948
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