TY - JOUR T1 - Phenotyping acute exacerbation of COPD: what more can we do for hospitalised patients? JF - ERJ Open Research JO - erjor DO - 10.1183/23120541.00362-2021 VL - 7 IS - 3 SP - 00362-2021 AU - Lai-Jian Cen AU - Xiao-xian Zhang AU - Wei-Jie Guan Y1 - 2021/07/01 UR - http://openres.ersjournals.com/content/7/3/00362-2021.abstract N2 - COPD is a complex and largely heterogeneous disease [1, 2]. The global prevalence of COPD is estimated to be 11.7% [3], with an estimated mortality in 2010 of around three million people [4]. The clinical management strategy has mostly been guided by the magnitude of airflow limitation, symptom burden and exacerbation risk [5]; however, these cannot fully take into account the heterogeneity of COPD. Acute exacerbations of COPD (AECOPDs) are defined as the significant worsening of respiratory symptoms which exceed the normal daily variations thus requiring changes to the current treatment [5]. AECOPD accounted for a substantial proportion of the socioeconomic burden of COPD [6], and a marked heterogeneity of the aetiology, pathophysiology and clinical manifestations of AECOPD existed [7]. In light of these heterogenous characteristics, efforts have been made to phenotype AECOPD [8]. There have been some studies focusing on the findings from clinical assessments or biomarker expression levels, highlighting the role of the exacerbation frequency [9], pathogen [10] and blood eosinophilia [11]. Nevertheless, most of these studies were restricted to the analysis of single biomarkers, some of which were not readily detectable in clinical practice, and phenotyping of AECOPD was mostly confined to the identification of infectious pathogens.Hospitalised #AECOPD are characterised by multiple facets of aetiology. The clinical interpretation of the composite phenotypes of AECOPD and the robustness of the AECOPD phenotype need to be discussed further. https://bit.ly/3grzQEO ER -