title: Diagnosis, assessment, and phenotyping of COPD: beyond FEV₁.
abstract: COPD is now widely recognized as a complex heterogeneous syndrome, having both pulmonary and extrapulmonary features. In clinical practice, the diagnosis of COPD is based on the presence of chronic airflow limitation, as assessed by post-bronchodilator spirometry. The severity of the airflow limitation, as measured by percent predicted FEV1, provides important information to the physician to enable optimization of management. However, in order to accurately assess the complexity of COPD, there need to be other measures made beyond FEV1. At present, there is a lack of reliable and simple blood biomarkers to confirm and further assess the diagnosis of COPD. However, it is possible to identify patients who display different phenotypic characteristics of COPD that relate to clinically relevant outcomes. Currently, validated phenotypes of COPD include alpha-1 antitrypsin deficiency, and "frequent exacerbators". Recently, a definition and assessment of a new phenotype comprising patients with overlapping features of asthma and COPD has been suggested and is known as "asthma COPD overlap syndrome". Several other phenotypes have been proposed, but require validation against clinical outcomes. Defining phenotypes requires the assessment of multiple factors indicating disease severity, its impact, and its activity. Recognition and validation of COPD phenotypes has an important role to play in the selection of evidence-based targeted therapy in the future management of COPD, but regardless of the diagnostic terms, patients with COPD should be assessed and treated according to their individual treatable characteristics.
authors.affiliation: Respiratory Section, Hvidovre Hospital, Copenhagen, Denmark; Department of Health, University of Copenhagen, Copenhagen, Denmark.
authors.forename: Peter
authors.initials: P
authors.lastname: Lange
authors.affiliation: Royal Devon and Exeter Hospital, Exeter, UK.
authors.forename: David M
authors.initials: DM
authors.lastname: Halpin
authors.affiliation: Respiratory Investigation Unit, Queen's University and Kingston General Hospital, Kingston, ON, Canada.
authors.forename: Denis E
authors.initials: DE
authors.lastname: O'Donnell
authors.affiliation: MRC Centre for Inflammation Research, The Queen's Medical Research Institute, University of Edinburgh, Edinburgh, UK.
authors.forename: William
authors.initials: W
authors.lastname: MacNee
mesh_terms: D001249:Asthma / Q000175:diagnosis* / Q000503:physiopathology / Q000628:therapy; D003937:Diagnosis, Differential; D005541:Forced Expiratory Volume; D006801:Humans; D008168:Lung / Q000503:physiopathology*; D010641:Phenotype; D011237:Predictive Value of Tests; D029424:Pulmonary Disease, Chronic Obstructive / Q000175:diagnosis* / Q000503:physiopathology / Q000628:therapy; D015203:Reproducibility of Results; D012129:Respiratory Function Tests
keywords: ACOS; COPD; asthma; diagnosis; phenotype