The identification of phenotypes in patients with severe Chronic Obstructive Pulmonary Disease

In patients with Chronic Obstructive Pulmonary Disease (COPD), the degree of
airflow limitation itself does not adequately describe the complexity of COPD
because significant heterogeneity exists between patients with respect to
clinical presentation, physiology, imaging, response to therapy, decline in
lung function and survival. Currently, a clear alternative for describing COPD
does not exists but the identification of subgroups of COPD patients based on
clinical or genetic factors (phenotypes) could be useful. The continuous flow
of very severe COPD patients to the UMCG gives us the unique opportunity to
perform a study on the phenotypes of very severe COPD and the underlying
gene-environment interaction. We anticipate that the findings of this study
will lead to an earlier identification of those subjects who are at risk to
develop severe or very severe COPD. In addition, it will lead to a better
clinical characterisation of established COPD, possibly enabling a more
tailored treatment of different COPD subphenotypes.

Primary Objective:
To identify new clinical phenotypes in patients with severe chronic obstructive
pulmonary disease (COPD) using a cluster analysis.

Secondary Objectives:
To:
- identify clinical phenotypes (based on e.g. lung function parameters,
clinical parameters, radiologic parameters, systemic parameters, pathological
parameters and immunological parameters) in patients with severe COPD.
- identify endotypes/ intermediate phenotypes in patients with severe COPD.
- investigate the contribution of genotypes (including gene expression) in
patients with severe COPD.

Observational cross-sectional study with a 2 phase design

This low risk study does not have individual benefits for the participating
patients. Furthermore, the study will only take in total ± 2 extra hours and
will be performed during regular visits. Hopefully, the identification of novel
phenotypes will be useful for obtaining a more complete and realistic diagnosis
and a more tailored approach in the management of patients with severe COPD.