1 Department of Pneumology Centro Hospitalar de São João Porto, Portugal and Life and Health Sciences Research Institute (ICVS) School of Health Sciences University of Minho Braga, Portugal and ICVS/3B's-PT Government Associate Laboratory Braga/Guimarães, Portugal.
2 Department of Pneumology Centro Hospitalar de São João Porto, Portugal.
3 Department of Pneumology Centro Hospitalar de São João Porto, Portugal and Faculty of Medicine University of Porto Porto, Portugal.