1 2nd Pulmonary Medicine Dept, General University Hospital "Attikon", Medical School, National and Kapodistrian University of Athens, Athens, Greece.
2 First Academic Dept of Pneumonology, Hospital for Diseases of the Chest "Sotiria", Medical School, National and Kapodistrian University of Athens, Athens, Greece.
3 Iatriko Medical Center, Athens, Greece.
4 Pulmonary Dept, "G Papanikolaou" General Hospital, Thessaloniki, Greece.