1 1st Department of Respiratory Medicine, Medical School of National and Kapodistrian University of Athens, "Sotiria" Hospital of Chest Diseases, Athens, Greece.
2 Clinical Research Unit, 401 General Army Hospital, Athens, Greece.
3 5th Department of Respiratory Medicine, "Sotiria" Hospital of Chest Diseases, Athens, Greece.
4 2nd Department of Respiratory Medicine, Medical School of National and Kapodistrian University of Athens, "Attikon" Hospital, Athens, Greece.