1. First University Department of Respiratory Medicine, Medical School, ‘Sotiria’ Hospital, National and Kapodistrian University of Athens, 11527 Athens, Greece
2. Department of Biological Chemistry, Medical School, National and Kapodistrian University of Athens, 11527 Athens, Greece
3. Laboratory of Clinical Biochemistry, Medical School, ‘Attikon’ University General Hospital, National and Kapodistrian University of Athens, 12462 Athens, Greece