1. Department of Medicine, Division of Pulmonary and Critical Care Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, Massachusetts, USA
2. Chronic Obstructive Pulmonary Disease Program, Lovelace Biomedical Research Institute, Albuquerque, New Mexico, USA
3. Applied Sciences, Lovelace Biomedical Research Institute, Albuquerque, New Mexico, USA
4. Department of Medicine, National Jewish Health, Denver, Colorado, USA