1. Division of Pulmonary, Allergy and Critical Care Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15261, USA;
2. Pittsburgh Heart, Lung and Blood Vascular Medicine Institute, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15261, USA
3. Sickle Cell Center of Excellence, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15261, USA
4. Division of Hematology/Oncology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15261, USA