1. Department of Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee, USA
2. Division of Allergy, Pulmonary, and Critical Care Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee, USA
3. Department of Pathology, Microbiology, and Immunology, Vanderbilt University School of Medicine, Nashville, Tennessee, USA
4. Tennessee Valley Healthcare System, United States Department of Veterans Affairs, Nashville, TN, USA