1. Division of Respirology, Department of Medicine, University of Calgary, Calgary, Alberta, Canada;
2. Department of Medicine, University of Calgary, Calgary, Alberta, Canada;
3. Division of Respirology, Department of Medicine, Dalhousie University, Halifax, Nova Scotia, Canada;
4. Department of Pathology and Laboratory Medicine, University of Calgary, Calgary, Alberta, Canada;
5. Division of Rheumatology, Department of Medicine, University of Calgary, Calgary, Alberta, Canada