1. Department of Autoimmune Diseases, Institut Clínic de Medicina i Dermatologia, Hospital Clínic, Spain
2. Departments of Medicine, (Division of Clinical Immunology and Rheumatology) and Epidemiology, Schools of Medicine and Public Health, The University of Alabama at Birmingham, USA
3. Escuela de Estadística, Universidad Nacional de Rosario, Argentina
4. University of Maryland Dental School, USA
5. Johns Hopkins University School of Medicine, USA
6. Hospital Provincial de Rosario, Argentina