1. Division of Rheumatology, IIS-Fundación Jiménez Díaz, 28040 Madrid, Spain
2. Department of Nuclear Medicine, Fundación Jiménez Díaz University Hospital, 28040 Madrid, Spain
3. Division of Rheumatology, Hospital Universitario de La Princesa, IIS-Princesa, 28006 Madrid, Spain
4. Medicine and Psychiatry Department, University of Cantabria, 39008 Santander, Spain