1. Autoimmune Diseases Research Unit, Department of Internal Medicine, BioCruces Bizkaia Health Research Institute, Hospital Universitario Cruces, University of the Basque Country, Barakaldo, Spain
2. Autoimmune Diseases Unit, Department of Internal Medicine, Hospital Universitario de Bellvitge, ĹHospitalet de Llobregat, Barcelona, Spain
3. Department of Autoimmune Diseases, Hospital Clinic, Barcelona, Spain
4. Department of Internal Medicine, Hospital Universitario Central de Asturias, Oviedo, Spain
5. Department of Internal Medicine, Hospital Clínico Universitario Lozano Blesa, Zaragoza, Spain
6. Department of Internal Medicine, Hospital Universitario Virgen del Rocío, Seville, Spain
7. Department of Internal Medicine, Hospital Universitario Mutua de Terrasa, Terrasa, Spain
8. Department of Internal Medicine, Hospital Universitario de Cabueñes, Gijón, Spain
9. Department of Internal Medicine, Hospital General Universitario Gregorio Marañón, Madrid, Spain
10. Department of Internal Medicine, Hospital Universitario Son Espases, Palma de Mallorca, Islas Baleares, Spain