1. Autoimmune Diseases Research Unit, Department of Internal Medicine, Biocruces, Hospital Universitario Cruces, UPV/EHU Bizkaia, The Basque Country, Spain
2. Rheumatology Department, Hospital J.M. Ramos Mejía, Buenos Aires, Argentina
3. Systemic Autoimmune Diseases Unit, Department of Internal Medicine, Hospital Clínico San Cecilio, Granada, Spain
4. Department of Internal Medicine, Hospital Universitario Central de Asturias, Oviedo, Spain
5. Department of Dermatology, Hospital Universitario Cruces, Bizkaia, Spain