1. Systemic Autoimmune Diseases Unit, Department of Internal Medicine, IDIPHIM (Puerta de Hierro University Hospital Research Institute), Hospital Universitario Puerta de Hierro Majadahonda, 28222 Madrid, Spain
2. Department of Medicine, Facultad de Medicina, Universidad Autónoma de Madrid, 28029 Madrid, Spain
3. Department of Immunology, Hospital Universitario Puerta de Hierro Majadahonda, 28222 Madrid, Spain