1 Rheumatology Unit, Hospital Universitario de La Princesa, IIS-Princesa, Madrid, Spain.
2 Immunology Service, Hospital Universitario de La Princesa, IIS-Princesa, Madrid, Spain.
3 Rheumatology Unit, Hospital Universitario de La Princesa, IIS-Princesa, Madrid, and Cátedra UAM-ROCHE, EPID-Future, Department of Medicine, Universidad Autónoma de Madrid (UAM), Madrid, Spain. [email protected], [email protected].