1. Service of Rheumatology and Service of Immunology ‘Gregorio Marañón’ Hospital, Universidad Complutense of Madrid, Spain
2. Service of Rheumatology and Service of Immunology ‘Gregorio Marañón’ Hospital, Universidad Complutense of Madrid, Spain; Servicio de Reumatología, Hospital General Universitario `Gregorio Marañón', c/o Dr Esquerdo 46, 28007 Madrid, Spain.
3. Service of Immunology, Rheumatology and Allergology, `Ste Justine' Hospital, Université de Montréal, Québec, Canada