Brito-Zerón, Pilar, Kostov, Belchin, Fraile, Guadalupe, Caravia-Durán, Daniel, Maure, Brenda, Rascón, Francisco-Javier, Zamora, Mónica, Casanovas, Arnau, Lopez-Dupla, Miguel, Ripoll, Mar, Pinilla, Blanca, Fonseca, Eva, Akasbi, Miriam, de la Red, Gloria, Duarte-Millán, Miguel-Angel, Fanlo, Patricia, Guisado-Vasco, Pablo, Pérez-Alvarez, Roberto, Chamorro, Antonio J, Morcillo, César, Jiménez-Heredia, Iratxe, Sánchez-Berná, Isabel, López-Guillermo, Armando, Ramos-Casals, Manuel, SS Study Group GEAS-SEMI, The SS Study Group GEAS-SEMI, [Morcillo,C, Brito-Zerón,P] Autoimmune Diseases Unit, Department of Internal Medicine, Hospital CIMA-Sanitas, Barcelona, Spain. [Brito-Zerón, P: Sánchez-Berná,I, Ramos-Casals,M] Laboratory of Autoimmune Diseases Josep Font, IDIBAPS, Department of Autoimmune Diseases, ICMiD, Hospital Clínic, Barcelona, Spain. [Kostov,B] Transversal group for research in primary care, IDIBAPS, Consorci d’Atenció Primària de Salut Barcelona Esquerre (CAPSBE), Barcelona, Spain. [Fraile,G] Department of Internal Medicine, Hospital Ramón y Cajal, Madrid, Spain. [Caravia-Durán,D] Department of Internal Medicine, Hospital Universitario Central de Asturias, Oviedo, Spain. [Maure,B] Department of Internal Medicine, Complejo Hospitalario Universitario, Vigo, Spain. [Rascón,FJ] Department of Internal Medicine, Hospital Son Espases, Palma de Mallorca, Spain. [Zamora,M, and Sánchez-Berná,I] Department of Internal Medicine, Hospital Virgen de las Nieves, Granada, Spain. [Casanovas,A] Department of Internal Medicine, Hospital Parc Taulí, Sabadell, Spain. [ Lopez-Dupla,M] Department of Internal Medicine, Hospital Joan XXIII, Tarragona, Spain. [Ripoll,M] Department of Internal Medicine, Hospital Infanta Sofía, Madrid, Spain. [Pinilla,B] Department of Internal Medicine, Hospital Gregorio Marañón, Madrid, Spain. [Fonseca,E] Department of Internal Medicine, Hospital de Cabueñes, Gijón, Spain. [Akasbi,M] Department of Internal Medicine, Hospital Infanta Leonor, Madrid, Spain. [de la Red,G] Department of Internal Medicine, Hospital Esperit Sant, Santa Coloma de Gramenet, Spain. [Duarte-Millán,MA] Department of Internal Medicine, Hospital de Fuenlabrada, Fuenlabrada, Spain. [Fanlo,P] Department of Internal Medicine, Hospital Virgen del Camino, Pamplona, Spain. [Guisado-Vasco,P] Department of Internal Medicine, Complejo Hospitalario Ruber Juan Bravo, Madrid, Spain. [Pérez-Alvarez,R] Department of Internal Medicine, Hospital Alvaro Cunqueiro, Vigo, Spain. [Chamorro,AJ] Department of Internal Medicine, Hospital de Salamanca, Salamanca, Spain. [ Jiménez-Heredia,i] Department of Internal Medicine, Hospital de Sagunto, Valencia, Spain. [López-Guillermo,A] Department of Hematology, ICMHO, Hospital Clinic, Barcelona, Spain. [Ramos-Casals,M] Department of Medicine, University of Barcelona, Barcelona, Spain.