[1] Univ Barcelona, Serv Malalties Autoimmunes, Hosp Clin Barcelona, Inst Invest Biomed August Pi i Sunyer,Sch Med, E-08036 Barcelona, Spain
[2] San Martino Hosp, Oristano, Italy
[3] Univ Udine, I-33100 Udine, Italy
[4] Hosp Gen Valle Hebron, Barcelona, Spain
[5] Univ Modena, I-41100 Modena, Italy
[6] Hosp Especial, Ctr Med Nacl Siglo 21, Mexico City, DF, Mexico
[7] Univ Verona, I-37100 Verona, Italy