[1] Hosp Clin Barcelona, Serv Malaties Autoimmunes, Inst Clin Med & Dermatol, Dept Autoimmune Dis, Barcelona 08036, Spain
[2] CMN Manuel Avila Camacho Inst Mexicano Seguro Soc, System Autoimmune Dis Res Uni, HGZ 36, Puebla, Mexico
[3] Benemerita Univ Autonoma Puebla, Sch Med, Dept Rheumatol, Puebla, Mexico
[4] CMN Siglo XXI, Hosp Pediat, Res Unit, Mexico City, DF, Mexico