[1] Hosp Guillermo Almenara Irigoyen, Dept Rheumatol, Lima 33, Peru
[2] Univ Cient Sur, Lima, Peru
[3] GLADEL Consultant, Rosario, Santa Fe, Argentina
[4] Hosp Clin Barcelona, Dept Autoimmune Dis, Barcelona, Spain
[5] CREAR, Rosario, Santa Fe, Argentina
[6] Hosp Italiano Buenos Aires, Serv Clin Med, Secc Reumatol, Buenos Aires, DF, Argentina
[7] Hosp Italiano Buenos Aires, Escuela Med, Inst Univ, Buenos Aires, DF, Argentina
[8] Fdn Dr Pedro M Catoggio Progreso Reumatol, Buenos Aires, DF, Argentina
[9] Emory Sch Med, Div Rheumatol, Dept Med, Atlanta, GA USA
[10] Inst Invest Med Alfredo Lanari, Serv Inmunol, Buenos Aires, DF, Argentina
[11] Hosp Escuela Eva Peron, Serv Reumatol, Granadero Baigorria, Argentina
[12] Univ Sao Paulo, Hosp Clin HCFMUSP, Fac Med, Div Rheumatol, Sao Paulo, Brazil
[13] Univ Fed Sao Paulo, Hosp Sao Paulo, Escola Paulista Med UNIFESP, Disciplina Reumatol, Sao Paulo, Brazil
[14] Univ Fed Rio Grande do Sul, Hosp Clin Porto Alegre, Dept Internal Med, Div Rheumatol, Porto Alegre, RS, Brazil
[15] Univ Antioquia, Fac Med, Grp Reumatol, Hosp Univ San Vicente Fdn, Medellin, Colombia
[16] Ctr Invest Med Quirurg, Serv Reumatol, Havana, Cuba
[17] Univ San Sebastian, Fac Med, Santiago, Chile
[18] Ctr Invest Clin Morelia, Morelia, Michoacan, Mexico
[19] Inst Nacl Cardiol Ignacio Chavez, Dept Reumatol, Mexico City, DF, Mexico
[20] Hosp Univ Caracas, Ctr Nacl Enfermedades Reumat, Serv Reumatol, Caracas, Venezuela
[21] Univ Alabama Birmingham, Sch Med, Dept Med, Div Clin Immunol & Rheumatol, Birmingham, AL USA