[1] Emory Univ, Sch Med, Dept Med, Atlanta, GA 30303 USA
[2] Univ Oriente, Dept Med, Ciudad Bolivar, Venezuela
[3] Univ Sao Paulo, Hosp Clin HCFMUSP, Fac Med, Rheumatol Div, Sao Paulo, Brazil
[4] Univ Fed Sao Paulo, Escola Paulista Med, Sao Paulo, Brazil
[5] Sanatorio Guemes Hosp Privado, Buenos Aires, DF, Argentina
[6] Univ Cient Sur, Fac Med, Lima, Peru
[7] Univ San Ignacio Loyola, Lima, Peru
[8] Inst Nacl Reumatol Uruguay, La Habanna, Cuba
[9] Hosp Clin Quirurg, La Habanna, Cuba
[10] Hosp Italiano Buenos Aires, Bs As, Argentina
[11] Hosp Univ Ruiz & Paez, Ciudad Bolivar, Venezuela
[12] Univ Norte, Barranquilla, Colombia
[13] Ctr Reg Enfermedades Autoinmunes & Reumat GO CREA, Grp Orono, Rosario, Argentina