[1] Hosp Clin Porto Alegre, Laboratorio Doencas Autoimunes, Rheumatol, Porto Alegre, RS, Brazil
[2] Univ Fed Rio Grande do Sul UFRGS, Postgrad Program Med Sci, Med, Porto Alegre, RS, Brazil
[3] Hosp Clin Porto Alegre, Rheumatol, Porto Alegre, RS, Brazil
[4] Univ Fed Rio Grande do Sul, Sch Med, Med, Porto Alegre, RS, Brazil