1 Rheumatology Department, Faculty of Medicine, Saint Lucas Hospital, Pontifical Catholic University of Rio Grande do Sul, Porto Alegre, Brazil.
2 Hematology Department, Faculty of Medicine, Saint Lucas Hospital, Pontifical Catholic University of Rio Grande do Sul, Porto Alegre, Brazil.
3 Rheumatology Department, Faculty of Medicine, Saint Lucas Hospital, Pontifical Catholic University of Rio Grande do Sul, Porto Alegre, Brazil. Electronic address: [email protected].